Posted by Admin
Post Date : Thursday July 20 2006

Researchers are continually investigating the numerous health-protecting properties of the phytochemicals in fruits and vegetables. (Phytochemicals are substances produced by plants that help to protect them from insects, diseases and other threats to their health. These same substances help to protect human health.) While more than 4000 phytochemicals have been identified, fewer than 200 phytochemicals have been studied extensively. Summaries of recently published studies examining the health benefits of eating fruits and vegetables are presented here.

An Apple A Day May Keep the Heart and Lung Specialists Away

Researchers at the University of California Davis Medical School studied how eating apples and drinking apple juice every day affects heart disease risk.  The 12-week study showed that by simply including apples in the diet (and without making any other dietary changes), study participants were able to reduce their risk of heart disease.  Apples contain a variety of antioxidant phytochemicals that decrease LDL oxidation. Oxidized LDL cholesterol is more likely to build up in arteries, a process that can cause heart attacks and stroke.

Researchers from the University of Nottingham, located in the United Kingdom, recently reported that people who eat five or more apples a week have better lung function and lower risk of asthma and other respiratory disease compared to people who rarely eat apples.  Their findings were based on a 10-year study involving 2,633 people examining relationships between diet and respiratory health. The researchers suspect that antioxidants in apples lead to these health benefits. In 1997 Finnish researchers reported that the antioxidant flavonoids may reduce the risk of lung cancer. This finding is based on a 25-year study examining relationships between diet and health in nearly 10,000 Finnish men.

Carotenoids and Cancer

Carrots and other orange vegetables like squash and sweet potato and dark green vegetables like broccoli and spinach contain phytochemicals called carotenoids. The Nurses’ Health Study showed that women who eat the most carotenoid-rich vegetables have the lowest risk of breast cancer. Researchers report that raw vegetables contain the highest amounts of carotenoids, which are damaged by the heat of cooking.

The Cruciferous Crusaders

Cruciferous vegetables include bok choy, broccoli, brussels sprouts, cabbage, cauliflower, collard greens, rutabaga and turnips. Researchers from the Fred Hutchinson Cancer Research Center in Seattle reported in 2000 that men who eat at least 1.5 cups of cruciferous vegetables a week can reduce their prostate cancer risk by more than 40 percent. Researchers speculate that phytochemicals in cruciferous vegetables called isothiocyanates help the body produce enzymes that destroy cancer-causing compounds.

"Berry" Promising News

In a study of 40 fruits and vegetables done at Tufts University in Boston, blueberries ranked number one in antioxidant content. Reported in 1999, a later study conducted at Tufts University in Boston reported that older rats fed blueberry extracts outperformed their study counterparts on balance, coordination and memory tests. Researchers believe that the antioxidants in blueberries are responsible for the benefits. While rats are not little humans, this study has prompted researchers to explore the effects of blueberries on the effects of aging in older humans. The National Institute on Aging is funding studies in humans. Results have not been released yet.

In 2001 researchers from Indiana University and Ohio State University reported that phytochemicals in red and black raspberries and strawberries inhibit the growth of colon and esophageal cancer cells in rats resulting from exposure to benzopyrene, a carcinogen found in tobacco smoke.  While a similar study has not been tested in humans, there are numerous studies that show that diets rich in fruits and vegetables help reduce the risk of stomach, lung, mouth, colon and esophageal cancer by as much as 30 to 40 percent.

The Bottom Line

There is an abundance of research on the health benefits of eating a diet rich in fruits and vegetables. To reap the known and yet-to-be-discovered health benefits of fruits and vegetables eat a wide variety and eat 5 to 9 servings each day

*Based on a review of literature from 1999-2001 by Dianne Hyson, PhD, MS, RD. Produce for Better Health ® Foundation. Visit www.5aday.org for more information.