The omega-3 and omega-6-rich oils from flax and borage respectively also led to a decrease in skin roughness and so-called skin scaling, according to findings published in the British Journal of Nutrition.
Growing awareness of the link between diet and health, and by extension physical appearance, means that many consumers are receptive to the concept of 'beauty from within'.
There is a growing body of science focusing on the potential benefits of nutrients to boost skin health from within, with lutein, lycopene and superoxide dismutase (SOD) having been reported to improve skin health. The same researchers behind the new study previously reported that flavanol-rich chocolate may protect against skin reddening (Journal of Nutrition, Vol 136, pp 1565-1569).
The researchers, led by Wilhelm Stahl from the Heinrich-Heine University in Dusseldorf, recruited 45 non-smoking, healthy women between the ages of 18 and 65 and randomly assigned them to one of three groups. Two groups received daily supplements of flaxseed oil or borage oil (2.2 grams of total fatty acids), while a third received medium-chain fatty acids as the placebo.
Skin irritation was achieved using nicotinate applied to the skin. This would induce inflammation and reddening of the skin, said the researchers.
Fatty acid profiles
According to analysis of the oils, flaxseed consisted predominantly of the omega-3 fatty acid alpha-linolenic acid (ALA), but some omega-6 and monounsaturated oleic acid were present.
Borage oil consisted predominantly of the omega-6 fatty acids gamma-linolenic acid (GLA) and linoleic acid (LA), while oleic acid was also present in relatively high amounts.
After six and 12 weeks of supplementation with flaxseed, an increase in blood levels of ALA was observed, while increases in GLA were recorded in the group receiving borage oil.
Following nicotinate treatment, the researchers noted a significant decrease in reddening of the skin in the flaxseed and borage oil groups of 45 and 35 per cent, respectively, compared to baseline values. No differences were recorded in the placebo group.
Moreover, blood flow to the in skin also decreased in the oil groups
Measurements of water loss from the skin showed that the oil supplements were associated with decreases of about 10 per cent after six weeks, with only the flaxseed oil group showing further decreases at the end of 12 weeks (25 per cent).
The roughness and scaling – dry peeling skin – was also decreased significantly after 12 weeks of flaxseed and borage oil supplementation, with no differences in the placebo group.
The researchers did not perform a specific mechanistic study, but suggested various possibilities. These included changes to the membrane and cell structure since fatty acids play a role in cell membrane health. However, no effects were observed for wrinkling, “which results mainly from changes in the molecular structure of extracellular components, and was not affected by any of the treatments,” said the researchers.
Another possibility is the role of the fatty acids in inflammation. “GLA may be elongated to di-homo-gamma-linolenic acid, which is metabolized to PG of the series 1 and to 15-hydroxyeicosatrienoic acid.
“Products of these eicosanoids mediate anti-inflammatory and anti-proliferative effects. However, ALA cannot be metabolized to anti-inflammatory eicosanoids in tissues lacking desaturases. Thus, other mechanisms are likely operative.”
The other researchers involved in the trial were affiliated with the University of Witten-Herdecke in Germany and France’s Laboratoire Oenobiol.
Source: British Journal of NutritionPublished online ahead of print, First View article, doi: 10.1017/S0007114508020321“Intervention with flaxseed and borage oil supplements modulates skin condition in women”Authors: S. De Spirt, W. Stahl, H. Tronnier, H. Sies, M. Bejot, J.-M. Maurette, U. Heinrich