Inflammation and Whole Grains

According to the promoters of Paleo and other bad diets, people should avoid eating grains because they increase inflammation and cause disease.

“Whole grains” includes foods like whole wheat, oats, brown, basmati, and jasmine rice, rye, barley, buckwheat, bulgur, quinoa, corn, farro, kamut, millet, and spelt. Whole grains do not include bagels, pastry, cookies, white flour pasta, croissants, pretzels, and cereals like Lucky Charms. While this seems simple – whole natural foods vs highly processed junk foods, there is considerable misunderstanding about this issue. “Grain bashers” like William Davis (author of Wheat Belly) claim that their patients are sick because they eat grain-based products like Wonder Bread, Trix, Fruit Loops, HoHo’s, Oreos, Vienna Fingers and Fettuccini Alfredo. They apparently do not understand the difference between eating highly processed products and foods like wheat berries and millet loaf.

Those who advise against eating grains claim, among other things, that eating grains increases inflammation levels. While this might be true when consuming highly processed foods like cookies, the opposite appears to be the case for whole grain foods, which have been shown to reduce inflammation.

A very well-designed study involving 81 participants showed clearly both the benefits of consuming whole grains and the difference between diets based on refined vs whole grain products. For the first two weeks, subjects maintained their typical Western-style and weight-maintaining diet. For the next 6 weeks, 40 subjects stayed on this diet, while the other 41 were switched to a diet which included whole grain foods. Both diets were similar in calories, fat, the number of servings of fruit and vegetables, and the percentage of protein. The meals were prepared by trained staff and designed to make sure that the participants would not lose weight. These strategies were implemented to isolate the effects of whole grain consumption since factors like eating more fruits and vegetables and weight loss have also been shown to lower inflammation levels.

Those subjects eating whole grains had favorable changes in their gut microbiomes including a decrease in pro-inflammatory bacteria. They also showed small but statistically significant and favorable changes in plasma markers for inflammation and improvement in immune function. [1]

In another study, Iranian researchers looked at the impact of grain consumption for 44 overweight or obese girls between the ages of 8 and 15. The girls were randomized to two groups, one that consumed whole grains and a control group.  Girls in the whole grain group were give a list of whole grains and asked to make sure that half of their grain intake was from whole grains daily for 6 weeks, while the girls in the control group were given the same list and told to avoid whole grain foods.

Whole grain girls then entered a 4-week washout period after which they crossed over to the other arm for an additional 6 weeks.

Eating whole grains did not affect weight or BMI, but the girls eating whole grains did experience positive changes in inflammatory markers during the 6-week intervention  period. These included a 22% decrease C-reactive protein, and a 28% reduction in soluble intercellular adhesion molecule-1. The girls in the control group had increases of 12% and 6% respectively during the same period.[ii]

Overweight people have higher levels of inflammation, but these overweight girls still showed lower levels of inflammatory markers even though their weight did not change.  The girls did not convert to a program of dietary excellence; in fact, they were permitted to continue to consume half of their grains in refined and processed form. And the rapidity of effect – only 6 weeks – was notable.

A more recent study included 60 Danish adults who were considered high-risk for developing metabolic syndrome. In a randomized crossover trial, subjects were assigned to two 8-week dietary intervention periods during which they consumed either a whole grain diet or a refined grain diet. The first 8 weeks were followed by a 6-week washout period, after which the subjects switched diets.

Not surprisingly, the whole grain diet resulted in fewer calories consumed and more weight loss than the refined grain diet. But in addition, the whole grain diet reduced markers of inflammation such as interleukin-6 and c-reactive protein.[iii]

Other studies have shown not only that whole grain intake lowers inflammation, but that it also improves glucose metabolism and increases weight loss.[iv] Higher whole grain intake is also associated with decreased risk of developing type 2 diabetes, insulin resistance, cardiovascular disease, and obesity; and decreased fasting glucose.[v] [vi]

It’s important to be clear about the objective of this article. It is not to promote the idea that eating whole grains is the solution to our epidemic of disease. In fact, we have advised for many years that there are no magical foods and nutrients, and it is important to focus on adopting a health-promoting dietary pattern. People who eat whole grains as part of an optimal, low-fat, high-fiber plant-centered diet experience much better results than those shown in these studies. But even when the only variable is whole grain intake, the results are better. People who advise against whole grain consumption are giving incorrect advice which is not supported by evidence.