primer on medical studies

[paula]

September 30, 2008

Searching for Clarity: A Primer on Medical Studies

By Gina Kolata, The New York Times

Everyone, it seemed, from the general public to many scientists, was enthralled by the idea that beta carotene would protect against cancer. In the early 1990s, the evidence seemed compelling that this chemical, an antioxidant found in fruit and vegetables and converted by the body to vitamin A, was a key to good health.

There were laboratory studies showing how beta carotene would work. There were animal studies confirming that it was protective against cancer. There were observational studies showing that the more fruit and vegetables people ate, the lower their cancer risk. So convinced were some scientists that they themselves were taking beta carotene supplements.

Then came three large, rigorous clinical trials that randomly assigned people to take beta carotene pills or a placebo. And the beta carotene hypothesis crumbled. The trials concluded that not only did beta carotene fail to protect against cancer and heart disease, but it might increase the risk of developing cancer.

http://michaeljfox.org/newsEvents_pa...cle.cfm?ID=400

[grant r]

I was recently part of a video shoot of a presentation by a consultant (I don't know if I can identify him, but he is a Dr.) who had an interesting take on this. In response to a question on supplements, he spoke of lycopene being mostly a marketing ploy. Tomatoes have been shown to be helpful and lycopene can be synthesized and sold to us, yet there are many other compounds in the tomato... is it just lycopene that is efficacious, or the other compounds, or some combination thereof? His advice was nothing short of groundbreaking... eat foods as close to their natural state as possible, and save your money.