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It's the Fiber
Stupid! Despite the “eat more fiber” campaign sweeping across the nutritional landscape of America, a person living today will likely eat less fiber than at any other time in human history. Why? In 1900, the average American received more than 30% of daily calories from fiber-rich whole-grain products. Today that number is less than 1%. We eat less fiber-rich vegetables and fruits than did our grandparents and our low dietary intake of fiber has been fingered in just about every modern disease of “affluence” known to science, and probably a few others we have not wrapped our arms around yet. So why don’t Americans eat more fiber? Never mind what fiber is or how it actually works to make us healthier – we want more of it in our diet! At least that’s what we tell the nice people conducting nutritional surveys when they call. Yet, we eat less than half of the 25 to 35 grams a day the government says we should eat – and for many of us, those numbers keep dropping. The well-intended health message currently associated with fiber is simply not working – time to change the message. I think if consumers actually knew what fiber was really for, they would eat a lot more of it. We would all be healthier, live longer and more active lives, and would save a bundle of money on health care to boot. And here it is. Fiber is not food for us, its food for bacteria. As you read this, there are trillions of live bacteria feeding off the remains (fiber) of your last meal – mainly in the last five feet of your gastrointestinal tract – the colon. Humans have evolved with a complex population (500 plus species and counting) of bacteria that feed off the fiber we send down the pipe every day. In fact, the bacteria represent about 90-95% of all the cells in our body. Taken literally then, we are 20 times more microbe than mammal. Think about that for a minute. The bacteria have been with us every minute of every day from the moment we were born – and will be so until we die. The problem is, our current low fiber diet is literally starving the bacteria and disrupting the delicate balance between us and our evolutionary hitchhikers. This is not good. Fiber is technically any food item that cannot be broken down by enzymes in the small intestine, and thus is transferred to the colon – end of the line. Food manufacturers currently use over 100 different ‘fiber’ substances in foods. Once in the colon, the bacteria go to work and breakdown the fiber by a process known as fermentation – and this is where it gets interesting. I doubt many of you reading this are aware that nearly 70% (dry weight) of the last stool you passed is made up of live and kicking bacteria. Look next time if you don’t believe me! You will need to borrow your neighbor’s scanning electron microscope to see them, however. We also excrete our body weight in these bacteria each year in our feces. The bacteria serve as the first and last line of defense against invading pathogens – think Salmonella. A healthy and growing (read well-fed) population of good bacteria makes your colon more acidic and thus less inviting to invading pathogens. In sufficient numbers, the good bacteria out-compete the invaders for food making it difficult for the pathogen to grow in sufficient numbers to make you sick The soft, bulky and more frequent stools many folks associate with fiber consumption is in fact evidence of a growing and thriving population of bacteria in your colon. Remember, you poop bacteria. A further sign of a healthy, well-fed, population of bacteria in your colon can be measured by the frequency of your flatulents. Though considered anti-social in some circles, breaking wind ten or more times a day is a sign of a fiber-rich diet, as the bacteria produce gases as a byproduct of fermenting fiber. While bulky stools and gas are indicators of a healthy fiber-rich diet, they are not the most important reason you should eat more fiber. An additional byproduct of the fermentation, like the gases, are little compounds known as short chain fatty acids – SCFA for short. These are important compounds only produced by well-fed bacteria. SCFAs are absorbed by the body and serve as energy for the liver, skeletal muscle, brain, and importantly, your colon.
The acidic and SCFA-rich environment created
by the well-fed bacteria not only protects you from getting sick and
providing energy, it also dramatically increases your bodies ability to
absorb calcium, thus reducing your risk to osteoporosis, and decreases
your bad cholesterol, reducing your risk to coronary heart disease.
Further, this bacterial induced environment has positive effects on
biomarkers of colon cancer, reduces symptoms of inflammatory bowel
disease, and counteracts fat mass development. And the list goes on.
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C-sections,
breastfeeding, and bugs for your baby There I was, with a camera in one hand and wiping the tears from my eyes with other. It was delivery day – I was going to be a dad. Like an eerie scene from a B-rated alien movie, out popped his little head from an amazingly small incision in my ‘then wife’s’ stomach. The flash from my camera filled the room – this was the happiest day of my life. Since that day over 11 years ago, my ‘then wife’ and I had another beautiful child, also through cesarean delivery. I had not given much thought to the fact that both my children entered this world through a small incision rather than the birth canal until a few months ago, when the CDC’s National Center for Health Statistics released its update on births in the US. Since my first child was born, the rate of c-section deliveries appear to have been rising at a steady clip, jumping over 40 percent since 1996. In 2004, 29.1 percent of all children born in the US were delivered through c-section – that’s nearly 1.2 million incisions. The reasons for the increase are complicated, but have a lot to do with medical malpractice associated with vaginal deliveries, parental preference, health of the mother and or the unborn child, and just plain old convenience. In the days following the release of the CDC report, I scoured the media outlets that picked up the story to see if anyone mentioned an interesting and potentially alarming consequence of the rise c-sections. I was looking for the mention of words human biology, bacteria, mammals, and the new nine-letter curse word of 2005 – evolution. Nary a mention from a single report – not one. As a right of passage – a vaginal right of passage that is – the delivery of a fetus through the vaginal canal of the mother completes one of the most important cycles in the evolutionary history of humans. From an evolutionary point of view, our sudden adoption of c-sections as an increasingly preferred mode of child delivery, may be tinkering with some very important processes that took millions of years to develop. Let me explain. In what famed British ‘Darwinist’ Richard Dawkins calls an evolutionary stable strategy, humans have evolved a symbiotic relationship with a particular and complex set of bacteria in our intestinal system – a.k.a. the gut. The 500 or so species of bacteria, whose numbers are measured in the trillions, occupy every inch of our gut – with most of them living in an ecological niche they literally carved for themselves in our colon. As the evolutionary stable strategy suggests, the presence of these few hundred species, among all the tens of thousands of species of bacteria found in the air, water, and soil throughout the world, that theoretically have access to our “open” intestinal ecosystem (think mouth to anus), is not random. This means our established intestinal ecosystem is composed of a set of bacteria that can live in nutritional and physiological harmony with us. Importantly, current members make it their evolutionary determined job to keep out new members – i.e., pathogens that seek to do us harm. The intestine of the unborn fetus in the mother’s womb is sterile – devoid of any bacteria at all. However, during vaginal delivery the newborn comes in contact with bacteria-rich vaginal and fecal matter of the mother. These bacteria quickly invade and populate the newborn child. Saving of umbilical cords and the creepy