Nothing worth doing is easy, and working with natural products is no exception. The way you handle them makes a difference. I have just come across a good example, rosehip oil. When I was growing up rosehip syrup was routinely administered to growing children. I particularly remember a spoonful of it being added to a bowl of rice at school. We used to like it because it was sweet and had a nice flavour. I don’t think I realised at the time that we were being given it not as a treat but because it was particularly rich in vitamins.
The world has moved on and in the developed world most of us are not short of vitamins so rosehip syrup doesn’t have the special place it used to. But rosehip oil is still used in skincare and falls into the narrow category of things that might actually do some good.
The ingredient in rosehip oil that is interesting is the all trans retinoic acid or tretinoin as it is usually called. Tretinoin is a close relative of vitamin A and is used at high levels in pharmaceutical treatments for acne. It is a delicate molecule and needs very careful treatment. It is often handled in yellow light and sometimes stored under argon gas to keep it away from the oxygen in the atmosphere which breaks it down..
Tretinoin at lower levels has been shown to have a real anti-aging effect. However it also has some side effects and is classed as a drug and not a cosmetic, so you can’t buy cosmetics with clinically effective levels of tretinoin in them, and quite rightly. But you can use rosehip oil. This has only a trace of the level of tretinoin you’d get from a pharmaceutical cream. But it is there and although nobody has ever demonstrated a benefit in a proper clinical trial, it doesn’t seem too far fetched to me to imagine that you might see some modest improvement in the signs of ageing if you use rosehip oil on your skin.
Which brings me to my main point. Molecules of the same chemical are identical to one another so the tretinoin in rosehips is just as sensitive as the tretinoin in pharmaceutical premises.
There are three different ways of extracting rosehip oil. You can extract it with solvents, you can cold press it or you can treat it with enzymes and then cold press it. It turns out that the simple cold pressing technique gives you seven times more tretinoin in the final oil than using a solvent. This is far from a trivial difference.
There might well be a difference between organic and non-organic oils as well. Growing plants under different conditions does affect the chemicals they produce. As far as I can tell nobody has measured the difference. I think it is as likely that the organic grades are lower in tretinoin than higher, but without an analysis there is no way of knowing. (More on this in my blog post on essential oils.)
So if you are interested in rosehip oil or products that contain it, do research how it is made.
Journal of the American Academy of Dermatology Volume 15, Issue 4, Part 2 , Pages 836-859, October 1986• Topical tretinoin for photoaged skin Albert M. Kligman, M.D., Ph.D., Gary L. Grove, Ph.D., Ryoji Hirose, M.D., James J. Leyden, M.D.
Journal of the American Oil Chemists’ Society 2006, Volume 83, Issue 9, pp 771-775 Effect of rosehip extraction process on oil and defatted meal physicochemical properties J. Concha, C. Soto, R. Chamy, M. E. Zúñiga