BLOG

Based on a large number of epidemiological studies, it is well known that incorporating seafood into your diet on a regular basis has multiple benefits for brain health, heart health and even skin health. Seafood contains high levels of omega-3 fatty acids, protein, minerals, and vitamins like vitamin D making it one of the highest quality protein sources and staples of the Mediterranean Diet.

There are also dozens of different types of fish found at the grocery store from canned, to fresh to frozen, and with so many different options it can be difficult to figure out what the best choice is. When purchasing meat like beef and chicken, most experts suggest that grass-fed and pasture-raised options are best as they most closely mimic the natural environment of livestock and have a higher ratio of omega-3 to omega-6 fatty acids. When it comes to fish, however, is the more “natural” wild caught fish truly better than farm raised fish? In order to answer this question, we must look at the differences from both a human health perspective as well as an environmental perspective as there are many pros and cons to each source.

“…farm raised fish are crammed tightly in their nets or pens, which creates an environment that fosters diseases and parasites.”

However, similar to factory farmed livestock, farm raised fish are crammed tightly in their nets or pens, which creates an environment that fosters diseases and parasites. These diseases or infections can then spread to wild fish populations, as illustrated by the spread of sea lice to juvenile salmon in British Columbia. When such diseases arise in captivity, fish are treated with antibiotics much like animals raised on land. The overuse of antibiotics and disinfectants on a large scale leads to antimicrobial resistance which can pose a health risk for humans as well as lower drug efficacy, and aquaculture (fish farming) directly contributes to this antimicrobial resistance, In addition, we may ingest these antibiotics when we consume fish if they are still present.

“…there is no real way to know whether the fish you purchase was given antibiotics or not, or whether or not it was fed a diet free from pesticides and GMOs.”

There is currently no USDA certification for “organic” farm-raised fish the way that there is for livestock. Consequently, there is no real way to know whether the fish you purchase was given antibiotics or not, or whether or not it was fed a diet free from pesticides and GMOs. Many aquaculture operations also use chemicals like pesticides to try to keep fish healthy, which ends up in our food chain and surrounding water. And when it comes to wild caught fish, there is no control over the diets they consume or the environments they live in, so they also cannot be considered organic.

From a nutritional standpoint, wild caught fish, in particular small fish species which feed on plants in the oceans generally is more nutritious since it tends to be higher in omega-3 fatty acids, meaning it is higher in anti-inflammatory fats than farmed fish. This is due to the fact that farmed fish are typically fed supplemental diets of corn, soy and other vegetable oils that contain virtually no omega-3 fatty acids. Consequently, farmed fish end up containing more omega-6 fatty acids, and a lower ratio of omega-3 to omega-6 fatty acids, which are thought of as pro-inflammatory. Wild caught fish also contain higher amounts of vitamin D, an essential nutrient that we must obtain from the sun and our diets.

“Farm raised fish may contain slightly lower levels than wild caught fish, however when farmed in the ocean, they are exposed to similar levels of pollution.”

One of the other biggest factors when it comes to choosing which seafood to purchase is the level of mercury it contains, as eating fish puts consumers at risk of mercury toxicity. Low levels of mercury in our bodies can cause harm to brain development and cognition, and higher levels can lead to many negative health effects on the nervous system, digestive system, immune system and multiple other organs. While virtually all fish contain some level of mercury due to industrial pollution, it is known that larger fish like swordfish and tuna which are higher up on the food chain, typically contain much higher levels, while small fish contain the lowest. Farm raised fish may contain slightly lower levels than wild caught fish, however when farmed in the ocean, they are exposed to similar levels of pollution. They are also often given ground up fish from the wild as part of their feed, inevitably introducing heavy metals to their system.

“…many large-scale operations use trawls, which are essentially massive nets pulled by boats [and] other sea life often gets caught in the nets including sea turtles and dolphins.”

When it comes to the sustainability of the actual fishing for wild caught seafood, many large-scale operations use trawls, which are essentially massive nets pulled by boats that scoop up large schools of fish or crabs on the seafloor. Unfortunately, since there is not much attention to detail with this method, other sea life often gets caught in the nets including sea turtles and dolphins. Half of the catch can be discarded, which wastes large number of fish and the lives of wildlife in the process. Trawling can also lead to overfishing and consequently destroy ecosystems.

Pole and line caught fishing is a more sustainable method of fishing where fishermen catch fish in a more selective style with hooks and lines. When done right, this method can prevent the destruction of neighboring wildlife and minimizes risk of overfishing. Large scale operations, however, may drag multiple fishing lines or lines with multiple hooks through the water, catching more fish than needed and other unintended animals, which similar to trawling can lead to overfishing and the unnecessary death of other sea life. Additionally, fishing lines may break, entangling birds, fish, and mammals.

Sustainably catching wild, smaller fish, which are not threatened by extinctions come with the biggest benefits in terms of nutrient value (high concentrations of calcium, omega-3 fatty acids and vitamin B-12) with minimal impact on the environment.

“In terms of nutrient density, wild caught fish seem to have the most beneficial fatty acids and vitamins when compared to farm raised fish.”

Based on multiple factors, wild caught fish may not be the best choice across the board as is often believed. In terms of nutrient density, wild caught fish seem to have the most beneficial fatty acid ratio and vitamins when compared to farm raised fish. Consumption of small fatty fish, or of farm raised fish, however, may be a better choice when considering the issues surrounding overfishing as it allows for enough food to be produced to meet the ever-growing needs of our population without the risk of extinction or ecosystem destruction. Wild caught fish tends to also be more expensive and less readily available, which makes accessibility more difficult for some populations. Ultimately, sustainably sourced fish, whether farm raised or wild caught, and mainly coming from small fish such as anchovies, sardines, and mackerels, is an eco-friendly and nutritious addition to a healthy, balanced diet.