Is there a link between dietary phytoestrogens and reproductive health in men? A meta‐analysis of data from the USA and China

The human health implications of exposure to environmental pollutants and food components (e.g. phytoestrogens) that mimic the female hormone 17β‐estradiol (xenoestrogens) are a subject of significant debate. In this study, we use published data on human dietary phytoestrogen intake and sperm concentrations in the USA and China to assess effects on sperm concentration as a marker of male reproductive health. Comparison of the phytoestrogen intake and sperm concentration trends shows that in the USA phytoestrogen intake has increased from 0.8 mg day^?1 in 1993 to 13.7 mg day^?1 in 2005 and sperm concentration is trending down (not statistically significant), whereas in China phytoestrogen intake has decreased from 64.7 mg day^?1 in 1991 to 15.6 mg day^?1 in 2008, and the sperm concentration has increased from 55 × 10⁶ mL^?1 in 1999 to 74 × 10⁶ mL^?1 in 2008. We present this as evidence that phytoestrogen intake via food might, at least in part, be responsible for sperm concentration trends.     

Is there a future for antioxidants in atherogenesis?

Antioxidants, preferentially those of dietary origin, have for a long time been considered to help against diseases that are presumably aggravated by oxidative stress, such as cardiovascular diseases, cancer, and neurodegenerative disorders. The outcome of clinical trials undertaken to corroborate this hypothesis, however, remained largely inconclusive. Evidence is now emerging that some dietary "antioxidants" influence signaling pathways and the expression of genes relevant in atherosclerosis by mechanisms other than antioxidative ones. By concrete examples we show that (1) vitamin E has gene regulatory functions which might be more important than acting as an antioxidant in vivo, (2) selenium itself is not an antioxidant at all, and even not in general when incorporated into glutathione peroxidases, and (3) a moderate oxidative stress is beneficial rather than detrimental since it can induce defense mechanisms counteracting xenobiotic and oxidative stress. Thus, there is only a future for antioxidants in the prevention of any disease if their real mechanism of action is considered and suitable read-outs and biomarkers are established.     

Any link between integrin degradation and water-holding capacity in pork?

In order to investigate a possible relationship between integrin degradation and water-holding capacity (WHC), integrin was quantified using western blot, and water mobility and distribution was measured by proton NMR T(2) relaxometry at 24h postmortem in pork (n=30) with a large variation in WHC (drip loss varying from 2.8% to 11.3%). Regression analyses revealed correlation coefficients of r=-0.32 (P=0.08) and r=0.40 (P=0.03) for the correlations between the content of integrin determined by western blot analysis and WHC determined as either drip loss or by NMR, respectively. Water mobility and distribution was also measured in 18 meat samples upon 7 days of aging, which revealed a correlation (r=0.54) between integrin content determined by western blot analysis 24h postmortem and the mobility of the myofibrillar water (T(21) relaxation time) at day 7. In contrast, no correlation could be established between integrin content 24h postmortem and WHC at day 7 determined by NMR as the amount of extramyofibrillar water (T(22) population) (r=-0.01). In conclusion, both visualisation by CLSM and quantification of integrin by western blot analyses of suggested that a strong link between integrin degradation and WHC in pork is questionable, whereas integrin degradation seems to have impact on the succeeding development in the mobility of the myofibrillar water.     

Is there any difference between the phenolic content of organic and conventional tomato juices?

The present study aims to compare the phenolic and hydrophilic antioxidant profiles of organically and conventionally produced tomato juices. Comparisons of analyses of archived samples from conventional and organic production systems demonstrated statistically higher levels (P < 0.05) of phenolic compounds in organic tomato juices. This increase corresponds not only with increasing amounts of soil organic matter accumulating in organic plots but also with reduced manure application rates once soils in the organic systems had reached equilibrium levels of organic matter. Using principal component analysis, results show that phenolic compounds and hydrophilic antioxidant capacity were responsible for the differentiation between organic and conventional tomato juices. Thus, there appear to be genuine differences in the bioactive components of organic and conventional tomato juices not previously reported.     

