This is a great post from Stephan at Whole Health Source detailing some differences in people who consume high amounts of saturated fats like coconut oil and animal fats versus polyunsaturated fats (particularly omega 6 fats from vegetable oil). Definately worth your time reading.
People who eat predominantly traditional fats like butter and coconut oil usually have nice skin. It’s smoother, rosier and it ages more gracefully than the skin of a person who eats industrial fats like soy and corn oil. Coconut is the predominant fat in the traditional Thai diet. Coconut fat is about 87% saturated, far more than any animal fat*. Coconut oil and butter are very low in omega-6 linoleic acid, while industrial vegetable oils and margarine contain a lot of it.
I saw a great movie last week called “The Betrayal”, about a family of Lao refugees that immigrated to the U.S. in the late 1970s. The director followed the family for 23 years as they tried to carve out a life for themselves in Brooklyn. The main fats in the traditional Lao diet are lard and coconut milk. The mother of the family was a nice looking woman when she left Laos. She was thin and had great skin and teeth, despite having delivered half a dozen children at that point. After 23 years in the U.S., she was overweight and her skin was colorless and pasty. At the end of the movie, they return to Laos to visit their family there. The woman’s mother was still alive. She was nearly 100 years old and looked younger than her daughter.
Well that’s a pretty story, but let’s hit the science. There’s a mouse model of skin cancer called the Skh:HR-1 hairless mouse. When exposed to UV rays and/or topical carcinogens, these mice develop skin cancer just like humans (especially fair-skinned humans). Researchers have been studying the factors that determine their susceptibility to skin cancer, and fat is a dominant one. Specifically, their susceptibility to skin cancer is determined by the amount of linoleic acid in the diet.
In 1994, Drs. Cope and Reeve published a study using hairless mice in which they put groups of mice on two different diets (Cope, R. B. & Reeve, V. E. (1994) Photochem. Photobiol. 59: 24 S). The first diet contained 20% margarine; the second was identical but contained 20% butter. Mice eating margarine developed significantly more skin tumors when they were exposed to UV light or a combination of UV and a topical carcinogen. Researchers have known this for a long time. Here’s a quote from a review published in 1987:
Nearly 50 years ago the first reports appeared that cast suspicion on lipids, or peroxidative products thereof, as being involved in the expression of actinically induced cancer. Whereas numerous studies have implicated lipids as potentiators of specific chemical-induced carcinogenesis, only recently has the involvement of these dietary constituents in photocarcinogenesis been substantiated. It has now been demonstrated that both level of dietary lipid intake and degree of lipid saturation have pronounced effects on photoinduced skin cancer, with increasing levels of unsaturated fat intake enhancing cancer expression. The level of intake of these lipids is also manifested in the level of epidermal lipid peroxidation.