Major Study Reveals How Many Servings of Whole Grains You Need to Reduce Heart Risk: ScienceAlert

Whole grains are an essential part of a healthy diet, rich in fiber, carbohydrates and nutrients.

Yet many people don’t get enough of it on their plate.

A major systematic review of 87 randomized trials has now determined how many servings of whole grains you should eat per day to reduce your risk of heart disease.

This may be more than current guidelines suggest.

The results are published in the European Journal of the Heart.

The new journal covers many more trials than ever before and includes more than 6,500 participants from Asia, Europe, the United States, Canada, Brazil and Australia.

Additionally, researchers specifically studied the short-term impact of whole grain dose on cardiovascular risk factors.

Strong evidence suggests that over the longer term, diets rich in whole grains, such as brown rice, oats and quinoa, are associated with a reduced risk of type 2 diabetes, hypertension and coronary heart disease.

But randomized controlled trials have not always produced consistent results.

“Although higher consumption of whole grains has long been associated with better heart health in population studies, clinical trials have produced mixed results,” says lead author Helda Tutunchi of Tabriz University of Medical Sciences in Iran.

“This left an important practical question unanswered: How much whole grains should people eat to significantly improve cardiovascular health? To address this issue, we systematically combined and analyzed all available randomized controlled trials to identify the amount of whole grains associated with the greatest benefits.”

Results consistently showed that eating whole grains reduced body weight, blood pressure, “bad” cholesterol, glucose levels, and inflammatory markers.

Benefits generally appear from 30 to 40 grams per day (dry weight), or approximately 2 servings per day.

But the greatest reductions in most cardiovascular risk factors occurred with consumption of about 60 to 100 grams per day of whole grains, or about four to six servings.

The United States Dietary Guidelines currently advise Americans to eat an average of two to four servings of whole grains per day.

But according to this recent analysis, more servings could be associated with even greater health benefits, depending on the risk factor.

The greatest improvements in blood pressure, for example, were seen with about 60 grams per day (four servings) of whole grains.

But the greatest benefits against bad cholesterol were observed at 220 grams per day. That’s about a dozen servings of whole grains.

Relatively few randomized trials have evaluated very high intakes of whole grains, greater than 140 grams per day, so the effects at these intake levels are more uncertain.

But the team found “high certainty evidence” on the effect of whole grains on body weight, waist circumference and total cholesterol.

“Evidence from the trial indicates that a higher whole grain intake than currently recommended in some guidelines may be optimal for cardiometabolic health,” reads an accompanying editorial, led by Cecilie Kyrø of the Danish newspaper. Cancer Institute.

The randomized trials considered in this analysis were short-term, but the benefits they found may add up, reducing the risk of future cardiovascular disease in a clinically meaningful way.

This may be why, according to epidemiological studies, people who eat more whole grains tend to have a lower risk of heart disease over the years.

“These findings do not necessarily call for major changes to existing guidelines, but they support public health strategies that help people increase their consumption of whole grains and move toward the upper end of current goals,” says Tutunchi.

Further research is now needed to determine the impact of higher doses of whole grains on long-term health.

Until these trials are conducted, Kyrø and colleagues say the message for clinicians and patients is “reassuringly simple.”

“Encouraging patients to replace refined grain foods with minimally processed whole grains is likely to result in modest but significant improvements in body weight, waist circumference, and blood lipids,” they write, “perhaps particularly in people with type 2 diabetes.”

The study is published in the European Journal of the Heart.