Myocardial infarction in relation to mercury and fatty acids from fish: a risk-benefit analysis based on pooled Finnish and Swedish data in men

• Published in: The American journal of clinical nutrition Vol. 96; no. 4; pp. 706 - 713
• Main Authors: Wennberg, Maria, Strömberg, Ulf, Bergdahl, Ingvar A, Jansson, Jan-Håkan, Kauhanen, Jussi, Norberg, Margareta, Salonen, Jukka T, Skerfving, Staffan, Tuomainen, Tomi-Pekka, Vessby, Bengt, Virtanen, Jyrki K
• Format: Journal Article
• Language: English
• Published: Bethesda, MD American Society for Clinical Nutrition 01.10.2012; American Society for Nutrition; American Society for Clinical Nutrition, Inc
• Subjects: Adult; Aged; Animals; Biological and medical sciences; blood serum; Case-Control Studies; clinical nutrition; Cohort Studies; Diet; Fatty Acids, Omega-3 - administration & dosage; Fatty Acids, Omega-3 - blood; Feeding. Feeding behavior; Finland; Fish; fish consumption; Fishes; Food Contamination; Fundamental and applied biological sciences. Psychology; Hair - chemistry; Health Sciences; Heart attacks; Human exposure; Humans; Hälsovetenskap; Logistic Models; Male; Medical and Health Sciences; Medicin och hälsovetenskap; men; Mercury; Mercury - analysis; Mercury Poisoning - etiology; Mercury Poisoning - physiopathology; methylmercury compounds; Methylmercury Compounds - administration & dosage; Methylmercury Compounds - toxicity; Middle Aged; myocardial infarction; Myocardial Infarction - blood; Myocardial Infarction - etiology; Myocardial Infarction - metabolism; Myocardial Infarction - prevention & control; Nutrition and Dietetics; Näringslära; Näringslära och dietkunskap; omega-3 fatty acids; polyunsaturated fatty acids; Prospective Studies; regression analysis; risk; Risk Assessment; risk reduction; risk-benefit analysis; Seafood - adverse effects; Sweden; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Sweden; Finland; Human; Myocardial infarction; Lipids; Cardiovascular disease; Finnish; Pool; Risk analysis; Coronary heart disease; Myocardial disease; Fatty acids; Mercury; Heavy metal
• ISSN: 0002-9165; 1938-3207; 1938-3207
• DOI: 10.3945/ajcn.111.033795

Background: Exposure to methylmercury from fish has been associated with increased risk of myocardial infarction (MI) in some studies. At the same time, marine n−3 (omega-3) PUFAs are an inherent constituent of fish and are regarded as beneficial. To our knowledge, no risk-benefit model on the basis of data on methylmercury, PUFA, and MI risk has yet been presented.Objective: The objective of this study was to describe how exposure to both marine n−3 PUFAs and methylmercury relates to MI risk by using data from Finland and Sweden.Design: We used matched case-control sets from Sweden and Finland that were nested in population-based, prospective cohort studies. We included 361 men with MI from Sweden and 211 men with MI from Finland. MI risk was estimated in a logistic regression model with the amount of mercury in hair (hair-Hg) and concentrations of n−3 PUFAs (EPA and DHA) in serum (S-PUFA) as independent variables.Results: The median hair-Hg was 0.57 μg/g in Swedish and 1.32 μg/g in Finnish control subjects, whereas the percentage of S-PUFA was 4.21% and 3.83%, respectively. In combined analysis, hair-Hg was associated with higher (P = 0.005) and S-PUFA with lower (P = 0.011) MI risk. Our model indicated that even a small change in fish consumption (ie, by increasing S-PUFA by 1%) would prevent 7% of MIs, despite a small increase in mercury exposure. However, at a high hair-Hg, the modeled beneficial effect of PUFA on MI risk was counteracted by methylmercury.Conclusions: Exposure to methylmercury was associated with increased risk of MI, and higher S-PUFA concentrations were associated with decreased risk of MI. Thus, MI risk may be reduced by the consumption of fish high in PUFAs and low in methylmercury.