Choosing your protein sources

Most of the foods that we think of as protein sources are, in fact, excellent protein sources. This is because the bioavailability (usefulness) of protein in diary, meats, fish, eggs, tofu and products made from these things are all very high. However, the HEALTH value of these protein sources are very different because of how the protein sources are typicalllyprepared and what types of fats are in the protein sources. Protein from red meat and dairy are high in saturated fats, which contributes to many diseases, particularly circulatory diseases. In addition, certain types of meats have a greater frequency of being cooked to the point where they are blackened or are dark brown (when grilling, for example), which increases cancer risk. The healthiest protein sources are either low in fat or are high in unsaturated fat. The healthiest protein sources are therefore soy and fish. But there are potential risk with extremely large amounts of soy intake (high manganese intake negatively impacts neurological development in the developing child and the estrogen-like impact of isoflavones may increase breast cancer risk when soy is consumed in very large amounts), as well as with fish intake (due to mercury content), so a broad spectrum of a variety of protein sources, none of them over-cooked, is likely the best approach. Note that cheese and peanut butter are both so high in fat content that it would take nearly 2000 Calories of them to get enough protein for the day. Additionally, cheese (which is about 100 Calories for every cubic inch!) is high in saturated fat. Peanut butter, on the other hand, contains mainly unsaturated fat (very healthy!) but has been found to contain a liver-cancer causing agent (a fungus called aspergillus) due to peanuts often being stored too long under humid conditions by companies that make peanut butter (this problem can also occur with other nuts and with soy beans, but peanut butter is made in large amounts in the US so it is the food that has been shown to have the highest levels). BOTTOM LINE: Don't over-emphasize any one protein source in your diet. Eat a variety and don't over-cook (blacken) it.