Is there a fit in cognitive and sensory evaluation of yogurt? The moderating role of nutrition training

Food selection at a particular occasion is guided by properties of the food itself (sensory or intrinsic properties), but also by the information provided with the food, for example, packaging information (extrinsic properties). We compared preference responses of 71 consumers with a considerable type 2 diabetes risk, who had undergone nutrition counseling in a prevention program, in sensory assessments and product evaluation integrated into Adaptive Conjoint Analysis with the response of a healthy control group (n = 101). Vanilla yogurt, varied in composition (fat content, sugar content, flavor intensity) and packaging information (fat content, sugar content, flavor intensity), was used as stimulus material. Both groups of consumers preferred yogurt with a higher fat content on the basis of sensory evaluation, but rejected products with a higher fat content (10 g/100 g) when this information was available on the package. The degree of rejection was significantly higher for the high risk group. Whereas both groups preferred reduced-sugar yogurt on the basis of declaration, preferences towards the less sweet product were only observed for the high risk group.     

Is there a protease that preferentially cleaves the M-line in partially dehydrated muscle?

When a partially dehydrated muscle fibre bundle (PDM, 65% H(2)O, pH 5.5, at 4 °C) was treated with a supernatant fraction (M-line-cleaving fraction: MCF) of muscle homogenate for 5 hr, the M-lines disappeared. MCF was extracted from rabbit skeletal muscles by homogenization with 15 mM HCl containing 0.5 M NaCl (pH 3.7), fractionated with 25-65% (NH(4))(2)SO(4) and clarified by Sephadex G-75. Rabbit psoas PDM was obtained with an osmotic dehydration sheet and glycerinated. One end of the bisected fibre bundle was incubated with 10 mM Na-acetate (pH 5.5), 1 mM EDTA, 5 mM β-mercaptoethanol (β-MCE), 150 mM KCl, 10 mM NaN(3) with MCF at 25 °C for 5 hr, the muscle being stretched and relaxed several times. The other end was incubated in the same solution, except that MCF was omitted (control). Electron microscopy showed the myofibrils broken down at the M-line in the presence of MCF. The myofilaments were closely packed near the Z-line and flared out at both ends near the centre of the sarcomere (bow-tie shape). Thus, the Z-line is not the only target of proteases and structural decomposition can also occur at the M-line under specific conditions. An M-line cleaving protease may exist in the MCF muscle extract.     

Food Allergens: Is There a Correlation between Stability to Digestion and Allergenicity?

Food allergy is a major health problem in the Western countries, affecting 3–8% of the population. It has not yet been established what makes a dietary protein a food allergen. Several characteristics have been proposed to be shared by food allergens. One of these is resistance to digestion. This paper reviews data from digestibility studies on purified food allergens and evaluates the predictive value of digestibility tests on the allergenic potential. We point out that food allergens do not necessarily resist digestion. We discuss how the choice of in vitro digestibility assay condition and the method used for detection of residual intact protein as well as fragments hereof may greatly influence the outcome as well as the interpretation of results. The finding that digests from food allergens may retain allergenicity, stresses the importance of using immunological assays for evaluating the allergenic potential of food allergen digestion products. Studies assessing the allergenicity of digestion products, by either IgE-binding, elicitation or sensitizing capacity, shows that digestion may abolish, decrease, have no effect, or even increase the allergenicity of food allergens. Therefore, the predictive value of the pepsin resistance test for assessing the allergenic potential of novel proteins can be questioned.     

Acrylamide in a fried potato dish (rösti) from restaurants in Zurich,Switzerland

Rösti, a fried potato product, is a large contributor to acrylamide exposure locally in Switzerland. A survey of 55 dishes prepared by 51 restaurants in the city of Zurich showed that the average rösti contained 702 µg/kg acrylamide. By analysing the content of reducing sugars in the potatoes used for frying, it is shown that with simple measures, the exposure to acrylamide could easily be reduced by factor 2 or more, while even improving the culinary experience. Though rösti is a typical dish in the German-speaking areas in Switzerland, the result may be of general interest for fried potato products which are popular in large areas of Central Europe.     

