Known as "brain food," fish has long been considered a lean protein that should be part of a healthy, balanced diet. That is still true for the most part, but as society changes the environment, the choices become a bit more complicated.
First, decades of research has shown fish - especially oily varieties like salmon, sardines, tuna and mackerel - to be beneficial to human health. In fact, the Mayo Clinic and the American Heart Association recommend eating fish twice a week to decrease the risk of a heart attack. Omega 3 fatty acids are responsible for these recommendations. They are essential acids, meaning necessary but not produced by the body.
Omega 3s in particular are important for neurological and brain development in fetuses and young children. Most widely promoted is the benefit to cardiovascular health by regulating blood clotting and vessel constriction, and some research indicates that it may assist with irregular heartbeat and high blood pressure. These acids can alleviate inflammation throughout the body, and rheumatoid arthritis sufferers specifically seem to respond to Omega 3 treatment. Later studies show Omega 3s reducing depression and bipolar disorder and lowering the risk of Alzheimer's and dementia. Current research is being conducted on the effects of Omega 3s in the treatment of autism and hyperactivity in children.
While there are some side effects of taking in too much Omega 3 (blood thinning, bleeding, stroke and increased levels of LDL cholesterol in diabetics), there is more risk in ingesting harmful chemicals thanks to industrialization. To weigh those risks, one has to look at how the fish grows.
Salmon is one of the most popular commercial species. It's meaty with a pleasant flavor and is full of those beneficial Omega 3s. It became so popular that native, wild caught Atlantic salmon is virtually non-existent. In the United States and Canada, wild salmon are only available in the Pacific Northwest and Alaska, where Coho, Chinook, silver, pink and sockeye begin their lives as eggs along rocky crevices in cold streams and rivers. As they grow, they travel downstream to lakes and possibly the ocean feeding on high protein plankton, algae, plant life and smaller fish as they build lean muscle.
After a few years of living a relatively peaceful existence, and if they haven't been snatched by larger predators like bears and humans, the salmon hear nature calling and set off on their epic, frenzied journey back to their birthplaces to spawn their own offspring and die.
Meanwhile, on the Atlantic coast and in Chile, Japan, Iceland and Europe among other places, commercial fishing has decimated the native fish populations, so companies and countries have developed fish "farms." Fish are hatched and fed in controlled environments then herded to live their lives in the companies' netted bays in the lake, ocean or river. While they may snag some local algae or plant life on occasion, these fish are fed manufactured food with antibiotics. They live in pens with thousands of other fish swimming only a few yards to and fro, waiting for the next feeding.
As far as protein and vitamin content, the wild and farmed fish are similar, but here are the differences.
Wild fish are leaner. They spend their time swimming in search of natural food. In general, wild fish ingest and retain fewer chemicals and contaminants unless they are caught in industrial areas or streams fed by an abundance of agricultural run-off. They are the products of their environments. If they are caught in a pristine mountain stream or lake, they will be healthier fish and healthier for human consumption. Wild caught fish is more expensive.
Farm fish contain more fat because they have less space to swim and eat food that accelerates their growth, bulking them up for sale. The food is often a concentrated mix of ground up lesser fish, meal and hormones rather than plankton and plants. Thus any chemicals in the bodies of the lesser fish are ingested by (and stored in the fat of) the farm fish. Compounding this issue is the fact that many of these farms are located on busy shores of oceans, lakes and rivers. Contaminants from boat traffic, runoff and industrial sites pollute the waters, though, to a certain extent, companies can filter water in the pens. They are mass produced and priced accordingly.
The differences between wild and farmed are much like those of grass-fed, free range livestock and their factory farm counterparts.
Mercury is an issue in all seafood, but especially that of freshwater and coastal areas. It is a naturally occurring element that is in the air, water and earth and never breaks down. Both wild and farmed fish contain mercury, and that is one reason fish is only recommended for human diets twice a week. Women who are pregnant or nursing should check with a doctor, and children should also limit their intake of fish. Toxic levels can cause neurological and developmental damage and disabilities in babies and children. Adults with mercury poisoning will experience fatigue, numbness or tingling in the extremities, loss of memory, weakness, blurred vision and damage to the brain, kidneys or circulatory system.
Local fisherman Ron Preston says that fishermen and those eating fish from area streams, lakes and rivers should always check the Department of Natural Resources sites for Ohio and West Virginia for mercury and contaminant advisories. He has noticed the levels dropping over the past decade because of the decline in manufacturing and mining, but cautions that there are still limits. "The mercury and [contaminants] are still here and will be here for a long time."
According to Preston, most people fish for "native warm water" species here. Particular favorites include largemouth bass in ponds, lakes and streams; smallmouth bass in small streams; the crappie and walleye in Seneca, Piedmont and Salt Fork Lakes; and the channel catfish in the Ohio River. He notes that the state agencies also stock limited numbers of some non-native species like the hybrid striped bass for sport fishing.
The Environmental Defense Fund (EDF) is a non-partisan, nonprofit that keeps a global eye on rescuing, preserving and maintaining ecological balance on land and sea. They work with corporations like McDonald's and Walmart to find environmentally friendly ways to do business. At www.seafood.edf.org, they have published up-to-date lists of the best seafood choices, the worst seafood choices and information on the farmed fish industry.
For instance, the site says that the channel catfish is one of the best choices for eating in the U.S. Though it, like many other warm water fish, contains little in the way of Omega 3s, catfish is a good source of protein, thiamin, B12, selenium, potassium and Vitamin D. When it is farmed, it is in ecologically safe aquaculture ponds and has low mercury levels. Adults and children can eat catfish safely at least four times per month. On the other hand, orange roughy is one of the worst choices because overfishing has depleted the populations, the fishing is unregulated and its mercury levels are elevated. For Atlantic salmon, also a worst choice, the site notes that most of the Atlantic salmon sold in the United States actually comes from Chile or Canada where contamination is high.
Overall, most experts say that the benefits of adding fish to the diet outweigh the risks of contaminants and poisoning. Being aware of what is safe in quality and quantity will enhance both your menu and health.