Women who drink milk daily are less likely to develop breast cancer than those who drink little or no milk, a new study, published last month in the International Journal of Cancer, found.
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October 9, 2001
By Alice Chang, M.D.
Harvard Medical School
How does this article relate to you?
This study links drinking milk to lower risks of breast cancer. It seems to support the folk wisdom many of us grew up with ? "Drink your milk, it's good for you". In the study, women followed for six years in their mid-thirties to early forties had half the rate of breast cancer if they drank milk as children and had at least three glasses of milk each day.
It is not clear what component of milk could be responsible for lowering the breast-cancer risk. Candidates include calcium, vitamin D and CLA (conjugated linoleic acid). Other studies cited in this article suggest that deficiency of CLA may increase the risk for breast cancer and could be a good candidate for the risk-lowering effects of milk.
It will be important to figure out exactly what part of milk lowers the risk for breast cancer, as many adults become lactose intolerant, losing the enzyme that digests milk, responsible for mild to more severe symptoms of gas, abdominal cramping and diarrhea.
What changes do you need to make?
This article is not going to make me run out and start drinking milk with every meal, nor would I recommend this to my patients. Fortunately, I did drink milk as a child. But having one glass of milk with each meal as an adult seems less practical. Common sense tells me that the most prudent course is to avoid dietary deficiencies in order to lower my risk for breast cancer and many other health problems.
When supplementing any part of your diet, remember that too much of a good thing can be bad. There can be serious health consequences to overdoing just about every component of the diet. In particular, taking too much calcium can be a problem for people with a history of kidney stones. So if you doctor has cautioned you on limiting the calcium in your diet, do not neglect those instructions because of this study.
Right now, recommendations for dietary requirements of calcium and vitamin D are unchanged. In fact, three glasses of milk used in this study is roughly equivalent to the adult recommendation of 1000 milligrams of calcium in the diet. Most multivitamins include at least the recommended 400IU of vitamin D each day.
What can you expect in the future?
Studies like this are helpful in starting to identify ways to reduce our risk for cancer. The next step will be to test theories about the benefits of different components of milk. Identifying the right factor that decreases breast-cancer risk could tell us what specific part of the diet should be supplemented, or help us to create a supplement with just this one factor.
Related areas:
Breast Cancer
