Low-grade metabolic acidosis is a condition characterized by a slight decrease in blood pH, within the range considered normal, and feeding is one of the main factors that may influence the occurrence of such a condition. The excessive consumption of acid precursor foods (sources of phosphorus and proteins), to the detriment of those precursors of bases (sources of potassium, calcium, and magnesium), leads to acid-base balance volubility. If this condition occurs in a prolonged, chronic way, low-grade metabolic acidosis can become significant and predispose to metabolic imbalances such as kidney stone formation, increased bone resorption, reduced bone mineral density, and the loss of muscle mass, as well as the increased risk of chronic diseases such as type 2 diabetes mellitus, hypertension, and non-alcoholic hepatic steatosis. Considering the increase in the number of studies investigating the influence of diet-induced metabolic acidosis on clinical outcomes, this review gathers the available evidence evaluating the association of this disturbance and metabolic imbalances, as well as related mechanisms. It is necessary to look at the western dietary pattern of most countries and the increasing incidence of non-comunicable diseases for the balance between fruit and vegetable intake and the appropriate supply of protein, mainly from animal sources, so that it does not exceed the daily recommendations.

Phytochemical-rich foods consumption may be a valid nutritional strategy to reduce the risk of weight gain and obesity. The phytochemical index (PI) is a simple and nonspecific method to evaluate the phytochemical intake, defined as the percentage of dietary calories derived from foods rich in phytochemicals. We aimed to conduct a systematic review to evaluate whether high consumption of phytochemical-rich foods evaluated by the PI is associated with lower values of anthropometric measurements. The available literature suggests that the PI seems to be inversely associated with body weight and waist circumference. Analyzing the longitudinal changes in anthropometric variables, individuals with high intake of phytochemicals gained less weight and fat mass when compared to those with lower PI. Our findings suggest that higher PI is associated with lower body mass index, waist circumference and adiposity. Whether the results are a reflex of a lower calorie intake or the anti-obesity properties of phytochemicals remains to be elucidated.

The aim of this commentary was to discuss the last studies regarding the effect of antioxidant vitamins supplementation on oxidative stress in exercise in humans. The inclusion criteria encompassed published studies done in adult males and females between 2006 and 2013. The keywords used in the search engine were: endurance athlete, diet, oxidative stress, physical activity, diet, nutrition, antioxidant, antioxidant status, vitamin C, vitamin A, vitamin E, β-carotene and combinations. Twelve studies were identified and organized according to the methodology and results of supplementation: ergogenic, ergolytic, partial or no difference between groups. The results of these studies showed no effect on physiological parameters and activity of antioxidant enzymes (n = 07), better response of the placebo treatment (ergolytic effect; n = 02), partial results (n = 01) and ergogenic results of antioxidant supplementation (n = 02). It is concluded that supplementation with antioxidant vitamins has controversial effects to oxidative damage induced by endurance exercise. The discordances among the studies are presented and discussed.

Background: Epidemiologic studies have suggested an inverse association between polyphenol intake and the risk of chronic diseases. However, the lack of comprehensive data on population-level intakes, especially in Latin American countries, has limited research on this topic. Objective: We aimed to estimate total and individual polyphenols intakes and determine the major dietary contributors in a representative sample of the Brazilian population. Design: Data were obtained from the Brazilian Household Budget Survey, a cross-sectional survey which included data on individual food intake of 34,003 subjects aged 10 years and over collected using two 24-h dietary records. Polyphenol content of foods was identified using Phenol-Explorer database and Brazilian Food Composition Database. Total and individual polyphenol intake was calculated, as well as the intake distribution by socio-demographic factors. Results: The median and 25-75th percentile of polyphenol intake were 364.3 and 200.9-1008 mg/d. After energy-adjustment, the median and 25-75h percentile of polyphenol intake were 204 and 111.4-542.1 mg/1000 kcal/d. Non-alcoholic beverages and fruits were the major polyphenol suppliers, and coffee and orange juice the main individual food contributors to polyphenol intake. The individual compounds most consumed were isomers of chlorogenic acid (5-caffeoylquinic acid, 4-caffeoylquinic acid, 3-caffeoylquinic acid), naringenin and hesperetin. Conclusions: This study provides, for the first time, data on dietary intake of total and individual polyphenols by Brazilian population and illustrate the low quality of their diet. These results will facilitate the study associations between the polyphenol classes intake and health outcomes, and will also be useful for future dietary intake recommendations.

Background: There is an inverse association between bioactive compounds intake and disease risk. The knowledge of its consumption according to socioeconomic strata is important, which allows identification of potential intervention targets. Objective: To investigate bioactive compounds intake according to income level in Brazilian population. Design: Data were obtained from the Brazilian Household Budget Survey, a cross-sectional survey which included data on individual food intake of 34,003 subjects aged 10 years and over collected using two 24-h dietary records. Polyphenol and carotenoid content of foods was identified using published databases. Total polyphenol and carotenoid intake were determined according to per capita income, as well as main food sources. Results: Total polyphenols and flavonoids intake increased with income level, and subjects with lower income showed higher phenolic acids intake than individuals in highest income (p=0.0001). Total carotenoids and classes intake (with exception to β-cryptoxanthin and zeaxanthin) were higher among subjects in highest income quartile, compared to the lowest quartile (p=0.0001). Coffee was major source to total polyphenols and phenolic acids intake, and orange juice was main flavonoid provider in individuals from all income levels. In the upper income quartile, total carotenoid was supplied mainly by tomato and kale, and fruits had important contribution to carotenoid intake in the lowest income quartile. Conclusions: There is important influence of income level on diet quality regarding intake of foods with bioactive compounds, and individuals with lower income may experience lower quality diets due to less availability of foods with bioactive compounds.