Four to six servings of whole grains a day may be the sweet spot for protecting your heart.An analysis of 87 clinical trials involving more than 6,500 people found that eating more whole grains improves several major risk factors for cardiovascular disease.The higher intake reduced body weight, waist size and blood pressure, according to researchers.It also lowered both total and LDL — or "bad" — cholesterol, triglycerides, blood sugar and a key marker of inflammation in the blood.Benefits started to appear at roughly two servings of whole grains a day. But the greatest effects were generally seen at four to six servings — about 60 to 100 grams — a day.That's roughly a bowl of oatmeal, a sandwich on whole-grain bread, and a serving of brown rice.The lead investigator says, "Increasing whole-grain intake is a relatively simple, accessible and affordable dietary strategy that can complement other lifestyle and medical interventions."One final note from researchers: oats, brown rice and rye each affected different heart risk factors, suggesting a varied diet may offer the broadest protection.Source: European Heart JournalAuthor Affiliations: Tabriz University of Medical Sciences, Imperial College London, University of Western Ontario, Norwegian Institute of Public Health, Oslo New University College .Sign up for our weekly HealthDay newsletter