Innate Immunity and Inflammation in Ageing: a Key for Understanding Age-Related Diseases
The process of maintaining life for the individual is a constant struggle to preserve his/her integrity. This can come at a price when immunity is involved, namely systemic inflammation. Inflammation is not per se a negative phenomenon: it is the response of the immune system to the invasion of viruses or bacteria and other pathogens. During evolution the human organism was set to live 40 or 50 years; today, however, the immune system must remain active for much a longer time. This very long activity leads to a chronic inflammation that slowly but inexorably damages one or several organs: this is a typical phenomenon linked to ageing and it is considered the major risk factor for age-related chronic diseases. Alzheimer’s disease, atherosclerosis, diabetes and even sarcopenia and cancer, just to mention a few – have an important inflammatory component, though disease progression seems also dependent on the genetic background of individuals.
Licastro F, Candore G, Lio D, Porcellini E, Colonna-Romano G, Franceschi C, Caruso C. Innate immunity and inflammation in ageing: a key for understanding age-related diseases. Immun Ageing. 2005 May 18;2:8. PubMed PMID: 15904534; PubMed Central PMCID: PMC1166571. View Abstract View Full Paper
The Immune System and the Impact of Zinc During Ageing
The trace element zinc is essential for the immune system, and zinc deficiency affects multiple aspects of innate and adaptive immunity. There are remarkable parallels in the immunological changes during aging and zinc deficiency, including a reduction in the activity of the thymus and thymic hormones, a shift of the T helper cell balance toward T helper type 2 cells, decreased response to vaccination, and impaired functions of innate immune cells. Many studies confirm a decline of zinc levels with age. Most of these studies do not classify the majority of elderly as zinc deficient, but even marginal zinc deprivation can affect immune function. Consequently, oral zinc supplementation demonstrates the potential to improve immunity and efficiently down regulates chronic inflammatory responses in the elderly. These data indicate that a wide prevalence of marginal zinc deficiency in elderly people may contribute to immunosenescence.
Haase H, Rink L. The immune system and the impact of zinc during aging. Immun Ageing. 2009 Jun 12;6(1):9. [Epub ahead of print] PubMed PMID: 19523191. View Abstract View Full Paper
The immune system is prone to the same grave misfortunes as any defense system handling weapons: collateral damage that comes with the destruction of the enemy on one’s own territory and friendly fire due to mistaken identity. Whereas the collateral damage is the price we pay for clearance of infections, autoimmunity is a pathological process. Nevertheless, the effector mechanisms involved in both processes are the same. Whether environment can be a cause, a trigger or an amplifier of an autoimmune disease are questions that are being intensively investigated.
