Supplements – Caveat Emptor (BUYER BEWARE)

Filed in Articles and Presentations on February 11, 2014

Dietary supplements are hugely popular a big industry worth billions of dollars of business. University of Guelph researchers recently published a study (PMID: 24120035) in the BMC highlighting some of the problems in the ‘off the shelf’ herbal supplement industry. Based on their DNA library for plants, the researchers looked for the DNA of plants in 44 products in order to check whether the contents matched the label.  They tested 44 products from 12 manufacturers reporting “Product substitution occurred in 30/44 of the products tested and only 2/12 companies had without any substitution, contamination or fillers.  Some of the contaminants we found pose a serious health risk to consumers”. Unfortunately there is no mechanism for Health Canada to implement such checks.  Until recently in Europe and Canada, the industry was an unregulated minefield.  The EU initially brought in tighter controls and Canada followed with its system of NPN numbers. In brief, the legislation says that you have to show the contents are not harmful, not at a therapeutic medical dose level, and broadly will do what the manufacturer says it will do.  There is much room for improvement in controls of advertising and claims regarding these products.

Resveratrol (PMID 12939617), is a much touted compound is found in the natural state in plants such as Pueria lobata. (Kudzu) and fruits, and is widely available as an off the shelf supplement. Resveratrol is  a phytoalexin,( PMID 20623546), a compound that plants make de novo to defend themselves and rapidly accumulate at areas of  infection. First identified in 1940, in the last 20 years the compound has been revisited and shown to be cardioprotective and even more importantly have anti-cancer properties.( PMID: 15517885)

Sadly no products were publicly identified either by Guelph or Health Canada.  So I decided to review the first available brand that came up on a web troll.  This was Resveratrol by Jamieson.  The container on their website contains 30 capsules and a well-known pharmacy chain priced it at $24.99.  It does not state on the web or on inspection in the store the total weight of the contents.  Content is broken down by weight/element. Vitis vinifera is listed as 50mg of the capsule. Of which, some 10% is stated to be t- resveratrol. In nature, compounds can have two isomeric forms cis and trans but humans can only absorb trans, hence t-resveratrol.  But the name on the container implying the contents is RESVERATROL and in much smaller print the words red wine extract with grape seeds.  A consumer would normally expect that product with the emphasis on one word to contain a totality of the compound.  Further investigation on the Jamieson website disclosed they are relying on research conducted by Wang et al  (PMID: 11745001as well as other papers.  The research by Wang et al. is the only reference provided where the product was tested in vivo on resveratrol and red wine and it showed:  “we investigated the effects of resveratrol and red wine on aggregation of platelets isolated from healthy, normotensive male volunteers and in rabbits with experimental hypercholesterolemia.”  In other words there is no evidence of achieving a medicinal effect on humans with cardiac disease or any other disease where resveratrol has been shown to have an inhibiting effect. “Hypercholesterolemic rabbits was inhibited when animals received intragastrically Chinese red wine (with or without alcohol, 4 ml/kg/day).” 10% of 50mg is 5mg per capsule. The total size of the capsule according to the breakdown on the label is 150mg – that is 3.3 % of resveratrol in the contents!   For an average female whose weight is likely to be @ 60kgs., to achieve the generally accepted dosage level of 5-10mg per kg per person (PMID: 24076568) you need a minimum of two bottles per day to achieve a physiological response.

That is a monthly cost of $1745 to consumers, It is unreasonable they would have to do this kind of research just to understand the contents of the container with a label Resveratrol which is just 5g of a 150mg capsule.

The data arising from the Guelph study, indicates that one cannot rely that there is actually even this modest amount of resveratrol in a capsule as only 2 unnamed manufacturers had been sown not to have adulterated their products. Guelph should have named and shamed.  If you are concerned about cancer prevention and interested in compounds such as Resveratrol (PMID: 21261654 )  then you may consult a professional specialising in this area such as a Medical Herbalist.  Cancer has many metabolic pathways and no one chemical compound has been shown in isolation to achieve an inhibition of this disease. The only plant, Turmeric / Curcuma longa which is its latin name – (PMID: 21261654), has been shown to have more effect on these pathways than any other chemical compound based on current knowledge


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Indian Solid Gold PMID: 21261654

Originally published in Prevent Cancer Now, Winter 2014

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