Healthy Brain Ageing and Longevity; the Harmony of Natural Products, APOE Polymorphism, and Melatonin

Healthy ageing and longevity in humans are determined by a combination of genetic and non-genetic factors. To attain longevity, interventions that modulate the interaction between genetic background and the environment and/or lifestyle are essential. Apolipoprotein E (APOE) ε4 allelic variant is recognized as a longevity determinant genetic polymorphism in different ethnic populations, probably through its associations with various pathological conditions such as Alzheimer’s disease (AD) and atherosclerosis. Melatonin, a pineal hormone which decreases with ageing, has various physiological functions in the brain, including regulation of circadian rhythms, clearance of free radicals, inhibition of biomolecular oxidation, suppression of neuroinflammation, and neuroprotection. There is a strong association between sleep quality and memory consolidation, and the diminished production of melatonin which is a physiological regulator of sleep–wake cycle has been demonstrated in ageing diseases including AD. Nutritional factors could have an impact on healthy ageing as diets that are rich in natural products that contain high amounts of plant bioactive molecules including polyphenols, antioxidant vitamins, and melatonin which are promising dietary strategies in preventing chronic diseases and ensuring healthy ageing.