ST. LOUIS -- New research helps explain how soy may contribute to heart health, through a process scientists refer to as "decreased platelet aggregation."

By reducing the density of platelet receptors, a natural component in soy called isoflavones may contribute to a reduced risk of blood clotting, which in turn decreases the risk of heart attack and stroke.

According to the study published in the journal Maturitas, Chilean researchers recruited post-menopausal women to take part in the double-blind, randomized, placebo-controlled study. The study randomly assigned the participants to receive a daily supplement of 100 mg isoflavones or an identical placebo for three months.

At the end of the three-month period, the group receiving the isoflavone supplement showed a significant decrease in the density of a particular platelet receptor (known as TxA2), while the placebo group remained mostly unchanged.

Excessive aggregation of platelets may contribute to cardiovascular diseases, such as heart attack and stroke. By decreasing the density of platelet receptors, such as the TxA2, the risk of forming a blood clot that could lead to heart attack or stroke is also reduced.

Lisa Kelly, a dietitian speaking on behalf of the United Soybean Board, said, "These findings are significant because they suggest a new understanding of the ways in which soy isoflavones may positively effect cardiovascular health.

"Previous research has shown that soy offers a modest reduction of LDL cholesterol -- the bad cholesterol -- which may help reduce the risk of heart disease by 10 percent on a population-wide basis. There are also studies linking soy to lowered blood pressure. This study uniquely demonstrates that soy may contribute to heart health through a reduced risk of blood clotting as well, and therefore a reduced risk of heart attack and stroke."

These findings create a more nuanced understanding of the American Heart Association Nutrition Committee's recent statement in the journal Circulation that downplayed the degree to which soy can help reduce cholesterol, pointing to a more modest benefit than previously thought. However, by linking soy isoflavones to reduced platelet aggregation, the new study suggests the need for scientists to examine a variety of heart health factors, including but not limited to cholesterol in order to gain a thorough understanding of the ways in which soy may contribute to heart health.