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Providing perspectives on recent research into vitamins and nutritionals

Pills / vitamins woman

How To Spot an Unsafe Dietary Supplement

By Julia Bird

Yesterday, the US FDA announced the results of a widespread investigation into the safety of dietary supplements on the market. The sweep has led to civil injunctions and criminal actions against 117 manufacturers of distributors of dietary supplements. Information about hundreds of supplements that contain hidden or potentially harmful ingredients have been identified. In the most egregious case, the dishonestly named USPlabs*, who have produced some widely popular weight loss and muscle building supplements, has received may charges related to falsification of documentation and knowingly placing unsafe products on the market.

The issue is that dietary supplements in the US are not subjected to the same scrutiny as medicines at the moment and the onus is on the manufacturer to put products on the market that are safe. While most manufacturers do not want their products to cause harm to consumers, a few are more interested in investment accounts and luxury sports cars than consumer safety. This search by the FDA has uncovered serious problems in some supplements, however they are limited in their ability to stop all unsafe products on the market. Consumers need to be aware of the contents and risks of dietary supplements that they buy. Here follow some tips about how to select a safe supplement.

Be wary of supplements promising weight loss, muscle building, or sexual enhancement

These three indications are the most common found in the list of adulterated products, even though they make up only a small percentage of total products. These three categories combined are around one quarter of dietary supplements in the US, yet only 18 of the 664 products on the FDA’s “Tainted Products List” are not in one of these three categories.

If it sounds too good to be true, it probably is

Obesity is a globally-recognised problem that has a major impact on chronic disease rates. The problem is, losing weight is very difficult to do. Even obesity medication, which undergoes stringent safety and efficacy testing, only has a modest effect. For example, a recent one-year study of obesity drug naltrexone/bupropion only showed a 6.4% weight loss after one year in overweight or obese patients (mean weight at baseline was around 100 kg, so this is equal to weight loss of around 6 kg, or 13 pounds). Diet and exercise also only show a very small impact on body weight (see review by Hartmann-Boyce and co-workers). I have researched various nutritional ingredients for their effect on weight loss in the past years and the best evidence shows only a modest effect. Why do people think that a dietary supplement is going to be incredibly effective when drugs and intensive behavioral programs are not? It appears that one cannot be too thin, too rich, or too gullible.

Check the scientific backing behind the products

Dietary supplement manufacturers often like to stress the scientific backing of their products. It is good policy for the manufacturers to place a reference to the particular studies that provide this scientific backing on their product or website. Check the reference carefully to make sure that it is appropriate to what is being claimed. If no reference is given, it is still possible to find the particular study in question and check the data. There are other small details that can tip you off that the information has not been written or reviewed by a scientist. For example, this text was extracted from information about a weight loss supplement:

“Cirsium Oligophyllum is another perennial plant. In studies, this incredible extract safely reduced gains in bodyweight by 6.6%, subcutaneous fat mass by 26.2%, yet visceral fat mass by only 3%!

This is big news because it’s subcutaneous fat that is just below the skin, which is exactly what we’re going for. Visceral fat, however, is the “organ fat” that your body needs a fair amount of.”

Here are the following issues with this small piece of text:

(1) The first sign that the information has not been written or checked by a scientist is that the scientific name of the plant has not been written in italics or between quotation marks, and the second part of the name has a capital letter. Although it appears to be minor, this is Biology 101 and scientists should not make this mistake.

(2) The phrase “reduced gains in bodyweight by 6.6%” does not make much sense to me without knowing the background of the study. Did it prevent weight regain? Or did it cause weight loss? Be careful of weasel words.

(3) There is no citation given for the “studies” that are referred to, however with a very minimal amount of searching I was able to uncover a published article with the same numbers, by Mori et al. It seems that a 10% solution of Cirsium oligophyllum was able to reduce body weight by 6.6%, but in rats!

(4) The next blunder is regarding the different effects on subcutaneous vs. visceral fat. Visceral fat is the fat around organs and is linked to the negative health effects of obesity (see review from Gonçalves, Glade and Meguid). Therefore, the enhanced effect of this particular herbal extract on rat subcutaneous fat is not an advantage but rather a disadvantage.

Don’t be afraid to look for the sources of information. The absence of citations for the “scientific” work is a giveaway that the evidence is not strong. Where possible, look for the original research studies. A good resource is the database of biomedical literature Pubmed:

Choose products that are USP verified

The US Pharmacoepial Convention standards (USP) provides reference materials to enable dietary supplement manufacturers and suppliers to determine “product and ingredient identity, strength, quality, and purity”. The USP verifies that products are produced safely and conducts product testing. Manufacturers are allowed to state on their label that their product meets USP standards. This is a mark of quality to consumers. The USP also conducts random off-the-shelf tests of products with the certification to confirm that they conform to standards. Here is a list of companies that have products that are USP verified:

*USPlabs is in no way related to the US Pharmacoepial Convention (USP)

Main citation:

U.S. Department of Health and Human Services. Food and Drug Administration. FDA takes action to protect consumers from potentially dangerous dietary supplements. November 17, 2015.

Supporting citations:

Apovian CM, Aronne L, Rubino D, Still C, Wyatt H, Burns C, Kim D, Dunayevich E; COR-II Study Group. A randomized, phase 3 trial of naltrexone SR/bupropion SR on weight and obesity-related risk factors (COR-II). Obesity (Silver Spring). 2013 May;21(5):935-43. doi: 10.1002/oby.20309.

Gonçalves CG, Glade MJ, Meguid MM. Metabolically healthy obese individuals: Key protective factors. Nutrition. 2015 Aug 13. pii: S0899-9007(15)00327-5. doi: 10.1016/j.nut.2015.07.010. [Epub ahead of print]

Hartmann-Boyce J, Johns DJ, Jebb SA, Aveyard P; Behavioural Weight Management Review Group. Effect of behavioural techniques and delivery mode on effectiveness of weight management: systematic review, meta-analysis and meta-regression. Obes Rev. 2014 Jul;15(7):598-609. doi: 10.1111/obr.12165. Epub 2014 Mar 18.

Mori S, Satou M, Kanazawa S, Yoshizuka N, Hase T, Tokimitsu I, Takema Y, Nishizawa Y, Yada T. Body fat mass reduction and up-regulation of uncoupling protein by novel lipolysis-promoting plant extract. Int J Biol Sci. 2009;5(4):311-8. Epub 2009 Apr 28.