We performed a systematic review of the prevalence of metabolically healthy obesity (MHO). Medline, Web of Science and EMBASE were searched for original articles from inception to November 2013. Only prospective and cross-sectional studies were included. After screening 478 titles, we selected 55 publications, of which 27 were population-based studies and were used in the narrative synthesis. From the 27 studies, we identified 30 definitions of metabolic health, mainly based on four criteria: blood pressure, high-density lipoprotein cholesterol, triglycerides and plasma glucose. Body mass index ≥30 kg m(-2) was the main indicator used to define obesity (74% of the studies). Overall, MHO prevalence ranged between 6% and 75%. In the studies that stratified the analysis by sex, prevalence was higher in women (seven out of nine studies) and in younger ages (all four studies). One-third of the studies (n = 9) reported the response rate. Of these, four reported a response rate of ≥70% and they showed MHO prevalence estimates between 10% and 51%. The heterogeneity of MHO prevalence estimates described in this paper strengthens calls for the urgent need for a commonly established metabolic health definition.

The prevalence of dementia among older adults from low socioeconomic backgrounds is high. This may be partly due to adverse socioeconomic conditions and consequent failure to compress morbidity into the latter stages of life. The increasing survival of poorer older adults with dementia living in developing countries may lead to a rapid increase in the prevalence of dementia worldwide.

Cataract is an important visual problem of older people and a substantial health care cost in many countries. Most studies investigating risk factors for cataract have been conducted in the United States, and there is less information on the possible role of dietary factors in European populations. We conducted a case-control study to investigate the association of antioxidant vitamins (vitamin C, vitamin E, vitamin A, beta-carotene, alpha-carotene, beta-cryptoxanthin, lycopene, zeaxanthin and lutein) and minerals (zinc and selenium) and risk of cataract in a Mediterranean population. Cases with cataract (343) and 334 age/sex frequency-matched controls aged 55 to 74 y were selected from an ophthalmic outreach clinic in Valencia, Spain. Participants were interviewed about their diet using a Food Frequency Questionnaire, and other information on potential confounders, such as smoking, alcohol, and education. Blood samples were analyzed by a colorimetric method for vitamin C and by reversed-phase HLPC for other blood antioxidants. Blood levels of vitamin C above 49 micromol/L were associated with a 64% reduced odds for cataract (P < 0.0001). Dietary intake of vitamins C, E and selenium were marginally associated with decreased odds (P = 0.09, P = 0.09, P = 0.07, respectively), whereas moderately high levels of blood lycopene (>0.30 micromol/L) were associated with a 46% increased odds of cataract (P = 0.04). Our results strengthen the evidence for a protective role for vitamin C on the aging lens as this effect was seen in a population characterized by high vitamin C intakes.