Does cardiovascular disease cause Alzheimer’s disease? There is no definitive answer to this question yet. However, there is good circumstantial evidence that heart and vascular risk factors are associated with memory loss and Alzheimer’s disease.

Studies have been consistent in showing an association of cardiovascular disease with impaired cognitive function and with Alzheimer’s disease. But whether this is a result of common risk factors or whether cardiovascular disease directly influences the pathology of Alzheimer’s disease is not clear.

One relatively strong risk factor for both Alzheimer’s disease and for heart disease is having the E4 form of the Apolipoprotein gene. We discussed this last week and the link here may be that E4 influences cholesterol and hence adds to cardiovascular disease. The other strongly related cardiovascular risk factor that is associated with Alzheimer’s disease is type 2 diabetes. Diabetes often causes vascular damage. Additionally, high levels of insulin may increase the risk of cognitive impairment.

Weaker links exist between cognitive decline, hypertension and high cholesterol. The relationship to hypertension is very complex with high blood pressure in middle age being correlated with increased risk of Alzheimer’s disease in later life but the association of hypertension in later life is not clear. Findings from studies addressing the effects of treatment with antihypertensive drugs are mixed. In the case of cholesterol, it appears that high low density lipoproteins and low high density lipoproteins may increase the risk of dementia.

Despite much press and considerable marketing, the association of Alzheimer’s disease with inflammation and antioxidant vitamins is not very convincing. Indeed, short term use of vitamin supplements (less than 10 years) does not protect against cognitive impairment. However, long term use (more than 15 years) may be neuroprotective.

The one dietary substance that has shown promise as a neuroprotective agent is alcohol. Drinking moderate amounts of alcohol (up to 13 drinks per week) has consistently been associated with better cognitive function. The decreased risk appears to hold for all types of alcohol: beer, wine and liquor. However, there is a clear dose effect here in that there is increased risk of cognitive decline associated with three or more drinks per day.

The good news here is that lifestyle modifications may decrease cardiovascular disease and, in turn, reduce the risk for or the severity of cognitive decline later in life. The findings from the studies on blood pressure suggest that lifestyle choices in midlife may have a great deal of impact on later cognitive function. But keep in mind that we are discussing overall risk factors and not cause and effect.

There are no guarantees but I am hedging my bet on exercise, eating a heart healthy diet most of the time, drinking some alcohol each week, not smoking, as well as monitoring blood pressure, blood sugars and cholesterol.