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Fish oil is consumed in foods or taken as a supplement to prevent or treat a wide range of conditions. Its nutrients also produce a number of cosmetic effects. Fish oil, and particularly the healthful fatty acids found within it, can improve some skin conditions, protect against the sun's damaging rays and even boost hair quality. Some potential benefits of these fatty acids remain yet unproven in humans, despite showing promise in recent animal testing.

Fatty Acids and Hair Care

According to a 2009 article in "Dermatoendocrinology," polyunsaturated fatty acids, such as those found in fish oil, can improve hair quality and density, decrease instances of hair loss and restore an overall hair cycle balance. In a 2004 study published in the "Journal of Biological Chemistry" that was conducted on mice, very-long-chain fatty acids, such as those found in fish oil, were shown to play a critical role in normal hair and skin functioning. While much is unknown about the particulars of fatty acid chain length, the very-long-chain elongase protein known as Elovl3, found throughout the body, contributes to improved hair function on the cellular level. A lack of Elovl3 in testing led to hair sparseness, an inability to repel water and lipid imbalances.

Omega-3s and Sun Protection

A study published in a 2003 edition of "Carcinogenesis" found that beneficial omega-3 fatty acids contained in fish oil have properties that protect skin from the sun's damaging effects. One fatty acid in particular, eicosapentaenoic acid, or EPA, reduced incidences of sunburn and ultraviolet radiation-induced skin breaks, even showing protection at the DNA level, when added to participants' diets. Researchers suggest long-term supplementation of EPA could therefore be linked to greater protection against sun damage and skin cancer. According to the Skin Cancer Foundation, sun damage is responsible for up to 90 percent of changes to the skin over time, including brown spots, dryness, wrinkles and a leathery appearance.

Getting the Most Out of Fish Oil

Simply popping a fish oil supplement here or there won't do you much good. In the study published in "Carcinogenesis," researchers propose long-term dietary modification, incorporating fish oil's fatty acids, in order to see any sort of major effect. Fish oil, which has been rated for its effectiveness in treating a variety of skin conditions, is also considered possibly effective for treating the effects of the skin condition psoriasis when taken intravenously. The Centers for Disease Control and Prevention recommends replacing saturated and trans fats with monounsaturated fats and polyunsaturated fats, including those found in fish and fish oil.

Sources of Fish Oil

Fish oil can be found both in dietary and supplement form. Some fish have higher amounts of beneficial oils. These fish include mackerel, tuna, salmon, anchovy, sardines, herring and trout. They should be baked or broiled for maximum health effects. Fish oil can also be taken in liquid or capsule form, which occasionally contain other vitamins. Always consult a doctor before starting a new vitamin regimen, as fish oil may in some cases interact with medications or pre-existing health conditions.