Introduction Infection with M tuberculosis is a necessary but not sufficient condition for development of clinical Tuberculosis (TB). The reasons why some tuberculosis infections progress to clinical TB while most remain latent is not clear. A vegetarian diet has been implicated as a risk factor for tuberculosis among South-Asians in the UK.
Methods To explore whether this is the case in India we analysed data from the nationally representative National Family Health Survey-3 (2006) which collected information on TB and diet, and tested for HIV-1. Tuberculosis was reported by heads of households.
Results Vegetarianism was not a risk factor for tuberculosis among HIV-1 negative married men and women between 15 and 49 (women) or 54 (men) years [OR 0.66 (95% CI 0.49 to 0.89)] while poverty and a history of blood transfusions were. Individuals reporting TB were slightly older than those who did not (31.8 vs 29.4 in women, 39.3 vs 37.2 in men). Vegetarians were also slightly older than non-vegetarians (29.5 vs 29.4 in women, and 37.9 vs 37.0 in men). Except for 11 men and 11 women all individuals with TB were reported to have received treatment for their condition. Urban residence, poverty, higher age, and blood transfusion were positively associated with TB.
Conclusion Vegetarianism appeared to be protective against TB, perhaps due to confounding by unmeasured life-style factors. As it seems unlikely that confounding has masked a strong positive association between vegetarianism and TB, we conclude that vegetarianism is not a risk factor for TB in India.