Higher Niacin Intake Lowers Glaucoma Risk, Especially Among Women 

Higher niacin intake is associated with a lower risk of developing glaucoma, especially among women, according to a cross-sectional study published in the Journal of Glaucoma. In the 2005-2008 National Health and Nutrition Examination Survey (NHANES) population, each additional 1 mg of dietary niacin intake is associated with 6% lower adjusted odds of glaucoma overall, and 11% lower adjusted odds of glaucoma for women, according to the report. 

The weighted study population included 5371 adults (109,734,124 weighted) of the 2005-2008 NHANES, of whom 55 (1.0%) had glaucoma. The mean age of the participants was 59.4 years, 49.8% were women, and the most common race/ethnicity was non-Hispanic White, representing 53.8% of the study population. The primary exposure of interest was dietary niacin intake and the study outcome of interest was glaucoma as defined by regraded disc images.

The researchers found that each 1 mg of increased niacin is associated with 6% lower odds of glaucoma (adjusted odds ratio [aOR]=0.94, 95% CI=0.90, 0.98). 

According to the sex stratified analyses, each 1 mg higher dietary niacin intake was associated with 11% lower odds of glaucoma among women (fully adjusted OR = 0.89, 95% CI = 0.80, 0.99), but no equivalent association was seen among men (fully adjusted OR = 0.96, 95% CI = 0.91, 1.02). 

When niacin intake was assessed as a binary variable, the fully adjusted model revealed a significant association between higher amounts of niacin intake and lower glaucoma odds among women (fully adjusted OR = 0.35, 95% CI = 0.14, 0.90), but not among men (fully adjusted OR =1.12, 95% CI = 0.32, 2.31). 

“With regard to niacin’s potential role in glaucoma pathogenesis, Williams et al provide a hypothesis using mouse models,” according to the researchers. “Most recently, there have been human studies investigating the use of high-dose nicotinamide as a tertiary preventive agent to induce short-term vision improvement in patients with glaucoma.” 

Study limitations include its observational nature, possibility of an inaccurate diagnosis of glaucoma, failure to provide information on glaucoma subtype, and failure to establish causality regarding the association between niacin intake and glaucoma.