Science is the key to improving our crops and our farms
By A.D. Bettge, ADB Wheat Consulting in conjunction with the Washington Grains Commission
Americans are on a perpetual search for easy answers to difficult, complicated questions. One ongoing issue is diet and health problems. The U.S. population is experiencing an increase in obesity and diabetes (Read Study). This situation should be of concern to everyone, since not only are those whose health is affected are involved, but the rest of the population as well since their health insurance rates will rise to help cover treatment for those with weight problems.
As a result of this, nutrition and diet are commanding more attention from the public. Unfortunately, the general public in the U.S. is not well-versed in science, especially not food science or cereal science. This allows the promulgation of simple, incomplete or even false information to be taken as truth. The situation is further exacerbated by the fact that many pronouncements provide simple solutions to complex problems. The easily presented solutions are therefore easy to accept due to their lack of complexity, but present only a portion of the issue, and that may have unintended consequences or that are downright wrong.
Lately, wheat and products produced from wheat have become the center of attention as anti-nutritive or even pathogenic. As health issues become more of a concern, the popular press has communicated pronouncements from sources that extend, without scientific basis, legitimate health concerns affecting some people to the general population, or that cherry-pick anecdotal reports that are modified to suit the author’s current theories, but without testing.
Currently, there exist several foci of concern to the wheat industry:
Each of these positions has been put forth by individuals with advanced degrees, that may, or may not be relevant to cereal science or nutrition, but who also benefit from book or publication sales. Moderate discourse and accuracy in presentation of ideas does not help to increase sales or publicity. Sweeping pronouncements and extreme interpretations of meager data do, however, sell well.
Some of the areas of concern above have a small kernel of scientific truth that is misinterpreted or extended beyond the scope of the research. Other ideas are utter fabrication. Aspects of each issue above will be discussed here, but with alternative perspectives and scientific data that illuminate the areas of truth, or distortion.
The solution to the fundamental, causal issues of American obesity and diabetes is moderation in caloric intake, exercise and a healthier overall lifestyle. The fundamental solutions are difficult to implement and difficult to maintain which is why simple, albeit misleading solutions are easier for the general public to absorb. Listening to the loudest voice is not as difficult as becoming sufficiently educated to enable sifting through data to determine what is best.
During attempts at diet and weight loss, the most successful programs (eg. Weight Watchers) all involve focusing on how much and what sort of food one consumes. Keeping track of food “points”, keeping a food diary, reading labels for calories, etc, all cause the dieter to focus on what and how much is being consumed, with the result that total calories consumed are less due to vigilance and elimination of casual food consumption.
Eliminating wheat from one’s diet follows exactly this model. By focusing on eliminating one component of daily intake, wheat in this case, total calories consumed also decrease. Further, eliminating most carbohydrates from the diet do cause rapid weight loss in the beginning (eg. Atkins diet), but are difficult to maintain and are problematic to health in the long run (eg. Ketosis, low blood pH, liver and kidney problems, etc). Unbalanced diets are difficult to follow and do not demonstrate the long term benefits of diets that are more balanced. (HTTP://WWW.HEALTH.GOV/DIETARYGUIDELINES/DGA2005/DOCUMENT/HTML/EXECUTIVESUMMARY.HTM ; Wing, R.R. and Phelan, S. 2005. Long-term weight loss maintenance. Am J Clin Nutr 82: 222S-225S)
Relative to wheat and wheat consumption, each of the misleading theories above identify wheat as the central cause of recently increasing obesity and health problems. However, wheat consumption per capita in the U.S. has been decreasing, or holding steady, for years, yet obesity, diabetes, cardiovascular problems and general health issues have increased (see chart below). The theories above are clearly incorrect at the outset, given this information. Other countries with much higher wheat consumption (per capita) than the U.S., such as in North Africa and the Middle East, do not have the obesity/overweight problems of the U.S. An exploration of the various wheat-bashing theories is presented in this paper.
