The role of oxidative stress in skeletal health is unclear. The present study investigated whether a high dietary intake of antioxidant nutrients (vitamins C and E, β-carotene, animal-derived vitamin A, retinol equivalents, Zn and Se) is associated with a reduced risk of hip fracture in elderly Chinese. This 1:1 matched case–control study involved 726 elderly Chinese with hip fracture and 726 control subjects, recruited between June 2009 and May 2013. Face-to-face interviews were conducted to determine habitual dietary intakes of the above-mentioned seven nutrients based on a seventy-nine-item FFQ and information on various covariates, and an antioxidant score was calculated. After adjustment for potential covariates, dose-dependent inverse associations were observed between the dietary intake of vitamin C, vitamin E, β-carotene, and Se and antioxidant score and the risk of hip fracture (P for trend ≤ 0·005). The OR of hip fracture for the highest (v. lowest) quartile of intake were 0·39 (95 % CI 0·28, 0·56) for vitamin C, 0·23 (95 % CI 0·16, 0·33) for vitamin E, 0·51 (95 % CI 0·36, 0·73) for β-carotene, 0·43 (95 % CI 0·26, 0·70) for Se and 0·24 (95 % CI 0·17, 0·36) for the antioxidant score. A moderate-to-high dietary intake of retinol equivalents in quartiles 2–4 (v. 1) was found to be associated with a lower risk of hip fracture (OR range: 0·51–0·63, P< 0·05). No significant association was observed between dietary Zn or animal-derived vitamin A intake and hip fracture risk (P for trend >0·20). In conclusion, a higher dietary intake of vitamins C and E, β-carotene, and Se and a moderate-to-high dietary intake of retinol equivalents are associated with a lower risk of hip fracture in elderly Chinese.

The exact mechanisms of the relationship between obesity and cardiovascular events are not yet fully understood; however, oxidative stress may be involved. Thus, the aim of the present study was to evaluate the effects of resveratrol and fish oil on catecholamine-induced mortality in obese rats. To begin with, rats were divided into five groups: (1) lean, (2) obese, (3) obese supplemented with resveratrol, (4) obese supplemented with fish oil and (5) obese supplemented with resveratrol and fish oil (n 18 rats per group), for 2 months. After supplementation, the groups were subdivided as with (n 10) and without (n 8) cardiovascular catecholaminergic stress after isoproterenol (60 mg/kg) injection. At 24 h later, the survival rate was analysed. The obese group showed lower survival rates (10 %) when compared with the lean group (70 %). On the other hand, resveratrol (50 %) and fish oil (40 %) increased the survival rate of obese rats (χ2 test, P= 0·019). Biochemical analyses of the myocardium and aorta revealed that obese rats had higher levels of superoxide and oxidative damage to lipids and protein. This was associated with reduced superoxide dismutase and glutathione peroxidase activity in both the myocardium and aorta. The supplementation increased antioxidant enzyme activities and reduced oxidative damage. We also evaluated the nuclear factor-erythroid 2 p45-related factor 2 (Nrf2)/Kelch-like ECH-associated protein 1 antioxidant pathway. Nrf2 protein levels that were reduced in obese rats were increased by the antioxidant treatment. Taken together, these results showed that resveratrol and fish oil reduce catecholamine-induced mortality in obese rats, partly through the reduction of oxidative stress.

The objective of this review is to provide an overview of nutritional factors involved in cognitive aging and dementia with a focus on nutrients that are also important in neurocognitive development. Several dietary components were targeted, including antioxidant nutrients, dietary fats and B-vitamins. A critical review of the literature on each nutrient group is presented, beginning with laboratory and animal studies of the underlying biological mechanisms, followed by prospective epidemiological studies and randomised clinical trials. The evidence to date is fairly strong for protective associations of vitamin E from food sources, the n-3 fatty acid, DHA, found in fish, a high ratio of polyunsaturated to saturated fats, and vitamin B12 and folate. Attention to the level of nutrient intake is crucial for interpreting the literature and the inconsistencies across studies. Most of the epidemiological studies that observe associations have sufficient numbers of individuals who have both low and adequate nutrient status. Few of the randomised clinical trials are designed to target participants who have low baseline status before randomising to vitamin supplement treatments, and this may have resulted in negative findings. Post-hoc analyses by some of the trials reveal vitamin effects in individuals with low baseline intakes. The field of diet and dementia is a relatively young area of study. Much further work needs to be done to understand dietary determinants of cognitive aging and diseases. Further, these studies must be particularly focused on the levels of nutrient intake or status that confer optimum or suboptimal brain functioning.