Dr. Roberts on Bad Diet Supplements in the News

In the headlines this week, we saw an incredible exposure of one small area of the supplement industry published in the journal Drug Testing and Analysis.

The backstory to this paper is that a couple of years ago the FDA found that weight loss supplements containing Acacia rigidula (a shrub native to Texas), contained an unlabeled amphetamine that must have been added during the manufacturing process, because it was present in the supplement but not in the plant itself. The chemical in question would not be illegal if contained in the plant, but is banned in Europe because, in common with its illegal street-drug cousins, it has dangerous side effects including stimulation of the central nervous system, increasing heart rate and blood pressure, and in some cases tremors, hallucinations and insomnia.

The FDA didn’t specifically ban the amphetamine (their bar is set ridiculously high) but they did object to the fact that it was not derived from the specified plant. The purpose of the new study was simply to re-test the Acacia rigidula supplements to see if the manufacturers had removed the unlisted chemical. The study showed that, in the 2 years since identification… nothing happened. The amphetamine was still there, and the FDA still had not warned consumers despite their earlier tests. Supplement manufacturers apparently think they can get away with almost anything, and clearly they are not wrong.

Although it is tempting to buy into the hope that herbal supplements can help weight loss, the lack of evidence that they do anything useful, combined with the very substantial concerns about safety, make them a bad bet. My benchmark for issues like this is to ask myself how I would feel if my family wanted to take them. In the case of herbal supplements marketed for weight loss that contain untested amphetamines of uncertain origin, my answer to myself is clear — I would throw them in the trash.