Wheat Belly by Dr. William Davis and Grain Brain by Dr. David Perlmutter are two best-selling books that tell you to avoid wheat and other grains. Dr Davis claims that wheat makes you fat and causes many diseases, and by eliminating wheat you will lose weight and prevent these diseases. Actually, he proposes a low-carbohydrate diet that may cause you to lose weight, but he does not have data to show that it helps you keep that weight off over time. He and Dr. Perlmutter both claim that avoiding wheat cures diseases, but they have no data to support these wild claims, except in the small minority of people who suffer from an intolerance to gluten called celiac disease. Scientific research does show that ANY diet that reduces calories and causes weight loss helps prevent diabetes and heart attacks.
No Data Shows That Whole Wheat Causes Obesity
Dr. Davis writes in his introduction: "I'd like to make the case that foods made with wheat make you fat . . . wheat consumption is the main cause of the obesity and diabetes crisis in the United States." That is his opinion. He has no data to show that wheat causes obesity or diabetes. Furthermore, he fails to make a distinction between refined and unrefined foods.
What are Refined Carbohydrates?
Fruits, vegetables, whole grains and other seeds are rich sources of carbohydrates. Most of these foods have fiber and many have a capsule structure that delay absorption to prevent a high rise in blood sugar. However, when these foods are crushed, ground, juiced or otherwise processed, or when the fiber is removed, they become very easy to absorb and cause a high rise in blood sugar to increase risk for obesity.
Huge Difference Between WHOLE Grains and Foods Made from Flour
Contrary to what Dr. Davis claims, most studies show that unrefined wheat can prevent weight gain and obesity. Whole grains prevent diabetes and weight gain because they do not cause a high rise in blood sugar (American Journal of Epidemiology, 2003:58(3):243-250; American Journal of Clinical Nutrition, online Dec. 12, 2012; American Society for Nutrition, July, 2013). Studies on animals and humans show that whole grains increase insulin sensitivity and help prevent and treat diabetes and heart attacks (American Journal of Clinical Nutrition, 2003;78(5):965-971).
Whole grains are seeds of grasses. They have such a thick capsule that your body can't break them down and you can't eat them unless they are softened by cooking. Blood sugar after eating whole grains is relatively flat. On the other hand, when you grind a whole grain into flour, you break the capsule, and foods made with flour cause a much higher rise in blood sugar. Dr. Davis is misleading when he uses data on foods made from flour (bakery products and pastas) to "prove" that wheat is harmful. See WHOLE grains are better than any flour.
Why a High Rise in Blood Sugar Is Harmful
Foods can be classified by glycemic load, a measure of how high a person's blood sugar rises after eating a particular food. Foods that cause a high rise in blood sugar are associated with increased risk for obesity, heart attacks, strokes, and premature death. When blood sugar levels rise too high, sugar sticks to the outer surface of cell membranes. Once there, it cannot get off. The attached sugar is eventually converted to sorbitol that destroys the cell and can damage every kind of cell in the body. That is why high blood sugar can lead to dementia, nerve damage, impotence, cancer, heart attacks, strokes and so forth.
A high rise in blood sugar causes the pancreas to release large amounts of insulin. Insulin converts sugar to triglycerides, a fat that can be stored in your body to make you fat. Refined carbohydrates cause a high rise in blood sugar, while wheat berries and other whole grains do not cause a high rise in blood sugar.
Most Scientists Disagree with Dr. Davis and Dr. Perlmutter
Many studies show that people who eat whole grains have a lowering of blood cholesterol, blood sugar and blood pressure, and are less likely to suffer diabetes, heart disease or strokes. The Dietary Guidelines of the American Heart Association and American Diabetes Association both recommend whole grains.
Just Two More Low-Carbohydrate Diets
Dr. Davis recommends reducing carbohydrates to between 50-100 grams a day (diabetics to fewer than 30 grams a day). His diet is almost identical to the old Atkins Diet. However, his diet is not low in calories. The key to weight loss is to take in fewer calories or burn more calories. Dr. Davis's first-day meals provide up to 3000 calories, and his last-day meals add up to about 3500 calories. This huge intake of calories will make most non-exercising North Americans fat.
Other Unsupported Claims
Dr. Davis is not a researcher, but he makes absurd, unsupported claims that avoiding wheat improves athletic performance, improves mood, reduces mood swings, improves concentration, improves sleep, increases energy, slows skin aging and improves coordination. Dr. Perlmutter wants you to believe that avoiding gluten will prevent or treat dementia, depression, ADHD, migraines, epilepsy, Tourette's syndrome and much more.