ritual of eating the mother’s placenta aside, this cycle links the co-evolution of intestinal “microflora” of the mother to child, and may represent a more significant bond for those who understand it exist. This evolutionary bacterial right of passage has been and continues to be critical to the success of our species – and all mammals for that matter. A child born through c-section essentially skips this critical evolutionary process. Though a c-section baby does receive bacteria from the mother, it’s not the diverse and dense “base population” that it would have received from the vaginal fluids and fecal matter via a traditional birth. In either birthing method, the baby is subject to all the bacteria in the room – that even means the weird looking rubber-gloved fellow in the corner – who appears to be assisting the delivery staff in some way. But who can be sure. Once this truly amazing and scary ritual of child birth is completed, the newborn is typically cleaned, shown to the mother for short period, and then whisked off to some warm place to spend some quality time with other new members of our species. The mother usually settles in for some much needed rest and the new father anxiously paces the corridors mumbling to his self all the things his is going to change or do better in his life. Seems some things are timeless. But the next 24 for 48 hours pose another critical evolutionary step for mother and child – breast feeding. Like all other mammals – and that includes are tree swinging cousins – the secretion and release of fluid from breasts (mammae) is the sole nourishment or food for the newborn child. Yet, over 30 percent of new mother’s do not breast feed in the hospital. It is often the case that some mother’s never get their milk, others have problems getting the newborn to suckle, and others are just not interested. At six months of age, the number of baby’s receiving breast milk drops to around 31 percent, and at 12 months it drops further to 17 percent. The number of baby’s receiving some level of breast milk at 24 months hardly makes a blip on the radar. C-sections and short-term breast feeding have no precedence in our evolutionary past. Before insurance companies and organized medicine, all children entered this world via the birth canal and participated in the time honored cycle of transfer of bacteria from mother to child. Like our tree swinging cousins and a few of the modern forager groups that still follow traditional lifeways today, breast feeding by the mother or other women in the group (wet nursing) continued for 24 to 36 months, sometimes longer. Breast feeding newborns, like the evolutionary process of vaginal birth, is about bacteria. The breast milk of a human mother, like other mammalian mothers, is species-specific, having been adapted over eons to deliver specific and sufficient nutrition to guarantee proper growth, health, and immunity development. Researchers have long known that breast fed babies possess an intestinal flora that is measurably different than formula-fed infants. Of specific interest is a group of bacteria known as bifidobacterium. Some of you may immediately recognize the name, as they are often added to dairy-based foods such as yoghurts – often advertised as “live cultures” on the packaging. These are probiotics. Studies have shown that at one month of age, both breast-fed and formula-fed infants possess bifidobacterium but population densities in bottle-fed infants is one-tenth that of breast-fed infants. The presence of a healthy and robust population of bifidobacterium throughout the first year or two of life contributes significantly to the child’s resistance to infection and overall development of defense systems – not to mention the physical development of the intestinal system in general. Aside from the substances secreted by these specific bacteria that are known inhibit the growth of pathogenic bacteria, they also work to make the intestinal environment of the infant more acidic, creating an additional barrier against invading pathogens. In short, breast-fed babies are sick less, are less fussy, have fewer and shorter duration of bouts of diarrhea, and have more frequent – and softer – bowel movements. The dominance of health-giving bifidobacterium in breast-fed babies is due the presence of special carbohydrates in mother’s milk known as oligosacchrides. These special carbohydrates are virtually absent in cow’s milk. From a physiological point, these special carbohydrates escape digestion and absorption in the small intestine of the infant, and thus reach the colon intact – where they serve as food for, among other bacteria, the all important bifidobacterium. As the bacteria thrive on this “food” from mother’s milk, they grow in number and absorb water, resulting in more regular and soft bowel movements. It’s important to know that the bulk of infant feces are made up of live and kicking bacteria. Look next time if you don’t believe me! Baby formula manufacturers are catching on and creating products that contain these special carbohydrates – which are known as prebiotics (remember, prebiotics are food for bacteria and bacteria are called probiotics). While it’s virtually impossible to mimic the exact composition of mother’s milk, it is possible to mimic some of the physiological effects – specifically targeting the growth of select bacteria through the delivery of oligosacchrides. One Belgium-based company (www.orafti.com) in particular, has developed a natural variant of the mother’s oligosacchrides from chicory roots (think chicory coffee). After years of careful study and peer review, they are being added in greater and greater frequency to formula for infants. They love this stuff in Japan. Any company that wants to stay in the lucrative baby formula business will need to adapt their products to include these ingredients, or else be left in the dust. In the dozens of doctor visits my ‘then wife’ and I made during pregnancy, and through two births, never once did the doctor or any other person involved tell us what I just told you. In all of the “how to be a new parent” and “how to take care of your new baby” books we read, not one detailed reference to the critical passing of mother’s microflora to the child via the birth canal or the importance of feeding bifidobacterium, was ever provided. In many cases, c-sections are absolutely necessary and should be performed. But a 40 percent increase in just the last ten years? This makes no sense. As a father of two, I am acutely aware of the physical and emotional toll that breast feeding has on an active mother – the little creature literally sucks the life right out of you. Face it we live in a very different world than our not-so-distant ancestors occupied. Things are hard, but in different ways. It’s important that expecting parents understand some of the basic evolutionary processes of bringing a new member of our species into the world. A few snips and stitches, followed by only by a small number of sips, ain’t going to cut it. The physical, nutritional, and metabolic features that make us uniquely human have been shaped by millions of years of evolution. The debate in this country over evolution should not preclude health practitioners from understanding the basics of evolutionary biology. While we are culturally and socially modern, driving around in hybrid cars and arguing about stupid things, we are literally and biologically ancient hunter-gatherers. Ignoring our evolutionary past and its role in modern medicine and health, not just in birthing but for all ailments and diseases of modern civilization, is nothing short of medical malpractice. Ignoring and tinkering with nature has consequences, it always does. ___________________________ Unintended Consequences: What happed to the Human Hybrid? by Jeff D Leach **Special Note: You may want to read the article "So go the Pima, so go the rest of us" before reading this column. This article is located just to the right of this one. As you read this, there are millions of tiny microbes swimming around in the fluid surrounding your eyeballs. But you can’t see them. There are millions more under your finger nails, on your hands, arms, legs and just about every imaginable section of your fleshy real estate. There