The passing years of life result in progressive, increased exposure to various diseases. Nutritional intervention, as seen, can increase the mental and physical well-being of the over-65s and boost their immune defenses.
Moreover, a clinical study published in Nutrients on 14.8.20 shows the ability of multi-vitamin and multi-mineral supplements to strengthen the immune system already in the over-55s. (9) A perspective not to be overlooked, in that logic of widespread prevention that should inspire health policies. Also noteworthy in this regard are recent guidelines from ESPEN(European Society for Clinical Nutrition and Metabolism). Brief scientific review.
Immunosenescence and nutrition
Aging is a process that involves numerous molecular and cellular mechanisms which result in so-called ‘immunosenescence’. That is, an alteration in the defenses- innate and adaptive, with reduced response to vaccine action-of the immune system. Which manifests itself in a higher incidence and prevalence of various diseases. The increase in the average age and the elderly, globally, therefore calls for interventions to ensure their better health status. (1)
Nutritional status significantly affects the immune system of the general population, as shared above. All the more so in the over-65s, who are more vulnerable to infection and disease due to recurrent protein and micronutrient deficiencies.
Appropriate nutritional interventions cannot reverse the motion of time but rather improve the immunity and general well-being of the elderly. (2) Especially when they live at home, where nutrition is not subject to planning and supervision by doctors and nutritionists. Psychomotorfrailty (frailty) is in turn often caused, or exacerbated, by malnutrition and underweight. (3)
Microbiota and nutrition
The microbiota is the set of microorganisms that populate the gut and transmit signals that serve to modulate metabolism, immune system, and other functions. Therefore, its composition and functionality are essential to maintaining health status. Particularly in old age, as aging results in alterations in the gastro-intestinal tract and microbiota that reduce immune defenses, with increased risk of infection and increased frailty (4,5).
Some nutritional interventions appear to be effective in modulating the microbiota and immune system, albeit with varying intensity by subject and age. (6) Refers specifically to probiotic and fiber intakes. As well as to ‘phytochemicals,’ that is, vitamins, micronutrients and polyphenols obtained from fruits and vegetables. Their synergistic combination helps regulate immune responses against respiratory viral infections, which includes SARS-CoV-2. (7)
Fig. 1. Key nutrients for the immune system (Salazar, 2017)
Vitamins and minerals for the immune system
Vitamin and mineral deficiency is common in the elderly and can lead to a decline in the immune system. Especially with regard to vitamins C, D, and zinc, the deficiency of which is markedly associated with weakening of the immune system. (8)
The randomized double-blind versus placebo clinical trial (Fantaconte et al., 2020) shows the favorable effect of taking a multivitamin and mineral supplement containing vitamin C, D, and zinc on the immune system as early as age 55 years. Researchers at the Linus Pauling Institute at the University of Oregon observed both improvement in a number of indicators of immune system efficiency and an attenuation in the duration and severity of infections in volunteers receiving this treatment, compared with the control group. (9)
Nutritional recommendations
The Spanish Society of Geriatrics and Gerontology, in a consensus statement on nutrition in the elderly (2015), highlighted the key role of vitamins and minerals, to be provided by supplementation or through a balanced varied diet. (10) With particular regard to β-carotene, vitamin A and B6, which are also involved in improved immune response. As well as an adequate supply of energy, water and macronutrients.
The Spanish experts focus particularly on protein, as an amino acid deficiency can compromise the immune system, as well as muscle mass and strength. As well as on monounsaturated fatty acids (e.g. oleic acid, also useful for the prevention of cardiocoronary diseases), and polyunsaturated (Omega 3, for the health of the mind and immune system).
In turn, the European Society for Clinical Nutrition and Metabolism (ESPEN) published guidelines in 2020 for boosting the immune system in immunocompromised individuals at risk of malnutrition, including the elderly, so as to reduce the incidence of COVID-19. (11) Highlighting the need for their diet to be followed by professionals. In fact, malnutrition can lead to the development of more diseases and increased susceptibility. Among micronutrient supplements, the essential role of vitamins A, B and D is confirmed.