The Mediterranean and DASH Diets Include Whole Grains
Most of the recent scientific reviews on how diet affects health have proclaimed the Mediterranean and DASH diets to be the most healthful. Both recommend wheat and whole grains. These high-plant, high-carbohydrate diets are supported by studies showing that they are associated with reduced rates of dementia, heart attacks, blood pressure, cancers and strokes.
Celiac Disease
A small percentage of North Americans suffer from celiac disease and they should avoid wheat, as well as rye, barley and possibly oats. (Oats are often stored in the same silos used to store wheat, rye and barley, so they can be contaminated with gluten from the other grains). When a germ gets into your body, your immunity recognizes that its surface proteins on cells are different from your proteins, so you produce cells and proteins called antibodies that attach to and kill the germs. Sometimes a person's immunity treats certain foods as invading germs and attacks the food to cause disease. Wheat, rye and barley contain gluten, a protein that can turn on a person's immunity to cause disease.
If you have chronic indigestion or suspect that wheat makes you sick, check with your doctor and get blood tests for antibodies to gluten. Do not just avoid wheat and go on a gluten-free diet. Long-term avoidance of gluten can lower blood levels of gluten antibodies that are used to diagnose celiac disease. So long-term avoidance of wheat will cause a negative test for wheat antibodies, even if you have celiac disease. If the test shows that you have antibodies to gluten, you will need a biopsy of the small intestine to confirm the diagnosis. Since celiac disease is genetic and runs in families, you can get a genetic test to see if you are susceptible to developing celiac disease. It is controversial whether people can have negative antibodies and biopsy for celiac disease and still be sensitive to wheat, so sometimes doctors prescribe a gluten-free diet to see if a person's symptoms improve.
Unrealistic Promises and Major Failings of Wheat Belly
1) Dr. Davis blames wheat for the health problems that are caused by refined carbohydrates. Most scientists disagree with his blanket condemnation of wheat.
2) He has no discussion of exercise, which is essential for long-term weight loss.
3) He restricts healthful foods like oatmeal, quinoa, brown rice, sweet potatoes, legumes and fruits. This requirement has no scientific support whatsoever.
4) He allows beef, pork and full-fat cheeses, which I believe (supported by many studies) are associated with increased risk for heart attacks, certain cancers and premature death.
5) He claims that wheat increases belly fat that causes diabetes. The Framingham study shows that people who eat at least two servings per day of refined grains or three servings per day of whole grains have the least belly fat (Am J of Clin Nutr, 2010;9:1165)
6) He claims that rheumatoid arthritis can be cured by avoiding wheat. This is contrary to what the literature shows. People who suffer from rheumatoid arthritis have the same incidence of gluten intolerance as those who don't have that disease (Scand J Rheumatol, 2010;39:292). Furthermore, people with celiac disease are not at increased risk for rheumatoid arthritis (Clin Exp Rheumatol 2006;24:325)
7) His list of conditions caused by eating wheat is unbelievable: Type 2 Diabetes, Acid reflux, Irritable bowel syndrome, Rheumatoid arthritis, Asthma, Schizophrenia, Autism, Breast cancer, Pancreatic cancer, Colon cancer, Prostate cancer, Type 1 diabetes, Osteopenia and osteoporosis, Osteoarthritis, Cataracts, Erectile dysfunction, Kidney disease, Dry eyes, Alzheimers, Atherosclerosis, Hyperlipidemia, Non-alcoholic fatty, liver disease, Non-alcoholic steatosis, Heart disease, Cerebellar ataxia, Nystagmus, Myoclonus, Chorea, Peripheral neuropathy, Migraines, Dementia, Seizure disorders, ADHD, Acne, Gangrene, Skin ulceration, Dermatitis herpetiformis, Intestinal lymphoma, Angular chelitis, Glossitis, Cutaneous vasculitis, Acanthosis nigricans, Erythema nodosum, Psoriasis, Vitiligo, Behçet's diseases, Dermatomyositis, Icthyosiform dermatoses, Pyoderma gangrenosum, Alopecia areata, Gynecomastia, Leg edema, Bipolar illness, Dandruff.
Summing Up
Dr. Davis recommends a low-carbohydrate diet to help people lose weight. He masks it under a diatribe against wheat, even though no scientific studies have shown that avoiding wheat causes weight loss. This book is so full of scientific inaccuracies that I do not recommend it. Don't demonize wheat; instead, work on reducing the sugars and other refined carbohydrates in your diet and stay active enough to burn all of the calories you consume.
Checked 12/25/18
