Fish and Seafood

Fish and seafood are especially important for cardiovascular health. Fish is generally low in saturated fat, and often times high in omega-3 fatty acids. Fatty acids from fish are the primary source of omega-3 fatty acids. Omega-3s have an anti-inflammatory effect, which is beneficial for preventing and treating heart disease, since atherosclerosis causes inflammation of the blood vessel wall. In 1980, two Danish physicians, Drs. Bang and Dyerberg made a remarkable observation in their research. They noted that Greenland Eskimos have a very low chance of having a heart attack (one-tenth that of the average American), even though they eat a very high-fat diet consisting of whale blubber.

The answer to this puzzle is the fat itself. About 40 percent of the fatty acids in fish are omega-3 polyunsaturated fatty acids that have several heart-healthy benefits. They help keep cells more flexible, and the blood vessels more elastic, which reduces the work of the heart. Additionally, they improve the health of the endothelium, enabling increased production of nitric oxide.

In another study researchers followed more than 20,000 male physicians between 40-80 years of age for 11 years and observed the amount of fish they consumed. The results showed that the physicians who ate fish once a week were 52 percent less likely to die of an irregular heartbeat (cardiac arrhythmia) than those who only ate fish once per month. In addition, a published study reported that eating one serving of salmon per week reduces the chance of a heart attack in half.

Cold-water marine fish have the highest levels of omega-3 fatty acids. These fish include: salmon, tuna, mackerel (also includes a substantial amount of saturated fat; if you have cardiovascular problems, salmon or tuna would be a preferable choice), herring, halibut, and sardines.

Fish and seafood are also heart-healthy choices for low-fat protein. Amino acids are building blocks for protein. L-arginine and L-citrulline are two of these amino acids, and they are especially important for the production of nitric oxide. The best sources of protein from seafood are: tuna, salmon, snapper, swordfish, lobster, shrimp, and cod. Women who are pregnant or lactating should be cautious. Recent studies have shown that some fish are high in mercury and PCBs, which are dangerous to fetuses and young children. They should limit their intake of swordfish, shark, king mackerel, tile fish, and albacore tuna ("chunk light" tuna that comes in a can is alright).

It is sometimes reported that shellfish is dangerously high in cholesterol, and should be avoided by people with high cholesterol levels. However, the LDL content of certain shellfish, like lobster and crab meat, is as low or lower than skinless white meat of chicken or lean beef. If you have preexisting cariovascular problems, it is probably wise to limit your consumption to shrimp and squid, with only 160 mg and 233 mg of LDL cholesterol per serving respectively.

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