Fig. 2. ESPEN’s suggestions for individuals at risk of SARS-CoV-2 infection in home or intensive care unit (ICU) settings (ESPEN, 2020)
Interim conclusions
Zinc in turn turns out to be crucial in boosting the immune defenses of elderly individuals and helping to counteract Covid-19, but it is important to combine it with other elements such as iron and selenium and vitamins A, C, D, E, B2, B6 and B12 for best effect. (12) Probiotic and antioxidant supplementation in turn appears to be helpful in further boosting the immune system, although the effects on the new coronavirus cannot yet be confirmed. (13)
Malnutrition in the elderly is recognized as a disease. The consequence is a deficiency of energy, amino acids, vitamins, minerals, and other nutrients that do not allow the maintenance of optimal health (also affecting the immune system) and well-being (reduced motility, cognitive problems, etc.) (14) More attention is required to adequately feed these people, ensure their better life expectancy and defense against serious diseases.
For more on how to strengthen the immune system with diet, please refer to the first ebook – People – of the Covid-19 trilogy , the ABCs, at https://www.greatitalianfoodtrade.it/covid-19-abc-volume-i-persone_1
Dario Dongo and Andrea Adelmo Della Penna
Notes
(1) Sadighi Akha (2018). Aging and the immune system: An overview. Journal of Immunological Methods 463:21-26 ,doi:10.1016/j.jim.2018.08.005
(2) Yaqoob (2017). Aging alters the impact of nutrition on immune function. Proceedings of The Nutrition Society 76:347-351, doi:10.1017/S0029665116000781
(3) Beck (2018). Nutritional interventions among old people receiving support at home. Proceedings of The Nutrition Society 77:265-269, doi:10.1017/S002966511700413X
(4) Salazar et al. (2017). Nutrition and the gut microbiome in the elderly. Gut Microbes 8(2):82-97, http://dx.doi.org/10.1080/19490976.2016.1256525
(5) Odamaki et al. (2016) Age-related changes in gut microbiota composition from newborn to centenarian: a cross-sectional study. BMC 16:90, http://dx.doi.org/10.1186/s12866-016-0708-5
(6) Salazar et al. (2019). Age-associated changes in gut microbiome and dietary components related with the immune system in adulthood and old age: A cross-sectional study. Nutrients 11:1765, doi:10.3390/nu11081765
(7) Shinde et al. (2020). Microbiota modulating nutritional approaches to countering the effects of viral respiratory infections including SARS-CoV-2 through promoting metabolic and immune fitness with probiotics and plant bioactives. Microorganisms 8:921, doi:10.3390/microorganisms8060921
(8) Gombart et al. (2020). A review of micronutrients and the immune system-working in harmony to reduce the risk of infection. Nutrients 12:236, doi:10.3390/nu12010236
(9) Fantaconte et al. (2020). The effect of a multivitamin and mineral supplement on immune function in healthy older adults: A double-blind, randomized, controlled trial. Nutrients 12:2447, doi:10.3390/nu12082447
(10) Camina-Martìn et al. (2015). Nutritional status assessment in geriatrics: Consensus declaration by the Spanish Society of Geriatrics and Gerontology Nutrition Work Group. Maturitas 81:414-9, http://dx.doi.org/10.1016/j.maturitas.2015.04.018
(11) ESPEN (2020). ESPEN expert statements and practical guidance for nutritional management of individuals with SARS-CoV-2 infection. Clinical Nutrition 39:1631-1638, https://doi.org/10.1016/j.clnu.2020.03.022
(12) Guiomar de Almeida Brasiel (2020). The key role of zinc in elderly immunity: A possible approach in the COVID-19 crisis. Clinical Nutrition ESPEN 38:65-66, https://doi.org/10.1016/j.clnesp.2020.06.003
(13) Infusino et al. (2020). Diet supplementation, probiotics, and nutraceuticals in SARS-CoV-2 infection: A scoping review. Nutrients 12:1718, doi:10.3390/nu12061718
(14) Rémond et al. (2015) Understanding the gastrointestinal tract of the elderly to develop dietary solutions that prevent malnutrion . Oncotarget 6(16):13858-13898, doi:10.18632/oncotarget.4030
Dario Dongo, lawyer and journalist, PhD in international food law, founder of WIISE (FARE - GIFT - Food Times) and Égalité.
Graduated in Food Technologies and Biotechnologies, qualified food technologist, he follows the research and development area. With particular regard to European research projects (in Horizon 2020, PRIMA) where the FARE division of WIISE Srl, a benefit company, participates.
