Prostate cancer in men is a hormone-dependent cancer; much like breast cancer is in women. Dr. Neal Barnard, president of The Cancer Project, does an excellent job of explaining what we can do to help prevent it as well as helping us fight it, for those who have already been diagnosed.
In the nine minute video below, Dr. Barnard discusses dairy products and how dairy increases the risk of developing prostate cancer. Evidence of this can be seen in those countries that consume the most dairy products. The higher the consumption, the greater the incidence of prostate cancer. Countries that consume the least dairy have the lowest rates.
Several studies have confirmed these findings, including a study that followed over 48,000 men. Men who consumed two or more servings of dairy a day had a 60% higher risk of cancer compared to other men.
Why would a food which is considered to be "nature's most perfect food" be linked to promoting cancer? Dr. Barnard describes how a natural hormone in milk, called IGF-1 (Insulin-like Growth Factor) promotes cell growth. For example, he says that when the IGF-1 hormone is mixed with prostate cancer cells in a test tube, they grow and multiply rapidly. He relates this to adding fertilizer to weeds.
A small group of researchers used this information to see how a diet excluding dairy and rich in fruits and vegetables would affect those men who already had prostate cancer. Researchers measured the PSA doubling time in the blood of the ten men in the study. At the beginning of the study, the PSA doubling time was measured at 6.5 months. After switching their diets to a low-fat vegan diet, their PSA doubling levels were extended to 17.7 months, indicating that the rate of cancer growth had considerably slowed. Some PSA levels even began to fall.
Dr. Barnard also discusses calcium needs, and how green vegetables and beans are excellent sources of calcium. The calcium in greens is actually absorbed at higher rate than in dairy. The absorption rate in broccoli is 50% compared to milk, which is about 32%.
What can we do to help prevent getting prostate cancer? Dr. Barnard encourages us to eat a diet rich in whole foods, fruits and vegetables, especially those that are red like tomatoes. The red color represents lycopene, which is a powerful antioxidant. Studies have demonstrated that men who consume just two tomato servings per week have a 23% reduced risk of prostate cancer. Men who have 10 or more servings per week have a 35% reduction in prostate cancer.
For more information regarding dairy and cancer, see:
(6) Blogs on cancer
(10) Prostate Cancer