Increasing the amount of whole grains in the diet may help reduce body weight, blood pressure and cholesterol levels, according to a new analysis of clinical trials.
The study, published in the European Heart Journal on September 15, 2026, was conducted by researchers from Tabriz University of Medical Sciences in Iran and Imperial College London.
Researchers reviewed 87 clinical trials involving more than 6,500 people from Asia, Europe, the United States, Canada, Australia and Brazil to examine the effects of whole-grain consumption on cardiovascular and metabolic risk factors.
The analysis found that higher intake of whole grains was associated with reductions in body weight, waist circumference and blood pressure, as well as lower levels of total cholesterol, LDL cholesterol — commonly referred to as “bad” cholesterol — triglycerides and blood glucose.
The researchers also found a reduction in interleukin-6, a marker associated with inflammation.
Some benefits were observed among people consuming about 30 to 40 grammes of whole grains per day, while the greatest improvements were associated with intake of between 60 and 100 grammes daily. The latter amount is roughly equivalent to four to six servings of whole-grain foods.
Examples include oatmeal, whole-grain bread, brown rice, quinoa and other minimally refined grain products.
The researchers cautioned, however, that the improvements in individual risk factors were generally modest. They noted that improving several risk factors at the same time could nevertheless contribute to lower cardiovascular risk over the long term.
Experts who commented on the findings also stressed that the study examined risk factors rather than directly measuring outcomes such as heart attacks, strokes or new cases of diabetes.
Professor Kathleen Melanson of the University of Rhode Island said the findings were consistent with previous research supporting higher whole-grain consumption, but noted that overall dietary quality remains important. She highlighted vegetables, legumes, fruits and healthy sources of protein and fats as important parts of a healthy diet.
Professor Frank Hu of Harvard University said the findings support replacing refined grains with whole grains as part of a heart-healthy diet rather than focusing on individual nutrients such as fibre.
Whole grains contain the bran, germ and endosperm of the grain, unlike refined grains, from which some of these components are removed during processing. Foods such as oats, barley, brown rice, whole-grain bread, quinoa, corn and buckwheat are examples.
Researchers say the fibre and other plant compounds found in whole grains may contribute to their effects on cholesterol, blood pressure, blood sugar, inflammation and body weight. Soluble fibre such as beta-glucan, particularly abundant in oats and barley, is known to help lower LDL cholesterol.
The researchers noted that the trials included in the analysis generally lasted for relatively short periods, with a median duration of about eight weeks. They said longer studies are needed to determine the long-term effects and whether particular types of whole grains provide greater benefits for certain individuals.
The findings also suggest that replacing refined grains with whole grains may be more beneficial than simply adding whole-grain foods to an otherwise unchanged diet.