The basic ideas associated with this theory are iterated in the book Wheat Belly by William Davis. In the book, the author lists a series of health concerns and then links these issues to wheat consumption through anecdotal stories without requisite scientific rigor or by cherry picking data and extending the conclusions beyond the scope of the research. Several broad categories of health concerns are discussed by the author:
In turn, each is discussed here:
FALSE: Increased wheat consumption causes increased waist size and obesity
Any time the number of calories consumed exceed the number of calories expended, weight gain will occur. As anyone with celiac disease knows, wheat is present in a great number of food products. In the U.S., people, even children, are expending fewer calories per day and are becoming overweight or even obese. This has little to do with wheat consumption per se and more to do with number of calories consumed per day. The film Supersize Me by Morgan Spulock is a prime example of calorie overconsumption. Portion size has increased markedly over the past 20 years. The desire of consumers to see huge portions on their plates and confusing quantity with value, has led restaurants and food producers to increase serving sizes beyond rational amounts (Nielsen, S.J., Popkin, B.M. Patterns and Trends in Food Portion Sizes, 1977-1998. 2003. JAMA 289:450-453). Consumers are not aware, and may not care, about how many calories they consume, preferring instead to become partners in blaming one particular food group for their increasing physical dimensions. Between 1985 and 2000, the average daily caloric intake in America increased 12% (300 calories) per day without concomitant increase in physical activity. This can lead only to weight gain.
If one examines the trends in the chart below, the argument that wheat is the major contributor to obesity is incorrect. In the chart, US statistics are in blue, Moroccan statistics are green (data derived from Centers for Disease Control and indexmundi.com). Solid lines are wheat consumption per capita and dashed lines represent the adult obesity rate (not overweight; just obese - >20% above what is normal weight). Per capita wheat consumption in the U.S. has remained steady, or decreased, while obesity rates are rising. The implication of the data is that increased wheat consumption does not increase obesity and that the obesity increase is from calories from other foods, or a sedentary lifestyle. In countries with very high consumption of wheat, those in N. Africa and the Middle East, obesity rates are much lower.
In the case of Morocco, per capita wheat consumption is over 4 times that of the US, yet the adult obesity rate is less than half of that in the US. The number of products containing wheat may be greater n the US, but the basic products that are primarily wheat remain the same (i.e. bread). If the “wheat belly” thesis that wheat alone makes people fat is true, almost every Moroccan would be obese. Total wheat consumption is holding steady in the US, yet the rate of obesity rises. Obviously, something else is causing the incidence of obesity to rise. Essentially, waist size increase and obesity are due to broad-based consumption of too many calories without regard to the source of the calories.
Lack of exercise is also a factor in obesity. More time is spent in front of TVs and computers and less time is spent walking, jogging, doing household chores and generally being active. Labor-saving devices lead to far less energy expenditure in daily activities. In the past, doing laundry by hand, manual lawn care, fewer elevators/escalators, increased walking due to fewer private cars, all led to more calories expended per day. General sloth is a great cause of obesity (Putnam, J., Allshouse, J. and Kantor, L.S. U.S. per capita food supply trends: More calories, refined carbohydrates and fats. 2002. Food Review 25:2.
In other words, it isn’t wheat, it’s lethargy and overconsumption in general that lead to obesity and weight-related problems.
Wheat and Glycemic Index (GI):
Refined, white flour does have a fairly low GI. Starch accounts for about 65% of a wheat kernel by weight. Starch is a wheat kernel’s primary energy reserve for sprouting. As such, it provides calories in an easily metabolized fashion. GI measures blood glucose response from a particular food versus that of pure glucose. The claim in “Wheat Belly” is that wheat has a worse GI (72) when compared to table sugar (59). This is grossly misleading. Starch is composed of 100% glucose. I will, by nature have a high glycemic index. Table sugar is sucrose, which is 50% glucose, 50% fructose. Fructose requires an additional enzymatic step in order to be transformed into glucose, meaning that sucrose will have the lower GI when the same amount is presented to a subject than glucose alone. Further, to achieve the same starch weight in wheat, it would take about 140g (about 4 slices) of whole wheat bread to equal 50 g of comparable glucose or sucrose due to the other components in the wheat bread. Or, to compare products, four slices of whole wheat bread compare to one 2.5 oz candy bar. This does not mean starch calories should be devoured with impunity. What it does mean is that wheat has many more nutrients and fiber than does pure sugar and should be considered in a more holistic light. These claims mix comparisons between wheat and other foods inappropriately due to nutrient and caloric density.
