It has just been in the news that vitamin C and E did not protect against cancer, referring to an article appearing in the Journal of the American Medical Association (Gaziano JM, et al, 2008). The study included 14,691 participants including 1,307 men with a history of prior cancer when enrolled. 400 IU of vitamin E every other day and 500 mg of vitamin C daily was used. Researchers are quoted in the news saying that “large-scale, randomized trials” must still be conducted on the use of vitamin supplements and cancer, which is fine.
What is bad is that some of these news reports make it sound like nutritional supplements in general does not provide any benefits whatsoever.
Does this mean that nutritional supplements don’t provide any health benefits? To draw a conclusion like that would be to make a huge error since numerous studies have documented a variety of benefits from supplements.
There are many ways to design a research study. In general the more participants involved in a study the more reliable the study would be if the researchers have paid attention to important details. This does not mean that studies not having huge amount of participants would be invalid. If they are conducted properly they can give very valuable information. Most publish studies does not include 15,000 participants or more.
To call for more studies is good, but would you stop watching for cars before you cross a street just because you want more studies to prove that it would prevent injuries? I don’t think so because you believe there is enough existing evidence present even if there have been no large-scale studies conducted on the topic.
However, if you look at this a certain way there are a lot of reasons why it is pointless to watch for cars before you cross the street. There are of course times when there would be no cars coming, and even if one was coming the driver may be able to see you in time to stop, even if you did get hit, maybe you would not get hurt.
Still with all these maybe’s most sensible people would think it would be really irresponsible not to watch for cars when crossing a street.
Maybe we should ask these reporters to participate in a study on this topic. I suggest they should volunteer to be in the group that did not watch for cars when crossing.
Gaziano JM, et al. Vitamins E and C in the prevention of Prostate and Total Cancer in Men: The Physicians’ Health Study II Randomized Controlled Trial. JAMA. 2008 Dec 9.