are millions more lining your moist nasal passage, many more maneuvering about your liver, heart, lungs, pancreas and trillions more living throughout your continuous gastrointestinal tract – from mouth to anus. And as you ponder this unimaginable invasion of invisible aliens, there are millions more setting up new beach heads on that all-important organ between your ears every minute of every day from the moment you entered this world. But that’s the good news. The bad news is we are literally starving, depressing and killing off an alarming number of these little evolutionary hitchhiking friends with our so-called modern, westernized diet. Our modern food supply, with its 300,000 or so processed products for sale in the U.S alone, is one stunning example of the cultural, technological and political prowess of a species gone wild. So freakish is our modern food supply, I doubt our ancestors would recognize much of it as food at all. Our internal ‘friendly’ bacteria are equally puzzled. As we fill our shopping carts and pantries with the latest neatly boxed and wrapped goodies of industry, we continue down a path that began some ten thousand years ago with the emergence of agriculture – an event that would eventually, along with steel roller mills in the 1880s and farm subsidies in the 1970s, lead to the greatest “unintended consequence” in human history: The shift in how and where the human body captures much-needed energy (calories) to power our demanding bodies and lifestyle. Let me explain. This admittedly dramatic pronouncement – “the greatest unintended consequence in human history” – underlies something I have come to call the Human Hybrid. The Human Hybrid is an evolutionary-based way of thinking about nutrition and the tragic epidemic of obesity and its growing list of acute and chronic byproducts (disease). But nowhere is the Human Hybrid more potentially applicable than when trying to wrap your head around the metabolic syndrome of insulin-resistance (sometimes referred to as Syndrome X). If you are overweight, diabetic, have hypertension, low HDL-cholesterol levels, high triglycerides, or have ever suffered a mild heart attack or stroke, then you probably have the insulin-resistance syndrome. More on this in a moment. The easiest way to begin to explain the Human Hybrid is to think about hybrid cars – the latest must-have techno gadget for the social and environmentally conscious – and financially stable – among us. The concept behind hybrid cars is simple: a mixture of power technologies such as internal combustion engines and electric batteries (and in some cases electric motors) are applied to create a more efficient system. In other words, two power sources. On the front end you have a gas-powered engine that works to push the car forward part of the time, with the second power source (batteries) in the backend making up the difference a certain percentage of the time. The clever engineers who devised the hybrid car designed it to run on both sources – not one or the other full-time. They share the work. Running the entire system on one or the other exclusively, would result in the system malfunctioning and falling part. The two energy system was designed to share in delivering the power needs. Like the hybrid car, humans have two major power sources – one in front end (small intestine) and the other, quite literally, on the back end (the colon). Our Human Hybrid is a hold over from our days of hanging out with other primates and enjoying those low-energy dense meals of roots, leaves, fruits, bark, seeds, insects, and flowers. The good ol’ days. Between 5 to 7 million years ago, the diet of our ancestors – who looked nothing like us at the time, and pretty much like our friends at the zoo – was dominated by lots and lots and lots of fiber. To extract enough calories from this bulky diet, our early tree swinging cousins relied on millions of years of co-evolution with an unlikely cast of microscopic hitchhikers and some ingenious arrangements. As food passed through our early ancestors stomach and small intestine, enzymes broke down the material allowing for fats, proteins, carbohydrates, minerals, vitamins and so on to be absorbed. Anything not broken down (fiber) was moved on. By definition, fiber is pretty much anything that escapes digestion and absorption in the small intestine and ends up in the colon – end of the line. Far from being wasted plant material at this last station in the gastrointestinal system, the trillions of bacteria that lived in our early ancestors colons went about the task of breaking down that fiber through a process called fermentation and turning it into energy. The bacteria relied on this “fiber” to live (i.e., fiber is food for bacteria!). In the process of fermentation, a byproduct known as short chain fatty acids, with names such as acetate, butyrate and propionate, were generated and then absorbed and used by cell and organs of the body as energy. Voilà! Energy (calories) from bark. Rough estimates suggest that our early ancestors generated as much 25 to 35% of their energy needs by this hybrid energy technology. Primates living today still rely on the bacteria and the energy they generate to continue to make a living on the lush greens of the world’s tropical – but shrinking – forests. As our earliest ancestors took those first tentative steps onto the open savannahs of Africa – and began their march to global mammalian dominance all those millions of years ago – they took with them this fully-developed hybrid energy technology and its bacterial power plant for the evolutionary ride. Today, this same cast of characters is still with us, known by names like bifidobacterium and lactobacillus (If you eat yogurt you will recognize these names as they are added today under the heading of probiotics). But during that long march that ultimately ended in us, our diet improved as we explored new lands and developed technologies to extract more energy and nutrients from our environment. Over each new horizon, novel plants and animals presented themselves – and we ate them. We learned to fish, hunt, and to master fire – cooking food, making it more digestible and unlocked nutrients in quantities and diversities never before seen in primate-human history. And then within the last 10,000 years or so, pay dirt – agriculture, pottery, towns, cities, the wheelbarrow, Roman bathhouses! We never looked back. As the quality and diversity of diet improved with every novel plant and animal we added to the menu, we digested and absorbed more and more energy and nutrients in our small intestine – the front power plant in our Human Hybrid. Through time, this resulted in an increase in the size of our small intestine to handle the windfall. Over the course of a few million years, our small intestine essentially doubled in volume – thus increasing the amount of energy absorbed in the front end. On the flipside, our colon (back end energy source), with its reduced role as a function of us eating less and less fibrous material, reduced in size by more than half (Click here for a colorful graph comparing the stomach, small intestine, and colon of modern humans to that of modern primates). Nevertheless, our modern colon still accounts for approximately 20% of the total volume of our omnivorous gastrointestinal system. Compared to the colon of meat-eating carnivores, such as the wolf, it’s down right huge. The simple fact that the colon still represents a significant portion (by volume) of our modern gastrointestinal system, speaks to its continued and important role in our Human Hybrid as an energy source. If we did not need it to generate energy, evolution would reduce its size, say to that of a strict carnivore. Put another way: though our genome has evolved to less dependence on fibrous plant material through time, the fermentation factory – and its bacterial workers – is open for business today and will likely be so into the foreseeable future (a few hundred thousand years without a doubt). So 1,300 words or so later, you are probably wondering what this has to do with obesity and diabetes among the Pima Indians of Arizona or for modern humans in general. Quite alot, actually. Even though our modern colons still occupy an important place in our