At the University of Minnesota, epidemiologist David R. Jacobs has found that those who ate whole-grain products daily had about a 15 percent to 25 percent reduction in death from all causes, including heart disease and cancer (The Washington Post: 8-4-99). This finding is in keeping with guidelines by the American Heart Association, the American Cancer Society, the National Institutes of Health, and the American Society for Clinical Nutrition, who would all like to see an increased consumption of whole-grain foods to at least three servings per day.
Current dietary guidelines recommend that consumers eat six to 11 servings of grain products daily, including at least three whole-grain foods. A draft of health goals published by the Department of Health and Human Services calls for 75 percent of Americans to meet this intake by the year 2010. The fact is that most Americans fall short of those goals, with only 7 percent eating three or more whole-grain foods daily, according to the latest U.S. department of Agriculture consumption figures. Whole-grain foods contain higher amounts of fiber. But research suggests that it's the whole-grain that delivers abundant amounts of antioxidant vitamins and phytochemicals that appear to act together to provide protective effects.
Now the U.S. Food and Drug Administration is allowing whole-grain products to carry a new health claim that touts their potential to help reduce the risk of heart disease and some types of cancer. Under the new claim, foods that contain 51 percent or more of whole-grain ingredients by weight may say on their labels "Diets rich in whole-grain foods and other plant foods and low in total fat, saturated fat and cholesterol may reduce the risk of heart disease and certain cancers." Whole Grain Total and Wheaties are just two cereals that fall in this category. Look for more of this type of advertising on whole-grain products.
The Other Side Of The Story
Very few people know that there are strong arguments against eating a lot of whole-grain products, and that researchers don't agree on their value. Those interested in a natural "Darwinian" diet may be in the minority, still, the arguments are strong that whole-grain products may have their health costs.
One individual who has researched this problem extensively is Dr. Loren Cordain, Professor of Exercise Physiology at Colorado State University in Ft. Collins, Colorado, 80523.Dr. Cordain is a well-known expert in the area of Paleolithic nutrition. This newsletter features some of his work on grain and grain products. Readers are referred to a recent interview of Dr. Cordain in Life Service Supplement News of July 26, 1999 and an exhaustive recent chapter, Cereal Grains: Humanity's Double-Edged Sword, A.P. Simopoulos (Ed.), (1999), Evolutionary aspects of nutrition and health: Diet, exercise, genetics and chronic disease. Basel: Karger, pp 19-73. Unfortunately this remarkable book chapter will likely be buried along with the book, which costs about $187 with tax.
Building The Evidence
Approximately 17 plants species provides 90 percent of the world's food supply. The top 10 are: wheat, maize, rice, barley, soybean, cane sugar, sorghum, potato, oats, and cassava. Without these plants there is no way that the world could support the existing 6 billion people and the anticipated 12 to 15 billion people expected during the next century. If agriculture gave us anything, it was an easily grown mass diet that was calorically dense that could be stored, shipped, and processed in hundreds of different ways.
Around 20,000 to 10,000 years ago there was a mass extinction of large mammals throughout Europe, North America, and Asia. The environment was exploited until other forms of hunting and gathering was demanded. Birds and waterfowl appeared more frequently in the fossil record, and for the first time grindstones and crude mortars appeared in the archaeological record in the near east. This was the beginning of humanity's use of cereal grains for food.
Hunters and gatherers derived most of their calories from about 100-200 different species of wild animal fruits and vegetables. But with the advent of agriculture man became dependent upon a few staple cereal foods, 3-5 domesticated meat species, and 15-20 other plant foods. Many populations got up to 80 percent of their calories from a single cereal staple.
This was the turning point in human evolution. We abandoned the typical hunter-gatherer lifestyle, with its dependence on wild meat, fruits, vegetables, and nuts and took up dietary and activity patterns that were entirely new to us. We had evolved to adapt to the life of hunters and gatherers and now accepted a life that was incompatible with our adaptive qualities. The consequences were evident in a reduction in body size, from which we have only recently recovered, and in the appearance of diseases of sedentary and agricultural populations, such as cardiovascular disease, cancers, diabetes, high blood pressure, and bone diseases.
