Are Diet Preferences Associated to Skulls Shape Diversification in Xenodontine Snakes?

Snakes are a highly successful group of vertebrates, within great diversity in habitat, diet, and morphology. The unique adaptations for the snake skull for ingesting large prey in more primitive macrostomatan snakes have been well documented. However, subsequent diversification in snake cranial shape in relation to dietary specializations has rarely been studied (e.g. piscivory in natricine snakes). Here we examine a large clade of snakes with a broad spectrum of diet preferences to test if diet preferences are correlated to shape variation in snake skulls. Specifically, we studied the Xenodontinae snakes, a speciose clade of South American snakes, which show a broad range of diets including invertebrates, amphibians, snakes, lizards, and small mammals. We characterized the skull morphology of 19 species of xenodontine snakes using geometric morphometric techniques, and used phylogenetic comparative methods to test the association between diet and skull morphology. Using phylogenetic partial least squares analysis (PPLS) we show that skull morphology is highly associated with diet preferences in xenodontine snakes.     

Adherence to the WHO’s Healthy Diet Indicator and Overall Cancer Risk in the EPIC-NL Cohort

Background

A healthy dietary pattern defined by international recommendations of the World Health Organisation (WHO) has been shown to reduce overall mortality risk. It is unknown whether this healthy dietary pattern is associated with overall cancer incidence.

Design

In total 35,355 men and women within the Dutch European Prospective Investigation into Cancer and Nutrition-cohort were followed for cancer occurrence. Diet was assessed through a validated food-frequency questionnaire. We computed a dietary score for all participants based on the seven WHO dietary guidelines for the prevention of chronic diseases (Healthy Diet Indicator (HDI)). We used the existing HDI score based on the 1990 WHO guidelines, and adapted it to meet with the 2002 WHO guidelines. Multivariate-adjusted Cox proportional hazards analysis was used to examine the association between adherence to the HDI and subsequent overall cancer risk.

Results

A number of 3,007 new cancers were identified during a mean follow-up of 12.7 years. Adherence to the HDI was not associated with a reduced overall cancer risk. The hazard ratio (HR) of overall cancer associated with a one-point increment of the HDI was 0.96 (95% CI 0.89–1.03) in men, and 1.00 (95% CI 0.96–1.04) in women. Adherence to the HDI was not associated with smoking-related cancer ((HR men: 0.94 (95% CI 0.84–1.04); HR women: 1.00 (95% CI 0.94–1.07)), or alcohol-related cancer ((HR men: 1.02 (95% CI 0.87–1.20); HR women: 1.03 (95% CI 0.98–1.08)).

Conclusions

Greater adherence to the WHO’s Healthy Diet Indicator, a dietary pattern for prevention of chronic diseases, was not associated with reduced overall, smoking-related or alcohol-related cancer risk in men or women.     

A Western Diet Ecological Module Identified from the ‘Humanized’ Mouse Microbiota Predicts Diet in Adults and Formula Feeding in Children

The interplay between diet and the microbiota has been implicated in the growing frequency of chronic diseases associated with the Western lifestyle. However, the complexity and variability of microbial ecology in humans and preclinical models has hampered identification of the molecular mechanisms underlying the association of the microbiota in this context. We sought to address two key questions. Can the microbial ecology of preclinical models predict human populations? And can we identify underlying principles that surpass the plasticity of microbial ecology in humans? To do this, we focused our study on diet; perhaps the most influential factor determining the composition of the gut microbiota. Beginning with a study in ‘humanized’ mice we identified an interactive module of 9 genera allied with Western diet intake. This module was applied to a controlled dietary study in humans. The abundance of the Western ecological module correctly predicted the dietary intake of 19/21 top and 21/21 of the bottom quartile samples inclusive of all 5 Western and ‘low-fat’ diet subjects, respectively. In 98 volunteers the abundance of the Western module correlated appropriately with dietary intake of saturated fatty acids, fat-soluble vitamins and fiber. Furthermore, it correlated with the geographical location and dietary habits of healthy adults from the Western, developing and third world. The module was also coupled to dietary intake in children (and piglets) correlating with formula (vs breast) feeding and associated with a precipitous development of the ecological module in young children. Our study provides a conceptual platform to translate microbial ecology from preclinical models to humans and identifies an ecological network module underlying the association of the gut microbiota with Western dietary habits.     

