Here’s a link to the study, Dietary Supplements and Mortality Rate in Older Women: The Iowa Women’s Health Study.
“So,” you’re wondering, “What does this have to do with horses?”
Well, honestly, a good bit. Here are five good parallels.
1. I’ve noted for years that there’s not much good evidence for using supplements in horses, except in specific instances where certain nutrients are deficient (for example, some parts of the Northern US are deficient in selenium).
What did the authors say? – “Based on existing evidence, we see little justification for the general and widespread use of dietary supplements,” they wrote, citing a body of literature generally supporting no association with mortality, with some suggestions of harm. “We recommend that they be used with strong medically based cause, such as symptomatic nutrient deficiency disease.”
In an invited commentary on the article, Drs. Goran Bjelakovic, MD, DMSc, and Christian Gluud, MD, DMSc, of Copenhagen University Hospital noted, “We cannot recommend the use of vitamin and mineral supplements as a preventive measure, at least not in a well-nourished population. Those supplements do not replace or add to the benefits of eating fruits and vegetables and may cause unwanted health consequences.”
Just like horses.
What’s the situation in human medicine? Taking dietary supplements to improve health and prevent diseases is widespread, with about half of U.S. adults using one or more in 2000, according to the authors of the study. Annual sales top $20 billion.
Think you could find something to do with all that money?
4. Nobody knows if supplement do horses any good in the long term anyway.
How about in humans? The long-term impact of supplementation is unknown, and some studies (not just this one) have suggested a relationship between supplements and increased mortality.
How about in humans? As Rita Redberg, MD, of the University of California San Francisco, wrote in an editor’s note to the study, “Manufacturers are not required to disclose to the FDA or to consumers the evidence they have regarding their products’ safety, nor must they empirically back up claims of purported benefits.”
Trying to do this study in horses would be really difficult. Still, the fact is, there’s absolutely no evidence that giving routine dietary supplements to your horse does anything at all. If they’re so good, let the manufacturers prove it before you buy it. You’ve got a lot more important things to spend your money on.
Listen to Mr. Ed.