Not everyone agrees about grains. Some nutrition experts (and would-be experts) believe that grains should be a major part of everyone’s diet. Others believe that grains should be marginalized in the diet. Whom should you believe? Let’s take a look at what science and common sense say about the place of grains in a healthy diet.
The Anti-Grain Arguments
There are two distinct camps that stand against grains: the low-carb advocates and the ancient diet advocates. The Low-carb advocates argue that grains should have a small place in the diet because they are high in carbohydrates, and carbohydrates should be limited in the diet because they cause weight gain, diabetes and other horrors.
The problem with this argument is that there is no solid evidence that a high-carbohydrate diet causes weight gain or metabolic disorders. In a recent review of the scientific literature, University of Virginia nutritionist Glenn Gaesser, Ph.D., found no association between carbohydrate consumption and overweight or metabolic diseases. In fact, he found that the balance of research indicated that those who consume high-carbohydrate diets tend to be slimmer than those who eat fewer carbs.
The ancient diet advocates have a more credible argument against grains. Their position is based on the fact that grains did not become a significant part of the human diet until the agricultural revolution occurred in approximately 10,000 B.C. Since humans were more or less fully evolved by this time, according to this argument, grains are not ideally suited to the human genotype, which represents an adaptation to the vegetables and other foods that humans ate for tens of thousands of years preceding the incorporation of grains.
The nutritional profile of grains is certainly very different from that of the vegetables, which contain a greater density and variety of vitamins, minerals, and phytonutrients and a lower density of calories than grains do. Research has clearly shown that fruits and vegetables are the most indispensable foods in the human diet. Men and women who eat the most fruits and vegetables have fewer chronic diseases and live longer than others. By contrast, grains can be completely eliminated from the diet without consequence as long as the level of fruit and vegetable consumption remains high. No vital nutrient is underrepresented in the diet of those who follow “Neanderthal” or “Paleolithic” diets.
That which is unnecessary is not necessarily harmful, however. The scientific literature contains no evidence that high levels of grain consumption are harmful. In fact, studies have found that higher levels of whole grain consumption are associated with lower risk of overweight, heart disease, diabetes, and various types of cancer. Notice I wrote “whole grains,” though, and not simply “grains”. I’ll say more about this distinction below.
The bodies of many men and women do not react well to grains. Some are allergic to the gluten contained in wheat and other grains while others experience sluggishness, slow thinking and other such symptoms due to the high carbohydrate load that comes with grain consumption. These problems have a genetic basis and provide a solid indication that grains are not the human genome’s preferred source of nourishment. Life is better for gluten-allergic and carbohydrate-sensitive individuals when they minimize grain consumption. Everyone else can maintain a fairly high level of grain consumption without consequences as long as the overall diet is balanced and the activity level is high.
What The Establishment Says
Mainstream nutrition experts have long recommended that people eat more grains than any other type of food. The nutritional establishment is most fully represented in the MyPyramid nutrition guidelines created by the U.S. Department of Agriculture, which advise men of my age, height, weight, and activity level to consume nine servings of grains per day and only five and a half servings of fruits and vegetables combined.
The problem with these guidelines is that they suggest that high levels of grain consumption are necessary for good health, when they are not. You can be perfectly healthy with a diet that includes no grains whatsoever. One must understand, however, that the MyPyramid guidelines are based not only on nutrition science but also on cultural dietary norms. Grains are the most abundant food in the typical American diet, and most of us would be loathe to eliminate them.
The MyPyramid guidelines also include a recommendation that half of one’s daily servings of grain be whole grains. If I could, I would tweak this recommendation to read: “Get as many of your grains as possible in the form of whole grains.” As you know, refined grains such as processed wheat flour have been stripped of most of their fiber and vitamins and minerals, leaving only the calories. Consequently, replacing most of the refined grains in your diet with whole grains will have a significant, positive long-term impact on your health.
For example, a new study from Penn State University provides new evidence that a diet rich in whole grains may promote weight loss and reduce the risk of chronic diseases such as diabetes. Participants in the study were 25 men and 25 women with metabolic syndrome. All 50 subjects were placed on the same weight-loss diet for 12 weeks, except that half of them were counseled to get all of their grains in the form of whole grains. Members of both groups lost weight
8 to 11 poundsbut those in the whole grain group lost more abdominal fat. In addition, members of the whole grain group exhibited a 38 percent decrease in C-reactive protein, a marker of whole-body inflammation, which underlies various chronic diseases, whereas C-reactive protein levels remained unchanged in members of the control group.
The straight dope on grains can be summarized as follows: Eat as many or as few grains as you like, as long as your overall diet is well balanced and your body seems to tolerate grains well. Regardless of how much grain you eat, make sure most of it is whole grain.