Cognitive decline refers to the gradual decrease in cognitive abilities such as memory, attention, and problem solving. It’s a natural part of aging, but it can also be caused by various medical conditions, such as Alzheimer’s disease and other forms of dementia. It can also be caused by certain lifestyle choices, such as poor diet, lack of physical activity, and social isolation.
Dementia is a debilitating disease that affects a person’s ability to remember, think and make decisions, making it difficult to perform daily activities. It has become one of the leading causes of death and disability among older people worldwide. In China, which has both the largest elderly population and one of the most aging populations, dementia poses significant economic, health and social challenges.
Because dementia is irreversible and effective treatments are limited, prevention and early detection of cognitive decline are crucial. Studies have shown that certain lifestyle factors, such as physical activity, diet, and sleep, can affect cognitive function. However, the impact of dietary sodium and potassium on cognitive function remains poorly understood.
In a prospective study published in the journal KeAi Global Transitions, a group of Chinese researchers examined the impact of dietary sodium, potassium, sodium/potassium ratio, and salt on the cognitive function of a group of elderly people in China. The participants numbered 4,213 and were at least 50 years old at the start. Results are based on cognitive testing and self-reporting by participants.
Association between mean sodium, potassium, sodium/potassium, and salt intake and self-reported memory. Model 1 is adjusted for age, gender, place of residence, area of residence, level of education, employment status, marital status, physical activity levels and tobacco and alcohol consumption habits. Model 2 is adjusted for energy, carbohydrate, protein, and fat intake (adjusted potassium intake additionally for the sodium model and sodium intake for the potassium model) based on Model 1. Model 3 is adjusted for BMI, sleep time, cardiovascular effects and cerebrovascular disease, and cognitive test scores at baseline based on Model 2. Abbreviations: Q1-Q4, quartile 1-quartile 4; OR, odds ratios; CI, confidence interval; and BMI, body mass index. Orange squares indicate a significant association (P < 0.05). 1 credit
The research team found that high sodium intake (>5593.2 mg/day) and high sodium to potassium ratio (>3.8/day) increased the risk of memory impairment in older adults . Conversely, higher potassium intakes (>1653.3 mg/day) were associated with a higher cognitive score; the mean cognitive test score (13.44 at baseline, total score was 27.00) increased by about 1 point when 1000 mg/day of sodium was replaced by an equal intake of potassium.
Additionally, the researchers built on previous studies by demonstrating that the effects of dietary sodium, sodium-to-potassium ratio, and potassium on cognitive function may be mediated by cardiovascular and cerebrovascular disease (CCVD), while the link between salt and impaired cognitive function may be mediated by sleep.
Although China has attempted to limit salt and sodium in people’s diets for more than a decade, the population’s intake remains alarmingly high, exceeding many other countries and the World Health Organization’s recommendation. health of a maximum of 1400 mg/day of sodium for people aged 50 to 79 years. years and 5 g/day of salt. This high salt intake is usually accompanied by insufficient potassium intake (1499.0 mg/day in this study versus the Chinese recommended level of 3600 mg/day).
The study results also support previous findings that the dietary sodium to potassium ratio may provide a better measure of the impact of these elements on cognitive function, rather than looking at separate sodium or potassium values.
Corresponding author Ai Zhao adds, “Based on our findings, it is reasonable to suggest that decreasing sodium intake and appropriately increasing potassium intake are beneficial for cognitive function. Given our results and the nutritional situation of the Chinese, it will be important for future studies to focus on determining the optimal ratio of dietary sodium to potassium in the elderly. Moreover, the development of strategies to improve the sodium/potassium ratio in the Chinese diet should be a priority.
Reference: “Association of dietary sodium, potassium, sodium/potassium, and salt with objective and subjective cognitive function in the elderly in China: a prospective cohort study” by Xiaona Na, Menglu Xi, Yiguo Zhou, Jiaqi Yang , Jian Zhang, Yuandi Xi, Yucheng Yang, Haibing Yang and Ai Zhao, November 3, 2022, Global Transitions.
DOI: 10.1016/j.glt.2022.10.002
The study was funded by the Sanming Project of Medicine.