Diets high in fiber and yogurt are associated with a reduced risk of lung cancer, according to a study published in JAMA Oncology. “Our findings suggest a potential protective role of prebiotics and probiotics against lung carcinogenesis,” the researchers wrote.
Researchers conducted a pooled analysis from 10 prospective cohorts including 1,445,850 adults. The studies were conducted in the United States, Europe, and Asia. Patients with a history of cancer at enrollment or developed any cancer, died, or were lost to follow-up within two years after enrollment were excluded.
The study included 627,988 men (mean age, 57.9 years) and 817,862 women (mean age, 54.8 years). During a median follow-up of 8.6 years, there were 18,822 incident lung cancer cases.
Reduced lung cancer risk with higher fiber and probiotic intake
Fiber and yogurt intake were inversely associated with lung cancer risk after adjusting for smoking status, smoking pack-years, and other lung cancer risk factors (hazard ratio [HR] = 0.83; 95% CI, 0.76-0.91) for the highest versus lowest quintile of fiber intake (HR=0.81; 95% CI, 0.76-0.87).
The fiber or yogurt associations with lung cancer were significant in never-smokers, and this correlation was observed consistently regardless of patient sex, race/ethnicity, and tumor histologic type.
High yogurt and fiber intake resulted in a more than 30% reduction in the risk of lung cancer compared with patients who did not eat yogurt and were in the lowest quintile of fiber intake for the total study population (HR=0.67; 95% CI, 0.61-0.7). This correlation was also observed among never-smokers (HR=0.69; 95% CI, 0.54-0.89), “suggesting potential synergism,” the researchers noted.