Pancreatic cancer risk in relation to sex,lifestyle factors,and pre-diagnostic anthropometry in the Malmö Diet and Cancer Study

Background

Lifestyle factors may influence the risk of developing pancreatic cancer. Whereas cigarette smoking is an established risk factor, the effects of high alcohol intake and obesity are more uncertain. The aim of the present study was to examine the associations of pre-diagnostic anthropometry, alcohol consumption, and smoking habits with pancreatic cancer risk in a Swedish prospective, population-based cohort, with particular reference to potential sex differences.

Methods

The studied cohort consists of 28,098 participants, including all incident cases of pancreatic cancer, in the Malmö Diet and Cancer Study up until December 31, 2013 (n?=?163). Non-parametric and chi-squared tests were applied to compare the distribution of risk factors between cases and non-cases. Cox regression proportional hazards models were used to estimate the relationship between investigative factors and pancreatic cancer risk. Anthropometric factors included height, weight, body mass index (BMI), waist and hip circumference, waist-hip ratio (WHR), and body fat percentage.

Results

BMI was not a significant risk factor for pancreatic cancer, but a higher WHR was significantly associated with an increased risk in the entire cohort (hazard ratio (HR) 2.36, 95% confidence interval (CI) 1.28–4.35, p for trend?=?0.009). Regular smoking was a significant risk factor among both women (HR 2.62, 95% CI 1.61–4.27) and men (HR 3.57, 95% CI 1.70–7.47), whereas occasional smoking was a significant risk factor only in women (HR 3.29, 95% CI 1.50–7.19). Passive smoking at work for >20 years was significantly associated with an increased risk in the entire cohort (HR 1.73, 95% CI 1.15–2.58) and in women selectively (HR 2.01, 95% CI 1.21–3.31). Alcohol consumption was not a significant risk factor. A significant interaction was found between female sex and age (p?=?0.045), but no other factor, in relation to pancreatic cancer risk.

Conclusions

WHR was the only pre-diagnostic anthropometric factor associated with pancreatic cancer risk, with no sex-related differences. Regular smoking was confirmed as a significant risk factor in both sexes, whereas occasional and passive smoking were significant risk factors only in women. Despite the lack of a significant interaction between smoking and sex in relation with pancreatic cancer risk, potential sex differences should be considered in future epidemiological studies.

     

Diet of juvenile cod (age 0–2) in the Barents Sea in relation to food availability and cod growth

Diet investigations were carried out on 0-, 1- and 2-year-old Northeast Arctic cod (Gadus morhua) sampled in the Barents Sea during 1984–2002. Stomach-content analyses showed that the 0 and 1 group cod fed mainly on crustaceans, with krill and amphipods composing up to 70% of their diet. Krill (Thysanoessa spp. and Meganyctiphanes norvegica) and amphipods (Themisto spp.) were mainly found in cod stomachs sampled in the central and close to the Polar Front region in the Barents Sea where these prey organisms are reported to be abundant in summer. A shift in the main diet from crustaceans to fish was observed from age 1 to age 2. The diet of 2-year-old cod mainly comprised capelin (Mallotus villosus) and other fish, and to a lesser degree, krill and amphipods. Shrimp (mainly Pandalus spp.) was also an important prey in both age 1 and 2 cod. A statistically significant positive relationship was obtained between capelin stock size and the amount of capelin in the diet of 2-year-old cod. Results from this study also show that the larger age-2 cod preyed more on capelin in winter and that larger cod (>22 cm) prefer larger capelin (>12 cm). During periods of low capelin abundance, the 2-year-old cod shift their diet more to crustaceans, such as krill and amphipods. A positive significant relationship was also obtained between Total Fullness Index (TFI) and the amount of capelin in the diet and between TFI and the growth of 2-year-old cod, indicating that the growth of age-2 cod is to a large extent dependent on the amount of capelin consumed. Growth of age-1 cod was also positively correlated to TFI.     

