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Health experts About 200 world experts on diet and health met in Waikiki this week to review research on carotenoids, a plant pigment found in green leaves and yellow and red vegetables that holds promise in fighting cancer and other diseases.
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on carotenoids
About 200 authorities gather
here to discuss medical research
on the plant pigmentBy Helen Altonn
haltonn@starbulletin.comThe meeting, at the Renaissance Ilikai Hotel, helped explain the importance of eating more fruit and vegetables.
Findings indicate, for example, that carotenoids may protect adults from lost vision through macular degeneration. They could prevent or slow progression of prostate and other cancers, among other medical benefits.
The Cancer Research Center of Hawaii hosted the 13th International Carotenoid Symposium. Dr. John Bertram, a cancer center researcher and professor of cell and molecular biology at the University of Hawaii medical school, was program chairman and symposium organizer.
Although cancer is his interest, Bertram said the plant pigments have much wider implications, such as the carotenoid lutein's relationship to vision.
If green leaves stopped producing carotenoids, he said, they would shrivel up and die because the pigments protect the leaves from sun damage. Carotenoids appear to have the same protective function in the retina as in a green leaf, he said.
Eight local ophthalmologists were among those listening to data indicating higher rates of macular degeneration occur among people who consume low levels of green leaves, Bertram said. Macular degeneration is the major cause of blindness in older people, affecting more than 10 million people in America.
A number of companies that supported the symposium are extracting luteins from marigolds and putting them in multivitamin supplements as protection against eye disease, Bertram said. There are also some indications that early eye disease might be reversed, he said.
As for cancer, Bertram noted "increasing excitement about the role of the carotenoid lycopene, the red pigment found in tomatoes."
He said there is pretty strong evidence that men who consume higher amounts of tomato sauce and tomato-containing foods -- particularly processed foods such as pastas and pizza -- have lower prostate cancer rates.
Lycopene's benefits to decrease prostate cancer or reduce the severity of cases were described by a number of scientists, including Omer Kucuk, formerly with the Cancer Research Center of Hawaii, now at Wayne State University.
The scientists emphasized that much more research and clinical studies are needed.
Some laboratory studies show prostate cancer cells can be induced to undergo a type of suicide, Bertram said. Cancer cells generally evade mechanisms to rid the body of unused cells, but lycopene can push even existing cancer cells into programmed cell death, he said.
Kucuk said he is always being asked what can be done to prevent prostate cancer. "We always tell patients we don't know the answer," he said, but added that "common sense" dictates that people eat more fruit and vegetables and exercise more.
Studies also were described indicating increased lycopene intake through tomato-rich food may help prevent cardiovascular disease.
Presentations also focused on the role of vitamin A in diet. Many Third World countries, particularly in Asia, do not receive enough of the vitamin, resulting in thousands of unnecessary deaths and millions of blind children, Bertram said.
Death rates could be reduced by about 30 percent with vitamin A, he said.
Attempts are under way to genetically modify staples such as potatoes and rice with beta-carotene for introduction in Third World countries, Bertram said.
This would dramatically affect child mortality rates, but political problems arise from environmentalists who fight any genetic modification of foods, he said.
"It's very difficult to see where the objections are coming from," he added. "Most foods already have this enzyme, but it is not in the rice grain or potato tuber."