Nutraceuticals in immunosenescence

The progressive decline of the immune system with advancing ageing is accompanied by an increased frequency of infectious, autoimmune and neoplastic diseases. Nutraceuticals contain a plethora of compounds able to recover the impaired immunity in ageing. In this framework, deficiency of micronutrients (zinc, copper, iron and selenium) causes a downregulation of the immune response, while their supplementation leads to a recovery of cellular functions. Probiotics, prebiotics and dietary fatty acids, when administered to older people, exhibit anti-inflammatory activities, also improving innate and adaptive immunity as well as reconstituting intestinal microbiota. Finally, polyphenols, in addition to promoting the release of nitric oxide, a potent vasodilator, are also able to exert anti-inflammatory activities, either activating T-regulatory cells or decreasing leukocyte respiratory burst. In in vivo studies polyphenols tend to polarize aged human T lymphocytes toward the Th1 subset. In conclusion, a balanced mix of nutraceuticals in the human diet may result in an advantageous effect in older humans.