Vitamin E and infectious diseases in the aged

Han, Sung Nim; Meydani, Simin Nikbin

doi:10.1017/s0029665199000919

Cited by 34 publications

(15 citation statements)

References 72 publications

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“…Vitamin E supplementation in old mice resulted in significantly lower viral titers on 2, 5, and 7 days postinfection, and a significant inverse correlation was observed between hepatic vitamin E levels and lung viral titers [107,121]. Han et al [108] showed that vitamin E supplementation of old mice infected with influenza significantly increased production of IL-2 and IFN-␥ but had no effect on IL-4 production.…”

Section: Mechanistic Studies For the Direct Effect Of Vitamin E On T mentioning

confidence: 99%

Age-associated changes in immune and inflammatory responses: impact of vitamin E intervention

Meydani

2008

Journal of Leukocyte Biology

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158

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Aging is associated with dysregulated immune and inflammatory responses. Declining T cell function is the most significant and best-characterized feature of immunosenescence. Intrinsic changes within T cells and extrinsic factors contribute to the age-associated decline in T cell function. T cell defect seen in aging involves multiple stages from early receptor activation events to clonal expansion. Among extrinsic factors, increased production of T cell-suppressive factor PGE(2) by macrophages (Mphi) is most recognized. Vitamin E reverses an age-associated defect in T cells, particularly naïve T cells. This effect of vitamin E is also reflected in a reduced rate of upper respiratory tract infection in the elderly and enhanced clearance of influenza infection in a rodent model. The T cell-enhancing effect of vitamin E is accomplished via its direct effect on T cells and indirectly by inhibiting PGE(2) production in Mphi. Up-regulated inflammation with aging has attracted increasing attention as a result of its implications in the pathogenesis of diseases. Increased PGE(2) production in old Mphi is a result of increased cyclooxygenase 2 (COX-2) expression, leading to higher COX enzyme activity, which in turn, is associated with the ceramide-induced up-regulation of NF-kappaB. Similar to Mphi, adipocytes from old mice have a higher expression of COX-2 as well as inflammatory cytokines IL-1beta, IL-6, and TNF-alpha, which might also be related to elevated levels of ceramide and NF-kappaB activation. This review will discuss the above age-related immune and inflammatory changes and the effect of vitamin E as nutritional intervention with a focus on the work conducted in our laboratory.

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Section: Mechanistic Studies For the Direct Effect Of Vitamin E On T mentioning

confidence: 99%

Age-associated changes in immune and inflammatory responses: impact of vitamin E intervention

Meydani

2008

Journal of Leukocyte Biology

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158

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“…Clearly, the use of more effective vaccine strategies is needed and is likely to have a major impact on morbidity and mortality of respiratory tract infections in the elderly. Fuente et al, 1998;Enioutina et al, 2000;Moriguchi and Moruga, 2000), likely on the basis of antioxidant properties, and vitamin E has been shown to significantly reduce influenza virus titers in aged mice (Han and Meydani, 1999). Caloric restriction, a significant modulator of the aging process in laboratory animals, also appears to attenuate age-associated immunosenescence (Pahlavani and Richardson, 1996).…”

Section: Discussionmentioning

confidence: 99%

The role of immunity in susceptibility to respiratory infection in the aging lung

Meyer

2001

Respiration Physiology

124

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Respiratory tract infections, particularly pneumonia, are a leading cause of death in persons 65 years or older in both developed and developing countries. Because many attributes of immunity wane with advancing age, the elderly may be more susceptible to respiratory infections, even if they appear to be in good health. A decline in the ability of lymphoid tissues to mount an antigen-specific response (adaptive immunity) to specific microorganisms such as influenza virus or Streptococcus pneumoniae is thought to be an important factor in increasing susceptibility to respiratory tract infection with advancing age. However, abnormalities in innate immunity may also contribute to increased susceptibility to respiratory infections and have been poorly characterized in the elderly. Although changes in immune parameters such as T cell subsets and immunoglobulin concentrations have been observed in respiratory secretions from older healthy individuals compared to younger subjects, the significance of these changes for protective immunity in the lung is unknown. The incidence of pneumonia may be lessened by measures such as optimizing treatment of comorbid conditions, optimizing nutrition, and addressing swallowing disorders. The use of vaccines directed against the influenza virus and S. pneumoniae appears to have made an impact on the degree of morbidity and mortality, and perhaps, the incidence, of community-acquired pneumonia. However, better stimulation of specific immune responses with improved vaccines and more widespread use of these vaccines for protection of elderly individuals are needed.

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“…Vitamin E is perhaps one of the most studied nutrients in relation to its immunoregulatory effect. Results from animal and human studies indicate that vitamin E deficiency impairs both humoral and cell‐mediated immune functions,1,2 while supplementation with vitamin E above the recommended levels has been shown to enhance immune response and to be associated with increased resistance against several pathogens 3,4…”

Section: Introductionmentioning

confidence: 99%

“…Results from animal and human studies indicate that vitamin E deficiency impairs both humoral and cell-mediated immune functions, 1,2 while supplementation with vitamin E above the recommended levels has been shown to enhance immune response and to be associated with increased resistance against several pathogens. 3,4 A recommended dietary allowance (RDA) for vitamin E is currently set at 15 mg/ day of α-tocopherol for adults (ages above 19), 5 increased from the 10 mg recommended in the 10 th edition of the RDA book. 5 The average daily intake of vitamin E in the United States and other Western countries is estimated to be around 10 mg. Certain population groups, such as the elderly, are at greater risk for inadequate dietary intake of vitamin E. 6,7 Ryan et al 6 reported that more than 40% of elderly (65 to 98 years) persons had intakes of vitamin E that were below two-thirds the 1989 RDA.…”

Section: Introductionmentioning

confidence: 99%

Vitamin E and Respiratory Infection in the Elderly

Meydani¹,

Han²,

Hamer³

2004

Annals of the New York Academy of Sciences

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Respiratory infections are prevalent in the elderly, resulting in increased morbidity, mortality, and utilization of health care services. Contributing to the increased incidence of infection with age is the well-described decline in immune response, which has been correlated with patterns of illness in the elderly. For example, there are higher morbidity and mortality from cancer, pneumonia, and post-operative complications in those who have diminished, delayed-type hypersensitivity skin test responses. Nutritional status is an important determinant of immune function. We have shown in double-blind, placebo-controlled trials that vitamin E supplementation significantly improved immune response, including DTH and response to vaccines. Furthermore, subjects receiving vitamin E in the 6-month trial had a 30% lower incidence of infectious diseases. That study, however, was not powered to demonstrate statistical significance, and the infections were self-reported. To overcome these limitations, we conducted a double-blind, placebo-controlled trial to determine the effect of one-year supplementation with 200 IU/day vitamin E on the incidence and duration of respiratory infections in 617 elderly nursing home residents. The results of this clinical trial show that vitamin E supplementation significantly reduces the incidence rate of common colds and the number of subjects who acquire a cold among elderly nursing home residents. A nonsignificant reduction in the duration of colds was also observed. Because of the high rate and more severe morbidity associated with common colds in this age group, these findings have important implications for the well being of the elderly as well as for the economic burden associated with their care.

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Vitamin E and infectious diseases in the aged

Cited by 34 publications

References 72 publications

Age-associated changes in immune and inflammatory responses: impact of vitamin E intervention

Age-associated changes in immune and inflammatory responses: impact of vitamin E intervention

The role of immunity in susceptibility to respiratory infection in the aging lung

Vitamin E and Respiratory Infection in the Elderly

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