PPARγ in Vagal Neurons Regulates High-Fat Diet Induced Thermogenesis

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Can Captive-Bred Varecia variegata variegata Adapt to a Natural Diet on Release to the Wild?

We compared the diets of 3 groups of released captive-bred Varecia variegata variegata (RG1, RG2, RG3) in the Betampona Reserve to that recorded for a resident wild group, between 1998 and 2001. We investigated whether the released captive-bred Varecia, from differing captive backgrounds, could cope with seasonal changes in climate and consequently food availability, finding sufficient food to meet their nutritional requirements, and dietary choices and selection. We collected data on diet, including plant part, family, genus and, if known, species. In addition, we collected data on seasonal variation in dietary composition. Dietary overlap is significant at the familial level between RG1/RG3 and the wild group. There is some dietary overlap between RG2 and the wild group, but it is not significant. In general, RG1 and RG3 more closely followed the dietary choices and seasonal changes in diet exhibited by the wild group. We conclude that Varecia raised in free-ranging environments are better adapted to meet their nutritional requirements in the wild than those raised in cages are. However, even they struggle to deal with seasonal climatic changes and consequent changes in food availability. We suggest that future re-introduction efforts for primates include attempts to integrate released individuals rapidly into wild groups so that they can learn to cope with a seasonal environment through direct observation of wild conspecifics.     

Do Differences in Childhood Diet Explain the Reduced Overweight Risk in Breastfed Children?

Breastfeeding has been associated with a reduced risk of overweight later in life. This study investigates whether differences in diet and lifestyle at 7 years of age between breastfed and formula-fed children can explain the difference in overweight prevalence at 8 years of age. We studied 2,043 Dutch children born in 1996-1997 who participated in the Prevention and Incidence of Asthma and Mite Allergy birth cohort study. Data on breastfeeding duration and diet and lifestyle factors at 7 years were collected using questionnaires. Weight and height were measured at 8 years. Overweight was defined according to international gender- and age-specific standards. Compared to nonbreastfed children (15.5%, n = 316), children breastfed for >16 weeks (38.0%, n = 776) consumed fruit and vegetables significantly more often and meat, white bread, carbonated soft drinks, chocolate bars, and fried snacks less often. Overall, breastfed children were less likely to have an unhealthy diet (adjusted prevalence ratio: 0.77, 95% confidence interval: 0.61-0.98). The associations could only partly be explained by maternal education, maternal overweight, and smoking during pregnancy. At 8 years, 14.5% (n = 297) of the children were overweight. Breastfeeding for >16 weeks was significantly associated with a lower overweight risk at 8 years (adjusted odds ratio: 0.67, 95% confidence interval: 0.47-0.97), and the association hardly changed after adjustment for diet (adjusted odds ratio: 0.71, 95% confidence interval: 0.49-1.03). Breastfed children had a healthier diet at 7 years compared to nonbreastfed children, but this difference could not explain the lower overweight risk at 8 years in breastfed children.     

