Interesting stuff from Stephen at Whole Health Source on Thai skin being observed as nice, and inferring that the type of fats Thais eat (High saturated – coconut oil and lard) being the predominant reason. Stephen goes on to look at studies into linoleic acid (Omega-6, high amounts found in vegetable oils) and the anti-inflammatory/anti-cancer properties of Omega-3 fatty acids.
Some good stuff at WHS, per usual.
A series of semi-purified diets containing 20% fat by weight, of increasing proportions (0, 5%, 10%, 15% or 20%) of polyunsaturated sunflower oil mixed with hydrogenated saturated cottonseed oil, was fed to groups of Skh:HR-1 hairless mice during induction and promotion of photocarcinogenesis. The photocarcinogenic response was of increasing severity as the polyunsaturated content of the mixed dietary fat was increased, whether measured as tumour incidence, tumour multiplicity, progression of benign tumours to squamous cell carcinoma, or reduced survival… These results suggest that the enhancement of photocarcinogenesis by the dietary polyunsaturated fat component is mediated by an induced predisposition to persistent immunosuppression caused by the chronic UV irradiation, and supports the evidence for an immunological role in dietary fat modulation of photocarcinogenesis in mice.
In other words, UV-induced cancer increased in proportion to the linoleic acid content of the diet, because linoleic acid suppresses the immune system’s cancer-fighting ability! …
It doesn’t end at skin cancer. In animal models, a number of cancers are highly sensitive to the amount of linoleic acid in the diet, including breast cancer. Once again, butter beats margarine and vegetable oils….
Conversely, omega-3 fish oil protects against skin cancer in the hairless mouse, even in large amounts. In another study, not only did fish oil protect against skin cancer, it doubled the amount of time researchers had to expose the mice to UV light to cause sunburn!