Good fish/bad fish: a composite benefit-risk by dose curve

Area of Science:

• Public Health Nutrition
• Environmental Health
• Risk Assessment

Background:

• Fish consumption offers health benefits, including prenatal development and cardiovascular health, linked to omega-3 polyunsaturated fatty acids (PUFAs).
• Concerns exist regarding methylmercury and polychlorinated biphenyls (PCBs) in fish, especially for fetal neurodevelopment.
• Most advisories overlook commercial fish, which is the primary source for most people.

Purpose of the Study:

• To analyze methylmercury levels in common commercial fish.
• To develop a compound dose-response curve for fish intake, balancing PUFA benefits against contaminant risks.
• To inform public health advisories on safe and beneficial fish consumption.

Main Methods:

• Analysis of methylmercury concentration in nine common fish species from New Jersey markets.
• Review of existing meta-analyses on fish intake and health outcomes (prenatal and cardiovascular).
• Calculation of fish intake thresholds for benefit and harm based on PUFA content and EPA Reference Dose for methylmercury.

Main Results:

• Weighted average methylmercury concentration in analyzed fish was 0.23 ug/g.
• Benefit thresholds for maternal fish intake were estimated at 8-15 g/day for pregnancy outcomes and 7.5-22.5 g/day for adult cardiovascular health.
• Harm thresholds for methylmercury intake ranged from 27 g/day to 65 g/day, depending on fish contaminant levels.

Conclusions:

• A dose-response framework is proposed to guide "what should I eat" decisions regarding fish consumption.
• Better data on dose-response curves is needed to refine benefit and harm thresholds.
• Socioeconomic factors and displacement of less healthy foods may confound observed benefits of fish consumption.