Meat And Milk Firmly
Linked To Prostate Cancer Deaths
By Maggie Fox - Reuters
Health and Science Correspondent

WASHINGTON (Reuters) - Men who eat the most meat and dairy products are the most likely to die from prostate cancer, while those who eat plenty of grains and nuts are the least likely to succumb to the disease, an international study showed Wednesday. A survey of prostate cancer deaths in 59 countries showed that diet is strongly linked to mortality from the disease, the second-biggest cancer killer of men after lung cancer. ``Animal energy was positively associated with prostate cancer mortality,'' James Hebert of the University of Massachusetts Medical School and his colleagues wrote in a report in the Journal of the National Cancer Institute.
``Overall, we observed protective effects from higher levels of intake of cereals, nuts and oil seeds (which include soy consumption) and fish,'' they wrote. They found what a number of other studies looking at diet's role in heart disease and cancer have found -- that the plant-based diets found in many less-advanced societies are the healthiest, as long as people get enough to eat.
``Our results showed that prostate cancer mortality is positively associated with dietary factors associated with affluence, including estimated intakes of energy, total fat and animal products (specifically milk, meat and poultry),'' they wrote. ``On the other hand, intakes of cereals, soybeans, other nuts and oilseeds, and fish were negatively associated with prostate cancer mortality,'' they added. They noted that several studies have proposed a mechanism for this. ``For prostate cancer and cancers of other sites that are sensitive to serum (blood) hormone levels, animal fat may influence the risk for cancer by raising adult's sex hormone levels,'' they wrote. Prostate cancer is linked with testosterone levels, and is often treated by cutting testosterone production -- sometimes by surgical or chemical castration.
Breast cancer in women is linked with estrogen levels -- and has also been linked with a high-fat diet. Hebert's team noted that black American men have a prostate cancer rate that is 40 percent higher than the rate found in white men, and that black men tend to have higher testosterone levels. Colon cancer, the third-biggest cancer killer in the United States, has also been linked with a diet high in animal fat and low in fruits, vegetables and whole grains. Hebert's team looked at the numbers in several different ways. Men who drank the most alcohol were also the most likely to die from prostate cancer, while those who ate the most soy products were the least likely to die.
They said it was not entirely clear whether fish had a protective effect, because the men who ate the most fish also ate the most soy. Both fish and soy contain omega-three fatty acids, which have been shown in tests to inhibit the growth of tumors. The researchers noted that the lowest death rates from prostate cancer are in countries such as Japan, where people eat a great deal of soy and fish and less meat. The differences persisted even when the environment, exercise and other factors were considered. ``On the basis of the results of this study and other studies, it appears that the Western diet may contribute to the risk for prostate cancer mortality,'' they concluded.