gastrointestinal system and our overall nutrition, and the lights are on in the fermentation factory and trillions of bacteria (some 1,000 plus species) are standing at their stations waiting to do what they do best, our so-called modern and technically slick food supply and industrial and political landscape over which it flows, have something else in mind – and fiber (food for bacteria and fuel for the backend power station of the Human Hybrid) ain’t it. By all estimates, modern humans should still be generating between 12 to 18% of our daily basal energy needs from the colon part of the Human Hybrid system through fermentation of dietary fiber. For the average American or European who consumes a scant 12 to 15 grams of dietary fiber a day, the energy being provided by the backend is somewhere less than 5% - even less for some. So how does this short fall translate into something tangible for or about modern human health? Quite simply, it means the front end component (small intestine) of the Human Hybrid is providing the majority of the energy demands and in the process, being over worked – exactly what we do not want in a hybrid system of any kind. The overworking of the front end is coming in the form of rapidly digested and absorbed foods that dominate our modern diet. This includes all those foods our ancestors would not recognize that are laced with added sugars, fats and highly processed nutrient- and fiber-poor grains (think sodas, ice cream, donuts, most breads, chips, most pizzas and burgers, a lot of the dairy products, and so on). As we eat more and more of these front end fuels, we are eating less of the backend fuel (fiber). The average American and European is getting nearly 60% to 70% of their total daily calorie needs from these front end fuels. This would be like pouring kool-aid in your gas tank and expecting everything to run the same as usual. Something has to give, and it is. Enter the hormone insulin and insulin-resistant syndrome – a root problem in a staggering number of modern ailments. Since this important story needed to be told in such detail – hence it’s length so far – I will restrict the remainder of the discussion to the development of diabetes and the role of the Human Hybrid (hang in there almost done!). The eating habits of our ancestors more or less adhered to the Human Hybrid diet that developed from the nutritional landscape on which our genome was selected. Our food supply consistently included up to and more than 100 grams of fiber a day – sometimes more, sometimes less. This meant our “minimally processed foods” contained copious amounts of slowly digested carbohydrates – an essential fuel for the red blood cells and brain, and the main source of energy for muscles under conditions of exercise (something that characterized everyday life for our ancestors). For over 99% of human history (>2 million years), our ancestors main source of carbohydrates (primary energy source) were wild plants foraged from the ancient landscape. The sugars and starches (carbohydrates) in these plants were broken down by the enzymes in the mouth, stomach and small intestine (front end of the Human Hybrid) and absorbed into the blood stream along with other nutrients and utilized by the cells as energy. Plant parts that are, due to their either chemical or physical structure (fiber), not broken down in this front end of our Human Hybrid are moved along to the next energy station, the colon. The most common and important of these energy sources is glucose – a building block of starch. Once glucose is absorbed into the blood stream the pancreas jumps into action and excretes the hormone insulin that binds with the glucose and allows it to be utilized as energy. A cellular key of sorts. Without insulin, the glucose cannot be utilized. And this is where the problem begins.
Our ancestral diet
Our recent adoption (mainly in the last 200 years, but more so in the last 30) and obsession with industry and government promoted “quick” energy in the form of easily digested and absorbed sugars and highly-processed grains, is throwing everything off. (To get my take – rant – on the U.S. Food Pyramid click here). When we start overwhelming the finely tuned Human Hybrid with too much glucose from highly-processed foods we are asking the pancreas to excrete more and more insulin at a faster rate. At the same time, we are also bombarding the cells in our muscles and organs with this never-ending flood of glucose and insulin at a rate and quantity never before seen in human history – something they were not engineered to handle. Asking the insulin-generating pancreas to put in overtime often (and usually does) results in it finally malfunctioning (lower insulin levels) or giving out entirely. Without insulin to bind with, the glucose stays in the bloodstream. We know this condition of too much blood glucose as hyperglycemia, or by its more common name, diabetes (type 1 diabetes, of course, is when the pancreas can no longer produce insulin). Of specific interest to our Human Hybrid is insulin-resistance, which occurs when the normal amount of insulin secreted by the pancreas is not able to unlock the door to cells. To maintain normal blood glucose, the pancreas secretes additional insulin. In some cases, when the body cells “resist” or do not respond to even higher levels of insulin, glucose builds up in the blood resulting in the dreaded type 2 diabetes. So why do the cells resist this much-needed energy? Like a sponge full of water, the cells are saying “enough!” – even when they are not full. Have they become exhausted from trying to keep up with all that insulin and glucose? The science says, maybe – most likely, yes. We know that our unfamiliar, rapidly absorbed, diet is triggering some deeply buried genetic instruction to do so. In other words, the Human Hybrid is out of whack. And for the Pima Indians of southern Arizona, with the highest recorded rate of diabetes of any group on the planet, it seems to be “just a little” bigger problem. What in their evolutionary past – or more correctly, their nutritional past – predisposes them to this terrible disease over, say, a European? I think it might be in the “fine-tuning” or “final touches” on their Human Hybrid fuel system. Up until about 10,000 years ago, all humans on earth were hunter-gatherers – making a living on wild plants and animals gathered about the landscape. No pottery, no agriculture, no animal husbandry. Pottery and agriculture first took hold in southeastern Asia, then Mediterranean and then spread throughout what is today modern Europe. So over a period from 5,000 to 10,000 years ago just about everyone in Europe was making a living on a limited number of agriculture products and cooking pots (minus a few pockets here and there). For our Human Hybrid, this meant easier to digest grains – shifting from whole grains to minimally processed ones. And as the grains become smaller and smaller (think coarse flour) with each new grinding technology, the sugars and starches become more digestible and thus required “slightly” more insulin for these increasing levels of glucose in the bloodstream. So far so good, as the process was slow and gradual taking place over thousands of years. But for the Pima of southern Arizona, dependence on finer and finer flours from cultivated grains occurred much later. Throughout much of the American Southwest people started dabbling with agriculture about 3,000 to 4,000 years ago – but it was not until about 1,250 years ago that it started to dominate the menu. This is thousands of years after it already took hold in the ancient European diet. And for the arid American Southwest, the recent agricultural grain diet was heavily subsidized by a broad spectrum menu that still included an extraordinary variety of wild plants – hundreds of species. So while Europeans were starting to introduce more rapidly absorbed agricultural grains and seeking acceptance from the genome through making slight dietary adjustments (slow ones) to the Human Hybrid engineering (i.e., shifting more of the energy demands to front end – less fiber that is), our Pima friends were still clicking along on the same diet and Human Hybrid blueprint. They would not start to challenge their genome for thousands of more years.
