The association of protein intake (amount and type) with ovarian antral follicle counts among infertile women: results from the EARTH prospective study cohort.

OBJECTIVE: To evaluate the association between protein intake (amount and type) and antral follicle count (AFC). DESIGN: Prospective cohort. SETTING: Academic fertility centre. POPULATION: Two hundred and sixty-five women undergoing fertility treatments at an academic fertility centre and participating in an ongoing study on environment and reproductive health. METHODS: We measured AFC in ultrasonographic evaluation among women undergoing infertility treatments. Women completed a previously validated semi-quantitative food frequency questionnaire. We used Poisson regression to evaluate the relation between protein intake and AFC while adjusting for age, body mass index, race, smoking status, and total energy intake. MAIN OUTCOME MEASURES: Antral follicle count. RESULTS: Among 265 women (mean age: 35.0 ± 3.9 years, 85% Caucasian), total protein intake (% energy) was unrelated to AFC. When protein from different food sources was considered separately, we found a negative association between dairy protein intake and AFC. The mean AFC was 14.4% (3.9-23.7%) lower for women in the highest quintile of dairy protein intake than for women in the bottom quintile after adjusting for potential confounders (P-trend = 0.04). This association was stronger among women who had never smoked (P-trend = 0.002) but was not observed among previous smokers (P-trend = 0.36). There were no associations between protein intake from either non-dairy animal or vegetable sources and AFC. CONCLUSION: Higher dairy protein intake (≥5.24% of energy) was associated with lower antral follicle counts among women presenting for infertility treatment. These findings should be further investigated in prospective studies also designed to clarify the biology underlying the observed associations. TWEETABLE ABSTRACT: Higher dairy protein intake was associated with lower antral follicle counts in an infertile population.

Dairy intake in relation to in vitro fertilization outcomes among women from a fertility clinic.

STUDY QUESTION: Is dairy food consumption associated with live birth among women undergoing infertility treatment? SUMMARY ANSWER: There was a positive association between total dairy food consumption and live birth among women ≥35 years of age. WHAT IS KNOWN ALREADY: Dairy food intake has been previously related to infertility risk and measures of fertility potential but its relation to infertility treatment outcomes are unknown. STUDY DESIGN, SIZE, DURATION: Our study population comprised a total of 232 women undergoing 353 in vitro fertilization (IVF) treatment cycles between February 2007 and May 2013, from the Environment and Reproductive Health study, an ongoing prospective cohort. PARTICIPANTS/MATERIALS, SETTING, METHODS: Diet was assessed before assisted reproductive technology (ART) treatment using a validated food frequency questionnaire. Study outcomes included ovarian stimulation outcomes (endometrial thickness, estradiol levels and oocyte yield), fertilization rates, embryo quality measures and clinical outcomes (implantation, clinical pregnancy and live birth rates). We used generalized linear mixed models with random intercepts to account for multiple ART cycles per woman while simultaneously adjusting for age, caloric intake, BMI, race, smoking status, infertility diagnosis, protocol type, alcohol intake and dietary patterns. MAIN RESULTS AND THE ROLE OF CHANCE: The age- and calorie-adjusted difference in live birth between women in the highest (>3.0 servings/day) and lowest (<1.34 servings/day) quartile of dairy intake was 21% (P = 0.02). However, after adjusting for additional covariates, this association was observed only among women ≥35 years (P, interaction = 0.04). The multivariable-adjusted live birth (95% CI) in increasing quartiles of total dairy intake was 23% (11, 42%), 39% (24, 56%), 29% (17, 47%) and 55% (39, 69%) (P, trend = 0.02) among women ≥35 years old, and ranged from 46 to 54% among women <35 years old (P, trend = 0.69). There was no association between dairy intake and any of the intermediate outcomes. LIMITATIONS, REASONS FOR CAUTION: The lack of a known biological mechanism linking dairy intake to infertility treatment outcomes calls for caution when interpreting these results and for additional work to corroborate or refute them. WIDER IMPLICATIONS OF THE FINDINGS: Dairy intake does not appear to harm IVF outcomes and, if anything, is associated with higher chances of live birth. STUDY FUNDING/COMPETING INTERESTS: This work was supported by NIH grants R01-ES009718 and R01ES000002 from NIEHS, P30 DK046200 from NIDDK and T32HD060454 from NICHD. M.C.A. was supported by a Ruth L. Kirschstein National Research Service Award T32 DK 007703-16 from NIDDK. She is currently employed at the Nestlé Research Center, Switzerland and completed this work while at the Harvard School of Public Health. The other authors declare no conflicts of interest.

Fruit and vegetable intake and their pesticide residues in relation to semen quality among men from a fertility clinic.

