Neuroprotective Effects of Apples on Cognition and Alzheimer'S Disease

Consumption of apples is known to reduce risk of some cancers, cardiovascular disease, asthma, and diabetes. Studies over the last decade reviewed herein, demonstrate that apples also provide neuroprotection, to the extent that they can impact hallmarks and some symptoms of Alzheimer's disease (AD). Studies in cell culture and mice demonstrate that supplementation with apple juice provides neuroprotection against multiple factors that accompany aging and contribute to AD, including reducing PS-1 expression, Abeta levels and toxicity, oxidative stress (including that resulting from or exacerbated by Abeta), increasing glutathione, and acetylcholine, compensating for apolipoprotein E deficiency, preventing cognitive decline and fostering organized synaptic activity. Such biochemical markers and hallmarks have not been investigated in the clinic, but an open-label clinical trial with 21 institutionalized individuals with moderate to severe AD demonstrate that consumption of two 4oz glasses of apple juice daily for I month did not alter cognitive performance but reduced behavioural and psychotic symptoms associated with dementia by 27 percent (p<0.01) with the largest changes in anxiety, agitation and delusion. These latter findings suggest that apple juice may be a useful supplement, perhaps to augment pharmacological approaches, for attenuating the decline in mood accompanies the progression of AD.