As an extension of this, Davis claims that the structure of starch, amylopectin-A, is detrimental to GI as well. To an extent, this is true. What he calls amylopectin-A is actually a starch crystallization pattern that leaves the glucose moieties more exposed and more vulnerable to enzymatic hydrolysis by amylases (Zhang, G., Venkatachalam, M. and Hamaker, B.R.. 2006. Structural basis for the slow digestion property of native cereal starches. Biomacromolecules 7:3259). The pattern of crystallization is determined by botanical origins; type A is particular to cereals, type B (slightly less susceptible to amylase attack) is within bananas and potatoes and type C is preferred in legumes and is also less susceptible to amylase hydrolysis (Blazek, J. and Gilbert, E.P. 2010. Effects of enzymatic hydrolysis on native starch granule structure. Biomacromolecules 11:3275). Because wheat (and corn, and barley, and rice, etc) all have A type amylopectin crystallization patterns, they are more easily degraded by enzymes into glucose, hence eliciting a higher GI than starch from other sources. The easy remedy is to eat a balanced diet that includes numerous food groups and to eat sensible amounts.
FALSE: Wheat peptides are addictive and cause people to eat more:
The human digestive system is designed to break down and reconstitute food. Essentially, we eat food, digest it and use the resulting fragments as ingredients to make compounds, energy, tissues, muscle and such for our own bodies. Part of the digestive process involves breaking down proteins into smaller, more easily recycled peptides (short chains of amino acids that are too small to be called proteins) or amino acids.
“Wheat Belly” claims that some of the peptides produced from wheat during digestion act like opioids. Opioids are psychoactive compounds. The name opioid derives from opium. Biochemical studies have shown that peptides resulting from digesting wheat proteins bind to opioid receptors, in vitro (Zioudrou, C., Streaty, R.A. and Klee, W.A. 1979. Opioid peptides derived from food proteins: the exorphins. J.Biol.Chem. 254:2446). In vitro is a scientific term meaning “in a test tube” essentially. This is not the same as in vivo which means “in a living organism”. The response of an organism to compounds binding to opiod receptors is not as simple as an on/off switch, as Davis purports. Many foods also have proteins that produce peptides that also bind to opiod receptors: milk, rice, spinach, meat all interact in this fashion (Teschemacher, J. 2003. Opioid receptor ligands derived from food proteins. Curr. Pharm Des. 9:1331; Meisel, H. 2004. Multifunctional peptides encrypted in milk proteins. Biofactors 21:5). The question becomes whether the in vitro studies apply in vivo and further, whether mere binding to opioid receptors provokes the same psychoactive results as is observed in vivo when opium or other analgesics are used.
Davis states that wheat peptides produce such an addictive response that people can’t stop eating and suffer withdrawal symptoms when one does not ingest more wheat. One could equally validly argue that the action of the peptides results in low blood pressure, enhanced learning and satiety (the feeling of “fullness” or satisfaction after a meal), all of which would serve to decrease consumption. Further, it could be argued that when the “opioid effect” wears off, one wants to eat again. Most people might call this feeling “hunger” (Geraedts, M.C., Troost, F.J., Tinnemans, R., Soderholm, J.D., Brummer, R.J. and Saris W.H. 2010. Release of satiety hormones in response to specific dietary proteins is different between human and murine small intestinal mucosa. Ann. Nutr. Metab. 5:308; Choi, S., Disilvio, B., Fernstrom, M.H., and Fernstrom, J.D. 2009. Meal ingestion, amino acids and brain neurotransmitters: Effects of dietary protein source on serotonin and catecholamine synthesis rates. Physiol.Behav. 98:156).
