Thursday, January 3, 2008

Health Benefits of Fish and Seafood

Fish and other seafood are excellent sources of protein while being relatively low in saturated fats and calories compared to other sources of protein such as fatty meats. This fact alone makes fish a worthwhile addition to one's diet. However, there is an even greater benefit. Fish is one of the richest natural sources of Omega 3 essential fatty acids. Fatty fish such as salmon and trout in particular have high levels of Omega 3 fatty acids.

Many studies have shown that Omega 3 fatty acids provide protection against cardiovascular disease by lowering the levels of bad cholesterol and blood pressure. Other studies have also shown many health benefits ranging from prevention of asthma in children to reduced risk of prostate cancer. Omega 3 also prevents the onset of diseases such as macular degeneration, one of the most common causes of blindness associated with aging. It also helps diabetics maintain better control of blood sugar levels and has been shown to delay the onset of dementia and even Alzheimer’s disease. More recent studies which have focused on its impact on the nervous system have proven benefits in brain function and even in combating depression.

Omega 3 fatty acids do not occur naturally in cells of the body and must therefore be obtained through one's diet. Clearly Omega 3 fatty acids have many health benefits but do they have to come from fish and seafood?

There are 3 main types of omega 3 fatty acids.

ALA - alpha-linolenic acid
EPA - eicosapentaenoic acid and
DHA - docosahexaenoic acid

ALA is found in tofu, soybeans, canola walnuts and flaxseed and oils derived from these products. However, alpha-linolenic acid needs to be converted in the body before it can be absorbed. The body is not very efficient at making this conversion and evidence that this conversion actually takes place is rather tenuous. As a result EPA and DHA become the most significant dietary sources of Omega 3 fatty acids and this is where fish comes into its own. They are one of the most abundant sources of DHA and EPA.

Naturally, too much of anything can have negative effects and eating fish is no exception. One major negative of eating too much fish is the incidental and unintended consumption of contaminants which the fish have picked up in the waterways. While there are a variety of industrial contaminants that are of concern the primary problem is mercury. Due to differences in food sources mercury levels in fish vary depending on whether the fish are farmed or caught in the wild. However, in general larger fish, higher up in the food chain have a greater accumulation of contaminants including mercury. In normal circumstances the levels of mercury in most fish are not likely to cause serious concern to a healthy adult unless consumed to excess. However, infants, children and pregnant women may be more susceptible to harm at lower levels of mercury. It is therefore important to limit the intake of fish by persons in these categories. Mercury could damage the growing nervous systems of young children or the developing fetus and may increase the risk of miscarriage in pregnant women.

The preponderance of evidence however falls squarely in favor of eating fish. The health benefits derived from Omega 3 far outweigh the possible risks from contaminants. If consumed in moderation there is little doubt that fish can be extremely beneficial.

1 comment:

oceana said...

While it’s true that incorporating fish into your diet may have health benefits, it’s important to also remember that mercury in seafood may counteract some of these benefits. Consumers, however, are not always aware of which types of fish combine the benefits of high levels of Omega-3s and low levels of mercury. The FDA advises women of childbearing age and children to avoid eating shark, swordfish, king mackerel, and tilefish completely because these fish tend to have the highest levels of mercury. Other species of fish, however, are full of Omega-3 fatty acids and have much lower mercury levels. The problem is that this information isn’t always available when you need it.

A simple solution to this dilemma would be to post the FDA advice at seafood counters right inside grocery stores. Oceana, a marine conservation organization, is running a campaign to persuade grocers to post this information so shoppers can make informed decisions about their seafood. Several national grocery chains have already made the choice to display this information inside their stores and are now on Oceana’s Green List. You certainly don’t have to give up the seafood you love if you know the facts about mercury. To learn more, please visit our mercury web page.