Association between dietary factors and plasma fetuin-A concentrations in the general population

Circulating fetuin-A, a novel marker for hepatic fat accumulation, has been related to a higher risk of type 2 diabetes and cardiovascular diseases in a growing number of prospective studies. However, little is known about dietary determinants of fetuin-A concentrations in the general population. Therefore, we aimed to investigate the association between dietary intake of energy, energy-providing nutrients, alcohol and major food groups and plasma fetuin-A concentrations in the Bavarian Food Consumption Survey II. Dietary intake was assessed by three 24-h dietary recalls, and plasma concentrations of fetuin-A were measured in 558 adults (18-81 years). After multivariable adjustment for lifestyle factors and body fatness, higher energy intake was nonsignificantly associated with higher fetuin-A concentrations (per 2092 kJ/d (500 kcal/d) 3·7 µg/ml, 95 % CI -0·5, 7·8 µg/ml). There was no clear association between energy-providing nutrients and fetuin-A concentrations. Higher alcohol intake was associated with lower fetuin-A concentrations (P trend 0·003): mean fetuin-A concentrations were 324 (95 % CI 313, 335) µg/ml in non-drinkers, and with 293 (95 % CI 281, 306) µg/ml significantly lower in participants who drank ≥30 g alcohol per d. Mean fetuin-A concentrations decreased across quintiles of milk and dairy product intake (lowest quintile 319 (95 % CI 309, 330) µg/ml; highest quintile 304 (95 % CI 293, 314) µg/ml; P trend 0·03), and each 150-g increment in milk/dairy products per d was associated with 5·6 (95 % CI -9·6, -1·5) µg/ml lower fetuin-A. Dietary intakes of vegetables, meat or fish were not associated with fetuin-A concentrations. Because of the preventive potential of our findings, further exploration is warranted

Gut Microbiome Composition in Obese and Non-Obese Persons: A Systematic Review and Meta-Analysis

Whether the gut microbiome in obesity is characterized by lower diversity and altered composition at the phylum or genus level may be more accurately investigated using high-throughput sequencing technologies. We conducted a systematic review in PubMed and Embase including 32 cross-sectional studies assessing the gut microbiome composition by high-throughput sequencing in obese and non-obese adults. A significantly lower alpha diversity (Shannon index) in obese versus non-obese adults was observed in nine out of 22 studies, and meta-analysis of seven studies revealed a non-significant mean difference (-0.06, 95% CI -0.24, 0.12, I2 = 81%). At the phylum level, significantly more Firmicutes and fewer Bacteroidetes in obese versus non-obese adults were observed in six out of seventeen, and in four out of eighteen studies, respectively. Meta-analyses of six studies revealed significantly higher Firmicutes (5.50, 95% 0.27, 10.73, I2 = 81%) and non-significantly lower Bacteroidetes (-4.79, 95% CI -10.77, 1.20, I2 = 86%). At the genus level, lower relative proportions of Bifidobacterium and Eggerthella and higher Acidaminococcus, Anaerococcus, Catenibacterium, Dialister, Dorea, Escherichia-Shigella, Eubacterium, Fusobacterium, Megasphera, Prevotella, Roseburia, Streptococcus, and Sutterella were found in obese versus non-obese adults. Although a proportion of studies found lower diversity and differences in gut microbiome composition in obese versus non-obese adults, the observed heterogeneity across studies precludes clear answers

Dietary vitamin K intake in relation to cancer incidence and mortality: results from the Heidelberg cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC-Heidelberg)

