I don't know what study they were talking about. I found this in a recent article in the British Daily Mail so they may be talking about the same study:
Researchers spent more than six years following 8,000 people and found that those taking supplements were just as likely to have developed cancer or heart disease as those who took an identical-looking dummy pill.
And when they were questioned on how healthy they felt, there was hardly any difference between the two groups.
A team of French researchers, led by experts at Nancy University, tracked 8,112 volunteers who took either a placebo capsule, or one containing vitamin C, vitamin E, beta-carotene, selenium and zinc, every day for just over six years.
Read more: http://www.dailymail...l#ixzz1jMgMQFg5
So it was just an observation with no info on the lifestyle of the participants, no measure of the nutrient levels in their body, etc. I found several other studies done the same way, including this response by the Linus Pauling Institute on an even larger study done in 2009 - http://lpi.oregonsta...tivitamins.html
Also an observational study with little controls. The response is about the many problems with the study. And that they just might have prevented/reduced other health conditions.
Since the RDAs of many nutrients are way to low to prevent these diseases, and the quality of the average supplement is poor, it's probably no wonder there was little difference between the multi takers and those on the placebo. Also, 6 years of a few extra nutrients might not be enough to prevent the cancer and heart disease those people were already headed for.
Edited by alternativista, 13 January 2012 - 12:56 PM.