Vegetarianism and mental health: Evidence from the 1970 British Cohort Study.

Reducing animal product consumption has benefits for population health and the environment. The relationship between vegetarianism and mental health, however, remains poorly understood. This study explores this relationship in a nationally representative cohort in Great Britain. We use data from the 1970 British Cohort Study, which collected information on vegetarianism at age 30 in 2000 (n = 11,204) and psychological distress (PD) at ages 26, 30, 34, 42, and 46–48 in 2016/18. We first developed a statistical adjustment strategy by regressing PD at age 30 on vegetarianism and 14 confounders measured at ages 10 and 26. We then ran multilevel growth curve models, testing whether within-person changes in PD between ages 30 and 46–48 differed by vegetarianism, before and after statistical adjustment. At age 30, 4.5 % of participants reported being vegetarian. In the cross-sectional models at age 30, vegetarians reported more distress compared with non-vegetarians in bivariate analysis (b = 0.30, 95%CI 0.09, 0.52), but this difference disappeared in the fully-adjusted model (b = 0.02, 95%CI −0.17, 0.21). In the longitudinal models between ages 30 and 46/48, there were no differences in within-person changes in psychological distress between vegetarians and non-vegetarians (p =.723). Sensitivity analyses using red meat consumption yielded similar findings. In this British cohort, vegetarianism at age 30 was not associated with changes in psychological distress during mid-adulthood. Since psychological distress in early adulthood predicted vegetarianism at age 30, more studies are needed to disentangle the progression of this relationship over the life-course. • Most studies on vegetarianism and mental health are methodologically weak. • Vegetarianism at age 30 was not associated with subsequent changes in psychological distress in the 1970 British Cohort Study. • Vegetarianism and mental health may still be related during the transition to aduthood. [ABSTRACT FROM AUTHOR]