Nutritional deficiency and poor sleep quality are independently associated with cognitive decline in Chinese older adults and demonstrate a significant synergistic interactive effect, underscoring the necessity of implementing integrated interventions that simultaneously address both nutritional and sleep-related factors.
The prevalence of cognitive decline among Chinese older adults aged 65 and above in this study was 13.02%.
Nutritional deficiency was independently associated with significantly higher odds of cognitive decline in older adults.
Poor sleep quality was independently associated with higher odds of cognitive decline in older adults.
Nutritional deficiency and poor sleep quality demonstrated a significant synergistic interactive effect on cognitive decline.
In sex-stratified analysis, the association between poor sleep quality and cognitive decline was significant in women but not in men.
The significant additive interactive effects between nutritional deficiency and poor sleep quality on cognitive decline were observed only in men, not in women.
This research suggests that among Chinese adults aged 65 and older, both poor nutrition and poor sleep quality are each independently linked to a greater likelihood of cognitive decline — meaning worse memory and thinking abilities. Notably, having poor nutrition was associated with more than three-and-a-half times the odds of cognitive decline, while poor sleep was associated with about 17% higher odds. The study analyzed data from over 10,000 older adults and used established statistical methods to identify these relationships. Beyond their individual effects, this research suggests that when poor nutrition and poor sleep occur together, their combined impact on cognitive decline is greater than what would be expected by simply adding their individual effects together — a phenomenon called a synergistic interaction. Roughly 23% of the joint effect of having both risk factors was attributable to this interaction. The study also found sex differences: women showed a significant independent link between poor sleep and cognitive decline, while men did not show this independent link but did show the synergistic interaction between poor sleep and poor nutrition. This research matters because it highlights that addressing nutrition and sleep separately may not be enough — tackling both together could be especially important for protecting brain health in older adults. It points toward the value of integrated public health strategies that simultaneously improve nutritional status and sleep quality in aging populations, rather than treating these as unrelated concerns.
Li L, Xiao S, Yu L, Jiang M, Yuan Y, Yang H. (2026). The independent association and interactive effect of nutritional deficiency and poor sleep quality on cognitive decline in older adults.. BMC public health. https://doi.org/10.1186/s12889-026-26236-4