We've been hearing that we should choose whole grains over processed grains for years, and they have become a staple of dietary guidelines; but the science regarding the benefits hasn’t always been consistent. For example, there have been little data about the role of whole grains play in prolonging life. A new study offers more clear-cut answers.
It found that people who ate more whole grains lived longer.
Researchers looked at the records on more than 74,000 women and 43,000 men who were free of cancer and cardiovascular disease (CVD) when the studies began.
They used data from the Nurses’ Health Study (1984-2010) and the Health Professionals Follow-Up Study (1986-2010) to look at the association between eating whole grains and the risk of dying. During the course of the study, nearly 27,000 participants died.
For every ounce of whole grains consumed, the study found that mortality rates dropped five percent and CVD deaths dropped nine percent.
When the data were adjusted for other factors that could have contributed to death, such as weight, age, and smoking status, researchers found that eating more whole grains was associated with lower overall mortality, as well as a lower risk of dying from cardiovascular disease. Cancer deaths were not affected.
For every 28 grams (one ounce) of whole grains consumed, the study found that mortality rates dropped five percent and death from heart disease dropped nine percent.
According to the Whole Grains Council, a nonprofit consumer advocacy group, one ounce of whole grains is equivalent to:
- 1/2 cup cooked brown rice or other cooked grain
- 1/2 cup cooked 100% whole-grain pasta
- 1/2 cup cooked hot cereal such as oatmeal
- 1 ounce uncooked whole grain pasta, brown rice or other grain
- 1 slice 100% whole grain bread
- 1 very small (1 oz.) 100% whole grain muffin
- 1 cup 100% whole grain ready-to-eat cereal
The Dietary Guidelines for Americans recommend eating six servings of grain products a day with half of those coming from whole grains. Currently, only three percent of kids and teens and eight percent of adults meet this guideline.
What is it about whole grains that confer health benefits? Whole grains provide more vitamins and minerals per calorie than refined or processed grains, as well as fiber and hefty amounts of health-promoting antioxidants.
Increasing whole grain consumption helps prevent chronic disease and also provides evidence for the idea that a diet enriched with whole grains can extend life expectancy, according to the authors.
The study was conducted by at team at Harvard School of Public Health. It is published in JAMA Internal Medicine.