Many of our current problems can be blamed on our current nutritional and activity differences from our early hunter-gatherer existence. Agriculture may have launched civilizations, with all their advantages, but it also led to disease, wars, and a restructuring of social organizations. This is why Dr. Cordain refers to the development of agriculture as a two-edge sword.
So What's The Problem With Cereal Grains?
All grains have nutritional deficiencies. Moreover, as we eat more and more grain products we tend to eliminate other nutritional meats, fruits, and vegetables. In half the world, bread provides more than 50 percent of the total caloric intake, and in a few countries of Southern Asia, Central America and the Far East and Africa cereal products comprise up to 80 percent or more of the total caloric intake.
Think about your own intake of grain products. In a month's time, most of us will have eaten several slices of bread, several bowls of cereal with milk, pasta, rice, bagels, rolls, muffins, crackers, cookies, pastries, corn or other forms of chips, and tortillas. Most of these are refined and lack many important nutrients. Cereal grains contain undetectable amounts of vitamin C, B12, carotenoids, and other vitamins and minerals, and they tend to displace foods rich in these substances that are associated with a decreased risk of heart disease and many forms of common cancers. Moreover, cereal grains may actually inhibit the metabolism of these nutrients and cause autoimmune reactions.
Where Have The Vitamins And Minerals Gone?
Diets based primarily on plant foods tend to be low or deficient in vitamin B12. This nutrient is found exclusively in animal products. Vitamin B12 deficiency is related to megaloblastic anemia that results in cognitive dysfunction, and it increases the risk for arterial vascular disease and thrombosis. Obviously a diet based primarily on grains will be deficient in vitamin B12, including strict vegetarian diets. We were not evolved to eat plants exclusively.
Not only are cereal grains deficient in vitamins but many contain substances that decrease the intestinal absorption of many other important nutrients. Both wheat and sorghum are not only low in biotin but seem to have elements within them that elicit a depression of biotin metabolism. Vitamin D utilization by the body can be inhibited by an excessive consumption of cereal grains.
Cereal grains are good sources of phosphorous, potassium, and magnesium, but are poor sources of sodium and calcium. The high phytate content of whole grain cereals forms insoluble complexes with calcium, so that the net effect is a low Ca/P ratio. Phytate is a salt or ester of phytic acid that is capable of forming insoluble complexes with calcium, zinc, iron, and other nutrients and interfering with their absorption by the body. Thus a high phytate content frequently induces bone mineral pathologies in populations dependent upon cereal grains as a primary food source.
Iron metabolism is affected negatively by a diet high in phytate and fiber. Iron deficiency is the most prevalent nutritional problem in the world today. An iron deficiency has been associated with an irreversible impairment of a child's learning capabilities. The bioavailability of zinc, copper, and magnesium in cereal grains is generally low. The absorption of manganese, chromium, and selenium does not seem impaired. Zinc deficiency can result in hypogonadal dwarfism in which there is arrested growth. In countries with high cereal grain intake and hence low zinc absorption, hypogonadal dwarfism is nearly 3 percent and skeletal growth may be limited. The bioavailability of zinc from meat is four times higher than that from cereals.
Essential Fatty Acids (EFA)
Increased consumption of n-3 fatty acids (omega-3 acids), particularly eicosapentaenoic acid (EPA) decreases triglycerides, decreases thrombotic tendencies, and reduces symptoms of many inflammatory and autoimmune diseases including arthritis and inflammatory bowel disease. In addition, n-3 fatty acids are associated with reduced mortality from coronary heart disease. N-3 fatty acids are found in meat and especially oily fish.
Cereal grains are low in fats, including the omega-3 fatty acids, including EPA and docasahexaenoic acid (DHA). Vegetarian diets based primarily upon cereals, legumes, and plant products have a high n-6 (omega-6) to n-3 ratio. Infants deprived of DHA show both visual and neural cortical abnormalities. In pregnant women with low DHA levels, duration of gestation is about 5.6 days shorter than for meat-eating controls. In these women emergency cesarean section were more common, and birth weight, head circumference, and body length were lower in the infants born to the vegetarian women.