On top of this, the
Pima were late comers to the pottery barn – only developing these handy
cooking and storage vessels in any appreciable quantities about 1,800
years ago – thousands of years after there European counterparts. Pottery
was a significant engineering change to the Human Hybrid as cooking So when you fast forward to today and level the playing field with our modern diet – everyone has equal access to the same technology and foods – the Pima may suffer just a little more because engineering changes to the Human Hybrid in the form of novel foods (agricultural grains) and technologies (cooking pots), genetic requests if you will, were introduced later in their evolutionary history. Thus, their genome has had less time to “try” (and I stress try) to adapt. On a metabolic level, this means when you a challenge a Pima Indian Human Hybrid system with more and more rapidly absorbed foods, their tissues exert a hyper reaction and become insulin-resistant just a tad quicker. This basic premise is similar to the issue of lactose intolerance – with some people who have been exposed to the lactose in the milk of domesticated animals for longer periods of time – suffering less from its affects. And on one final note about the Pima Indians, their ancestors inhabited the arid lands of the American southwest for thousands of years, where the available edible biomass – both plants and animals – is dominated by fiber-rich plants. In other words, arid environments are dominated by plants not animals and the plants are, as a function of their survival mechanisms in such settings, heavy on the fiber side of things – both soluble and insoluble fibers. In fact, when the ancestors of the Pima got around to growing corn, squash and beans (big time) about 1,250 years ago, they also planted fields and fields of the desert succulent agave (agave is the same genus that is used today to make that delicious tequila!). So if you squint just a little bit as you look back in time at the Pima ancestors, you see not the famous maize farmers of the American Southwest, but rather you see fiber farmers maintaining their Human Hybrid just as their ancestors had done before them and there descendants will need to do today if they want to break the cycle of disease and misery that a modern/processed diet has brought to these people. How’s your Human Hybrid?
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Fighting E. coli the old-fashioned way by Jeff D Leach
Unfortunately, this well-intended legislation will fall short of anything meaningful, as its patrons most certainly fail to understand the basic evolutionary rules of the germ warfare raging in the American gut and the bigger challenges facing the populace in this biological arms race. As executives of the produce industry hit hardest by the illness and deaths attributed to E. coli 0157:H7 in 2006 brace for a possible onslaught of new regulations and additional inspectors trudging about their fields and packaging plants, they need only look out to the fields beyond their office windows to see a better solution to what ails them and the American public. Among the lush greens, yellows and reds of the American produce landscape, lies a simple, but critical component, to our evolutionary success as a species and the best defense we have ever had – or will likely ever have – against reducing our risk from E. coli 0157:H7 and the assortment of pathogens that seek to do us harm on the biological battle field that is us. The simple defense to be found amid these fields is good old dietary fiber. As you read this, there are trillions of tiny microbes (including billions of harmless strains of E. coli) living throughout your continuous gastrointestinal tract – from mouth to anus. These tiny evolutionary hitchhikers have been with you every minute of every day from the moment you entered this world and will be so until you die. And then they will eat you. But that’s the good news. The bad news is our so-called modern diet of highly processed fiber poor grains, in addition to added sugars and fats, is literally starving our “friendly” bacteria and putting us at increased risk. The friendly bacteria in our bodies are the first line of defense against invading pathogens, such as E. coli 0157:H7. Like any good soldier they require nutrients to fight the good fight and dietary fiber is an important part of that nutrient base. Simply stated: Fiber is not food for us, it’s food for bacteria that live in our gut. Our not-so-distant ancestors regularly consumed between and often more than 50 and 100 grams of dietary fiber from diverse sources every day. This is the nutritional reality upon which our modern genome was selected and the symbiotic relationship which the trillions of bacteria in our gut evolved to depend upon. However, the average American today consumes about 12 to 15 grams a day – roughly half of what the government recommends and only a fraction of what our gut bugs need in order to resist infection and disease caused by a steady stream of pathogenic bacteria and viruses that enter our gut every day. No amount of government oversight will ever completely remove the threat of pathogens in our food supply. There are too many variables from plough to plate – not to mention that the bad bugs have us out numbered. While a cleaner and safer food supply has allowed our species to maintain mammalian dominance, we must not lose sight of the delicate nutritional requirements of our friendly gut bugs and the indispensable role they play in our tenuous existence on this microbe-dominated planet. The health implications of our staggering drop in consumption of dietary fiber has opened the door to E. coli 0157:H7 and its band of pathogenic brothers who make millions of people sick every year, sending hundreds of thousands to the emergency room with diarrhea, bloody diarrhea, intestinal cramping, and fever, and sending an increasing number of us, to the morgue. The important symbiotic relationship we share with our friendly microbes and their role in our natural resistance to infection should be taking center stage in the upcoming Congressional hearings on how to best protect “the people” from the inevitable food-borne pathogens associated with produce, and specifically, how to deal with this monster E. coli 0157:H7. The recent outbreaks have understandably made the American public skittish not only about spinach and other produce tainted with E. coli 0157:H7, but about produce in general. This may pave the way for an additional decrease of fiber in the American diet, resulting in poorer gut health and reduced ability to resist infectious agents. The media attention given to E. coli 0157:H7 in 2006 has once again raised the awareness of deadly pathogens in our environment. This may be an opportunity, though tragic in its realization, for industry and the government to highlight the importance of increasing fiber intake via fruits and vegetables. Current government health messages to do so have had little success. Maybe it’s time to change the message. For E. coli 0157:H7 specifically, stimulating the growth of a group of healthy bacteria in the human gut known as bifidobacterium by consuming special prebiotic dietary fibers known as oligosaccharides – found in plants such as onions, leeks, garlic, chicory, and artichokes – can fortify our natural resistance. Bifidobacteria exert powerful effects against pathogens through competition for colonization sites and nutrients in the gut, acid excretion and antimicrobial peptides. If properly fed and stimulated, these bacteria will do their evolutionary job and make life a living hell for invading pathogens. Interestingly, bifidobacterium dominate the gut of breast fed babies, but are known to decrease significantly as people get older. This may explain that even though a number of age groups were sickened during the 2006 outbreaks, two out of three of the deaths were elderly women. The third was a 2 year old boy. A similar pattern was seen in a deadly outbreak in Scotland in 1986 that affected hundreds and killed 20. All deaths were among the elderly. At a time when researchers are finally acknowledging that nearly 20% of all cancers are caused by infection – up from zero just a few decades ago – and with hints that infection may play a causal role in such big time killers as breast cancer and atherosclerosis, it may be time to start asking who or what opened the pathogens door. Ignorance of evolutionary biology and the nutritional landscape upon which humans and our microbes evolved should not preclude lawmakers and industry from exploring the role of dietary fiber in reducing our casualties in this evolutionary arms race. Continuing to ignore this simple and easy-to-implement strategy will only result in further human suffering.
