Note to retailers: Push those delicious red-hued fruits and vegetables with the knowledge that they offer more than just great flavors. Some of the most luscious summer produce—tomatoes, watermelons, red grapes—are loaded with lycopene, a natural antioxidant. Antioxidants are thought to prevent some diseases by digesting free radicals, or byproducts, of cellular processes. Researchers are finding, specifically, that the more lycopene people consume the lower their risk of contracting various cancers and heart disease. Lycopene may even contribute to fertility and bone health.
Lycopene belongs to a family of nutrients called carotenoids. They're natural plant pigments that are abundant in red, orange and yellow fruits and vegetables, and in dark-green leafies. Other good lycopene sources include pink grapefruit, red guava, papaya and apricots. It's important for consumers to include sources of lycopene in their diets because the human body cannot produce it naturally.
Because they are concentrated, processed tomato products such as sauces and pastes are particularly rich sources of lycopene. HJ Heinz Co.'s general manager of global nutrition, David Yeung, Ph.D., says processing the tomato also releases more lycopene for absorption. "When you process a tomato with a bit of oil, it will enhance absorption further because lycopene is fat soluble," he says.
Lycopene is a warrior among free-radical fighters. Its structure gives it better ability to take oxygen away from other molecules, Yeung says from his Pittsburgh office. "And as such it becomes ... one of the most powerful antioxidants we can find naturally."
Retailers should be aware of the numerous disease-fighting applications that lycopene has, and of the best ways for consumers to include the antioxidant in their diets.
Colorful fruits and vegetables have been a mainstay of cancer-prevention diets for some time, and new research is shoring up the value of red produce. High blood levels of lycopene, for example, correlate with lower prostate cancer risk and, especially in premenopausal women, lower ovarian cancer risk. In a study published in the October 2001 International Journal of Cancer, researchers reported that raw carrots and tomato sauce were the food items most strongly related to reduced ovarian cancer risk.
Edward Giovannucci, M.D., of Brigham and Women's Hospital and Harvard Medical School in Boston, reviewed 15 studies involving tomatoes, lycopene and prostate cancer and reported his findings in the November 2002 issue of Experimental Biology and Medicine. Although the research results were mixed, eight studies supported at least a 30 percent risk reduction when participants increased their tomato or lycopene consumption. The largest of the relevant studies showed that having two to four servings of tomato sauce per week reduced advanced prostate cancer risk by 50 percent and total prostate cancer risk by 35 percent.
Coronary heart disease is the leading cause of death in America. Oxidation of circulating low-density lipoprotein—the so-called "bad cholesterol"—is thought to contribute to plaque build-up in the arteries and to CHD. Lycopene, though, prevents LDL oxidation, according to studies reported in the November 2002 issue of Experimental Biology and Medicine. Researchers gave healthy adults tomato juice, tomato sauce or a daily lycopene soft-gel capsule for one week. Those with lycopene in their diets had significantly lower levels of LDL oxidation compared with control subjects.
"What happens in some forms of heart disease is the lipids in the blood or in the body are oxidized and they become clogged or stuck to the blood vessels and eventually fall off and block the blood vessel, causing a heart problem," Yeung says. "But lycopene picks up these free radicals and prevents the lipids from being oxidized."
And lycopene may be the best of the carotenoids. In a multicenter study, researchers analyzed fat samples from 1,379 European men who had suffered heart attacks and compared their carotenoid levels with samples from healthy controls. Lycopene stood out above the other substances for protecting against heart attacks. The study was reported in the October 1997 issue of the American Journal of Epidemiology.
Although research is still preliminary, evidence suggests lycopene could boost male fertility. Researcher Narmada Gupta of New Delhi, India, says a diet rich in lycopene can promote fertility in men who have poor sperm quality. Sperm are rich in high-unsaturated fatty acids and are, therefore, sensitive to free-radical damage. In his work, which he presented to the 34th Annual Conference of the Urological Society of India in 2001, Gupta discovered that lycopene is found in high concentrations in the testes—except in men with fertility issues.
Red food could also benefit bone health. "Lycopene's antioxidant properties [make it] a potential candidate for preventing osteoporosis," says Leticia Rao, Ph.D., an assistant professor of medicine at the University of Toronto as well as co-director of the Calcium Research Laboratory at St. Michael's Hospital, also in Toronto. Rao says that lycopene can stop the bone-destructive process of osteoporosis and can stimulate the cells that promote bone formation. Her clinical trial, which will use both tomato juice and lycopene capsules, is under way.
If all this seems confusing, a good goal for disease prevention is to get 15 milligrams to 20 milligrams of lycopene per day as part of a balanced diet, says Yeung.
Dena Nishek is a freelance writer and editor specializing in natural health, home and garden topics. She is based in Boulder, Colo.
Natural Foods Merchandiser volume XXIV/number 7/p. 20, 26
Natural Foods Merchandiser volume XXIV/number 7/p. 26
Natural Foods Merchandiser volume XXIV/number 7/p. 26