Dietary Intake of Antioxidant Vitamins and Carotenoids and Risk of Developing Active Tuberculosis in a Prospective Population-Based Cohort Study

Abstract

Antioxidants may protect against oxidative stress, which is associated with tuberculosis (TB) disease. However, direct evidence for a protective association between dietary antioxidants and TB incidence in humans has been lacking. The relationship between intake of antioxidant vitamins (vitamins A, C, D, and E) and individual carotenoids (α-carotene, β-carotene, β-cryptoxanthin, lycopene, and lutein) and TB incidence was examined in the Singapore Chinese Health Study, a prospective cohort study of 63,257 adults aged 45-74 years enrolled during 1993-1998. Baseline intake of these antioxidants was estimated using a validated semiquantitative food frequency questionnaire including questions on use of dietary supplements. After an average of 16.9 years of follow-up, 1,186 incident active TB cases were identified among cohort participants. Compared with the lowest quartile, reduced risk of active TB was observed for the highest quartile of vitamin A intake (hazard ratio = 0.71, 95% confidence interval: 0.59, 0.85; P-trend < 0.01) and β-carotene intake (hazard ratio = 0.76, 95% confidence interval: 0.63, 0.91; P-trend < 0.01), regardless of smoking status. Lower TB risk was seen for vitamin C intake among current smokers only. Other vitamins and carotenoids were not associated with TB risk. These results suggest that vitamin C may reduce TB risk among current smokers by ameliorating oxidative stress, while vitamin A and β-carotene may have additional antimycobacterial properties.

Epidemiological, clinical and mechanistic perspectives of tuberculosis in older people

“…Furthermore, undernourishment has been well shown to be associated with impairment of immune function of the host . Some micronutrients are possibly of importance in protecting against reactivated TB, through anti‐oxidative and other mechanisms . Interestingly, obesity appears to protect against development of TB .…”

“…83 Some micronutrients are possibly of importance in protecting against reactivated TB, through anti-oxidative and other mechanisms. 84,85 Interestingly, obesity appears to protect against development of TB. 86 The relevance of nutritional attention in preventing and managing TB is likely to be highest in geriatric patients, and more research appears warranted.…”

Alcohol drinking and cigarette smoking in relation to risk of active tuberculosis: prospective cohort study

“… 31–33 Hence, in this study that focused on the effect of alcohol consumption on active TB risk, we had included all these previously described factors as covariates in the model. Furthermore, since cigarette smoking is an established and strong risk factor of active TB and we had previously described the differential effects of vitamin C intake on the risk of active TB among smokers and non-smokers, 32 we also examined for possible differential effects of alcohol consumption by smoking status in this study. We were also able to adjust for other factors which could be potential confounders in our analysis.…”

Association of Dietary Micronutrient Intake with Pulmonary Tuberculosis Treatment Failure Rate: ACohort Study

“…Dietary intake is an important factor in modulating the nutritional status of pulmonary tuberculosis patients, and may ultimately affect the outcome of pulmonary tuberculosis treatment. Previous studies reported the association between dietary intake and the infection risk of pulmonary tuberculosis [7][8][9]. However, no effective adjunctive nutritional therapy is available for the treatment of pulmonary tuberculosis treatment.…”