I, for one, will be
having a salad tonight.
Mixed culture
fermentation studies on the effects of synbiotics on the human intestinal
pathogens Campylobacter jejuni and Escherichia coli. Pathogen survival in the external environment and the evolution of virulence. Biol Rev Camb Philos Soc. 2004 Nov;79(4):849-69. Review. Evolutionary perspective on dietary intake of fibre and colorectal cancer. Eur J Clin Nutr. 2007 Jan;61(1):140-2. Shiga toxin of enterohemorrhagic Escherichia coli type O157:H7 promotes intestinal colonization. Proc Natl Acad Sci U S A. 2006 Jun 20;103(25):9667-72. Carbohydrate preference, acid tolerance and bile tolerance in five strains of Bifidobacterium. J Appl Microbiol. 2006 Apr;100(4):846-53. Cochran, Gregory M. "Infectious Causation of Disease: An Evolutionary Perspective" Perspectives in Biology and Medicine - Volume 43, Number 3, Spring 2000, pp. 406-448 Evolutionary health promotion. Prev Med. 2002 Feb;34(2):109-18. Review. Human Evolution, Nutritional Ecology and Prebiotics in Ancient Diet. Bioscience & Microflora Vol. 25, No. 1. pp 1-8 "Children on the frontline against E. coli": typical hemolytic-uremic syndrome. Clin Lab Sci. 2005 Spring;18(2):90-9. Prevalence and risk factors of genital Chlamydia trachomatis infection. Medicina (Kaunas). 2006;42(11):885-94. Review. Introducing inulin-type fructans. Br J Nutr. 2005 Apr;93 Suppl 1:S13-25. Review. Non-toxic potentiation of cancer radiotherapy by dietary oligofructose or inulin. Anticancer Res. 2002 Nov-Dec;22(6A):3319-23. Inulin/oligofructose and anticancer therapy. Br J Nutr. 2002 May;87 Suppl 2:S283-6. Review.
The association of
Helicobacter pylori infection with the development of gastroesophageal
reflux disease (GERD).
J
Egypt Public Health Assoc. 2001;76(3-4):265-79. ___________________________
Amidst the usual mob of protesters and tear gas, WTO ministers met last December in Hong Kong to discuss – among many things – the crippling global affect of low-cost export commodities from the US made possible by mammoth farm subsidies. However, the effects of US agricultural policies on global pricing continue to overshadow the more devastating health effects of these policies within our own borders. The farm bill signed by President Bush in 2002, which pledged an astounding 190 billion in subsidies over the next ten years, was the latest in a long line of legislation that likely guaranteed that the next generation of Americans will suffer higher rates of obesity and diabetes, have more strokes and heart attacks, and consume less fiber than any previous generation in human history. While bulging waist lines and clogged arteries grab all the headlines, the decreasing health of our colons through diminishing amounts of dietary fiber as a function of government policy is a looming and disastrous health crisis that will knock the healthcare system flat on its back. As an anthropologist, I’ve had the opportunity to peer into our nutritional past at the bits and pieces of meals and lifeways left by our ancient ancestors. Fortunately, they were messy. In ideal preservation contexts we often see evidence for daily intake of diverse species of plants that provided 75, 100, and up to 150 grams of fiber a day. This is similar to fiber intake noted among many healthy, rural Asian people today, or what we saw 75 years ago in places like South Africa, Uganda, and other far away non-westernized regions. But in the US today, depending on gender, age, and activity level, our government recommends we only eat 25 to 38 grams a day – give or take. Based on this guidance, Americans promptly consume about half of that. The important physiological role of fiber in human health lies in its ability to stimulate the growth and health of the trillions of good bacteria that live permanently in our colons. These evolutionary hitch-hikers have evolved a special symbiotic relationship with humans over eons and have become so intertwined in our health and well-being they are considered an organ. Importantly, these healthy bacteria require fiber to live. Our diminishing dietary intake of fiber is literally starving our colonic bacteria, inhibiting their ability to defend us against invading pathogens that make millions of people sick, many of whom will die. A healthy and well-fed population of colonic bacteria increases mineral absorption (think calcium), has positive affects on biomarkers of colon cancer, reduces symptoms of IBS, and reduces the risk to coronary heart disease by modulating bad cholesterol. And the list goes on. We cannot simply go from a species that evolved on a diet of nutrient-rich fibrous plants, to one that eats almost no fiber. The current US guidelines for fiber intake are – from an evolutionary perspective – in actuality, low fiber recommendations that represent nothing more than the efforts of lobbyists who represent industries that have an interest in seeing the “number of servings” for their “food groups” maintained or increased. To understand the decreasing role of fiber in the American diet, we need not look farther than farm subsidies. Aside from boosting profits within the industry, these subsidies result in low-cost commodities – especially grains - which end up as highly processed (read: no fiber) ingredients in many popular foods. This is one of the reasons you can buy five boxes of macaroni and cheese – which supplies nearly 6,000 nutrient-poor calories – for $1. Further, the average American derives nearly 40 percent of daily caloric needs from heavily subsidized added sugars and fats/oils. Though the government says we should eat more fiber-rich fruits and vegetables, these categories historically receive very few subsidies. This is why fresh fruits and vegetables increased a whopping 120 percent in price from 1985 to 2000, while grain, fats/oil, and sugar-laden products increased far less. With an ever-increasing number of Americans barely making ends meet, choices for “what’s for dinner” have already been economically predetermined, and fiber-rich foods can barely be seen on the plate.
As anthropologists of the future look back
upon our society, what will they see? Unless we stem the tide of
unbalanced agricultural subsidies and honestly address the gaps in
nutrition education among consumers, I’m afraid we will be judged on a
never-ending sea of oversized caskets below a surface littered with empty
prescription bottles and crumbling Food Pyramids built by congressional
pharaohs run amok.
