Monday 13 July 2015

Retin-A and Retinol

There are two types of cosmetic 'science': magic and pharmaceutical.

The magic kind is where you take a substance that has value inside the body and use it in a way that can't deliver the same benefit. A good example is hyaluronic acid. This was original discovered as part of the gunk that fills eyeballs, and later was shown to be an important part of the matrix that supports cells in the body. The way it is generally sold is that it somehow replenishes this support function, plumping up skin. But this is a bit like saying that food gives you energy, so if you plaster food on your skin you should feel energised.

The good news about hyaluronic acid is that is a genuine humectant - it grabs water, so acts as a reasonable moisturiser - but no better than much cheaper substances like vaseline.

Products with a pharmaceutical background, on the other hand, certainly have an effect, but we have to recognize that all pharma comes with side effects, some of which can be worse than the condition treated. And they need to be used with care. Often the cosmetic industry gets round this by putting so little of an active substance in a product that it doesn't risk side effects, but equally produces very little in the way of results.

So we come to our topic, Retin-A, Retinol and various other names applied to chemical variants on Vitamin A. Retin-A is a brand name for tretinoin, aka retinoic acid, the carboxylic acid derivative of Vitamin A and has been a topical treatment for acne since the 1960s. In the 1980s it was accidentally discovered that it seemed to reduce the appearance of skin wrinkling. Since the original anecdotal benefits there has been some research suggesting positive results. It has since been sold as a skin treatment in the US, though is not widely available in this form elsewhere because of its pharmaceutical nature.

Weaker and more dilute forms turn up in commercial skin creams, often based on retinol, one of the animal forms of Vitamin A. In these cases there may be a small effect, but it certainly will be limited as the dosage is restricted to avoid the side effects. In the more concentrated form (Retin-A, Renova etc.) it can have make a more noticeable change, but can result in a number of side effects, most notably skin irritation and burning, dryness and increased sensitivity to sunlight. For some users this fades over time, for others it will come back each time the cream is used - and the product is only effective while in regular use.

Overall this seems a borderline product. It does have a genuine effect, but it is a pharmaceutical product with known side-effects being applied outside its intended use. As such, the negative aspects may outweigh the positive, and I have not been able to find any research on long-term impact, which may be another concern.


  • Hyaluronic acid - page 386

Sunday 12 July 2015

Can drinking tequila help you lose weight?

If I had £1 for every new story where [insert your favourite alcoholic drink] is shown to have some positive effect, I could retire immediately. And, surprise, surprise - this is yet another such story that has no basis whatsoever as far as the headline goes. But it does have one interesting possibility for an alternative to sugar.

All the press coverage comes up with statements like 'You won't believe why drinking tequila might actually help you lose weight,' or 'You won't feel so guilty after that extra shot.' To be clear. Tequila will definitely not help you lose weight, and even if the implied benefit were true, which it isn't, the dangerous impact of alcohol would far outweigh the benefit. In fact the research specifically points out that the beneficial substance this report is based on, of which more in a moment, is not found in tequila.

Hidden beneath the 'drink your way to weight loss' stories is a much more interesting possibility. The actual research, reported at an American Chemical Society meeting, showed that the agave plant, which happens to be the plant tequila is produced from, contains some very interesting sugars called agavins. Instead of the usual fruit sugar fructose, these sugars are fructans, which are effectively fructose polymers. The result of this different structure is that the sugars can't be used by the body and so don't have the negative impact of sugar. They even appear to somewhat reduce blood sugar levels - and they still give a sweet taste. Admittedly not as sweet as a conventional sugar, but still offering the hope of a sweetener that has few potential side effects (some people are intolerant to agavins) and no negative impact on blood sugar levels.

It should be noted that this was a trial on mice, and was funded by a food company and a company making agave products - but that doesn't necessarily mean that the research is dubious.

A really interesting story - but almost entirely hidden by the baloney about tequila being 'good for you.'


Saturday 4 July 2015

Balancing hormones

Thanks to reader Yuka for pointing out the wide range of products that are advertised to 'balance the hormones', particularly targeted at women consumers.

There are some parallels here with attempts to 'boost the immune system' (see page 301 in the book). We aren't talking about a simple system or individual entity that can somehow be put back in balance by taking a supplement.

Hormones comprise a vast range of signalling chemicals produced by various glands in the body to control different functions from digestion to sleep and the reproductive system. Various illnesses result in unusual hormone levels, and require proper medical treatment. But the idea that you can 'balance your hormones' by eating something seems more oriented to the ancient and baseless idea of your body having four humours that need to be kept in balance. There is no good scientific evidence for taking supplements to balance your hormones, nor any clear mechanism by which many recommended supplements could even have an influence on hormone levels.

There are many hormones and many products said to 'balance' them, but this article gives an example of some specific products claiming to be 'bioidentical hormones', recommended by their vendors as alternatives to hormone replacement therapy, and also said to improve quality of life. As the article makes clear (with proper testing to back it up) these products have serious potential problems.

Overall, then, if you suspect you have a hormonal problem, the last thing you want to do is self medicate. See your GP.