Onions Beat Steak or Ice Cream - More Dietary Links to Prostate Cancer
PSA
Rising, Dec 22 2003 — Links between animal products as risk
factors for prostate cancer, and vegetable products, especially onions,
as risk reduction factors are confirmed by a new multi-country study.
Now online at European
Urology,
the study looks at national diets and prostate cancer death
rates.
William B. Grant, an independent health researcher who did this investigation, thought dietary links might be a useful approach after comparing prostate cancer mortality rates for various parts of the world.
Prostate cancer death rates in the U.S. and northern Europe are about 5 times higher than in Hong Kong, Iran, Japan, and Turkey.
The strongest dietary risk factor for prostate cancer mortality, according to Grant's review of available evidence, is animal products, such as meat and dairy products. The strongest protective foods (or risk reduction factors) are vegetables. Top of the list are onions.
Onions are joined by other vegetables and by cereals/grains, beans and fruits. Alcohol, oils, and added sugar (sweeteners) do not seem to give any protection, Grant says.
Thus, fat and protein are risk factors, while complex carbohydrates and antioxidants are risk reduction factors. This finding points to insulin-like growth factor-I (IGF-I) as an important risk factor for prostate cancer. IGF-I is also increased by total energy consumption. (Another recent study finds that calorie restriction reduces risks of most cancers).
Grant's study
supports earlier reports that allium family vegetables (e.g., garlic,
leeks, and onions) are important risk reduction factors for prostate
cancer. This study also found that alcohol is a minor risk factor. No independent
correlation was found for tomatoes, a source of lycopene, thought to reduce
the risk of prostate cancer.
Prostate cancer mortality rates for 32 predominantly Caucasian countries for the late 1990s were obtained from the World Health Organization. Dietary supply data were obtained from the Food and Agriculture Organization. Grant ran statistical analyses for all 32 countries as well as the 20 European countries. Dietary supply data for 1979-81, he found, yielded the highest correlations, indicating that prostate cancer takes approximately 20 years to progress from initiation to death.
These results are similar to results reported by Dr. Grant last year for breast cancer, although onions were not found to play a role for breast cancer. Animal products including animal fat and alcohol are now recognized risk factors for breast cancer, and vitamin D is recognized as an important risk reduction factor. The more exposure to sunlight, which is the main source of vitamin D for many people, the lower the rate of prostate cancer death. In the USA, prostate cancer rates increase in states which receive less daily sunlight. (Other evidence suggests that some people have fewer receptors for Vitamin D and many people may be less able to absorb vitamin D as they age.)
Grant's results may provide more guidance for reducing the risk of prostate and other cancers.
William B. Grant does independent health research from his office in Newport News, Virginia. His health work is primarily related to identifying and quantifying links to chronic diseases from dietary factors and solar UV-B. He published the first paper linking diet to Alzheimer's disease in 1997.
European Urology (currently among "Articles in Press")
Grant WB. An ecologic study of dietary and solar UV-B links to breast carcinoma
mortality rates. Cancer, 94, 272-281, Jan. 1, 2002.
http://www3.interscience.wiley.com/cgi-bin/abstract/89012143/START
Grant WB. An estimate of premature cancer mortality in the United States due to inadequate doses of solar ultraviolet-B radiation, Cancer, 94(6), 1867-75, March 16, 2002.
A study at Cornell University, Ithaca, New York in 2002 looked at 10 of the commonest common US vegetables for protection value against chronic diseases. They say:
Broccoli possessed the highest total phenolic content, followed by spinach, yellow onion, red pepper, carrot, cabbage, potato, lettuce, celery, and cucumber. Red pepper had the highest total antioxidant activity, followed by broccoli, carrot, spinach, cabbage, yellow onion, celery, potato, lettuce, and cucumber..... Antiproliferative activities were also studied .... Spinach showed the highest inhibitory effect, followed by cabbage, red pepper, onion, and broccoli.
Anti-Prostate Cancer Effects of Onions and Garlic Allium Vegetables and Risk of Prostate Cancer: A Population-Based Study Ann W. Hsing and team. Journal of the National Cancer Institute, Vol. 94, No. 21, 1648-1651, November 6, 2002
Anti Cancer Effects of Garlic as a Supplement
Mechanisms of Inhibition of Chemical Toxicity and Carcinogenesis by Diallyl Sulfide (DAS) and Related Compounds from Garlic, Chung S. Yang and team. Laboratory for Cancer Research, College of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, NJ. Journal of Nutrition 2001
This page made
Dec 26 2003, edited by J. Strax
