The benefits of a diet high in fibre and yogurt have already been established for cardiovascular disease and gastrointestinal cancer. But researchers from Asiaby Vanderbilt University Medical Center wanted to discover the individual and joint associations of dietary fibre and yogurt consumption with lung cancer risk.
The results, published in JAMA Oncology, suggested that those with the highest yogurt and fibre consumption had a 33% reduced lung cancer risk as compared to the group who did not consume yogurt and consumed the least amount of fibre.
"Our study provides strong evidence supporting the U.S. 2015-2020 Dietary Guideline recommending a high fibre and yogurt diet," said senior author Xiao-Ou Shu, MD, Ph.D., MPH, Ingram professor of cancer research, associate director for global health and co-leader of the cancer epidemiology research program at Vanderbilt-Ingram Cancer Centre.
"This inverse association was robust, consistently seen across current, past and never smokers, as well as men, women and individuals with different backgrounds," she added.
Shu said the health benefits seen may be rooted in prebiotic and probiotic properties which may independently or synergistically modulate gut microbiota in a beneficial way.
This pooled analysis included 10 prospective cohorts involving 1 445 850 adults from studies that were conducted in the United States, Europe, and Asia, with data analyses performed between November 2017 and February 2019.
Using harmonised individual participant data, hazard ratios and 95% confidence intervals for lung cancer risk associated with dietary fibre and yogurt intakes were estimated for each cohort by Cox regression and pooled using random-effects meta-analysis.
Participants who had a history of cancer at enrolment or developed any cancer, died, or were lost to follow-up within 2 years after enrolment were excluded.
During a median follow-up of 8.6 years, 18 822 incident lung cancer cases were documented. Both fibre and yogurt intakes were inversely associated with lung cancer risk after adjustment for status and pack-years of smoking and other lung cancer risk factors.
The fibre or yogurt associations with lung cancer were significant in never smokers and were consistently observed across sex, race/ethnicity, and tumour histologic type.
When considered jointly, high yogurt and fibre intake showed more than 30% reduced risk of lung cancer than non-yogurt consumption and low fibre intake which the researchers say suggests potential synergism.
A Lancet review recently linked high intake of fibre and whole grains with a reduced risk of stroke, type 2 diabetes and colorectal cancer.
The review drew on 40 years of observational studies and clinical trials to reveal a 15-30% decrease in all-cause and cardiovascular-related deaths when comparing higher fibre intake to the lowest.
Commissioned by the World Health Organization (WHO), the review also pointed to a 16-24% decrease in coronary heart disease, stroke, type 2 diabetes and colorectal cancer cases resulting from eating fibre-rich foods.
Eating two or more servings of yoghurt could help lower the risk of cardiovascular disease in men and women with high blood pressure by around 20%, according to the researchers.
In 2018, a study by researchers from the Boston University School of Medicine, published in the American Journal of Hypertension, discovered that intake of yoghurt may be linked to cardiovascular risk.
The researchers looked at data from more than 55,000 women and 18,000 men who took part in the Nurses’ Health Study and Health Professionals Follow-Up Study and found that higher intake of yoghurt was associated with lower heart disease risks in both men and women with high blood pressure.
Source: JAMA Oncology
Jae Jeong Yang et al,
“Association of Dietary Fiber and Yogurt Consumption With Lung Cancer Risk”