New findings from UCLA indicate that Lutein -- a carotenoid recently discovered in California avocados and found in green vegetables -- can help protect against prostate cancer. This study was presented at the American Institute of Cancer Research (AICR) meeting in July 2001 in Washington D.C.
In recent studies, Lycopene -- a carotenoid found in tomatoes -- was associated with a reduced risk of prostate cancer, but lutein had not been linked to prostate cancer prevention until now.
According to Dr. David Heber, director of the UCLA Center for Human Nutrition and author of "What Color Is Your Diet," the study initially focused on a rural area of China, which had a low incidence of prostate cancer despite a diet virtually free of lycopene (due to lack of tomato intake) but rich in lutein (due to a high consumption of green vegetables). The study was then expanded to include Chinese American men and Caucasian men.
UCLA lab tests showed that lutein reduced prostate cancer cell growth by 25 percent while lycopene reduced cell growth by 20 percent. When lutein and lycopene were combined, prostate cancer cell growth was reduced by 32 percent. Thus indicating that both nutrients together help protect against prostate cancer better than either nutrient alone.
"Lutein and lycopene in combination appear to have additive or synergistic effects against prostate cancer," said Heber. "Our results suggest that further studies should be done to investigate the nutrient-nutrient interactions of lutein and lycopene at a subcellular and molecular level."
Traditionally, lutein has been found in green vegetables such as parsley, celery and spinach but was recently discovered in the avocado fruit. In fact, research shows that avocados are the highest fruit source of lutein among the 20 most frequently consumed fruits.
In addition to the new prostate cancer findings, lutein is also known to protect against eye disease such as cataracts and macular degeneration, the leading cause of blindness in the elderly. Studies from around the world sponsored by the AICR have shown that individuals eating 400 to 600 grams per day (more than one pound) of fruits and vegetables reduce their risk of certain cancers by 50 percent.
California avocados fall in the green-yellow group and contain such vital nutrients as vitamin E, which helps "mop up" free radicals that can damage cells and lead to disease; glutathione, which functions as an antioxidant like vitamin E; beta-sitosterol, which helps lower blood cholesterol; and the recently discovered lutein, now linked to prostate cancer and eye disease prevention.
American Institute of Cancer Research (AICR) meeting - July 2001