by Woods M

Chronic diseases, such as heart disease and cancer increase the likelihood of premature death and result in increased healthcare costs. Many of these disease are affected by how we live and what we eat, which means many conditions can be prevented or delayed through lifestyle choices and habits. Previous studies have strongly suggested that eating whole grains is an effective way to lower the risk of many chronic diseases but the amount of whole grains is not always clear. Whole grains come in many forms including wheat, corn, rice, oats, barley, quinoa, sorghum, spelt, and rye.

Researchers wanted to examine the relationship between the consumption of whole grain and specific types of grains and the risk of chronic disease and all cause and cause specific mortality. They also wanted to determine the amount of grains that need to be consumed for these benefits. The study, published in BMJ, found that 3-7 servings of whole grain everyday was associated with a reduced risk of a number of chronic diseases.

About the Study

The systematic review included 45 cohort studies that tracked grain intake and the development of several health outcomes and mortality. The review included 7,068 cases of coronary heart disease, 2,337 cases of stroke, 26,243 cases of cardiovascular disease, 34,346 deaths from cancer, and 100,726 deaths. The number of participants ranged from 245,012 to 705,253.

Participants who reported at least 3 servings of whole grain product (90g) per day had a reduced risk of:

  • Coronary heart disease
  • Stroke
  • Cardiovascular disease
  • Cancer
  • All cause mortality
  • Respiratory disease
  • Diabetes
  • Infectious disease

The benefits increased as the servings of whole grain increased up to 7-7.5 servings of whole grain per day.

How Does This Affect You?

A systematic review combines large numbers of smaller trials to create a large pool of participants. The larger the pool of participants the more reliable the outcomes are. However, the review is only as reliable as the studies that are included. In this case, all the included trials were observational trials which means researchers could only observe details they could not control other factors that can affect outcome. The review authors also indicated that there were some statistical challenges with how the trial outcomes were combined. These concerns may affect more specific details of the outcomes like the exact number of servings needed for benefits but since there are a number of trials that strongly support the benefits of a diet rich in whole grains, the overall outcome is likely reliable.

Whole grains provide a variety of nutrition, fiber, and may help you feel more full. When grains are highly processed to make food like white bread or white rice it removes a lot of the benefits of the grains. If you do not have whole grains in your diet gradually begin to add them in. Consider replacing a highly process food like white rice with whole grain options like whole grain pasta or quinoa. Try different whole grain options to find the one that work best for you, aim to have a whole grain at each meal. Talk to your doctor about your risk for chronic diseases and what steps you should take to stay well.


Choose My Plate—US Department of Agriculture 

Eat Right—Academy of Nutrition and Dietetics 


Aune D, Keum N, et al. Whole grain consumption and risk of cardiovascular disease, cancer, and all cause and cause specific mortality: systematic review and dose-reponse meta-analysis of prospective studies. BMJ. 2016 Jun 14; 353:i2716. Available at: Accessed July 7, 2016.

What foods are in the grains group? Choose My Plate—US Department of Agriculture website. Available at: Updated March 28, 2016. Accessed July 7, 2016.

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