Risks and Benefits of Increased Nut Consumption: Cardiovascular Health Benefits Outweigh the Burden of Carcinogenic Effects Attributed to Aflatoxin B1 Exposure

Nuts are rich in nutrients and mounting evidence shows that consumption reduces cardiovascular disease (CVD) incidence. Nuts may also be a major source of aflatoxin B₁, a potent liver carcinogen and the risk/benefit balance is unknown. Based on national statistics and data from the PREDIMED intervention trial, we estimated the potential CVD-reduction if Swedes aged 55-79 consumed 30 g nuts/day, instead of the current national average of five grams per day. We also assessed the reduction in disability-adjusted life years (DALYs) due to myocardial infarction (MI) and stroke. We estimated the aflatoxin B₁ exposure from nuts and calculated the margin of exposure. The approximation that one nanogram aflatoxin B₁/kg body weight/day results in one additional liver cancer case/10 million person-years was used to estimate the number of liver cancer cases. The increased nut consumption scenario prevented more than 7000 CVDs in 2013 (306/100,000 person-years) and contributed to about 55,000 saved DALYs for stroke and 22,000 for MI. The concomitant increase in aflatoxin B₁ exposure caused an estimated zero to three additional cases of liver cancer, corresponding to 159 DALYs spent, emphasizing the associated risks. Increased nut consumption, as part of a varied healthy diet, is warranted even when aflatoxin B₁ exposure is taken into account. However, efforts to reduce aflatoxin exposure from food are essential.