Re: Nonfat Milk Linked To Prostate Cancer


"El Castor" <No_One@xxxxxxxx> wrote in message
news:4ncqn3ha29e9ls80obk8m2t0vlhkop8961@xxxxxxxxxx
Non-fat and low-fat milk have been linked to an increased risk of
prostate cancer ... but whole milk reduces the risk. Strange.

Nonfat milk linked to prostate cancer
Wed Jan 2, 2008 1:50pm EST

NEW YORK (Reuters Health) - The amount of calcium and vitamin D in the
diet appears to have little or no impact on the risk of prostate
cancer, but the consumption of low-fat or nonfat milk may increase the
risk of the malignancy, according to the results of two studies
published in the American Journal of Epidemiology.

Dietary calcium and dairy products have been thought to increase the
risk of prostate cancer by affecting vitamin D metabolism. Data from
several prospective studies have supported an association, but many
other studies have failed to establish a link.

To explore this topic further, Dr. Song-Yi Park, from the University
of Hawaii in Honolulu, and colleagues, analyzed data from subjects
enrolled in the Multiethnic Cohort Study. This study, conducted
between 1993 and 2002, included adults between 45 and 75 years old,
were primarily from five different ethnic or racial groups, and lived
in California or Hawaii.

A total of 82,483 men from the study completed a quantitative food
frequency questionnaire and various factors, such as weight, smoking
status, and education levels were also noted, Park's group said.

During an average follow-up period of 8 years, 4,404 men developed
prostate cancer. There was no evidence that calcium or vitamin D from
any source increased the risk of prostate cancer. This held true
across all racial and ethnic groups.

In an overall analysis of food groups, the consumption of dairy
products and milk were not associated with prostate cancer risk, the
authors found. Further analysis, however, suggested that low-fat or
nonfat milk did increase the risk of localized tumors or
non-aggressive tumors, while whole milk decreased this risk.
More ...
http://www.reuters.com/article/healthNews/idUSHAR26781420080102

Epidemiological studies are notoriously flaky. For example, hormone
replacement therapy (HRT) in women was linked to lower probability of being
murdered, as the NY Times reported a few months ago. I told that to our
doctor, who burst out laughing. He said he would use my example for his
students (he is a teaching and research doctor).

It takes randomized testing as follow-up, which often isn't done due to
expense. Epidemiological studies have their use, but should not be relied on
exclusive of random controlled testing.

The clue in this low fat milk story is the hedge word "suggested." That
means take it with a grain of salt for now.


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