AbstractBackgroundElevated low‐density lipoprotein (LDL) cholesterol is a major contributor to cardiovascular diseases (CVD), which are associated with accelerated cognitive decline. However, recent studies suggest LDL cholesterol to be protective against cognitive decline in the very elderly (>85 years). We investigated associations between serum LDL cholesterol, cerebrovascular function and cognition in community‐dwelling adults aged 50‐80 years, testing for differences between mid‐life (50‐64 years) and older age (65‐80 years).MethodOur cross‐sectional analysis used baseline assessments from 236 older adults (78% female, age: 65±0.5 years, BMI: 28.2±0.3 kg/m2, LDL: 3.7±0.1 mmol/L) participating in two intervention trials investigating effects of vasoactive nutrients on cognition, cerebrovascular function and cardiometabolic biomarkers. None were taking statin medication. Assessments included a battery of 10 neuropsychological tests, transcranial Doppler ultrasound to measure cerebral blood flow velocity (BFV) and cerebrovascular resistance index (CVRi), clinic blood pressure and a fasted venous blood sample to measure serum cholesterol.ResultLDL cholesterol correlated with Framingham CVD risk in mid‐life (R=0.360, P<0.001), but not in older adults (R=‐0.124, P=0.174). In adults aged >65 years (n=122), higher LDL cholesterol correlated with higher mean BFV (R=0.255, P=0.009), lower CVRi (R=‐0.266, P=0.006) and higher overall cognitive performance (R=0.228, P=0.011). The latter two were inversely correlated (R=‐0.154, P=0.024, age adjusted).ConclusionLDL cholesterol appears to have a positive association with cerebrovascular and cognitive functions in advanced age; hence, pharmacologically reducing LDL cholesterol to <2mmol/L as currently recommended might not be beneficial for this age group. Further research is warranted to establish optimal LDL cholesterol levels in the elderly.