BACKGROUND: Anticarcinogenic activities of vitamin K have been observed in animal and cell studies. OBJECTIVE: On the basis of the growth inhibitory effects of vitamin K as observed in a variety of cancer cell lines, we hypothesized that dietary intake of phylloquinone (vitamin K(1)) and menaquinones (vitamin K(2)) may be associated with overall cancer incidence and mortality. DESIGN: In the prospective EPIC-Heidelberg (European Prospective Investigation into Cancer and Nutrition-Heidelberg) cohort study, 24,340 participants aged 35-64 y and free of cancer at enrollment (1994-1998) were actively followed up for cancer incidence and mortality through 2008. Dietary vitamin K intake was estimated from food-frequency questionnaires completed at baseline by using HPLC-based food-composition data. Multivariate-adjusted hazard ratios (HRs) and 95% CIs were estimated by using Cox proportional hazards models. RESULTS: During a median follow-up time of >10 y, 1755 incident cancer cases occurred, of which 458 were fatal. Dietary intake of menaquinones was nonsignificantly inversely associated with overall cancer incidence (HR for the highest compared with the lowest quartile: 0.86; 95% CI: 0.73, 1.01; P for trend = 0.08), and the association was stronger for cancer mortality (HR: 0.72; 95% CI: 0.53, 0.98; P for trend = 0.03). Cancer risk reduction with increasing intake of menaquinones was more pronounced in men than in women, mainly driven by significant inverse associations with prostate (P for trend = 0.03) and lung (P for trend = 0.002) cancer. We found no association with phylloquinone intake. CONCLUSION: These findings suggest that dietary intake of menaquinones, which is highly determined by the consumption of cheese, is associated with a reduced risk of incident and fatal cancer

Habitual intake of flavonoid subclasses and risk of colorectal cancer in two large prospective cohorts

Background: Flavonoids inhibit the growth of colon cancer cells in vitro. In a secondary analysis of a randomized controlled trial, the Polyp Prevention Trial, a higher intake of one sub-class, flavonols, was significantly associated with reduced risk of recurrent advanced adenoma. Most previous prospective studies on colorectal cancer evaluated only a limited number of flavonoid sub-classes and intake ranges, yielding inconsistent results.  Objective: To examine whether higher habitual dietary intakes of flavonoid subclasses (flavonols, flavones, flavanones, flavan-3-ols and anthocyanins) are associated with lower risk of colorectal cancer.  Design: Using data from validated food frequency questionnaires administered every four years and an updated flavonoid food composition database flavonoid intakes were calculated for 42,478 male participants from the Health Professionals Follow-up Study and for 76,364 female participants from the Nurses’ Health Study.  Results: During up to 26 years of follow-up, 2,519 colorectal cancer cases (1,061 in men, 1,458 in women) were documented. Intakes of flavonoid subclasses were not associated with risk of colorectal cancer in either cohort. Pooled multivariable adjusted relative risks (95% confidence interval) comparing the highest with the lowest quintile were 1.04 (0.91, 1.18) for flavonols; 1.01 (0.89, 1.15) for flavones; 0.96 (0.84, 1.10) for flavanones; 1.07 (0.95, 1.21) for flavan-3-ols; and 0.98 (0.81, 1.19) for anthocyanins (all p-values for heterogeneity by sex >0.19). In subsite analyses, flavonoid intake was also not associated with colon or rectal cancer risk.  Conclusion: Our findings do not support the hypothesis that a higher habitual intake of any flavonoid sub-class decreases the risk of colorectal cancer

Effects of Dietary Fibers on Short-Chain Fatty Acids and Gut Microbiota Composition in Healthy Adults: A Systematic Review

Abstract There is an increasing interest in investigating dietary strategies able to modulate the gut microbial ecosystem which, in turn, may play a key role in human health. Dietary fibers (DFs) are widely recognized as molecules with prebiotic effects. The main objective of this systematic review was to: (i) analyze the results available on the impact of DF intervention on short chain fatty acids (SCFAs) production; (ii) evaluate the interplay between the type of DF intervention, the gut microbiota composition and its metabolic activities, and any other health associated outcome evaluated in the host. To this aim, initially, a comprehensive database of literature on human intervention studies assessing the effect of confirmed and candidate prebiotics on the microbial ecosystem was developed. Subsequently, studies performed on DFs and analyzing at least the impact on SCFA levels were extracted from the database. A total of 44 studies from 42 manuscripts were selected for the analysis. Among the different types of fiber, inulin was the DF investigated the most (n = 11). Regarding the results obtained on the ability of fiber to modulate total SCFAs, seven studies reported a significant increase, while no significant changes were reported in five studies, depending on the analytical methodology used. A total of 26 studies did not show significant differences in individual SCFAs, while the others reported significant differences for one or more SCFAs. The effect of DF interventions on the SCFA profile seemed to be strictly dependent on the dose and the type and structure of DFs. Overall, these results underline that, although affecting microbiota composition and derived metabolites, DFs do not produce univocal significant increase in SCFA levels in apparently healthy adults. In this regard, several factors (i.e., related to the study protocols and analytical methods) have been identified that could have affected the results obtained in the studies evaluated. Future studies are needed to better elucidate the relationship between DFs and gut microbiota in terms of SCFA production and impact on health-related marker