Mercury Exposure Assessment in Iranian Pregnant Women’s Hair with Respect to Diet, Amalgam Filling, and Lactation

Our aim for carrying out this study was to estimate the levels of mercury in the hair of pregnant women and its association with fish consumption and amalgam fillings. From November 2007 to January 2008, 100 hair samples were collected randomly from three groups of pregnant women: Ahvaz in the south of Iran, Noushahr in the north, and the countryside of Noushahr. Significant differences were found in these three groups of pregnant women's samples (p>0.05). The mean mercury level in women's hair was found to be 0.37 μg/g (range, 0.11-3.57 μg/g). Only in 2 % of collected hair samples did the total mercury (THg) level exceed the United States Environmental Protection Agency-recommended 1.0 μg/g. In addition, there was a positive correlation of THg content in Ahvaz group's samples with respect to fish consumption (r=0.41, p=0.02) and a negative correlation of THg content in those who consumed vegetables and fruit. The level of education also played an indicating factor in this group. Moreover, significant association was found between the residence time and Hg concentration of women's hair samples collected from Noushahr (p>0.05). Similarly, the same correlations were found between hair mercury levels and the time since the first filling, number of dental fillings, pregnancy interval, and lactating period.     

Genetic susceptibility to obesity and diet intakes: association and interaction analyses in the Malmö Diet and Cancer Study

Gene–environment interactions need to be studied to better understand the obesity. We aimed at determining whether genetic susceptibility to obesity associates with diet intake levels and whether diet intakes modify the genetic susceptibility. In 29,480 subjects of the population-based Malmö Diet and Cancer Study (MDCS), we first assessed association between 16 genome-wide association studies identified obesity-related single-nucleotide polymorphisms (SNPs) with body mass index (BMI) and associated traits. We then conducted association analyses between a genetic risk score (GRS) comprising of 13 replicated SNPs and the individual SNPs, and relative dietary intakes of fat, carbohydrates, protein, fiber and total energy intake, as well as interaction analyses on BMI and associated traits among 26,107 nondiabetic MDCS participants. GRS associated strongly with increased BMI (P = 3.6 × 10^?34), fat mass (P = 6.3 × 10^?28) and fat-free mass (P = 1.3 × 10^?24). Higher GRS associated with lower total energy intake (P = 0.001) and higher intake of fiber (P = 2.3 × 10^?4). No significant interactions were observed between GRS and the studied dietary intakes on BMI or related traits. Of the individual SNPs, after correcting for multiple comparisons, NEGR1 rs2815752 associated with diet intakes and BDNF rs4923461 showed interaction with protein intake on BMI. In conclusion, our study does not provide evidence for a major role for macronutrient-, fiber- or total energy intake levels in modifying genetic susceptibility to obesity measured as GRS. However, our data suggest that the number of risk alleles as well as some of the individual obesity loci may have a role in regulation of food and energy intake and that some individual loci may interact with diet.     

A High Diet Quality Is Associated with Lower Incidence of Cardiovascular Events in the Malm? Diet and Cancer Cohort

Aims

To investigate if diet quality is related to incidence of cardiovascular (CV) events.

Subjects and Methods

A diet quality index based on the 2005 Swedish Nutrition Recommendations and the Swedish Dietary Guidelines was created and included six dietary components: saturated fatty acids, polyunsaturated fatty acids, fish and shellfish, dietary fiber, fruit and vegetables, and sucrose. The index ranked 17126 participants (59% women) of the population-based Malmö Diet and Cancer cohort (Sweden) on their dietary intakes. Total index score was categorized as low, medium or high. Cox proportional hazard regression was used to model associations between index score categories and index components with risk of incident CV events, with adjustment for potential confounders. The incidence of first CV events (non-fatal or fatal myocardial infarction or ischemic stroke or death from ischemic heart disease) was monitored from baseline (1991–1996) until December 31, 2008; 703 CV events occurred in women and 1093 in men.

Results

A high diet quality was associated with decreased risk of CV events when compared to a low diet quality. In multivariate analysis, the risk reduction was 32% (hazard ratio = 0.68, 95% confidence interval: 0.49–0.73) in men and 27% (hazard ratio = 0.73, 95% confidence interval: 0.59–0.91) in women. When examined separately and mutually adjusted for each other, the individual components were either not associated with CV risk or marginally decreased risks were seen.