Boron accumulation and toxicity in hybrid poplar (Populus nigra × euramericana)

Poplars accumulate high B concentrations and are thus used for the phytomanagement of B contaminated soils. Here, we performed pot experiments in which Populus nigra × euramericana were grown on a substrate with B concentrations ranging from 13 to 280 mg kg(-1) as H(3)BO(3). Salix viminalis, Brassica juncea, and Lupinus albus were grown under some growing conditions for comparison. Poplar growth was unaffected at soil B treatment levels up to 93 mg kg(-1). Growth was progressively reduced at levels of 168 and 280 mg kg(-1). None of the other species survived at these substrate B levels. At leaf B concentrations <900 mg kg(-1) only <10% of the poplar leaf area showed signs of toxicity. Neutron radiography revealed that chlorotic leaf tissues had B concentrations of 1000-2000 mg kg(-1), while necrotic tissues had >2000 mg kg(-1). Average B concentrations of up to 3500 mg kg(-1) were found in leaves, while spots within leaves had concentrations >7000 mg kg(-1), showing that B accumulation in leaf tissue continued even after the onset of necrosis. The B accumulation ability of P. nigra × euramericana is associated with B hypertolerance in the living tissue and storage of B in dead leaf tissue.     

Is the accumulation of osmoprotectant the unique mechanism involved in bacterial osmoprotection?

Sucrose, trehalose, maltose, cellobiose, gentiobiose, turanose and palatinose are very unusual osmoprotectants for Sinorhizobium meliloti, because these compounds, unlike other bacterial osmoprotectants, do not accumulate as cytosolic osmolytes in salt-stressed S. meliloti cells. Rather, these compounds were catabolized during early exponential growth, and contributed to enhance the cytosolic levels of the two endogenously-synthesized osmolytes: glutamate and the dipeptide N-acetylglutaminylglutamine amide (NAGGN). Furthermore, all of the disaccharides that acted as powerful osmoprotectants shared the same uptake routes in S. meliloti. Here, we show that these disaccharides, in fact, belong to a new family of non-accumulated sinorhizobial osmoprotectants and that two mechanisms of osmoprotection coexist in S. meliloti.     

Is colour brightness (L-value) a reliable indicator of water-holding capacity in porcine muscle?

A total of 265 pork carcasses representing a broad variation in quality was used to examine the relationship between colour (L-value) and water-holding capacity (WHC) in the longissimus thoracis et lumborum. Thirty-four samples appeared to possess 'normal' reddish pink colour (L-value 52·0-58·0) but had 'unacceptable' WHC (>5·0% drip loss). Conversely, 25 samples were pale in colour (L-value >58·0) but were 'acceptable' in WHC. When muscles were dark (L-value 52·0) the WHC was always acceptable. Some samples were subjected to further analysis. Variations in iron content, haematin content, sarcomere length and degree of soluble protein denaturation failed to explain why brightness and WHC were not more closely related. When L-value and WHC were compared to pH(45) (pH, 45 min post mortem), WHC exhibited a biphasic relationship to pH(45) whereas L-value did not. These results indicate that WHC and brightness are determined by independent pre-rigor biological phenomena, strengthening the argument that brightness is not necessarily a reliable predictor of WHC. Researchers selecting pork for specific investigations, or commercial companies using fresh pork for either further processing or for retail, should not rely on colour brightness alone to insure that other quality properties such as WHC and firmness will also be acceptable.     

Healthy is (not) tasty? Implicit and explicit associations between food healthiness and tastiness in primary school-aged children and parents with a lower socioeconomic position

Many people implicitly (automatically) believe that unhealthy foods are tastier than healthy foods, even when they explicitly (deliberately) report that they don’t. It is unclear whether this ‘unhealthy = tasty intuition’ is already present in childhood. Children from families with a lower socioeconomic position (SEP) consume poorer diets than children from families with a higher SEP. Paradoxically, populations with a lower SEP are underrepresented in research and least reached by lifestyle interventions. This study explored implicit and explicit associations between healthiness, tastiness and liking of foods in primary school-aged children and parents with a lower SEP.These associations and an estimate of dietary intake were assessed with implicit association tests and paper-and-pencil questionnaires, developed and adapted specifically for this target group. Participants were recruited at Dutch food banks.Results of 37 parent-child dyads indicated that children and parents implicitly associated healthy foods and tastiness more strongly with each other than healthy foods and not tasty (D = −0.19, p = .03 and D = −0.46, p < .001, respectively). Explicitly, parents showed similar results, while children rated pictures of unhealthy foods as tastier than pictures of healthy foods.Following the discrepancy between our hypotheses, results, and more unhealthy eating habits that often prevail in families with a lower SEP, potential explanations are discussed. We address the possibility that an internalised social norm was exposed, rather than an intrinsic belief. We propose that this research calls for in-depth qualitative research on food-related preferences and norms in the everyday life of low SEP families.     