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Strengthening bones
through bioavailability Osteoporosis. Just saying the word makes my bones ache. If you are a woman and over the age of 50, you have about 40% chance of suffering from an osteoporotic fracture. That’s higher than your risk to breast and ovarian cancer. Even worse, 50% of the osteoporotic hip-fracture patients never fully regain independence and more than 20% will die within 6 months. Not good odds. If you are someone who thinks osteoporosis is a “women’s disease,” think again. It affects 25% of men over the age of 50 and an alarming number of young people. If the current trends continue, the problem is expected to worsen by 60% in the next 20 years – regardless of gender. Most folks are aware that osteoporosis is characterized by bone fragility and related to dietary intake of calcium, or the lack of. Simply put – calcium is used to build bones and to a lesser extent, teeth. From the time we are born until our mid twenties, our bones are continually growing and require calcium to do so. The goal during this critical growth period is to achieve peak bone mass. Thick, mineral dense, bones. Your peak bone mass – which again, you can only control until your mid twenties – will strongly influence your risk of osteoporosis later in life. From our mid twenties to about age 50, the density of our bones is relatively stable. This means no matter how much calcium you consume, your bones are not going to get any denser. The goal now is to maintain the bone mass you developed in youth and minimize bone loss associated with aging. This is especially important for women, who must contend with a number of bone loss issues exaggerated during and after menopause – not to mention the demands of pregnancy and lactation on bone health. While you are older and wiser, the efficiency at which your body absorbs calcium in later years, like some many things associated with aging, isn’t what it used to be. Despite the fact that we are confronted daily with the “eat more calcium” message for “healthy bones” on TV, in newspapers and magazines, on annoying billboards, and along the isles of our favorite grocery store, nearly 70% of Americans consume less than the daily recommended allowance of 1,000 mg of calcium a day – give or take. Our daily intake may in fact be lower when you consider that, depending on our particular genetic makeup and the composition of a given meal, our bodies may in fact only absorb 30-35% of the total calcium advertised for a given serving. Think about that little piece of critical information for a minute. Calcium that is not absorbed is mostly excreted in our urine and feces, which brings up an important issue – and the point of why I am writing this column on osteoporosis – bioavailability. The terms “bioavailability” and “absorption” are critical nutritional terms that are often used incorrectly. Absorption describes the process of transport of a mineral like calcium from your intestine across the intestinal mucosa (the wall) into the circulatory system, so that it may be utilized or stored by the body. On the other hand, the bioavailability of a mineral like calcium means the “proportion” that is “actually” absorbed and thus utilized or stored. The key here is solubility. A swallowed penny, for example, has zero bioavailability. It will simply enter one end and come out the other, intact. Whereas a glass of water is highly soluble and will be easily absorbed – nearly 100% bioavailability. Even though you think you are getting 500 to 1,000 mg of calcium from a given food item, meal, or “supplement,” you may not. Given this piece of information, it’s not only important that we increase our daily intake of calcium to recommended levels, we should seek out means to increase the bioavailability of the calcium that we do consume – so that it’s not wasted, so to speak. One way of doing this is to lower the pH of your gastrointestinal system by delivering food to the trillions of tiny bacteria that live in your colon. Food items that are not digested in the small intestine are therefore end up in the colon, are known collectively as fiber. Once in the colon, fiber is broken down by the bacteria through a process called fermentation, which produces, among other things, short chain fatty acids and lactic acid. These acids then in turn make the colon more acidic which increases the solubility of the calcium, making it more absorbable. One of the short chain fatty acids produced (butyrate) has been shown to induce cell growth in the colon, which in turn increases the “absorptive surface” of the colon. This means more calcium is absorbed and less is excreted in feces. Among the 500 plus species of bacteria living in your colon, you want to increase the number of the bifidobacteria and lactobacillus. These two particular groups are known to be especially useful in increasing the acidity of your colon – and they thrive well on special inulin and oligofructose-type fibers that occur naturally in onions, garlic, artichokes, asparagus, and in lesser amounts in wheat-based products. They are also commercially extracted from chicory roots (think chicory coffee) and added as a food ingredient in a growing number of foods. These special fibers are known as prebiotics. By increasing the bioavailability of the calcium that we do consume by a more acidic colon, we can add an additional dietary measure to the preventive strategies for fighting this terrible disease.
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So go the Pimas, so go
the rest of us Anyone familiar with the American Southwest may have heard of the Pima Indians of south-central Arizona. The Pima are the modern descendents of the famous desert Hohokam who occupied vast swaths of south-central Arizona from roughly 200 BC to AD 1450. Famous among archaeologists for their massive and intricate canal systems built to deliver water to the arid and ecologically defiant agricultural fields of the parched Southwest, the Hohokam are a true success story of the ancient world. While history paints the Hohokam as masters of their ancient environment, medical researchers fear our modern environmental landscape may be undermining their modern Pima Indian descendants. In the 1960s epidemiologists started noting an alarming trend among the 11,000 or so Pima Indians living in the Gila River Indian Community just east of Phoenix, Arizona. For some unknown reason, a startling number of Pima were developing type 2 diabetes. Diabetes affects tens of millions of Americans, resulting in the death of more than 300,000 people annually. It’s also the leading cause of end stage kidney disease, adult blindness and amputation. The prevalence of diabetes among African Americans is nearly 70% higher than in Caucasians. Like obesity, diabetes dominates our national discussion on health care. But for the Pima, type 2 diabetes and its complications are acutely devastating. With the prevalence of diabetes estimated at 5.1% of the global population, and 7.9% of the US population, the 38% recorded among the Pima of central Arizona gives them the distinction of being the most diabetes-prone group on the planet. Once the trend started rearing its ugly head in the 1960s, researchers saw not only a looming health crisis among the modern Pima, but also an opportunity to study the disease in a genetically ‘pure’ group, as many of the Pima married within their own community. Importantly, they had multiple generations within families in which to follow the development of the disease and the genetic predisposition. With millions in funding from the National Institutes of Health (NIH) and the blessing and cooperation of the Pima, the Phoenix Epidemiology and Clinical Branch of the NIH was established. It is now several decades and 100 million dollars later, and researchers are still grappling with the Pima diabetes enigma. So why are the Pima prone to diabetes? Diabetes research in general has determined that lifestyle (diet, smoking, physical activity, etc) and genetic factors clearly play a role. For example, there seems to be a significant correlation between ones weight and predisposition to developing diabetes and suffering from its complications. But among the Pima, given the genetic isolation of the group, it seems genes may play a major causal role in individual susceptibility. Or does it? A new study may shed some light. If you happen to be thumbing through the latest issue of the journal Diabetes Care, you would have come across a fascinating study by researchers who examined and compared adult Pima Indians of central Arizona with their genetic cousins, the Mexican Pima of northern Mexico (see map here). As mentioned above, the Pima of central Arizona are descended from the ancient Hohokam, who originally migrated to southern Arizona from what is today northern Mexico (several hundred kilometers to the south). Based on genetic, linguistic, and archaeological data, this migration is thought to have occurred a little over 2,000 yrs ago. Not all of the ancient population migrated and settled in southern Arizona, however, some stayed behind to farm the highlands of Mexico. This situation has provided a unique opportunity for researchers studying diabetes and other diseases among the Pima of southern Arizona. On the one hand, you have Pima who have embraced the modern western civilization and its lifestyle (diet) as it swept over them, and on the other, you have genetically identical ‘cousins’ who essentially stayed on the farm.
