A new analysis of 1.4 million adults from the United States, Europe and Asia reveals that adhering to a high-fiber and -yogurt diet is linked to a lower risk of lung cancer, reports VUMC Reporter of Vanderbilt University Medical Center.

For the investigation, published in JAMA Oncology, participants were divided into five groups based on fiber and yogurt consumption. Those with the highest amount of fiber and yogurt consumption had a 33% lower risk of lung cancer in comparison with those who consumed the least amount of both foods. Those who ate large amounts of yogurt averaged about a half a cup a day. While eating high-fiber foods and eating yogurt regularly were each associated with reduced cancer risk, those who included both kinds of foods in their diets saw the greatest reduction in their risk, according to Medpage Today.

“Our study provides strong evidence supporting the U.S. 2015–2020 Dietary Guidelines recommending a high fiber and yogurt diet,” said senior author Xiao-Ou Shu, MD, PhD, MPH, Ingram Professor of Cancer Research at Vanderbilt University, associate director for Global Health and coleader of the Cancer Epidemiology Research Program at Vanderbilt-Ingram Cancer Center. “This inverse association was robust, consistently seen across current, past and never smokers, as well as men, women and individuals with different backgrounds.”

According to those guidelines, foods with high fiber levels include legumes and beans—for example, navy beans, chickpeas and lentils; high-fiber ready-to-eat cereal and whole grains; fruits and vegetables; and nuts and seeds. Fat-free and low-fat yogurt is recommended.

Shu hypothesizes that the prebiotic and probiotic properties of such a diet may modulate gut bacteria in a positive way. Fiber, the indigestible part of plant-based foods, is a prebiotic—it provides beneficial gut bacteria with the raw ingredients they need to thrive. Yogurt with active cultures is a probiotic—it directly supplies potentially beneficial bacteria to the gut. Those bacteria, collectively known as the gut microbiome, are of emerging interest both for cancer prevention and treatment (see “The Microbiome Frontier”).

For related prevention coverage, read “Can Mushrooms Lower Prostate Cancer Risk?” and “Whole Grains Linked to a Reduced Risk of Liver Cancer.”