Conclusion

High quality diets in line with current recommendations may reduce the risk of CV events. This study illustrates the importance of considering a combination of dietary factors when evaluating diet-disease associations.     

Shift in Black Rhinoceros Diet in the Presence of Elephant: Evidence for Competition?

In African large herbivore assemblages, megaherbivores dominate the biomass and utilise the greatest share of available resources. Consequently, they are considered a separate trophic guild that structures the food niches of coexisting large herbivores. However, there exists little empirical evidence on how food resources are shared within this guild, and none for direct competition for food between megaherbivores. Using the histological analysis of faeces, we explore this phenomenon for African elephant Loxodonta africana and black rhinoceros Diceros bicornis in the Addo Elephant National Park, South Africa, where the accumulated impacts of elephant have reduced browse availability. Despite being unable to generalise beyond our study sites, our observations support the predictions of competition theory (as opposed to optimality theory) by showing (1) a clear seasonal separation in resource use between these megaherbivores that increased as resource availability declined, and (2) rhinoceros changed their selectivity in the absence of elephant (using an adjacent site) by expanding and shifting their diet along the grass-browse continuum, and in relation to availability. Although black rhinoceros are generally considered strict browsers, the most significant shift in diet occurred as rhinoceros increased their preferences for grasses in the presence of elephant. We speculate that the lack of specialised grazing adaptations may increase foraging costs in rhinoceros, through reduced harvest- and handling-efficiencies of grasses. In the short-term, this may be off-set by an enhanced tolerance for low quality food and by seasonally mobilising fat reserves; however, the long-term fitness consequences require further study. Our data suggest that managing elephant at high densities may compromise the foraging opportunities of coexisting browsers. This may be particularly important in small, fenced areas and overlapping preferred habitats where impacts intensify.     

Poor Diet in Shift Workers: A New Occupational Health Hazard?

The PLoS Medicine Editors discuss the link between shift work, diet, and type 2 diabetes, and argue that unhealthy eating should be considered a new form of occupational hazard.     

Deletion of CDKAL1 Affects High-Fat Diet–Induced Fat Accumulation and Glucose-Stimulated Insulin Secretion in Mice,Indicating Relevance to Diabetes

Background/Objective

The CDKAL1 gene is among the best-replicated susceptibility loci for type 2 diabetes, originally identified by genome-wide association studies in humans. To clarify a physiological importance of CDKAL1, we examined effects of a global Cdkal1-null mutation in mice and also evaluated the influence of a CDKAL1 risk allele on body mass index (BMI) in Japanese subjects.

Methods

In Cdkal1-deficient (Cdkal1 ^−/−) mice, we performed oral glucose tolerance test, insulin tolerance test, and perfusion experiments with and without high-fat feeding. Based on the findings in mice, we tested genetic association of CDKAL1 variants with BMI, as a measure of adiposity, and type 2 diabetes in Japanese.

Principal Findings

On a standard diet, Cdkal1 ^−/− mice were modestly lighter in weight than wild-type littermates without major alterations in glucose metabolism. On a high fat diet, Cdkal1 ^−/− mice showed significant reduction in fat accumulation (17% reduction in %intraabdominal fat, P = 0.023 vs. wild-type littermates) with less impaired insulin sensitivity at an early stage. High fat feeding did not potentiate insulin secretion in Cdkal1 ^−/− mice (1.0-fold), contrary to the results in wild-type littermates (1.6-fold, P<0.01). Inversely, at a later stage, Cdkal1 ^−/− mice showed more prominent impairment of insulin sensitivity and glucose tolerance. mRNA expression analysis indicated that Scd1 might function as a critical mediator of the altered metabolism in Cdkal1 ^−/− mice. In accordance with the findings in mice, a nominally significant (P<0.05) association between CDKAL1 rs4712523 and BMI was replicated in 2 Japanese general populations comprising 5,695 and 12,569 samples; the risk allele for type 2 diabetes was also associated with decreased BMI.

