|
My
husband has prostate cancer. I recently read that a high calcium intake
may cause prostate cancer. How high is too high? Should I be restricting
his calcium intake? A study with nearly 21,000 men found that those who consumed more than 600 milligrams of calcium daily from dairy products had a 32% higher risk of prostate cancer than men who consumed no more then 150mg of calcium a day over 11 years. (American Journal of Clinical Nutrition 2001;74:549-554) Other studies have also observed a moderate increase in the risk of prostate cancer associated with a higher intake of dairy foods and dairy calcium. (1. Journal of the National Cancer Institute 385:1571,1993. 2. Cancer Research 58:442,1998.) A possible biological mechanism for a connection between dairy foods and prostate cancer is that higher intakes of calcium can reduce the body's level of Vitamin D, which we obtain mostly from sunlight, fortified milk, fatty fish, and multi-vitamin supplements. Vitamin D has been shown to protect the prostate by inhibiting prostate cancer cells from growing in size and number. Dr. June Chan of the Harvard School of Public Health states that calcium may really be only a concern for men who get more than 2,000 mg of calcium a day from both dietary sources and dietary supplements. Many researchers believe that the evidence is not strong enough to recommend that men change their calcium intake. However, men should be aware of the possible link, because they may not realize they are getting calcium from fortified foods (like some cereals and juices-become a label reader!), vitamin-mineral supplements, and antacids like Tums, in addition to the typical dietary dairy sources. Calcium is very important in the prevention of osteoporosis and lowering the risk of colon cancer and therefore should not be severely limited in the diet. The recommended level of calcium intake is 1000mg a day if your husband is under 50 years of age and 1200mg if he is over 50 years of age. Some common food and supplement sources that are high in calcium are:
(Sources: Bowes
and Church's Food Values of Portions Commonly Used. 17th edition, 1994,
www.tums.com, www.centrum.com) Some additional non-dairy food sources of calcium may be found on the following web site from the Baylor College of Medicine. New research at the Fred Hutchinson Cancer Research Center in Seattle, WA, (Cancer Epidemiol Biomark Prevent 11:719-725, 2002, Kristal et al) has shown an increased risk (112% - more than double) of being diagnosed with advanced prostate cancer vs. early localized prostate cancer in men whose calcium intake from food and supplements was higher than 1200 mg per day. In addition, this same study showed men who consumed diets with more than 30% fat also had double the risk of being diagnosed with the more difficult to treat advanced prostate cancer vs. early treatable prostate cancer. Researchers speculate that these nutritional factors may be involved with progression of the prostate cancer, not the initial causation of the disease, and thus nutritional interventions may play an important role after diagnosis of prostate cancer. "Moderating fat and calcium consumption may reduce the risk of cancer recurrence following treatment," states the study's lead author, Alan Kristal, Dr. P.H. Even though clinical trials have not yet been performed evaluating various nutritional changes on outcomes of prostate cancer, this research adds more important pieces to the puzzle, giving clues that nutritional intervention after a cancer diagnosis may be beneficial in slowing the course of the disease. The optimal
diet (including calcium, fat, and other nutrients along with soy and
other foods) to prevent recurrence, or slow progression, of prostate
cancer is not yet known. However, I would strongly suggest that every
patient with a prostate cancer diagnosis (both early localized disease
and also more advanced disease) insist on receiving a full nutritional
assessment by the Registered Dietitian (RD) at his cancer center. She
will make individualized dietary change recommendations that may help
decrease the rate of progression of the cancer, using the information
presented here in addition to information in the other FAQ on nutrition
and the prostate cancer patient on my web site. An additional resource on the topic of calcium and prostate cancer is at www.cspinet.org/nah/07_01. This question
was researched and written by Melissa Gerharter, as part of a graduate
level course in Nutrition and Dietetics at Eastern Michigan University.
The answer posted here was written under the direction of and edited
by Diana Dyer, MS, RD.
FAQ revised 09/02 These questions and answers are intended to be of a general informative nature. Please consult with the Registered Dietitian in your cancer center or your health care provider for nutritional advice that can be individualized to your specific medical condition. |
|
Contact Diana: |
|
|
| Phone: 734/996-9260 |
|
Fax: 734/996-9262 |
|
P.O. Box 130221, Ann Arbor, MI 48113 |
