An evolutionary perspective on the use of betel nut and its effects on health outcomes

The use of psychoactive substances appears to be a consistent behavior throughout human evolutionary history. In contemporary research, this is often attributed to the addictive properties of such substances; an evolutionary perspective offers a more nuanced view. We take the case of betel nut use in Bangladesh to investigate the relationship between betel quid and chronic health outcomes, and to consider local disease ecology and evolutionary explanations for consumption of this psychoactive substance.

We analyzed data from a random sample of 765 women and 499 men in Matlab, Bangladesh, to assess associations between betel quid use and anemia, type 2 diabetes (T2D), hypertension, and inflammation (C-reactive protein, CRP).

Betel quid use was associated with all health outcomes investigated. Use of betel quid was inversely associated with CRP (β = -0.34; P-value = .007). For other outcomes, there were important interactions between betel quid use and gender. A positive association with anemia (aOR: 2.56, CI: 1.62, 4.04) and inverse associations with diabetes and hypertension (aOR: 0.38, CI: 0.22, 0.66; aOR: 0.41, 1.03, respectively) were apparent among men, but not women (anemia: aOR: 1.03, CI: 0.72, 1.49; diabetes: aOR: 0.98, CI: 0.58, 1.65; hypertension: aOR: 1.25, CI: 0.85, 1.85).

Betel quid use was inversely associated with inflammation and, among men, positively associated with anemia and inversely associated with diabetes and hypertension. Together, these findings suggest that the use of betel quid, and possibly other addictive substances, may have been a behavioral adaptation to diverse socioecological challenges.