Circulating vitamin D concentration and risk of seven cancers: Mendelian randomisation study

Objective To determine if circulating concentrations of vitamin D are causally associated with risk of cancer.Design Mendelian randomisation study.Setting Large genetic epidemiology networks (the Genetic Associations and Mechanisms in Oncology (GAME-ON), the Genetic and Epidemiology of Colorectal Cancer Consortium (GECCO), and the Prostate Cancer Association Group to Investigate Cancer Associated Alterations in the Genome (PRACTICAL) consortiums, and the MR-Base platform).Participants 70 563 cases of cancer (22 898 prostate cancer, 15 748 breast cancer, 12 537 lung cancer, 11 488 colorectal cancer, 4369 ovarian cancer, 1896 pancreatic cancer, and 1627 neuroblastoma) and 84 418 controls.Exposures Four single nucleotide polymorphisms (rs2282679, rs10741657, rs12785878 and rs6013897) associated with vitamin D were used to define a multi-polymorphism score for circulating 25-hydroxyvitamin D (25(OH)D) concentrations.Main outcomes measures The primary outcomes were the risk of incident colorectal, breast, prostate, ovarian, lung, and pancreatic cancer and neuroblastoma, which was evaluated with an inverse variance weighted average of the associations with specific polymorphisms and a likelihood based approach. Secondary outcomes based on cancer subtypes by sex, anatomic location, stage, and histology were also examined.Results There was little evidence that the multi-polymorphism score of 25(OH)D was associated with risk of any of the seven cancers or their subtypes. Specifically, the odds ratios per 25 nmol/L increase in genetically determined 25(OH)D concentrations were 0.92 (95% confidence interval 0.76 to 1.10) for colorectal cancer, 1.05 (0.89 to 1.24) for breast cancer, 0.89 (0.77 to 1.02) for prostate cancer, and 1.03 (0.87 to 1.23) for lung cancer. The results were consistent with the two different analytical approaches, and the study was powered to detect relative effect sizes of moderate magnitude (for example, 1.20-1.50 per 25 nmol/L decrease in 25(OH)D for most primary cancer outcomes. The Mendelian randomisation assumptions did not seem to be violated.Conclusions There is little evidence for a linear causal association between circulating vitamin D concentration and risk of various types of cancer, though the existence of causal clinically relevant effects of low magnitude cannot be ruled out. These results, in combination with previous literature, provide evidence that population-wide screening for vitamin D deficiency and subsequent widespread vitamin D supplementation should not currently be recommended as a strategy for primary cancer prevention

Identification and Characterization of Human Observational Studies in Nutritional Epidemiology on Gut Microbiomics for Joint Data Analysis

In any research field, data access and data integration are major challenges that even large, well-established consortia face. Although data sharing initiatives are increasing, joint data analyses on nutrition and microbiomics in health and disease are still scarce. We aimed to identify observational studies with data on nutrition and gut microbiome composition from the Intestinal Microbiomics (INTIMIC) Knowledge Platform following the findable, accessible, interoperable, and reusable (FAIR) principles. An adapted template from the European Nutritional Phenotype Assessment and Data Sharing Initiative (ENPADASI) consortium was used to collect microbiome-specific information and other related factors. In total, 23 studies (17 longitudinal and 6 cross-sectional) were identified from Italy (7), Germany (6), Netherlands (3), Spain (2), Belgium (1), and France (1) or multiple countries (3). Of these, 21 studies collected information on both dietary intake (24 h dietary recall, food frequency questionnaire (FFQ), or Food Records) and gut microbiome. All studies collected stool samples. The most often used sequencing platform was Illumina MiSeq, and the preferred hypervariable regions of the 16S rRNA gene were V3-V4 or V4. The combination of datasets will allow for sufficiently powered investigations to increase the knowledge and understanding of the relationship between food and gut microbiome in health and disease

