Nutrients2015, 7(6), 4139-4153; doi:10.3390/nu7064139 (registering DOI) - published 29 May 2015 Show/Hide Abstract
Abstract: In the last decade, vitamin D was in the spotlight in many fields of research. Despite numerous publications, its influence on reproductive health remains ambiguous. This paper presents an up-to-date review of current knowledge concerning the role of cholecalciferol in human reproduction. It covers various infertility issues, such as polycystic ovary syndrome, endometriosis, myoma-induced infertility, male infertility, premature ovary failure and in vitro fertilization techniques. Vitamin D deficiency, defined as serum concentration of 25-hydroxycalciferol of less than 50 nmol/L, is commonly noted more frequently than only in fertility clinic patients. It is a global trend that is observed in all age groups. The results of original publications dated up to 2015 have been summarized and discussed in a critical manner. Most experts agree that vitamin D supplementation is a necessity, particularly in women suffering from obesity, insulin resistance or small ovarian reserve, as well as in men with oligo- and asthenozoospermia if serum concentration should fall below 50 nmol/L (normal range up to 125 nmol/L). High concentration of vitamin D and its metabolites in decidua during the 1st trimester suggests its important role in the implantation process and a local immunological embryo-protection. On the other hand, evidence-based research did not prove a significant difference so far in ovulation stimulation or embryo development depending on vitamin D level. In one of the publications, it was also found that vitamin D binding protein (VDBP) has a molecular similarity to anti-sperm antibodies, and another one concluded that both low (<50 nmol/L) and high (>125 nmol/L) concentration of vitamin D are associated with decreased number and quality of spermatozoa in semen. Vitamin D is definitely not a Trojan Horse in reproductive health, since there were no adverse effects reported for vitamin D intake of up to 10,000 IU/day, but to proclaim it the Golden Fleece, more evidence is needed.
Nutrients2015, 7(6), 4124-4138; doi:10.3390/nu7064124 (registering DOI) - published 29 May 2015 Show/Hide Abstract
Abstract: Previous studies have reported an association between a more pro-inflammatory diet profile and various chronic metabolic diseases. The Dietary Inflammatory Index (DII) was used to assess the inflammatory potential of nutrients and foods in the context of a dietary pattern. We prospectively examined the association between the DII and the incidence of cardiovascular disease (CVD: myocardial infarction, stroke or cardiovascular death) in the PREDIMED (Prevención con Dieta Mediterránea) study including 7216 high-risk participants. The DII was computed based on a validated 137-item food frequency questionnaire. Multivariate-adjusted hazard ratios (HR) and 95% confidence intervals of CVD risk were computed across quartiles of the DII where the lowest (most anti-inflammatory) quartile is the referent. Risk increased across the quartiles (i.e., with increasing inflammatory potential): HRquartile2= 1.42 (95%CI = 0.97–2.09); HRquartile3= 1.85 (1.27–2.71); and HRquartile4= 1.73 (1.15–2.60). When fit as continuous the multiple-adjusted hazard ratio for each additional standard deviation of the DII was 1.22 (1.06–1.40). Our results provide direct prospective evidence that a pro-inflammatory diet is associated with a higher risk of cardiovascular clinical events.
Nutrients2015, 7(6), 4107-4123; doi:10.3390/nu7064107 - published 27 May 2015 Show/Hide Abstract
Abstract: Blueberry consumption has been shown to have various health benefits in humans. However, little is known about the effect of blueberry consumption on blood pressure, endothelial function and insulin sensitivity in humans. The present study investigated the role of blueberry consumption on modifying blood pressure in subjects with metabolic syndrome. In addition, endothelial function and insulin sensitivity (secondary measurements) were also assessed. A double-blind and placebo-controlled study was conducted in 44 adults (blueberry, n = 23; and placebo, n = 21). They were randomized to receive a blueberry or placebo smoothie twice daily for six weeks. Twenty-four-hour ambulatory blood pressure, endothelial function and insulin sensitivity were assessed pre- and post-intervention. The blood pressure and insulin sensitivity did not differ between the blueberry and placebo groups. However, the mean change in resting endothelial function, expressed as reactive hyperemia index (RHI), was improved significantly more in the group consuming the blueberries versus the placebo group (p = 0.024). Even after adjusting for confounding factors, i.e., the percent body fat and gender, the blueberry group still had a greater improvement in endothelial function when compared to their counterpart (RHI; 0.32 ± 0.13 versus −0.33 ± 0.14; p = 0.0023). In conclusion, daily dietary consumption of blueberries did not improve blood pressure, but improved (i.e., increased) endothelial function over six weeks in subjects with metabolic syndrome.
