This research, drawing from initial data of a cohort study focused on a natural population, examined the influence of dietary habits on osteoporosis prevalence within the indigenous population of Sichuan, China. The findings suggest that for women, consuming tea once or twice a week may act as a protective factor against osteoporosis. Similarly, for men, a preference for spicy foods was associated with a reduced risk of osteoporosis and using olive oil as a dietary oil was identified as a risk factor for osteoporosis. No other dietary factors were found to significantly impact the prevalence of osteoporosis.
The initial findings of this study indicate that the prevalence of osteoporosis increases with age, and with the rate of osteoporosis in female patients significantly higher than in males (53.28% vs 3.19%). A systematic review and meta-analysis conducted previously in China reported a osteoporosis rates of 25.41% in females and 15.33% in males[13]. Meanwhile, data from the United States show that the incidence of osteoporosis among elderly women ranges from 13–18%, and among men, from 3–6%[14]. Additionally, a global study on the impact of osteoporosis revealed that, within the same socio-demographic index region and year, women's incidence rate was about 1.5 times higher than that of men[1].While it's clear that women consistently show higher rates of osteoporosis than men, the variability in these findings suggests that multiple factors contribute to its prevalence. The notably high disparity observed in Sichuan could be attributed to its position in one of China's four major basins, which results in reduced sunlight exposure. Moreover, the extensive geographical variations, ethnic diversity, and unique lifestyle patterns may also play a role. The accelerated bone loss in postmenopausal women, further aggravated by conditions leading to more rapid bone depletion compared to men[15], might explain the significantly elevated osteoporosis rates among women in the Sichuan region.
This study explores the association between dietary habits and osteoporosis in the Sichuan area, uncovering that women who drink tea once to twice a week may reduce their risk of developing osteoporosis. These findings are consistent with previous research suggesting, which suggest that moderate tea consumption could act as a preventive strategy against the loss of bone density. A cohort study from Taiwan, China, highlighted that, relative to individuals who don't drink tea, the hazard ratios (HRs) for low tea consumption (1–4 times per week) stood at 0.88 (95% CI 0.80–0.96), and for high consumption (≥ 5 times per week) at 0.87 (95% CI 0.80–0.94)[16]. Similarly, research from Korea showed that, in comparison to those drinking 1–3 cups of green tea daily, non-tea drinkers had an odds ratio (OR) of 1.81 (95% CI 1.20–2.71), while those drinking less than one cup daily had an OR of 1.85 (95% CI 1.23–2.77)[17].The underlying mechanisms for these effects may involve the beneficial influence of active compounds in tea, such as polyphenols and tea extracts, which have been shown to reduce oxidative damage markers in serum and urine[18], boosting the production of bone formation markers, and improving bone turnover rates[19]. Additionally, tea extracts have been shown to possess antioxidant qualities, diminish inflammation[20], and regulate the expression of genes linked to antioxidant activities, thereby fostering osteoblast differentiation and maturity[21], curtailing osteoclast formation[22, 23], and exerting significant phytoestrogen effects[24].
Moreover, our research indicates that among men, a preference for spicy foods may serve as a protective factor against osteoporosis. Presently, the research on the effects of spicy foods or capsaicin on osteoporosis is somewhat sparse. Existing studies have explored capsaicin's role in bone metabolism, including its activation of the TRPV1-CGRP neural pathway to encourage the proliferation, migration, and differentiation of osteoblasts[25], as well as how sensory denervation can lower Prostaglandin E2 levels, alleviating abnormalities in subchondral bone structure, joint degeneration, and associated pain[26]. In one randomized controlled trial focused on capsaicin's role in combating obesity, findings demonstrated that, in comparison to the control group, participants in the capsaicin group showed higher bone density levels[27].These findings pave the way for future research into capsaicin's potential benefits for osteoporosis management and the investigation of dietary patterns related to osteoporosis in the Sichuan region.
A major strength of this study is its pioneering exploration of the dietary factors affecting osteoporosis within Sichuan, China, using data from a natural population cohort. This research lays the groundwork for the development of dietary intervention strategies aimed at reducing osteoporosis in Sichuan and potentially across wider Western China. However, this study's scope, confined to a single area within Sichuan, may limit its ability to fully capture the province's diverse population. Additionally, because the dietary questionnaire contains limited information, which may introduce bias, and thus render the analysis of dietary habits preliminary.