Lowered serum cholesterol, famine and aggression: a Darwinian hypothesis

Lowering serum cholesterol, which appears to reduce mortality due to cardiovascular disease, may also increase mortality due to violent causes, including homicide, suicide and accidents. In animal research, lowering cholesterol has been linked to increased aggression. These findings suggest a Darwinian interpretation. During evolutionary history a reduction in serum cholesterol was probably invariably associated with famine. In times of famine an increased propensity for aggression may be adaptive as the struggle for survival intensifies. Evidence suggests that lowering cholesterol reduces CNS serotonergic activity and reduced serotonergic activity is known to effect an increase in impulsive, aggressive behavior. Lowered serum cholesterol may then function as an internal signal of threatened starvation, adaptively increasing aggressive behavior through effects on serotonergic activity.