Nutrients2015, 7(6), 4093-4106; doi:10.3390/nu7064093 - published 27 May 2015 Show/Hide Abstract
Abstract: Most previous studies of parental influences on children’s diets included just a single or a few types of food parenting practices, while parents actually employ multiple types of practices. Our objective was to investigate the clustering of parents regarding food parenting practices and to characterize the clusters in terms of background characteristics and children’s intake of energy-dense snack foods. A sample of Dutch parents of children aged 4–12 was recruited by a research agency to fill out an online questionnaire. A hierarchical cluster analysis (n = 888) was performed, followed by k-means clustering. ANOVAs, ANCOVAs and chi-square tests were used to investigate associations between cluster membership, parental and child background characteristics, as well as children’s intake of energy-dense snack foods. Four distinct patterns were discovered: “high covert control and rewarding”, “low covert control and non-rewarding”, “high involvement and supportive” and “low involvement and indulgent”. The “high involvement and supportive” cluster was found to be most favorable in terms of children’s intake. Several background factors characterized cluster membership. This study expands the current knowledge about parental influences on children’s diets. Interventions should focus on increasing parental involvement in food parenting.
Nutrients2015, 7(6), 4068-4092; doi:10.3390/nu7064068 - published 27 May 2015 Show/Hide Abstract
Abstract: The Mediterranean diet has been proven to be highly effective in the prevention of cardiovascular diseases. Paraoxonase 1 (PON1) has been implicated in the development of those conditions, especially atherosclerosis. The present work describes a systematic review of current evidence supporting the influence of Mediterranean diet and its constituents on this enzyme. Despite the differential response of some genetic polymorphisms, the Mediterranean diet has been shown to exert a protective action on this enzyme. Extra virgin olive oil, the main source of fat, has been particularly effective in increasing PON1 activity, an action that could be due to low saturated fatty acid intake, oleic acid enrichment of phospholipids present in high-density lipoproteins that favor the activity, and increasing hepatic PON1 mRNA and protein expressions induced by minor components present in this oil. Other Mediterranean diet constituents, such as nuts, fruits and vegetables, have been effective in modulating the activity of the enzyme, pomegranate and its compounds being the best characterized items. Ongoing research on compounds isolated from all these natural products, mainly phenolic compounds and carotenoids, indicates that some of them are particularly effective, and this may enhance the use of nutraceuticals and functional foods capable of potentiating PON1 activity.
Nutrients2015, 7(6), 4054-4067; doi:10.3390/nu7064054 - published 27 May 2015 Show/Hide Abstract
Abstract: Decreasing population sodium intake has been identified as a “best buy” for reducing non-communicable disease. The aim of this study was to explore 10-year changes in the sodium content of New Zealand processed foods. Nutrient data for nine key food groups were collected in supermarkets in 2003 (n = 323) and 2013 (n = 885). Mean (SD) and median (min, max) sodium content were calculated by food group, year and label type (private/branded). Paired t-tests explored changes in sodium content for all products available for sale in both years (matched; n = 182). The mean (SD) sodium content of all foods was 436 (263) mg (100 g)−1 in 2003 and 433 (304) mg (100 g)−1 in 2013, with no significant difference in matched products over time (mean (SD) difference, −56 (122) mg (100 g)−1, 12%; p = 0.22). The largest percentage reductions in sodium (for matched products) were observed for Breakfast Cereals (28%; −123 (125) mg (100 g)−1), Canned Spaghetti (15%; −76 (111) mg (100 g)−1) and Bread (14%; −68 (69) mg (100 g)−1). The reduction in sodium was greater for matched private vs. branded foods (−69 vs. −50 mg (100 g)−1, both p < 0.001). There has been modest progress with sodium reduction in some New Zealand food categories over the past 10 years. A renewed focus across the whole food supply is needed if New Zealand is to meet its global commitment to reducing population sodium intake.