It’s well known in natural health circles that commercial sunscreens are loaded with synthetic chemicals, but did you know that even natural sunscreens can be problematic? Natural sunscreens usually don’t have the same high level of man-made chemicals that commercial sunscreens do, but they do contain a lot of unsaturated fats like hemp, sunflower and soy oil.
Why is this a problem you ask? Good question. There is well-researched evidence indicating that polyunsaturated fatty acids (PUFA), in the diet and rubbed onto the skin, have negative health consequences.
Kidney transplantation began in the 1970s. That's when doctors first started encountering tissue rejection. In order to prevent foreign tissue rejection in transplant patients, they began giving them linoleic acid (a PUFA). Linoleic acid suppressed the immune system very effectively which prevented tissue rejection, but it also caused a big increase in cancer and so the treatment was discontinued.
Since then, linoleic acid and the PUFA oils that contain it, have been shown to increase the risk of several types of cancer, including skin cancers. Linoleic acid is the major fatty acid in all polyunsaturated vegetable margarines and cooking oils including soy, sunflower, safflower and corn at about 40-50 percent.
Australian doctors B S and L E Mackie have experience with skin cancers. Their opinion is: “In view of the work of Black and Erickson in mice and our own work in humans, we believe that human subjects who are at high risk of melanomas and other solar-induced forms of skin cancer should be advised to be moderate in their intake of dietary polyunsaturated fats.”
The increase in melanomas over the last 60 years could be a result of increased consumption on PUFA. Researcher Patricia Holborrow states, “Recently, I followed up four families that in 1976 started to use a diet with preferred oils as safflower and sunflower oil and low in salicylates and additives (that interfere with the metabolic pathway of these fats). There had been three cases of cancer resulting in two deaths in these families. The issue is further complicated by dietary factors that are co-factors for the metabolic pathways for the fatty acids and which may in addition favour or have a negative effect on the anticancer or cancer enhancing properties of the various prostaglandins (for example, the negative effects of vitamin E and the positive effects of vitamin C).”
What does all of this have to do with sun exposure? Carcinoma, the type of skin cancer which is clearly caused by sunlight, is relatively harmless and appears only on sun-exposed areas of the body such as the face and hands. Melanoma, often called a skin cancer because it sometimes begins in moles, does not have as close a relationship to sun exposure. Melanoma incidence is significantly increased by the use of oestrogen.
Some researchers argue that the increase in deaths from melanoma during the last 60 years has been caused by increased sunbathing, but there has also been a simultaneous rise in the incidence of prostate cancer over the same time period. The prostate of course gets no exposure to sunlight. What these two cancers have in common is a sensitivity to oestrogen, and we have been increasingly exposed to oestrogen-mimicking chemicals through mainstream personal care products, food, pollution in the environment from dioxins, phenols, chlorinated hydrocarbons, and DDT. It seems likely that these cancers are caused by the oestrogen-mimicking pollutants.
Getting back to PUFA oils, they have been identified as the main component in cells that solar radiation interacts with, causing oxidative damage in the presence of heat and light. High PUFA oils like flax, hemp, grapeseed, and so forth, build up in the body’s tissues – including in the skin – eventually compromising cellular integrity. The precise method by which this happens has to do with the fact that excess unsaturated fat scavenges vitamin E from the tissues. Vitamin E is a potent antioxidant, which inhibits aging and keeps the hormone oestrogen in check. When there is sufficient vitamin E present, oestrogen levels tend be balanced. Too many unsaturated oils in the diet and not enough vitamin E create an imbalance where oestrogen builds in the system, inhibiting proper cellular respiration which leads to faster oxidation. Vitamin E, taken internally or applied to the skin can reduce the damage from the sun caused by the oxidation of unsaturated oils.
Unsaturated fats are also highly correlated with the formation of age pigment, also known as liver spots. Unsaturated fats, plus oestrogen, plus iron, cause age pigment formation in the skin:
“Age pigment, lipofuscin, is produced in oxygen deprivation, apparently from reduced iron which attacks unsaturated fats. It has its own “respiratory” activity, acting as an NADH-oxidase. Melanin is produced by polymerization of amino acids, with copper as the catalyst. With ageing, iron tends to replace copper. Melanin is an antioxidant. Thus, there is a sort of reciprocal relationship between the two types of pigment. A vitamin E deficiency relative to consumption of polyunsaturated fats, and an oestrogen excess, accelerate the formation of lipofuscin.” Ray Peat
Moving away from the topic of sun exposure for a moment, the skin’s natural oil, called sebum, is a mostly saturated fat and is chemically similar to beef tallow. On the other hand, unsaturated fats are not chemically similar to our skin’s natural oil, so it’s no surprise that they can cause clogged pores and other skin problems. Oils applied to the skin are easily metabolized, so applying unsaturated fats to the skin causes the cells to take up calcium. This influx of calcium leads to abnormal keratinization in follicles, encouraging acne and other problems.
Back to sun exposure and premature aging, what can you do to protect your skin from sun damage? The first rule of thumb is to avoid overexposure to ultraviolet rays. Sun exposure is healthy and necessary, but don’t overdo it. The second step is of course to eat right. A diet low in unsaturated fats and higher in protective saturated fats can help you avoid liver spots and wrinkles. Traditional saturated fats like coconut oil and grass-fed tallow should be consumed in the diet and applied to the skin for optimum sun protection.
Saturated fats like coconut oil, which have been eaten for centuries, help to protect the body from sun damage. The protective effect of coconut oil has been demonstrated via research studies, including one conducted with rabbits. The rabbits were fed a diet either high in corn oil or high in coconut oil, and then exposed to ultraviolet light. The effect of the coconut oil diet was increased sun protection, whereas corn oil, (an unsaturated fat) lead to premature wrinkling:
“The rabbit experiment was using internal coconut oil and showing that it protected against skin ageing and sunburn, but if you happen to be sunburned, you can apply coconut oil quickly and get a protective antihistamine effect, because what happens when the sun hits your skin is the excitation quickly spreads to the polyunsaturated fats in your skin cells and creates a progressive after-effect, and the saturated fats can interrupt that spreading of destructive oxidation through the polyunsaturated fats, even right in your skin when you put it on the surface.” Ray Peat
The results of a second study indicated that people who ate a diet high in unsaturated fats tended to look much older than their peers who did not:
“In a study at the University of California, photographs of two groups of people were selected, pairing people of the same age, one who had eaten an unsaturated fat rich diet, the other who had eaten a diet low in unsaturated fats. A panel of judges was asked to sort them by their apparent ages, and the subjects who consumed larger amounts of the unsaturated oils were consistently judged to be older than those who ate less, showing the same age-accelerating effects of the unsaturated oils that were demonstrated by the rabbit experiments.” Ray Peat
So for optimum sun protection, actively avoid unsaturated fats in both your skin care products and in your diet. My preferred sunscreen is Reflect and you might want to check out this new one I just discovered Shade All-Natural Mineral Sunscreen it has only four ingredients and of course it’s low PUFA!