Dietary Diversity Linked to Lower Odds of Cognitive Impairment in Chinese Older Adults

In a population-based cross-sectional study of Chinese older adults from the Chinese Longitudinal Healthy Longevity Survey, good dietary diversity was associated with lower odds of cognitive impairment, while good intake of edible mushrooms and algae was associated with additional lower odds only when it occurred alongside a diverse diet. In the adjusted multivariable logistic regression, older adults with good dietary diversity but poor mushroom-and-algae intake had an odds ratio of 0.766, with a 95% confidence interval of 0.672–0.897, compared with the group having both poor dietary diversity and poor mushroom-and-algae intake. The strongest observed association was found among participants who had both good dietary diversity and good intake of edible mushrooms and algae.

Their adjusted odds ratio for cognitive impairment was 0.635, with a 95% confidence interval of 0.525–0.744, relative to the reference group with poor dietary diversity and poor mushroom-and-algae intake. In the unadjusted model, the corresponding odds ratio was 0.466, with a 95% confidence interval of 0.405–0.779. The unadjusted odds ratio for good dietary diversity alone was 0.653, with a 95% confidence interval of 0.591–0.873.

By contrast, good edible mushroom and algae intake without adequate dietary diversity was not significantly associated with cognitive impairment in any adjusted model. The study therefore did not find evidence that mushroom-and-algae intake was associated with lower odds independently of dietary diversity. Instead, its main joint-association analysis indicated that this food-category exposure was associated with lower odds only in the context of good dietary diversity.

The authors characterized dietary diversity as independently associated with lower odds of impairment, while mushroom-and-algae intake was associated with additional lower odds within the context of a diverse diet. The researchers also examined whether the two dietary exposures interacted on multiplicative and additive scales. The multiplicative interaction test was not statistically significant, with P = 0.405.

In the additive assessment using the relative excess risk due to interaction, the estimate was −0.174, with a 95% confidence interval of −0.750 to 0.402. The study also used the attributable proportion and synergy index to assess additive interaction. Technically, the researchers combined descriptive statistics with multivariable logistic regression models.

Participants were divided according to whether they had good or poor dietary diversity and good or poor intake of edible mushrooms and algae, producing four exposure groups. The reference category consisted of participants with poor dietary diversity and poor mushroom-and-algae intake. The regression models adjusted for demographic, lifestyle and health-related covariates, and the interaction assessment used measures intended to evaluate departures from multiplicative and additive interaction models.

The results are based on a cross-sectional analysis, so they describe associations in the sampled population rather than changes in cognition over time or evidence that either dietary exposure prevented cognitive impairment. The available summary does not report the number of participants, the dates of data collection, the instruments used to measure cognition or dietary intake, or the exact thresholds separating good and poor categories. It also does not provide detailed results for the attributable proportion and synergy index, although those measures were included in the additive interaction assessment.

Interpretive caution is particularly important because a cross-sectional design cannot establish whether dietary patterns preceded the presence of cognitive impairment. The study also cannot establish that mushrooms, algae or the combined category caused the observed lower odds. The authors’ conclusion was appropriately framed around joint association: dietary diversity showed an inverse association with cognitive impairment, whereas mushroom-and-algae intake was associated with additional lower odds only within the context of a diverse diet.

On that basis, the findings offer no intervention evidence but provide a detailed population-level association. The clearest pattern was not an independent association for edible mushroom and algae intake, but the combination of that intake with good dietary diversity. The adjusted estimates were 0.766 for good diversity alone and 0.635 for good diversity combined with good mushroom-and-algae intake, while the combination of poor diversity and poor intake formed the reference group.

The authors proposed that public-health strategies may promote overall dietary quality alongside targeted mushroom and algae consumption, particularly for older populations at high risk, but the cross-sectional findings do not demonstrate that such a strategy improves cognition or prevents impairment.

Subject of Research: Joint associations of dietary diversity and edible mushroom and algae intake with cognitive impairment in Chinese older adults

Article Title: Joint effects of dietary diversity and intake of edible mushrooms and algae on cognitive impairment among Chinese older adults: a population-based cross-sectional study

Article References: Yu, Q., Wang, Y., Yu, M., Chen, F., Qi, H., Jiang, M., Wang, X., & Wang, W. (2026). Joint effects of dietary diversity and intake of edible mushrooms and algae on cognitive impairment among Chinese older adults: a population-based cross-sectional study. Frontiers in Nutrition, 13, Article 1960150. https://doi.org/10.3389/fnut.2026.1960150

Image Credits: AI Generated

DOI: 10.3389/fnut.2026.1960150

Keywords: cognitive impairment, dietary diversity, edible mushrooms, algae, older adults, cross-sectional study, nutritional epidemiology, Chinese Longitudinal Healthy Longevity Survey, logistic regression, interaction analysis, Joint, effects