Voor wie zin heeft om hier nog een zinnige mening over te lezen (en over voedingssupplementen met ongefundeerde health claims in het algemeen:
Alpha Brain – What’s Wrong with the Supplement Industry
There is an endless stream of supplement products on the market that are of questionable value. They tend to follow a similar pattern: put an essentially random assortment of vitamins, minerals, perhaps herbs and nutritional elements into a pill and then make whatever pseudo-health claims you want. Usually the claim is implied in the name of the product itself – sleepwell, or brainboost. The popular product Airborne fits this mold. It is essentially a multivitamin with the unfounded claim that it will prevent infection by boosting the immune system.
In the US, regulations (under DSHEA) specifically allow “structure/function” claims without any requirement for evidence to back up the claims. In other words, as long as you don’t mention a disease by name, you can make pretty much whatever claim you want. This was supposed to be good for the consumer, when in fact it is springtime for industry at the expense of the consumer. If your claims are outrageous enough the FTC can still go after you, but they are playing a game of whack-a-mole and losing.
Another pattern that is common is for a supplement product to contain specific components that are claimed to have specific benefits. Often these claims are based upon evidence – just the wrong kind of evidence. Basic science evidence is used inappropriately to support clinical claims. This strategy is more insidious, as it gives the public the sense that the product is science-based when it isn’t.
Recently a product came to my attention which fits this mold perfectly – Alpha Brain. This is a supplement that claims to “enhance” mental function, sleep, creativity, and athletic performance. Their website includes a section called “The science behind alpha-brain.” I always find it amusing to following the links for promised evidence on such sites. What they never seem to contain is links or references to primary sources that actually demonstrate the claims they are making.
The site reviews all of the ingredients in Alpha-Brain explaining the science behind the claims – let’s look in detail at just one example, GPC choline, which is an essential nutrient and a precursor for the neurotransmitter acetylcholine. The site claims:
There is scientific evidence that proves that increased levels of acetylcholine in the body can dramatically increase memory and cognitive ability of men and women of all ages
The reference given is not to a peer-reviewed study, but to another promotional site that simply makes more claims about the benefits of choline. The concept here is not implausible, but also cannot be assumed, and is very common in the supplement industry. The idea is that a precursor of an important molecule in the body will increase the availability and therefore function of that molecule. That could be true, if availability of the precursor is the rate-limiting-step in the production and function of the molecule. Specifically in this case, is the nutritional availability of choline limiting the production and function of acetylcholine?
Choline is an essential nutrient, so (as is true with all nutrients) in someone who is undernourished or with specific deficits in their diet, supplementing will help. But in someone with an adequate diet, there is no reason to assume that more will be better. Supplements treat deficiencies – but there is no reason to think that taking additional nutrients beyond the minimum necessary will have functional benefits.
They then report:
>A study performed by Sangiorgi Barbagallo at the University of Palermo studied 2044 candidates who suffered from recent stroke or transient ischemic attack. The study concluded that administration of GPC choline confirmed its therapeutic role in improving cognitive ability in this group of study subjects.
They don’t give the reference, but I tracked in down. This is an excellent example of how a company can cite studies to make is seem as if their claims are evidence-based when they are not. The question is – how relevant is this study to Alpha-Brain? There are two major problems: The first is that the study (which was not blinded, but even if we take its results at face value) used 1000mg IM (intramuscular) for 28 days, followed by 400mg orally daily. Alpha-Brain contains 100mg of GPC choline. IM administration likely has a completely different bioavailability than an oral dose. And of course the dosing for 28 days was 10 times that in the supplement.
A bigger problem, however, is the study population – those recovering from a stroke or TIA. When the body is under physiological stress demand for nutrients are likely to become a limiting factor in the rate of recovery, even when those same nutrients are not a limiting factor in a healthy individual. You therefore cannot extrapolate from a disease population to a healthy population – just because a nutrient helps recovery does not mean it will enhance normal function.
The same is true for Alzheimer’s disease. There is evidence that choline supplements may improve the symptoms of dementia. But this does not mean they will enhance mental function in a healthy individual.
I am presenting just one illustrative example of the types of deceptive marketing practice by the supplement industry, specifically with their use of scientific evidence. They use the evidence as a marketing tool, not as a way to determine the net clinical effects of a product. Several types of deceptive use of evidence are common: using basic science studies to support clinical claims, using studies in ill subjects to make claims about enhancing normal function, referencing secondary sources or sources that do not support the claims being made, and making inappropriate comparisons to different doses and routes of administration.
The goal is to create the impression that the supplement being marketed has health benefits that are backed by science – but the devil is always in the details. What they never seem to provide is rigorous studies of their actual product published in the peer-reviewed literature showing the specific benefits they are claiming when used as directed.