Could Omega-3 Benefits be Partly Explained by Vitamin E?
For decades, the advice has been to reduce consumption of saturated and trans fatty acids. As evidence accumulated, people were urged to replace solid fats with oils and increase their seafood consumption. The intent was to encourage dietary patterns rich in long-chain monounsaturated and polyunsaturated fatty acids (LCPUFA) and better balance omega-3 to omega-6 fatty acids. What about antioxidants protecting LCPUFA?
In some cases, cooking oils are even fortified with vitamin A to help prevent night blindness (a vitamin A deficiency disease). As oils oxidize, vitamin A also degrades. Andarwulan and colleagues studied the stability and shelf-life of cooking oils sold in Indonesia. Oils had shelf lives ranging between 3 days and 3 months. As oils became rancid, peroxide content increases. Because of health concerns of oxidized cooking oils, the authors propose government action to prevent the sale of highly-oxidized cooking oils.
People forget that cooking oils are more than a source of fatty acids. Cooking oils are sensitive to oxidation. The total tocopherol content of oils is positively associated with their polyunsaturated fatty acid content. Co-localization of antioxidant vitamins with LCPUFA is one of nature’s charms – found in cooking oils, the germ of whole grain seeds, nuts, avocadoes, and LCPUFA-rich cell membranes in our bodies.
Not all oils have the same vitamin E content. Based on dietary intake records and approximate estimates of the vitamin E content of foods, ~90% of the population are not consuming recommended intakes of vitamin E. In reality, our vitamin E intake may be much worse. Why? Because we eat so many fried foods.
Deep-frying does not alter the vitamin E content of the food but some vitamin E is destroyed when oils are heated and as they become oxidized. In 1965, Bunnell and colleagues reported that much of the vitamin E is lost from foods that are deep-fried, frozen and stored. With more and more people bringing prepared and frozen foods home to be heated and consumed, nutritionists are likely overestimating vitamin E intake and α-tocopherol status.
The Samueli Institute just released a series of publications under the title, Nutritional Armor: Omega-3 for the Warrior, emphasizing the importance of elevating omega-3 status. Maybe the military should be examining the impact of vitamin E present in the omega-3 supplements as well.
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