Whole Grains 101

whole grains 101

Health Studies on Whole Grains

Whole grain bread is healthy.

Every day, more and more studies show the benefits of whole grains. We regularly post new studies here, where you can browse through them at random. Or, you can use our filters to hone in on a specific question, such as "Does barley reduce the risk of diabetes?" or "What's the research about whole grains and hypertension?"

Filter the studies below by selecting a grain and/or a disease/condition, then click apply.


Replacing Butter, Sugar, or Refined Grains with Whole Grains Cuts Heart Disease Risk

Harvard researchers followed over 120,000 adults for 24-30 years, tracking their diet and health records. The scientists found that replacing 5% of daily calories from saturated fat (like butter, cream, and red meat) with whole grains is associated with a 9% lower risk of heart disease, but replacing saturated fat with refined grains or added sugars does not lower heart disease risk. Additionally, they found that replacing 5% of daily calories from refined grains and added sugars with whole grains or polyunsaturated fats (found in fish, nuts, seeds, and safflower oil) can also significantly reduce heart disease risk. The researchers concluded, “Our findings provide epidemiological evidence of the current dietary guidelines, which recommend both “replacing saturated fatty acids with monounsaturated and polyunsaturated fatty acids” and “replacing refined grains with whole grains.””
Journal of the American College of Cardiology. 2015 Oct;66(14):1538-48. (Li Y et al.)

Carbs (Like Whole Grains) Vital to Early Human Brains

Whole grains are important to our brain health today, but new evidence suggests that they were also vital to our brain development millions of years ago. Researchers in Europe and Australia examined diet’s role in the development of early humans, and found that carbohydrates (such as whole grains, root vegetables, and other starchy plant foods) were “necessary to accommodate the increased metabolic demands of a growing brain.” While most depictions of early human foods emphasize hunter-gatherer diets full of meat, the scientists argue that cooked starches permitted “the acceleration in brain size increase from the Middle Pleistocene onward.”
The Quarterly Review of Biology. 2015 Sept;90(3):251-268. (Hardy K et al.)

Whole Grains Can Lower Cholesterol

Healthy blood cholesterol levels can help protect against heart disease, so foods that improve cholesterol are important to heart healthy diets. To determine the relationship between whole grains and cholesterol levels, Scandinavian researchers analyzed data from 24 clinical trials following over 2,000 people. The researchers found that those assigned to a diet with whole grains had significantly lower levels of LDL (“bad” cholesterol) and total cholesterol than those assigned to a diet without whole grains. However, the scientists did not find any significant links between whole grains and HDL (“good” cholesterol) or triglycerides (a type of fat in the blood). 
American Journal of Clinical Nutrition. 2015 August 12. (Hollaender PL et al.) [Epub ahead of print.]

Whole Grains May Prevent Early Death

Whole grains (like rye, oats, and whole wheat) have a strong history in traditional Scandinavian cuisine, but as in other regions, the food landscape is changing and refined grains have replaced some traditional foods. To see how eating whole grains relates to mortality, researchers analyzed the diets of over 120,000 people in Denmark, Norway, and Sweden.  The scientists found that those who ate the most whole grains had significantly lower risk of death from all causes. When analyzing individual whole grains, the researchers found significantly lower mortality rates in those who ate the most whole grain breakfast cereals, whole grain bread, oats, rye (only statistically significant for men), and whole wheat. These findings support existing evidence that whole grains may contribute to longevity.
British Journal of Nutrition. 2015 July 23:1-16. (Johnsen NF et al.) [Epub ahead of print]

Gluten Free Foods Are Not Healthier

While most whole grains are naturally gluten free (like quinoa, millet, and rice), many gluten-free packaged foods are made with refined, starchy flours, such as potato flour or white rice flour. To see how gluten free products stack up, researchers analyzed the nutrition on over 3200 food products in Australia, comparing the health of gluten free items to items containing gluten. Gluten free products were found to have significantly less protein across all major food groups, and gluten free pasta was found to be significantly less healthful than regular pasta (based on the Australian government’s “Health Star Rating”). Other than that, the researchers found no significant health differences between gluten free (GF) and gluten-containing products, concluding that “the consumption of GF products is unlikely to confer health benefits, unless there is clear evidence of gluten intolerance.”
British Journal of Nutrition. 2015 Jun 29:1-7. [Epub ahead of print]. (Wu JH et al.)

