Eating a bowl's worth of whole grains a day, whether oatmeal or brown rice, can lower the risk of cardiovascular disease, according to an international study.
Findings Drawn From Data on 6,529 People Over Eight Weeks
An international research team including Tabriz University of Medical Sciences in Iran reached the conclusion after analyzing 87 clinical studies on the link between whole-grain intake and health, according to a paper published recently in a European cardiology journal and reported on the 20th.
Many studies have examined the relationship between whole-grain consumption and cardiovascular health, but findings varied from trial to trial, making consistent evidence hard to establish, the team said. The researchers therefore pooled data on 6,529 people from clinical trials conducted in Asia, Europe, the United States, Canada, Australia and Brazil.
The analysis found that increasing daily whole-grain intake by 48 grams lowered blood cholesterol by 0.10 mmol/L and interleukin-6, an inflammation marker, by 0.12 pg/mL. LDL cholesterol, known as bad cholesterol, fell by 0.07 mmol/L, triglycerides by 0.04 mmol/L and fasting blood sugar by 0.03 mmol/L. Systolic blood pressure declined by 0.82 mmHg.
Health benefits began to appear at 30 to 40 grams a day and peaked at 60 to 100 grams. Some studies showed the best health outcomes at 180 to 220 grams a day, but the team added that the small number of participants makes it difficult to determine an optimal intake.
Recommended Amounts Vary by Country, and Long-Term Effects Remain Unclear
Recommended daily whole-grain intake ranges widely by country, from 48 grams to 150 grams, a gap attributed to differences in national diets. The team said the findings could serve as a new basis for revising those recommendations.
Many of the trials used in the analysis ran for an average of about eight weeks, however, so further work appears needed to confirm whether the benefits of whole-grain intake persist over the long term.
A separate study published in the European Heart Journal also found that consuming 60 to 100 grams of whole grains a day may help improve body weight, waist circumference and cholesterol levels.
Switching from ordinary bread and noodles to whole-wheat bread and whole-wheat pasta is one option, but because whole-wheat content differs by product, consumers should check whether whole wheat or whole-wheat flour appears near the top of the ingredient list and whether sugar and saturated fat levels are excessive.
