Fig. 1

Interaction between the patient’s and medication’s characteristics potentially influence the cognitive effects of statins. Two separate cholesterol pools in the body are thought to be connected to the risk of Alzheimer’s disease (AD), central and peripheral. The brain penetration of statins has been attributed to different factors linked to BBB crossing (lipophilicity of a statin, chemical structure, molecular weight and size of the molecule, different transporters and their genetic polymorphisms). The structure of the barrier itself additionally influences the permeability of statins and is affected by aging, neurodegenerative processes and possibly, peripheral hypercholesterolemia. The overall cognitive effects of statins are likely a result of their central and peripheral actions and are connected to the time of intervention in life and the pathogenesis of AD. Moreover, an interaction of comorbidities and comedication, a sufficient time of treatment and dosages are important. In midlife, protective effect of statins against AD could be achieved through lowering the metabolic risk of hyperlipidaemia. BBB blood–brain barrier, AD Alzheimer’s disease