Wild-Caught vs. Sustainably Farmed Fish

by Jordan Stachel MS, RDNNutrition
Fish on a cutting board.

Fish is a great source of protein and fatty acids; however, it can be difficult to make a health-conscious decision given all the options on the market. Fish has been generally accepted as a healthy component to a well-rounded diet, promoting longevity and an anti-inflammatory state of being. There are several buzzwords and labels surrounding fish and, as a consumer, it can be difficult to understand the differences and to make the most informed choice. This is an important subject, as the differences in type and quality of fish have the ability to affect health status. Health care practitioners often advise clients to choose wild caught fish for its superior health benefits to conventionally farmed fish. While this is sound advice, many fish markets now promote sustainably farmed fish as a healthier alternative to conventionally farmed fish, further complicating an already confusing area of grocery shopping. For the purposes of simplification, this review focuses on wild-caught versus sustainably farmed fish, as these health claims are commonly used and can often cause significant consumer confusion.

Wild-Caught Versus Sustainably-Farmed Fish

When surveyed, the majority of individuals believe that wild caught fish is healthier, tastes better, and is safer for consumption than farmed fish (1). The issue with proving if wild-caught fish is healthier than farmed fish lies within the complexities and variabilities of the specific fish consumed. The species, season of harvest, and composition of diet all play a role in the nutrient composition of the fish consumed. It is speculated that due to this variability, wild caught fish may actually become less desirable than farmed fish in the future, as fisherman may be able to control the presence of toxins and pathogens through the process of production. Wild caught fish cannot be controlled and therefore, the pollutant exposure, toxin level and diets are unknown. Only time will tell if future fisheries are able to eliminate toxins and pathogens from farmed fish.

One study examined the differences between farmed and wild caught salmon, comparing omega-3 levels and carcinogenic (cancer-causing) risk. The findings reported are consistent with the information provided above. Depending on the salmon’s geographical location, its carcinogenic levels differed. Of the areas researched, farmed salmon from Chile and Washington state proved to be the highest in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) per unit of non-carcinogenic risk (2). Overall, wild salmon was seen to be less carcinogenic than farmed salmon when assessing for geographical origin; however, at times, wild caught salmon was lower in EPA and DHA than farmed salmon. This raises the question of what is more important: carcinogenic risk level or fatty acid level? Findings from this research align with the conclusions previously mentioned in that the high contaminant levels in the farmed salmon are thought to be from the feed provided and thus, could be improved and made more beneficial and fit for human consumption if modified in the future. If contaminant levels were lowered, maintaining the current high EPA and DHA levels, farmed fish may be a promising option in the future.

Current research indicates that as far as contaminant levels are concerned, farmed fish are generally higher in contaminants due to the feed and geographical location of these fish (1). Due to the handling processes that occur in large production facilities, fish have direct and indirect exposure to sediment contamination, color additives and antibiotics. However, as mentioned above, not all aquaculture facilities are created equal and some are beginning to utilize more healthful practices that promote consumer wellbeing and that have the potential to potentially become safer than certain wild caught fish due to the higher regulations. While this is generally not the case as of yet, many speculate that this is the direction of the farmed fish industry moving forward.

Nutrient Profile

Fish are a great source of polyunsaturated fatty acids (PUFA), however research suggests that supplementing with fish oil does not provide the same benefits as consuming the fish itself due to the differences in absorption (3). Oily fish, such as salmon, trout, and sardines are better sources of PUFA than leaner fish such as cod, catfish and halibut. When consuming fish, opt for an oily fish so you receive the beneficial fatty acids.

The nutritional profile of fish that is sustainably farmed is able to be more easily manipulated due to the control over the feed. Research shows that while farmed fish are provided with a constant supply of nutrient-dense formulated feed, they typically have higher levels of lipids when compared to wild-caught fish (1). However, the EPA and DHA levels of farmed fish are generally lower when compared to wild caught fish, so total polyunsaturated fatty acid content is relatively equal. Research also indicates that cholesterol and protein levels are similar between wild caught and farmed fish and some vitamin levels may be higher in farmed fish (1). Overall, there is not enough evidence to support that either farmed or wild caught fish is superior in nutrient density to the other and thus, it is the consumer’s responsibility to educate themselves surrounding individual fish consumption.

What’s the Takeaway?

The research surrounding health implications of wild caught versus farmed fish is sparse and is a topic that requires further investigation. This is an ever changing area of research. One day, sustainably farmed fish may indeed be a better option than wild caught fish. However, until such a day when fisheries are able to completely eliminate the presence of toxins and pathogens in the fish they raise, wild caught is likely a safer option because the contaminants are lower, meaning that the risk of toxic exposure from eating wild-caught fish is lower. However, it is still essential to be a well informed consumer, and to choose wild caught fish from areas with low levels of contaminants. For more information about sourcing your seafood, speak with an Amos Institute dietitian.

References:

  1. Hossain MA. Fish as source of n-3 polyunsaturated fatty acids (PUFAs), which one is better- farmed or wild?. Advance Journal of Food Science and Technology. 2011;3:455-466.
  2. Foran JA, Good DH, Carpenter DO, Hamilton MC, Knuth BA, Schwager SJ. Quantitative analysis of the benefits and risks of consuming farmed and wild salmon. The Journal of nutrition. 2005;135(11):2639-2643.
  3. Verbeke W, Sioen I, Pieniak Z, Van Camp J, De Henauw S. Consumer perception versus scientific evidence about health benefits and safety risks from fish consumption. Public Health Nutrition. 2005;8(4):422-429.