A new vision of lutein: heart disease prevention Lutein, a yellow pigment found in dark green leafy vegetables and egg yolks, may help prevent clogging of neck arteries, researchers report in today's Circulation: Journal of the American Heart Association.
Lutein, like beta-carotene, is in a class of nutrients called carotenoids. There is some evidence that lutein supplementation may help prevent macular degeneration, the most common cause of irreversible blindness in the elderly.
In a three-part study involving humans, artery cell samples and mice, researchers studied the impact of lutein on atherosclerosis in carotid (neck) arteries. Carotid artery thickness is an indication of atherosclerosis throughout the body. Atherosclerosis is the disease that leads to most heart attacks and strokes.
In one part of the study, researchers studied 480 men and women, ages 40 to 60, who were part of the Los Angeles Atherosclerosis Study and had no history of heart disease. The thickness of their carotid arteries and plasma levels of lutein were measured at baseline and 18 months later. The individuals in the highest quintile of blood levels of lutein had just a 0.004-millimeter (mm) increase in carotid artery thickness. For those in the lowest quintile, carotid artery thickness increased an average of 0.021 mm.
In the laboratory portion of the study, researchers examined inner layer wall linings of human carotid arteries removed during surgery. They found that artery layers pretreated with lutein were less likely to attract monocytes, or white blood cells, which oxidize low-density lipoprotein (LDL), the "bad" cholesterol. Oxidized LDL in the artery wall is a major cause of atherosclerosis. The higher the lutein dose, the less interaction between LDL and monocytes.
In the mouse study, researchers found that mice given lutein supplementation had 43 percent smaller atherosclerotic lesions than mice that were not given lutein.
From these findings, the authors suggest that increased dietary intake of lutein may protect against the development of early atherosclerosis. The study may also help explain why diets rich in fruits and vegetables are associated with reduced risk of cardiovascular disease. This study and others failed to find a beneficial effect of beta-carotene. The American Heart Association recommends that individuals eat a variety of foods with emphasis on vegetables and fruits.
The work was funded in part by the National Heart, Lung and Blood Institute.