Association of medicinal plant consumption with all-cause mortality and cognitive impairment in older adult: A large prospective cohort study

Panax ginseng and other medicinal plants have long been believed to have beneficial effects on health, and there is substantial evidence supporting their mechanisms of action. However, the extent of the health benefits derived from consuming these medicinal plants lacks substantial evidence from large-scale longitudinal population studies. The purpose of this study was to analyze the effect of consuming these medicinal plants on all-cause mortality and cognitive impairment.A population-based cohort study was conducted using the Chinese Longitudinal Healthy Longevity Survey (CLHLS), which was established in 1998 and has been followed up till now. The main exposure was the frequency of eating medicinal plants, including Panax ginseng, Astragalus membranaceus, Lycium barbarum, Angelica sinensis, etc. According to the consumption patterns of medicinal plants, the participants were divided into three groups: frequent use, occasional use, and rarely or never use group. The participants were individually tracked to determine their mortality and cognitive impairment status during the period from 2008 to 2018. Cox proportional hazards regression and competing risk model were used to calculate the hazard ratio (HR) for the association between the use of medicinal plants and the all-cause mortality and cognitive impairment.Among 13,918 participants, the average age was 87.2 ± 11.3 years old, and 70.1% (9,754/13,918) of the participants died during follow-up. The proportion of those frequently using, occasionally using, and rarely using medicinal plants was 8.4%, 20.7%, and 70.8%, respectively. Compared with the rarely or never use group, the occasional and frequent use groups demonstrated significantly lower risks for all-cause mortality, with HR of 0.75 (95% CI: 0.71 - 0.79) and 0.53 (95% CI: 0.49 - 0.58), respectively. The protective effect of medicinal plants against all-cause mortality decreased with increasing age in the subgroup analysis. Additionally, frequent use of medicinal plants reduced the risk of cognitive impairment in the competing risk model (HR = 0.73, 95% CI: 0.60 - 0.87). However, there was no protective effect on cognitive function for those who occasional use medicinal plants.In elderly individuals, occasional and frequent use of medicinal plants was associated with reductions in risk of all-cause mortality, and frequent use of medicinal plants could reduce the risk of cognitive impairment.