Reduced Cd accumulation in Zea mays: a protective role for phytosiderophores?

Cadmium is a nonessential trace metal and a frequent soil contaminant. Because plants vary in their accumulation of Cd, an understanding of the specific processes that control uptake could reveal methods for reducing Cd levels in edible plant tissues and conversely increasing Cd accumulation in plants used for phytoremediation. Phytosiderophores are iron chelators excreted by graminaceous plants under conditions of iron limitation, but they also complex other metals including cadmium. Here we examine the influence of Cd exposure on phytosiderophore production by hydroponically grown maize. Cd increased the rate of the phytosiderophore 2'-deoxymugineic acid (DMA) release under both Fe-sufficient and Fe-limiting conditions (+/-Fe). In addition, the -Fe plants released more DMA while taking up less Cd than the +Fe plants. In other short-term Cd uptake experiments, plants exposed to Cd in the presence of root exudates in which the DMA-Cd complex was likely the dominant Cd species displayed reduced Cd accumulation in root tissue, and plants similarly exposed to strongly chelated Cd in the presence of EDTA (employed as a positive control) contained the least Cd. Collectively, these results indicate that Cd stress causes Fe deficiency symptoms that result in greater DMA production by maize roots, and then the DMA appears to reduce Cd accumulation.     

Polyphenols in chocolate: is there a contribution to human health?

Recently, polyphenols have gained much more attention, owing to their antioxidant capacity (free radical scavenging and metal chelating) and their possible beneficial implications in human health, such as in the treatment and prevention of cancer, cardiovascular disease, and other pathologies. Cocoa is rich in polyphenols particularly in catechins (flavan-3-ols) and procyanidins. Polyphenol contents of cocoa products such as dark chocolate, milk chocolate and cocoa powder have been published only recently. However, the data vary remarkably due to the quantity of cocoa liquor used in the recipe of the cocoa products but also due to the analytical procedure employed. For example, results obtained by a colourimetric method were 5–7 times higher for the same type of product than results obtained by high performance liquid chromatography (HPLC). In 1994, the per head consumption of chocolate and chocolate confectionery in the European Union ranged from 1.3 kg/year in Portugal to 8.8 kg/year in Germany. In general, consumers in the Northern countries consume on average more than people in the South. Thus, chocolate can be seen as a relevant source for phenolic antioxidants for some European population. However, this alone does not imply, that chocolate could be beneficial to human health. Some epidemiological evidence suggests a beneficial effect to human health by following a polyphenol-rich diet, namely rich in fruits and vegetables and to a less obvious extent an intake of tea and wine having a similar polyphenol composition as cocoa. In many experiments cellular targets have been identified and molecular mechanisms of disease prevention proposed, in particular for the prevention of cancer and cardiovascular diseases as well as for alleviating the response to inflammation reactions. However, it has to be demonstrated, whether polyphenols exert these effects in vivo. One pre-requisite is that the polyphenols are absorbed from the diet. For monomeric flavonoids such as the catechins, there is increasing evidence for their absorption. For complex phenols and tannins (procyanidins) these questions have to be addressed for the future. Some indication for the absorption of procyanidins derive from studies with the human colon cancer cell line Caco-2, believed to be a valuable model for passive intestinal absorption as proposed for polyphenols. However, it has to be clarified which concentration is effective and what concentrations can be expected from food intake. Another open question is related to polyphenol metabolism. For example, much effort has been invested to show antioxidative effects of free unbound polyphenols, especially of catechins and the flavonol quercetin. However, only a very small part can be found in plasma in the free form but conjugated or even metabolised to several phenolic acids and other ring scission products. From the papers reviewed, it is as yet to early to give an answer to the question, whether chocolate and/or other sources rich in catechins and procyanidins are beneficial to human health. Even though some data are promising and justify further research in the field, it has to be shown in future, whether the intake of these functional compounds and/or their sources is related to measurable effects on human health and/or the development of diseases.