The Mexican Pima live in remote areas of the
Sierra Madre Mountains and enjoy few modern amenities. Much of these
communities only recently became accessible by road. The Mexican Pima are
primarily farmers and work manual labor jobs, such as those available in
local saw mills. Almost every aspect of daily life includes physical
activity.
The researchers set out to test the following question by examining adults among the genetically similar but environmentally different sets of Pima: “Do type 2 diabetes and obesity have genetic and environmental determinants?” In other words, does environment (diet, obesity, physical activity, and other risk factors) play a role in the development of diabetes when you hold the genetic pool relatively constant? If genetics played a major role in the southern Arizona Pima’s astounding rate of type 2 diabetes, you would expect to see elevated levels in the Mexican Pima. To add an additional variable to their study, the researchers also included Mexicans living in the same environment as the Mexican Pima in the Sierra Madre Mountains. The Mexicans (not of Pima heritage), are a mix of local Indians and Spanish. Like the Mexican Pima, the Mexicans live a rural and physically demanding life as farmers and ranchers. Using Spanish-speaking interviewers and medical technicians, the data was collected. A brief medical history and physical activity questionnaire was completed on each participating individual, followed by measurements of blood pressure, and a 75-g oral glucose tolerance test. The entire sequence was performed on 193 adult male and female non-Pima Mexicans and 224 Mexican Pima near the town of Maycoba in the Sierra Madre Mountains of northern Mexico. In addition, obesity was assessed by BMI (weight in kg divided by the square of the height in meters), body fat was measured, and waist-to-hip ratio was determined. On top of all that, a 24-hour dietary recall was conducted to determine what everyone was eating. Using the data collected from these two groups, researchers compared the obesity, diet and prevalence of diabetes to some 888 Pima from southern Arizona. The prevalence of diabetes among the three groups is presented graphically below. The prevalence of diabetes between the two genetically similar Pima groups is striking. Among the Mexican Pima men, 5.6% had diabetes, along with 8.5% of the women. Compare this to the Pima Indians of Arizona where 34.2% of the men have diabetes and 40.8% of the women. Among the non-Pima Mexicans (no shared heritage with the Pima), 5% of the women were diabetic and none of the men. That last part is worth repeating: none of the non-Pima Mexican men had diabetes!
In other words, age- and sex-adjusted prevalence of diabetes in U.S. Pima Indians was 5.5 times higher than their Mexican cousins and 16 times higher than the non-Pima Mexicans. The researchers also point out that the differences seen between the two Mexican groups was not significantly different (i.e., basically the same). The differences between the prevalence of diabetes among the Pima Indians of Arizona versus the non-Pima Mexicans and Mexican Pima was also paralleled by differences in obesity, physical activity and diet. BMI, percent body fat, waist and hip ratios were about the same among the two Mexican groups, but significantly different from the U.S. Pima Indians. The average non-Pima Mexican weighed in around 158 pounds (72 kg), with the average Mexican Pima at 145 pounds (66 kg). However, the average U.S Pima Indian male weighed 215 pounds (98 kg). While the women in all three groups weighed less, they followed much the same trend with U.S. Pima Indian females weighing, on average, about 200 pounds (91 kg). As you may already sense, the levels of moderate to heavy physical activity among the groups was higher for the non-Mexican Pima and the Mexican Pima compared to the U.S. Pima Indians. For example, the average U.S. Pima Indian women spent 3.1 hours a week on moderate to demanding physical activity compared to 22 hours per week recorded for her Mexican Pima cousin. As for diet, nothing glaring jumps out between the non-Mexican Pima and Mexican Pima – other than a remarkably low percentage of calories derived from fat, ~25%. In the current study, the researchers did not collect dietary data on the U.S. Pima Indians. Previous studies, however, reveal that percentage of calories from fat for U.S. Pima Indians was much higher than the 25% recorded for the Mexicans groups. The dietary fiber measured in the diet among the non-Pima Mexicans and the Mexican Pimas deserves some special mention. No matter if they were male or female, non-Pima Mexican or Mexican Pima; they consumed greater than 50 grams of dietary fiber a day. Compare this to the 12 to 15 grams a day the average U.S. Pima Indian, or the average American for that matter, are consuming. Given the similar genetic background between the U.S. Pima Indians and the Mexican Pima, the nearly fivefold increase in diabetes among the U.S. Pima can only be attributed to differences in lifestyle and environments. While researchers continue to look for genes that make someone of a distinct genetic group susceptible to diabetes and other diseases such as heart disease, the current study among the westernized and nonwesternized Pima has taught us that obesity and physical activity have more to do with the likelihood that you will develop diabetes, regardless of your genetic makeup. The take home message from the current study is profound: the genetic likelihood that you will develop type 2 diabetes is NOT inevitable and is CLEARLY preventable if you balance a reasonable amount of energy intake with energy expenditure and follow a diet low in westernized, highly processed foods. However, the escalated levels of diabetes among the U.S. Pima and the increase of prevalence with age (for example, 77% of the U.S. Pima > than 55 years of age have diabetes) hint at some underlying genetic discordance with the modern food supply and environment. This is what keeps millions of tax dollars flowing into the genetic-arm of modern medical studies among the U.S. Pima Indians of southern Arizona. I would add to the current study that the dramatic shift (drop) in dietary fiber in the U.S. Pima Indian diet from that of their Hohokam and earlier ancestors (who consistently consumed >100 grams of dietary fiber from a diverse variety of plants), has dramatically influenced the amount of insulin secreted throughout life contributing to the metabolic condition of insulin resistance – a complication associated with type 2 diabetes. This metabolic condition, which I call The Human Hybrid Theory, potentially affects all modern humans who have shifted away from a diversity and quantity of dietary fiber that our ancestors once enjoyed and that our genome was selected upon. It is worth noting that the non-Pima Mexican men, a group that recorded the highest consumption of fiber at 56 grams a day, not a single case of diabetes was noted. Not one.
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