Dr. Cordain concludes from these studies that, "Human dietary lipid requirements were shaped eons ago, long before the agricultural revolution, and long before humanity's adoption of cereal grains as staple foods. Hence, the lipid composition of diets based upon cereal grains, legumes, vegetable oils and other plant products is vastly at odds with that found in wild game meat and organs, the primary, evolutionary source of lipids to which the human genetic constitution is optimally adapted." (p 36)
Protein Loss In Grain Diets
Cereal diets lead to inadequate growth because of a reduction of protein and amino acids, compared to meat-supplemented diets. The fossil record shows a characteristic reduction in stature with the adoption of cereal-based diets. Further, vegan and vegetarian children often fail to grow as well as their omnivorous cohorts. The associated deficiencies include energy, protein, zinc, iron, copper, calcium, vitamin D, vitamin B12, and vitamin A. Just looking at protein content, the content of protein in cereal grains is about 12 percent, whereas in lean beef it is about 22 percent. Inadequate protein intake in cereals depending on cereal grains, and especially in the elderly who have difficulties with plant-only diets, is probably quite common.
Antinutrients In Cereal Grains
Plants produce chemicals to defend against predators, such as insects and birds. These secondary metabolites may protect the plants but they can have negative effects on human metabolism. Without naming all of these chemicals, it is clear that some can cause slower growth in mammals either by depressing growth directly or by depressing appetite. Some of these plant chemicals can act as allergens. Alpha-amylase inhibitor proteins are responsible for bakers' allergenic reaction to cereal flours, and can result in hypersensitivity reactions following wheat ingestion in children.
Lectins, which are proteins that are widespread in the plant kingdom, are recognized as major antinutrients of food. Cereal grain lectins are wheat germ agglutinin (WGA). It can interfere with digestive/absorptive activities and can shift the balance in bacterial flora shown to cause problems with normal gut metabolism. The potential to disrupt human health is high.
Autoimmune Diseases And Cereal Grain Consumption
Autoimmune diseases occur when the body loses the ability to distinguish invading proteins from self-proteins that make up the body. The loss results in destruction of self-tissues by the immune system. These diseases are thought to result from a combined influence of environmental and genetic influences.
Dietary cereal grains are noted to be causative agents for celiac disease and dermatitis herpetiformis, both autoimmune diseases. While the incidence of celiac disease is only about 2 percent of the population exposed to cereal grains the consequences can be severe. There are a number of diseases that may occur simultaneously with celiac disease, including Addison's disease, asthma, autoimmune thyroid disease, dental enamel defects, epilepsy, liver disease, and rheumatoid arthritis. Withdrawal of gluten-containing cereals from the diet can ameliorate symptoms of celiac disease and herpetiformis.
The form of protein believed to be associated with celiac disease in gliadin, but since at least 40 different protein components occur in a single variety of wheat it is unlikely that a single gliadin protein causes the disease. Other autoimmune diseases may be related to a high intake of cereal grains, including insulin-dependent diabetes mellitus (IDDM), rheumatoid arthritis, nephropathy, aphthous stomatitis (canker sores), and even multiple sclerosis. A myelin basic protein (MBP) is a suspected target antigen in multiple sclerosis. There are epidemiological reports that link both wheat and milk consumption to the incidence of MS. And there are reports showing remission of MS on gluten-free diets.
Beyond this, many neurological complications may be associated with immune reactivity to antigens found in cereal grains. It is suspected that autoimmune processes are involved. Even autism and schizophrenia show susceptibilities to grain glutens that aggravate (or even cause) the conditions. There are clinical studies indicating that there is a rapid remission of schizophrenic symptoms by introducing gluten-free diets.
What All Of This Means For You
If you have digestive problems or suffer some of the classic autoimmune reactions (e.g. allergies) consider the possibilities that grains may be problematical. Look at your family members and your family history for clues about dietary problems. Adjust the ratio of cereal grains to meat, vegetables, and fruits and see if the adjustment has physiological and psychological effects. In my opinion one should supplement with vitamins, minerals, protein, and free fatty acids. Above all, eat a varied diet and not too much of one thing. And, finally, exercise regularly and with vigor. Put it all together and you have the "Darwinian" diet and exercise program.