A study links fermented dairy intake to lower mortality
Researchers Fan Zhang and Wenjian Li examined the relationship between fermented dairy consumption and mortality in data from the US National Health and Nutrition Examination Survey. The dataset covered survey cycles from 1999 to 2018 and included 37,366 participants. Their paper was published in Scientific Reports on 15 September 2026.
Dietary intake was measured with a 24-hour dietary recall. The researchers used Cox proportional-hazards models to estimate associations with death from any cause and cardiovascular causes. Kaplan-Meier methods were applied to examine cumulative incidence, while restricted cubic spline models were used to assess whether the relationship changed across intake levels.
Compared with people who did not consume fermented dairy products, consumers had an 18% lower observed risk of death from any cause, with a hazard ratio of 0.82. Their observed risk of cardiovascular death was 20% lower, corresponding to a hazard ratio of 0.80.
The spline analysis indicated a J-shaped, nonlinear association, with the test for nonlinearity producing a P value below 0.001. The estimated turning point was 150 grams of fermented dairy per day. In segmented analyses below that level, each standard-deviation increase in intake was associated with a hazard ratio of 0.96 for all-cause mortality, with P=0.004, and 0.94 for cardiovascular mortality, with P=0.027.
Above 150 grams a day, the segmented analysis found neutral effects for both mortality outcomes. The authors described the results as an association between moderate fermented-dairy intake and lower mortality risk, but explicitly noted that the study design and findings do not permit causal conclusions.
The study was conducted by researchers affiliated with the Affiliated Changzhou Hospital of Xuzhou Medical University and Changzhou Third People’s Hospital in Changzhou, Jiangsu, China. It was funded by the Science and Technology Project of Changzhou under grant CJ20253108. The authors reported no competing interests. The underlying NHANES studies received approval from the National Center for Health Statistics Ethics Review Board, and participants had provided written consent; the Changzhou hospital ethics committee waived additional review for the publicly accessible database and approved the protocol.