Wheat breeding has produced a genetically altered version of wheat that contains “new” proteins (gliadins) with toxic effects:
“Wheat Belly” argues that conventional wheat breeding has produced wheat varieties that are vastly different than wheat varieties of only 50 years ago and that the result of breeding programs are wheat varieties that contain toxic “new” proteins. DNA is the nucleic acid that contains the information for synthesis of proteins. Wheat breeding programs can only access DNA that is present in wheat germplasm that already exists. Some DNA can be introgressed, or brought into wheat breeding programs from other grasses through careful breeding, but all the genes that code for proteins are already in existence in wheat or closely related species (emmer, einkorn, durum, goat grass). A central tenet of biology is that no new organism can possess new genes that aren’t present in the parents and that no conventional breeding program can produce or access genes that aren’t present in the parental germplasm (Crick, F. 1970. Central dogma of molecular biology. Nature 227(5258): 561.).
Davis’ suggestion that new, novel and toxic proteins have been created through wheat breeding also needs to be addressed. Specifically, he indicates that gliadin proteins are the species of proteins he believes are both new and toxic. Firstly, gliadins are not new. They have always been a component of wheat protein and are present in ancient wheat. There are no new gliadins that have been formed in commercially produced wheat. Gliadins, specifically the alpha-gliadins have been implicated in celiac disease, but this is a separate and special case that involves <2% of the population.
Davis implicates hybridization as the source of the new toxic gliadin proteins. However, hybridization has been abandoned by the wheat breeding community as ineffective in producing economically useful wheat. The “hybridization experiment ” Davis cites actually is somatic cell protoplast fusion, which went through a series steps involving UV radiation (a powerful mutagen), protoplast fusion and tissue culture (also known to be factor causing mutation). Apparently, Davis doesn’t know the difference, or chooses to ignore the difference, of simple hybridization through crosses used in wheat breeding from somatic cell fusion hybridization. (Xia, G.M., Xiang, F.N. and Zhou, A.F. 2003. Asymmetric somatic hybridization between wheat (Triticum aestivum L.) and Agropyron elongatum (Host) Nevishi. Theor. Appl. Genet 107:299). Both cell culture and UV radiation can cause genome variation. However, somatic cell hybridization is not a conventional hybridization approach used by wheat breeders. None of the wheat cultivars in the U.S. were developed via somatic cell fusion hybridization.
There are no “new” proteins (gliadins) in commercial wheat that haven’t been present since wheat was wheat some 7,000 years ago. New proteins have been seen in research labs, due to mutagenic treatments of the embryo, to deliberately study the effect of altered proteins. None of these plants have been involved in conventional wheat breeding for consumption by people or livestock.
The incidence of celiac disease has increased:
Celiac disease is debilitating and difficult to manage. It is a very real immune response to certain wheat proteins, mostly the alpha gliadins. In those afflicted with celiac disease, the villi of the intestines are essentially stripped-off due to immune response and obtaining enough nutrition becomes difficult for the patients. Diagnosing celiac disease is difficult and involves invasive biopsies and blood analyses. Analyzing blood for antibodies to the gliadin epitopes (the part of the protein that elicits the immune response) can identify predisposition to celiac, but a true diagnosis involves much more diagnostic work.
“Wheat Belly” states that the rate of celiac disease has risen fourfold. This number was arrived at by comparing blood samples from military recruits 50 years ago with those of today. The actual rates were 0.2% and 0.9%. Indeed, a four-fold increase, but still less than 1% of the whole population (Rubio-Tapia, A., Kyle, R.A., Kaplan, E.L., Johnson, D.R. and Page, W. 2009. Increased prevalence and mortality in undiagnosed celiac disease. Gastroenterology 137:88). Further, presence of the antibodies does not necessarily mean that celiac disease is present. Colonoscopic biopsy of the intestinal lining is required for a complete, confirmatory diagnosis. Another issue is that reporting of celiac disease has increased as more physicians become sufficiently educated to entertain celiac as a diagnosis in patients who suffer from digestive system problems. These patients represent the true celiac disease sufferers. Many more individuals self-diagnose and attribute digestive system problems falsely to celiac disease.