Selbstberichtete Krebserkrankungen in der NAKO Gesundheitsstudie: Erfassungsmethoden und erste Ergebnisse

BACKGROUND: In the German National Cohort (NAKO Gesundheitsstudie), the largest prospective cohort study in Germany, data on self-reported cancer diagnoses are now available for the first half of participants. OBJECTIVES: Description of the methods to assess self-reported cancer diagnoses and type of cancer in the NAKO and presentation of first results. MATERIALS AND METHODS: In a computer-assisted, standardized personal interview, 101,787 participants (54,526 women, 47,261 men) were asked whether they had ever been diagnosed with cancer (malignant tumors including in situ) by a physician and how many cancer diagnoses they had. The type of cancer was classified with a list. Absolute and relative frequencies of self-reported cancer diagnoses and types of cancer were calculated and compared with cancer registry data. RESULTS: A physician-diagnosed cancer was reported by 9.4% of women and 7.0% of men. Of the participants who reported a cancer diagnosis, 88.3% reported to have had only one cancer diagnosis. In women, the most frequent malignancies were breast cancer, cervical cancer, and melanoma. In men, the most frequent malignancies were prostate cancer, melanoma, and colorectal cancer. Comparing the frequencies of cancer diagnoses reported by 45- to 74-year-old NAKO participants within the last five years to cancer registry-based 5‑year prevalences, most types of cancer were less frequent in the NAKO, with the exception of melanoma in men and women, cervical cancer and liver cancer in women, and bladder cancer and breast cancer in men. CONCLUSIONS: The NAKO is a rich data basis for future investigations of incident cancer

Dietary intake of vitamin K and risk of prostate cancer in the Heidelberg cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC-Heidelberg)

Anticarcinogenic activities of vitamin K have been observed in various cancer cell lines, including prostate cancer cells. Epidemiologic studies linking dietary intake of vitamin K with the development of prostate cancer have not yet been conducted

Association between alcohol consumption and serum paraoxonase and arylesterase activities: a cross-sectional study within the Bavarian population

High alcohol consumption is an important risk factor for chronic disease and liver degeneration. Paraoxonase (PON1) and arylesterase (AE) are functions of the enzyme paraoxonase, which is synthesised by the liver. Paraoxonase circulates in plasma bound to HDL and hydrolyses lipid peroxides, protecting lipoproteins against oxidative modification. It has been shown that excessive alcohol consumption leads to a reduction of serum PON1 and AE activities; however, studies investigating the association with low and moderate alcohol consumption are scarce. We investigated the cross-sectional association between alcohol consumption and serum activities of PON1 and AE using data from the population-based Bavarian Food Consumption Survey II survey. PON1 and AE activities were quantified in serum samples of 566 male and female study participants (aged 18-80 years), and dietary intake including alcohol consumption was estimated from three 24-h dietary recalls. The association between alcohol consumption and PON1 and AE activities was analysed using linear regression, adjusted for age, sex and socio-economic status. There was no strong association between alcohol consumption and enzymatic activities of PON1 and AE in the Bavarian population. PON1 activity was seen to be lowest in non-drinkers (0 g/d) and highest in people who consumed 15·1-30 g of alcohol/d. AE activity increased across alcohol consumption categories, with a mean maximum difference of 14 U/ml (P for linear trend 0·04). These associations were attenuated after adjustment for blood concentrations of HDL. The results of this study do not support the hypothesis that alcohol consumption is related to important alterations in PON1 and AE activities