Wednesday, 17 October 2012

Vitamin supplements may not be as useful as we once thought

Sorry for the delay on writing a new article.  It was a busy month with racing in France among a few other things.  This week I wrote an article for the New Hamburg Independent which takes a look at why vitamin supplements may not be as useful as you may think.  As per usual, my space is limited, and the article is more of a basic summary, but it's a good start.  Let me know if you have any other questions!

**EDIT** Keep in mind there is always two sides to the story.  It is pretty ironic that I just published this article, and then this study hits the news:

Thanks to Sweat Science for drawing my attention to this one!

Vitamin supplements may not be as useful as we once thought

It is undisputed that when dealing with a vitamin deficiency, supplementation is an excellent way to speed up the recovery process.  In addition, it has also long been thought that taking a daily multivitamin can go a long way in preventing disease and maintaining health, even in the absence of such a deficiency.  However, a new line of research is showing that the prophylactic use of vitamins may not be as useful as we once thought.

This issue was examined in a large 2011 study which looked at just under 39 000 middle aged women over the course of 20 years.  These women were followed to see what vitamins they were taking on a daily basis in conjunction with how long they lived. 

Throughout the 20-year block that the study took place, just under 16 000 of the subjects deceased.  Among these women, it was to the surprise of the researchers that most vitamins and minerals had little to no impact on the longevity of the subjects.  On top of that, there were a number of vitamins and minerals that were actually associated with a higher risk of death (including iron, copper, folic acid, and B-vitamins). 

This study is not the only one putting these supplements into question;  another 2011 study took a more specific approach, as they followed just under 36 000 men, and looked at the relationship between vitamin E supplementation and the frequency of prostate cancer.

Just to provide some background information, it is well established that free radical damage is associated with an increased risk of cancer.  Free radicals are essentially charged particles that bounce around in your body, create inflammation and cellular damage, and predispose you to cancer.  It is also thought that supplementing with anti-oxidants, which help rid the body of free radicles, reduce the risk of cancer.

Despite vitamin E being a strong anti-oxidant, the researchers of this study did not see what one would expect.  In fact, of 36 000 men who were followed, just over 1 200 developed prostate cancer within 12 years.  Of this 1 200, those who were taking a daily vitamin E supplement were 17% more likely to develop prostate cancer than those who were taking a placebo (a sugar pill they thought was vitamin E).  While it is highly unlikely that these supplements are causing disease, these studies are really starting to cast significant doubt in our daily multi-vitamin regimen. 

So what does this research show us?  It is important to note that these studies are not perfect.  First, they are looking at the correlation of taking supplements with the frequency of a disease, rather than actually trying to see what is causing the disease.   Just because more men who took vitamin E developed prostate cancer does not mean the vitamin E caused the cancer.  In fact, this is highly unlikely.  It is much more probable that there were other factors contributing to the disease frequency that the researchers did not account for. 

That being said, the good news is that when you repeat the same studies mentioned above, except with replacing supplements with a well-balanced diet of fruit and vegetables, we see exactly what one would expect: increased longevity and decreased frequency of cancer.  

Therefore, while we cannot definitely say if multivitamins are good or bad, maintaining a variable and consistently well-balanced diet is your best approach to maintaining optimal vitamin and mineral levels in your body.

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