The heritability of pescetarianism and vegetarianism

Genetic factors have a substantial influence on individuals' food preferences, but less is known about their influence on abstinence from eating meat and fish. Here we looked at the influence genetics may have on pescetarianism (not eating meat but eating fish) and vegetarianism (not eating meat and fish) in a Dutch twin sample (N = 8196). We also examined genetic and environmental influences on abstinence from eating beef, pork, poultry, fish or shellfish separately and explored the reasons individuals gave for not eating these types of meat and fish (e.g., disliking, health concerns or beliefs). Abstinence from eating various meats or (shell)fish varied from 5.3% for beef to 46% for shellfish, and 3.7% did not eat meat (1.9% was pescatarian and 1.8% vegetarian). The prevalence of all abstinences was higher in women than men. Genetic factors accounted for 74% and 77% of variation in pescetarianism and vegetarianism, respectively, with the remaining variance accounted for by non-shared environmental influences. Heritability for abstinence from eating beef, pork, poultry, fish or shellfish ranged from 70 to 80%. Abstention from pork was mostly due to health concerns, abstention from poultry, fish and shellfish because of dislike, and abstention from beef because of beliefs (i.e., religion or convictions). Most pescatarians and vegetarians reported beliefs as one of their reason for abstinence (∼75%). Overall, regardless of the fact that different reasons seem to play a role in pescetarianism, vegetarianism and abstinence from eating different meats and fish, genetic factors undergirded all with a similar large magnitude.