Whole grains are healthful, while refined grains (foods made from flour) can be harmful, particularly if you are overweight or have high blood sugar levels. A recent review of 20 studies, with 2,282,603 participants and 191,979 deaths during the study periods, found that greater intake of whole grains was significantly associated with lower risk of all-cause mortality (Adv Nutr, November 2016;7:1052-1065). Each additional three servings of whole grains per day was associated with a 25 percent lower risk of death from cardiovascular disease. Many other studies agree with these findings:
• Researchers followed 54,871 Danish adults, aged 50-64, for almost 15 years and found that those who ate a lot of whole grains, particularly rye and oats, had far fewer heart attacks (Am J Clin Nutr, Feb 17, 2016). Eating whole grain breads was not associated with reduced heart attack risk.
• Whole grains lowered total cholesterol and the bad LDL cholesterol (Am J Clin Nutr, Sept 2015;102(3):556-72).
• In a study that followed 108,000 Danish, Swedish, and Norwegian participants for 11 years, those who ate more whole grains had a significantly lower risk for colorectal cancer (Cancer Causes Control, July 2013;24(7):1363-74).
• 120,010 adults, ages 30-64, were followed for 10 years and those who ate lots of whole grain oats, rye and wheat lived longer than those who ate less (Br J Nutr, August 28, 2015;114(4):608-23).
• A survey of studies published between 1965 and 2010 showed a reduced risk for overweight, diabetes and heart attacks with high intake of whole grain cereals or mixtures of whole grains and bran (Am J Clin Nutr, Aug 2013;98(2):594-619).
• A review of 29 articles showed that people who ate whole grains had a 20 to 40 percent reduced risk for heart attacks and diabetes (Curr Atheroscler Rep, Nov 2004;6(6):415-23).
• The Physicians Study followed 86,190 male doctors, aged 40-84 for 5.5 years. Those who ate whole-grain breakfast cereals lived longer and had fewer heart attack deaths than those who ate refined-grain breakfast cereals (Am J Clin Nutr, March 2003;77(3):594-9).
Why Whole Grains are More Healthful than Flour
High rises in blood sugar can damage cells throughout your body. Whole grains are seeds that have a capsule-like coating of fiber that is difficult to break down. Even when whole grains are cooked and chewed, the contents of the capsules are digested very slowly and do not cause a high rise in blood sugar. However, when the seeds are ground into a powder (flour), the capsule is broken and the starches are quickly digested and broken down into single sugars, which can cause a high rise in blood sugar that increases risk for weight gain and diabetes (Diabetes Care, 2004;27:2701-6).
Don’t Let the Gluten-Free Craze Keep You From Whole Grains
Many of the people who believe they are being helped by a gluten-free diet are actually benefiting because they have cut out bakery products and other foods made from flour. However, if you load up on refined foods made with corn meal, rice flour and other gluten-free flours, you will not gain any benefit at all. Less than two percent of North Americans have celiac disease or gluten sensitivities that make it necessary for them to avoid wheat, rye and barley, but they can still eat many other whole grains such as brown rice, wild rice, buckwheat and quinoa. If you think you have symptoms caused by eating whole grains, check with your doctor for a blood test called “celiac panel” and possibly an intestinal biopsy. Whole grains can be part of any diet you choose to follow. If you are truly gluten sensitive, you will need to avoid wheat, rye and barley. Oats can be contaminated from storage in silos that have held wheat, so some gluten sensitive people will want to avoid them as well.
• If you are overweight or if you can pinch more than three inches of fat underneath the skin over your belly, or have diabetes or heart trouble, you should severely restrict all refined carbohydrates. Eat carbohydrates as nature packages them: in fruits, vegetables, whole grains, beans and other seeds. Restrict foods made from flour, such as bread, pasta, pretzels, bagels, crackers, cookies, chips and most cold breakfast cereals, and milled grains such as white rice. Also avoid sugared drinks including fruit juices and all sugar-added foods. See Hidden Sugars
• Realize that the term “whole grain” on the package label does not guarantee that a food actually contains all of the parts of the grains. The only way to know that you are getting whole grains is to eat the seeds themselves. See Is it Really Whole Grain?