Davis states that celiac patients lose weight when the eliminate wheat from their diet. This is clearly not true. True celiac patients tend to be malnourished when the disease is active; they cannot get enough nutrition or calories due to the absorbing surface of the intestines being vastly reduced. Celiac patients are underweight due to the malnutrition they suffer (Malandrino, N., Capristo, E., Farnetti, S., Leggio, L., Abenavoli, L., Addolorato, G. and Gasbarrini, G. 2008. Metabolic and nutritional features in adult celiac patients. Dig.Dis. 26:128). In fact, when wheat is eliminated from celiac patients, they tend to have higher Body Mass Indices (BMI) than those who do not (Freeman, H.J. 2008. Perils and pitfalls in the diagnosis of adult celiac disease. Can.J. Gastroenterol. 22:273). This also applies to those who eliminate wheat from their diet because they believe they “should” due to misinformation promulgated by Davis and his ilk. This is due in part to substitution of other plant starches for wheat. Tapioca, potato and corn starches are chief among them. Additionally, the amount of fiber in the diet decreases in non-wheat consuming individuals, on average (6 g vs 12 -15 g/day and recommended levels of 25 – 38 g/day).
To summarize, Davis has written a book that is misleading and cherry-picks data or misapplies the results of studies. Rather than propose a balanced and moderate approach to weight management, he has taken advantage of the public’s penchant for simple solutions to provide an easy way to lose weight in the short-term; eliminate wheat from one’s diet. Weight reduction may ensue, but the results are apt to be short-lived and include unnecessary health impacts to those who opt for the unbalancing of one’s diet. For those who are not afflicted with celiac disease, wheat contributes fiber, vitamins, minerals and a vast array of food products that provide a nutritious, tasty component of a balanced diet.
The Paleo-Diet is a sudden diet fad that follows many of the misperceptions of “Wheat Belly”. The Paleo-Diet’s underpinning is that as humans evolved, they did not eat cereal grains (Lindeberg, S. 2005. Palaeolithic diet ('stone age' diet). Scandinavian Journal of Food & Nutrition 49 (2): 75). Consumption was limited to fruits, vegetables, meat, insects/grubs and roots/tubers, and excludes grains, legumes, potatoes, dairy products, refined salt, refined sugar, and processed oils (Cordain, L. 2002. The Nutritional Characteristics of a Contemporary Diet Based Upon Paleolithic Food Groups. Journal of the American Nutraceutical Association 5:15). The proponents of Paleo-Diet espouse the notion that the human genome and digestive system are evolutionarily incapable of dealing with cereal grains in the diet and that the result of cereal consumption is at least being overweight if not obese. Those who espouse the Paleo-Diet believe that subsisting on the proposed diet frees people from diseases of affluence, just as our ancestors were free of diseases of affluence (diabetes, cardiovascular issues, gout, obesity, etc) (Kligler, B. and Lee, R. A. (eds.). 2004. "Paleolithic diet". Integrative medicine. McGraw-Hill Professional. pp. 139). However, this view neglects the fact that our ancestors died young, typically before 30 years old and hence there was no time for the “affluence-associated” diseases to manifest themselves (Nestle, M. 2000. Paleolithic diets: a skeptical view. Nutrition Bulletin 25 (1): 43; Elton, S. 2008). Environments, Adaptation, and Evolutionary Medicine: Should We Be Eating a Stone Age Diet. In Elton, S. and O'Higgins, P. Medicine and Evolution: Current Applications, Future Prospects. London: Taylor and Francis. pp. 9; Eaton, S.B., Cordain, L. and Sebastian, A. 2007. The Ancestral Biomedical Environment. In: Endothelial Biomedicine Aird, W.C. ed. Cambridge University Press. pp. 129 ).
Many of Paleo-Diets precepts will work, for the reasons already iterated: eliminating one food group from a diet forces focus on the diet and caloric intake in general. Thus weight loss ensues due to overall dietary monitoring. The diet also emphasizes more protein than is present in more balanced diets. Following this diet with modern food choices can be difficult and obtaining sufficient dietary fiber without the inclusion of cereals can be problematic as well. Finding the wild vegetables, herbs and roots that ancient humans might have eaten is difficult. And inclusion of grubs and insects as part of a diet receives little enthusiasm and are omitted from the Paleo-Diet food options, leaving the Paleo-Diet not as pure a diet as it purports to be.
