Recently, a population survey shows that vegetables and fruits can promote the improvement of bone health indicators; Correspondingly, the study of controlling hypertension also found that increasing the proportion of vegetables and fruits in the diet can reduce "bone transformation". Within 8 weeks, the intake of vegetables and fruits increased from 3.6 servings to 9.5 servings per day, and it was found that the urinary calcium excretion was greatly reduced. Experts explained that a diet rich in fruits and vegetables can reduce the "acid load".
What is the relationship between reducing acid load and bone health? After human body ingests acidic food, it can lead to the decrease of bicarbonate concentration and PH value, and the decrease of PH value can directly promote the "osteolysis" of osteoclasts. The intake of alkaline foods such as vegetables and fruits can buffer the acid load, increase the PH value, reduce the osteolytic effect of osteoclasts and promote bone calcium deposition.
The experiment further confirmed that osteoclasts and osteoblasts can react with the change of PH value of cell culture medium. A slight decrease in PH value can cause a sudden and sharp increase in osteolysis. In order to maintain the acid-base balance, it is necessary to mobilize the calcium pool in the body and increase the sustained release of alkaline substances.
Various nutrients rich in vegetables and fruits also have protective effects on bone health. The increase of dietary potassium intake is related to the decrease of bone loss. Studies on postmenopausal women show that supplementing potassium bicarbonate 18 days or potassium citrate for 3 months can reduce bone transformation, while potassium organic acid, the main nutrient in vegetables and fruits, can improve the balance. The reason may be that potassium salt can promote bone health by providing anions that can be completely metabolized into carbon dioxide or directly affecting calcium excretion. When high, medium and low sodium salt is ingested, a diet with a large proportion of vegetables and fruits can reduce bone turnover.
The action mechanism of vegetables and fruits can not be completely explained by acid-base balance and the role of potassium in diet. There are other ingredients in vegetables and fruits that affect bone metabolism, such as vitamin K, vitamin C, folic acid and phytoestrogens. Many studies have confirmed that these components can directly or indirectly promote bone calcium absorption or bone health. In addition, a recent study on ovarian rodents also found that there may be some pharmacological compounds in plants that inhibit osteolysis. More interestingly, in one study, the fruit intake of 12-year-old girls was still positively correlated with the heel bone mineral density. According to other studies, fruits and vegetables have different effects on all bone parts, and the bone density of heels (not wrists) is greatly influenced by fruits and vegetables. This may be because the heel is mainly composed of trabecular bone, and the forearm is mainly composed of cortical bone. The metabolic activity of trabecular bone is stronger than cortical bone, and it is more susceptible to nutritional factors.
The promotion of vegetables and fruits to bone health can occur at all ages, which is an advantage that many other nutrients do not have. Studies have shown that fruits and vegetables can promote the bone mass of premenopausal, perimenopausal, postmenopausal and elderly women. Other studies have shown that fruits and vegetables can affect bone loss in men. It is worth mentioning that compared with the eastern diet, the western diet produces significantly more acid, which may be detrimental to bone health.