Is wahoo safe to eat when pregnant? (Fishes to avoid)

In this brief guide, we will answer the question “Is wahoo safe to eat when pregnant?”. We also will discuss how mercury concentration can make some fish species not appropriate for pregnant women.

Is wahoo safe to eat when pregnant?

Yes, it is generally safe to include wahoo in your diet during pregnancy. Concerns about mercury exposure have often limited fish consumption for pregnant women. Excessive methylmercury, a form of mercury, can potentially harm neurocognitive development and is present in many fish varieties.

However, empirical evidence suggests that consuming fish in quantities beyond typical intake is necessary for mercury exposure to become a concern. The FDA and EPA have identified seven fish to avoid during pregnancy due to their high mercury levels, namely shark, king mackerel, swordfish, tilefish from the Gulf of Mexico, marlin, orange roughy, and bigeye tuna.

These recommendations are based on the known high levels of mercury in these fish and the limited neurocognitive benefits they offer. Therefore, wahoo is generally considered a safe option for pregnant women. (1)

What is the amount of mercury in wahoo?

On average, wahoo contains about 0.31 ppm of mercury. Generally, fish higher up the food chain tend to have elevated total mercury levels. Fish such as barracuda, escolar, marlin, orange roughy, sablefish, sea bass, shark, swordfish, and specific types of tuna were found to have total mercury levels averaging around or exceeding 0.5 ppm.

Marlin, shark, swordfish, and certain fresh tuna species were reported to have average total mercury levels exceeding 1.0 ppm and should be avoided by pregnant women. (2)

What are fish benefits during pregnancy?

Regularly including fish in your diet during pregnancy has been associated with several positive effects, such as higher birth weight and improved cognitive function in children. It also reduces the likelihood of developing food allergies and eczema. Seafood is a valuable source of essential proteins, vitamins, healthy fats, and trace elements, all of which contribute to a healthier diet.

Consuming seafood has been linked to a decreased risk of various diseases in adults. Notably, the consumption of fatty fish is inversely related to the risk of coronary heart disease and overall mortality. Fish and other seafood are highly nutritious, serving as primary dietary sources of long-chain omega-3 polyunsaturated fatty acids (PUFAs).

Ensuring an adequate intake of these omega-3 PUFAs during pregnancy, especially docosahexaenoic acid (DHA), is crucial for optimal fetal neurodevelopment and may protect against adverse perinatal and long-term outcomes. (3, 4)

What are the health hazards of methylmercury?

The central and peripheral nervous systems are the primary target organs for organic mercury-induced toxicity in humans, the developing fetus is the most sensitive subpopulation. Fetal exposure to methylmercury may affect the developing nervous system with a way lower concentration than in adults.

In cases of short to long-term exposure to exceptionally high levels of methylmercury, the initial neurological effects manifest as non-specific symptoms like tingling sensations, general discomfort, and blurred vision. Subsequently, additional symptoms such as narrowing of the visual field, hearing loss, difficulty speaking, and impaired coordination may develop.

In cases of extremely high exposure, methylmercury poisoning can progress to coma and even result in fatality. When organic mercury, such as methylmercury, is ingested, it is highly absorbable from the gastrointestinal tract and is distributed throughout the body.

Methylmercury can readily penetrate both the blood-brain barrier and the placenta, posing significant risks in terms of neurological and developmental health. (2)

What factors affect mercury accumulation in wahoo?

Mercury accumulation in wahoo is strongly linked to their growth patterns and their position in the food chain. Wahoo are characterized by their relatively short lifespan and rapid growth to a substantial size. While some wahoo have been observed to reach a maximum age of 9.3 years, they have the potential to live up to 10 years.

Their diet, which consists mainly of other fish, combined with their high trophic level, fast growth rate, and the associated high metabolic activity in tropical offshore pelagic environments, can result in comparatively higher mercury concentrations over their relatively brief lifespans.

The levels of mercury found in wahoo, a highly migratory species with a single global population, are likely influenced by regional factors. Large-scale spatial differences in the mercury content of their prey fish species, many of which are known to have relatively high mercury concentrations, can contribute to these variations. (5)

Should wahoo be avoided?

It is generally unnecessary to avoid wahoo because of excessive mercury intake. The risk of mercury overexposure remains low when women consume 2 to 3 servings of fish per week, excluding the seven types of fish that are advised to avoid during pregnancy.

It’s important to note that there are notable neurocognitive advantages associated with consuming fish during pregnancy, with the most compelling evidence pointing to stronger neurocognitive benefits during pregnancy compared to lactation. (1)

Conclusion

In this brief guide, we answered the question “Is wahoo safe to eat when pregnant?”. We also discussed how mercury concentration can make some fish species not appropriate to pregnant women In my perspective as a food scientist wahoo doesn’t pose risks to pregnant women, as 2 to 3 servings of fish per week will not overexpose them to mercury.

References