The evolutionary assumptions underlying the Paleo-Diet are disputable. A basic premise of the Pale-Diet is that the genotype of H. sapiens developed between 1.8 million and 11,000 years ago and is now fixed and immutable (Eaton S.B., Eaton, S.B. 3rd, and Konner, M.J. 1997. Paleolithic nutrition revisited: a twelve-year retrospective on its nature and implications. European Journal of Clinical Nutrition 51: 207). As such, the premise of the diet is that the human digestive system is not capable of processing cereals as part of the food consumed. This view does not consider that starving early humans would eat anything that sits still long enough to be devoured, including wild grass seeds, early, undifferentiated cereals and anything else possessing useful calories. Cereal grains had not yet been selected for agronomic traits (like yield and disease resistance), but they certainly existed in a pre-agricultural form and were certainly consumed.
Since the Paleo-Diet assumes that the human genome is fixed, the notion is then extended to include the false assumption that alteration in genetics is necessary to adapt to a diet that incorporates cereals (Ströhle, A., Wolters, M., and Hahn, A. 2007. Carbohydrates and the diet–atherosclerosis connection—More between earth and heaven. Comment on the article 'The atherogenic potential of dietary carbohydrate'. Preventive Medicine 44: 82). The digestive system is a complex bioreactor that works to reduce food to molecular products that can be absorbed by the body and then reassembled into tissues and energy. Pretty much, food that can be acid or enzymatically hydrolyzed can be used by the body, regardless of source.
Additionally, the human genome is not fixed. It is still evolving (Hawks, J., Wang, E.T., Cochran, G.M., Harpending, H.C. and Moyzis, R.K. 2007. Recent acceleration of human adaptive evolution. Proc Natl Acad Sci. 104: 20753). For example, genes that allow lactose to be digested by adults were not prevalent in humans a millennia ago. As animal husbandry increased, along with fixed, agricultural-based farms and villages, the adult lactase genes increased to a high percentage in populations in Europe. And the percentage of people worldwide who have adult lactase continues to increase. Similarly, lingual amylase (starch digesting enzymes in saliva) have also increased concomitantly with the advent and growth of agrarian diets. Had departure from the array of Paleo-Diet food products been detrimental to humans, there would have been active selection against cereal and agricultural-based food products (Ungar, P.S., Grine, F.E. and Teaford, M.F. 2006. Diet in Early Homo: A Review of the Evidence and a New Model of Adaptive Versatility. Annual Review of Anthropology 35: 209). To the contrary, use of cereals increased rapidly in time from 6,000 years BCE to the present. The problem is again the difficulty of people finding a balance in their diet and a balance of appropriate exercise and activity in their lives. Too many calories, regardless of source and a sedentary lifestyle lead to weight gain and associated health problems (Leonard, W.R. 2002. Food for thought: Dietary change was a driving force in human evolution. Scientific American 287: 106; Uauy, R. and Díaz, E. 2005. Consequences of food energy excess and positive energy balance. Public Health Nutrition 8: 1077). The contention that Paleo-Diet allows avoidance of cardiovascular disease, diabetes, obesity and other lifestyle afflictions because there is less record of it in the archaeological record does not take into account the fact that life spans were much less 8,000 years ago than today; the diseases didn’t have a chance to appear.
Paleo-Diet, just as “Wheat Belly”, does not acknowledge the health and nutritional benefits of cereals in general and wheat specifically. The nutrition provided by wheat certainly overshadows the problems with its consumption, excepting those who have celiac or gluten intolerance. To achieve health through diet, one does not need to eliminate entire food groups from consumption. What is needed is moderation and balance in diet and a lifestyle that incorporates sensible balances of activity, exercise and rest. Society’s desire for simple-minded solutions to complex problems leads to acceptance, without critical thought, of easy fixes such as “Wheat Belly” or Paleo-Diet. This illuminates a larger flaw in society: the lack of useful science education that would allow citizens to question and see through schemes that appear to exist only to benefit the proponents of quick weight-loss and health diets.