A new analysis shows that a diet rich in whole grains may extend lifespan by reducing the risk of certain common causes of early death. The meta-study found that those who ate three or more servings of whole grains per day were less likely to die from cancer or heart disease. The analysis examined 14 studies ranging in length from six years to more than ten years. These studies together included a total of 786,000 people, and 98,000 deaths – 37,000 from cancer and 23,000 from heart disease.
The meta-analysis supports existing US dietary guidelines advising three or more servings of whole grains daily. However, according to the study, most Americans today eat less than one serving of whole grains a day. Researchers note that the type of whole grains consumed varied across the 14 studies, but that most grain eaten by Americans comes from oats, barley, and rice. The researchers link specific compounds found within whole grains to the health benefits seen in the studies. Fiber may lower cholesterol and help people feel full with fewer calories. Magnesium may lower insulin sensitivity and reduce blood pressure. Whole grains also contain a variety of minerals and antioxidants. Coupled with the benefits inherent in whole grains are the benefits of replacing refined carbohydrates, which have been shown to cause a variety of health problems, including obesity, heart disease, and diabetes. Refined carbohydrates are found in white rice, many breads, white pasta, crackers, pretzels, and most pastries.
Whole grains were associated with a 14 percent lower risk of dying from cancer and a 25 percent lower risk of dying from heart disease. Each serving per day, or .5 ounces of whole grains, was linked to 7 percent lower risk of death in general, 9 percent reduced risk of dying from heart disease, and a 5 percent lower risk of dying from cancer, according to the data from these studies.
The study is not the first of its kind to reach these conclusions. Another 2015 study with similar results determined that the part of the whole grain called the bran was most responsible for reducing risk of death from cardiovascular disease. The Whole Grains Council also links a diet rich in whole grains to reduced stroke risk, more successful weight maintenance, healthier arteries, better blood pressure levels, and reduced gum disease and tooth loss.