: Grapes can reduce the risk for heart disease?
WHAT THEY’RE SAYING
The flavonoid compounds (antioxidants) in grapes and grape products may decrease risk factors associated with heart disease.
WHAT WE KNOW
One of the contributing factors to heart disease is atherosclerosis (fat deposits in the arteries).
The formation of fat deposits begins with damage to the lining of the blood vessels from high blood pressure, free radicals, or many other causes. After this damage occurs, inflammatory mediators arrive at the scene and signal LDL (bad) cholesterol to accumulate in the damaged area. The LDL cholesterol is then oxidized. The LDL cholesterol is entrapped in this damaged area by platelets. Over time, the fat deposits thicken and form a hard plaque which causes the diameter of the arteries to become smaller. This makes it harder for blood to move through and can cause an increase in blood pressure. Another serious danger is that the platelets that entrap the LDL cholesterol can rupture. Ruptured plaque could cause many different complications including a heart attack or stroke.
A body of research has suggested that the flavonoids (antioxidants) in grapes and grape products may reduce many of the risk factors associated with atherosclerosis. These include …
- Scavenging free radicals that cause damage to artery walls
- Decreasing the oxidation of LDL cholesterol
- Decreasing platelet aggregation to the artery wall
It is not yet clear exactly how these benefits of antioxidants and flavonoids occur, but several studies have been done to support these proposed benefits.
HOW DO WE KNOW THIS?
A recent review in Nutrition Reviews compiled accumulated findings about grapes and grape products to determine the link between grapes and heart disease.
LDL Oxidation: In one study, a 2-week supplementation with Concord grape juice reduced the LDL oxidation rate by 34.5% in a group of patients with coronary artery disease. In another study, healthy adults who were supplemented with Concord grape juice for 2 weeks were found to have a decreased LDL oxidation rate.
Platelet Aggregation: In one study, following a 2-week supplementation of purple grape juice, a noted reduction in platelet aggregation was observed in healthy adults. In another study involving post-menopausal women, platelet closure time (over the LDL cholesterol) was increased after an 8-week supplementation with grape seed extract.
The research presented in the review supports decreased LDL oxidation, improvement in atherosclerotic risk factors, and the reduction in oxidative stress (free radicals).*
The evidence found in this review is exciting and exemplifies a need for further conclusive studies in humans. We do know that fat deposits in the arteries and other blood vessels are inevitable with aging. However, a diet that is low in saturated fat and cholesterol and high in fiber can prevent an excessive amount of plaque formation. A balanced diet rich in fruits and veggies is the best way to keep your heart healthy for many reasons …
See our Top 10 Ways to Enjoy Grapes!
*Vislocky, Lisa M., Maria L. Fernandez. “Biomedical Effects of Grape Products.” Nutrition Reviews (2010); 68(11): 656-70.