Disappointing Results From Vitamins C and E
Since cancer and heart disease are the number one and two causes of death in the U.S., I would love to report that taking vitamins will lower your risk, but several recent research reports cast doubts at least on vitamins C and E. Actually, these recent studies are part of a research trend showing that many vitamins—taken in pill form that is—have not been as effective as many had hoped for in preventing various diseases.
There is even the suggestion that taking some vitamin pills, particularly the B vitamin folic acid or vitamin E, might increase your chance for certain diseases, but the data is inconclusive and controversial, and further analysis is needed (and being done). Still, caution seems to be in order as far as taking vitamin pills.
At the recent American Association for Cancer Research “Frontiers in Cancer Prevention” meeting, the results of a 10-year long study were presented. This was a randomized clinical trial (the best type of research study), and it followed nearly 15,000 physicians. Some were given 400 IU of vitamin E every other day, some 500 mg. vitamin C every day, and others given placebo (dummy) pills. After a 10-year period the number of cancers was analyzed, and those who had taken the vitamins showed the same cancer rate as those who had taken the placebo. They also measured the rate of heart attack, heart failure, stroke, and angina, and again there was no benefit for the group that took the vitamins.
People who eat a diet full of fruits and vegetables seem to have a lower cancer risk, so it was hoped this long-term vitamin study would show similar benefits. Does this mean that vitamins have no benefit? No, but it does indicate that perhaps the only way to get the anti-cancer and heart-protective benefit, at least for these vitamins, is through your diet, and not through pills or supplements. Most likely there are many more substances in fruits and vegetables, particularly “phytochemicals“, that are more important for disease prevention than the vitamin content.
The status of vitamins in the medical literature will be unsettled for some time; for example, while vitamins C and E are falling out of favor, other vitamins such as D and B12, even in supplement form, are currently showing promise. And keep in mind that today we only considered if these vitamins help decrease the risk of cancer and heart disease; we haven’t touched on other diseases, such as cataracts, where vitamin supplements might be effective. I will discuss this in future posts and more completely in my book.
The trends though in vitamin research indicate this general recommendation: get your vitamins through a diet rich in a variety of fresh vegetables and fruits. Don’t rely on pills. As further vitamin research is released (a good study is underway on multivitamin pills), I will report it here.
Greg B Said,
December 20, 2008 @ 8:12 am
I wish to respectfully share some information regarding the most recent SELECT (selenium/Vit E/Prostate) trial, which was also deemed “doubtful”. This information from a renowned selenium expert (see http://www.drpasswater.com articles) helps to set the record straight. This particular study used synthetic Vit-E (petrochemical sourced), rather than a complex form (sourced from food). Also, the form of selenium used, was not the yeast grown variety, which previous studies have shown to be superior in terms of cancer prevention. To put things into perspective, many, if not most of the studies the mainstream media has considered failures, (and by association the involved vitamins/minerals), the crucial details are left out of the story. Sadly, many of these poorly designed studies are funded with TAXPAYER money. Another example is folic acid’s association with colon cancer. The overconsumption of processed food (which are generally fortified with folic acid) is the most likely culprit in this case, yet folic acid, not the poor excuse for food its in, takes the rap. In my mind, until the media reports the pertinent facts, most nutritionally related stories are prime examples of irresponsible journalism. Greg B
drDave Said,
December 20, 2008 @ 12:23 pm
Greg B thank you for your input. You make a good point that we need to consider the source and form of vitamins used for any study, and the media doesn’t typically reveal that. Most people though, who take vitamins, probably take the types used in these studies; that is, they don’t take the more “natural” forms but the cheaper forms not derived from food sources. So the results of these widely published studies probably apply to them. For example, the vast majority of people who take E take the alpha-tocopherol form, whereas the more expensive (and difficult to find) mixed tocopherol (including gamma) form is probably far superior.
It would be great to see more studies done with the more natural forms of vitamins and supplements as double-blinded clinical trials published in peer-reviewed journals.
BTW, here’s a link for people who want to read more about the SELECT trial, from the National Cancer Institute:
http://www.cancer.gov/newscenter/pressreleases/SELECTQandA
The issue of supplements and health is SO complex. It’s difficult to parse out all the different factors. That is, a higher or lower dose of the vitamin could easily influence the results and sometimes researchers don’t seem to have a good handle on the best doses to even study, and what was the form and source, and how much and what other vitamins were the subjects getting from other sources in their diet? Was the study a double-blind clinical trial? What was the health and age of the subjects? and more…
I think it will take many more years of research to get the final answer on what mix of vitamins/supplements are ideal, if any. It’s all very controversial and unsettled now. Hopefully there is a good “mix”, especially tailored to one’s age and underlying medical condition and illnesses, that will be proven safe and beneficial! Right now it seems that some extra vitamin D and fish oil, for example, for many people are relatively safe and helpful, but all that could change in a couple years. In the meantime, I believe if you want to be safest and even the most natural, try to get your vitamins from a well-rounded diet of full of lots of grains, fruits, and vegetables, and as you imply, trying to avoid processed food as much as possible. Thanks again Greg B for stimulating the discussion.