Refined Grains Linked with Depression

It seems that comfort foods like refined sweets might not be so comforting in the long run. Scientists in New York analyzed the eating patterns of nearly 70,000 women without depression across the U.S. , then tracked their health records over three years to see how diet relates to developing depression. The researchers found that both refined grains and added sugars were significantly tied to a higher risk of developing depression over the three year study, while fiber, vegetables, fruit (excluding juice), and lactose (a sugar found in milk) significantly lowered the risk of depression. A higher intake of whole grains was also related to a lower risk of depression, although this relationship was not statistically significant. Overall, foods that contributed to a high glycemic index diet were associated with increased odds of developing depression. 
American Journal of Clinical Nutrition. 2015 Jun 24. [Epub ahead of print] (Gangwisch JE et al.)

Healthy Diet with Whole Grains May Improve Prostate Cancer Survival

Healthy diets are an effective way to help prevent diseases, like cancer, but emerging research shows that they can also improve survival in people who have already been diagnosed. In a study of over 900 male physicians diagnosed with prostate cancer, Harvard researchers analyzed their eating patterns and followed their health records for 14 years after diagnosis. They found that men who ate a typical “Western diet” (high in red and processed meat, high fat dairy foods, and refined grains) had more than twice the risk of prostate-cancer related death, and a 67% increased risk of death from all causes. On the other hand, those who ate a healthy diet (with whole grains, fruits, vegetables, fish, and healthy oils) had a 36% lower risk of death from all causes. This study affirms that nutritious, balanced diets promote the best health outcomes, and that whole grains are an integral component of an overall, healthy diet.
Cancer Prevention Research. 2015 June 1. [Epub ahead of print] (Yang M et al.)

Fiber from Whole Grains May Reduce Diabetes Risk

Studies have shown that fiber (especially from whole grains) may lower diabetes risk in Americans, but researchers wanted to know if the same was true in Europe. Analyzing the eating patterns of over 26,000 participants from 8 nations in Western Europe, the scientists found that total fiber was associated with a lower risk of diabetes, along with fiber from whole grains and vegetables (but not fruit). The researchers then combined these results with the results of 18 additional studies, following over 617,000 participants, and found that fiber from whole grains was the most protective. Indeed, for every additional 10g of total fiber or cereal fiber (the fiber in whole grains), the risk of type 2 diabetes was 9% or 25% lower, respectively. However, these results were not significant after adjusting for weight, meaning that whole grains and fiber likely play an important role in weight maintenance, another risk factor for type 2 diabetes.
Diabetologia. 2015 May 29. [Epub ahead of print] (InterAct Consortium).

Healthy Diets with Whole Grains Improve Longevity in Low Income Minorities

Minorities and low-income populations are often underrepresented in nutrition studies, but new research indicates that healthy diets with whole grains can benefit all of us, including underserved populations. In this study, researchers examined the diets and medical records of over 77,000 people from 12 states in the southeastern US, most of whom were low-income and African American. Researchers found that those most closely adhering to a healthy diet (including at least 1 ½ servings of whole grains per day) had a 14-23% lower death rate from all diseases, heart disease, cancer, and more. Additionally, while overall dietary patterns are the best way to assess health, whole grains specifically were associated with a lower death risk (as were dairy, seafood, and plant proteins).
PLOS Medicine. 2015 May 26;12(5):e1001830; discussion e1001830. (Yu D et al.)

Regular Whole Grain Consumption May Reduce Breast Cancer Risk

Eating whole grains daily may help keep breast cancer at bay. Approximately 1 in 8 women are diagnosed with breast cancer, and lifestyle factors are thought to play an important role in prevention. To determine the relationship between eating patterns and breast cancer, researchers analyzed the diets of 250 newly diagnosed female breast cancer patients, and 250 age-matched controls (without cancer). The scientists found that eating whole grains at least 7 times per week was associated with a decreased risk of breast cancer.
Journal of the American College of Nutrition. 2015 Apr 27:1-7 [Epub ahead of print] (Mourouti N et al.)

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