Conclusions

Cdkal1 gene deletion is accompanied by modestly impaired insulin secretion and longitudinal fluctuations in insulin sensitivity during high-fat feeding in mice. CDKAL1 may affect such compensatory mechanisms regulating glucose homeostasis through interaction with diet.     

A Spirulina-Enhanced Diet Provides Neuroprotection in an α-Synuclein Model of Parkinson's Disease

Inflammation in the brain plays a major role in neurodegenerative diseases. In particular, microglial cell activation is believed to be associated with the pathogenesis of neurodegenerative diseases, including Parkinson’s disease (PD). An increase in microglia activation has been shown in the substantia nigra pars compacta (SNpc) of PD models when there has been a decrease in tyrosine hydroxylase (TH) positive cells. This may be a sign of neurotoxicity due to prolonged activation of microglia in both early and late stages of disease progression. Natural products, such as spirulina, derived from blue green algae, are believed to help reverse this effect due to its anti-inflammatory/anti-oxidant properties. An adeno-associated virus vector (AAV9) for α-synuclein was injected in the substantia nigra of rats to model Parkinson''s disease and to study the effects of spirulina on the inflammatory response. One month prior to surgeries, rats were fed either a diet enhanced with spirulina or a control diet. Immunohistochemistry was analyzed with unbiased stereological methods to quantify lesion size and microglial activation. As hypothesized, spirulina was neuroprotective in this α-synuclein model of PD as more TH+ and NeuN+ cells were observed; spirulina concomitantly decreased the numbers of activated microglial cells as determined by MHCII expression. This decrease in microglia activation may have been due, in part, to the effect of spirulina to increase expression of the fractalkine receptor (CX3CR1) on microglia. With this study we hypothesize that α-synuclein neurotoxicity is mediated, at least in part, via an interaction with microglia. We observed a decrease in activated microglia in the rats that received a spirulina- enhanced diet concomitant to neuroprotection. The increase in CX3CR1 in the groups that received spirulina, suggests a potential mechanism of action.     

Genetic susceptibility to dyslipidemia and incidence of cardiovascular disease depending on a diet quality index in the Malmö Diet and Cancer cohort

Background

By taking diet quality into account, we may clarify the relationship between genetically elevated triglycerides (TG) and low-density lipoprotein-cholesterol (LDL-C), and better understand the inconsistent results regarding genetically elevated high-density lipoprotein-cholesterol (HDL-C), and cardiovascular disease (CVD) risk.

Methods

We included 24,799 participants (62 % women, age 44–74 years) from the Malmö Diet and Cancer cohort. During a mean follow-up time of 15 years, 3068 incident CVD cases (1814 coronary and 1254 ischemic stroke) were identified. Genetic risk scores (GRSs) were constructed by combining 80 validated genetic variants associated with higher TG and LDL-C or lower HDL-C. The participants’ dietary intake, assessed by a modified diet history method, was ranked according to a diet quality index that included six dietary components: saturated fat, polyunsaturated fat, fish, fiber, fruit and vegetables, and sucrose.

Results

The GRS_LDL-C (P?=?5?×?10^?6) and GRS_HDL-C (P?=?0.02) but not GRS_TG (P?=?0.08) were significantly associated with CVD risk. No significant interaction between the GRSs and diet quality was observed on CVD risk (P?>?0.39). A high compared to a low diet quality attenuated the association between GRS_LDL-C and the risk of incident ischemic stroke (P interaction?=?0.01).

Conclusion

We found some evidence of an interaction between diet quality and GRS_LDL-C on ischemic stroke.

     

Diet preference in the House Sparrow Passer domesticus: hooked on millet?

Capsule House Sparrows preferred millet over seeds of prairie forbs and grasses native to the USA. By reducing the abundance and availability of some grains, changing agricultural practices may contribute to the population declines of House Sparrows seen in some parts of their range.