STUDY QUESTION: Is consumption of fruits and vegetables with high levels of pesticide residues associated with lower semen quality? SUMMARY ANSWER: Consumption of fruits and vegetables with high levels of pesticide residues was associated with a lower total sperm count and a lower percentage of morphologically normal sperm among men presenting to a fertility clinic. WHAT IS KNOWN ALREADY: Occupational and environmental exposure to pesticides is associated with lower semen quality. Whether the same is true for exposure through diet is unknown. STUDY DESIGN, SIZE, DURATION: Men enrolled in the Environment and Reproductive Health (EARTH) Study, an ongoing prospective cohort at an academic medical fertility center. Male partners (n = 155) in subfertile couples provided 338 semen samples during 2007-2012. PARTICIPANTS/MATERIALS, SETTING, METHODS: Semen samples were collected over an 18-month period following diet assessment. Sperm concentration and motility were evaluated by computer-aided semen analysis (CASA). Fruits and vegetables were categorized as containing high or low-to-moderate pesticide residues based on data from the annual United States Department of Agriculture Pesticide Data Program. Linear mixed models were used to analyze the association of fruit and vegetable intake with sperm parameters accounting for within-person correlations across repeat samples while adjusting for potential confounders. MAIN RESULTS AND THE ROLE OF CHANCE: Total fruit and vegetable intake was unrelated to semen quality parameters. High pesticide residue fruit and vegetable intake, however, was associated with poorer semen quality. On average, men in highest quartile of high pesticide residue fruit and vegetable intake (≥1.5 servings/day) had 49% (95% confidence interval (CI): 31%, 63%) lower total sperm count and 32% (95% CI: 7%, 58%) lower percentage of morphologically normal sperm than men in the lowest quartile of intake (<0.5 servings/day) (P, trend = 0.003 and 0.02, respectively). Low-to-moderate pesticide residue fruit and vegetable intake was associated with a higher percentage of morphologically normal sperm (P, trend = 0.04). LIMITATIONS, REASONS FOR CAUTION: Surveillance data, rather than individual pesticide assessment, was used to assess the pesticide residue status of fruits and vegetables. CASA is a useful method for clinical evaluation but may be considered less favorable for accurate semen analysis in the research setting. Owing to the observational nature of the study, confirmation is required by interventional studies as well. WIDER IMPLICATIONS OF THE FINDINGS: To our knowledge, this is the first report on the consumption of fruits and vegetables with high levels of pesticide residue in relation to semen quality. Further confirmation of these findings is warranted. STUDY FUNDING/COMPETING INTERESTS: Supported by National Institutes of Health grants ES009718, ES022955, ES000002, P30 DK046200 and Ruth L. Kirschstein National Research Service Award T32 DK007703-16. None of the authors has any conflicts of interest to declare.

Sugar-sweetened beverage intake in relation to semen quality and reproductive hormone levels in young men.

STUDY QUESTION: Is consumption of sugar-sweetened beverages (SSB) associated with semen quality? SUMMARY ANSWER: Higher consumption of SSB was associated with lower sperm motility among healthy, young men. WHAT IS KNOWN ALREADY: The existing literature on the potential role of SSBs on male reproductive function is scarce and primarily focused on the relation between caffeinated beverages and semen quality. However, a rodent model suggests that SSBs may hamper male fertility. STUDY DESIGN, SIZE, DURATION: The Rochester Young Men's Study; a cross-sectional study of 189 healthy young men carried out at the University of Rochester during 2009-2010. PARTICIPANTS/MATERIALS, SETTING, METHODS: Men aged 18-22 years provided semen and blood samples, underwent a physical examination and completed a previously validated food frequency questionnaire (FFQ). Linear regression was used to analyze the association of SSBs with sperm parameters and reproductive hormone levels while adjusting for potential confounders. MAIN RESULTS AND THE ROLE OF CHANCE: SSB intake was inversely related to progressive sperm motility. Men in the highest quartile of SSB intake (≥1.3 serving/day) had 9.8 (95% CI: 1.9,17.8) percentage units lower progressive sperm motility than men in the lowest quartile of intake (<0.2 serving/day) (P, trend = 0.03). This association was stronger among lean men (P, trend = 0.005) but absent among overweight or obese men (P, trend = 0.98). SSB intake was unrelated to other semen quality parameters or reproductive hormones levels. LIMITATIONS, REASONS FOR CAUTION: As in all cross-sectional studies, causal inference is limited. An additional problem is that only single semen sample was obtained from each subject. WIDER IMPLICATIONS OF THE FINDINGS: To our knowledge, this is the first report on the relation between SSB intake and low semen quality beyond the contribution of caffeinated beverages. While our findings are in agreement with recent experimental data in rodents, more studies are required to draw conclusions on the relation of SSB with semen quality or male infertility. STUDY FUNDING/COMPETING INTEREST(S): Supported by the European Union Seventh Framework Program (Environment), 'Developmental Effects of Environment on Reproductive Health' (DEER) grant 212844. Grant P30 DK046200 and Ruth L. Kirschstein National Research Service Award T32 DK007703-16 and T32HD060454 from the National Institutes of Health. None of the authors has any conflicts of interest to declare.

Paternal physical and sedentary activities in relation to semen quality and reproductive outcomes among couples from a fertility center.

STUDY QUESTION: Is paternal physical activity associated with semen quality parameters and with outcomes of infertility treatment? SUMMARY ANSWER: Among men presenting for infertility treatment, weightlifting and outdoor activities were associated with higher sperm concentrations but not with greater reproductive success. WHAT IS ALREADY KNOWN: Higher physical activity is related to better semen quality but no studies to date have investigated whether it predicts greater reproductive success. STUDY DESIGN, SIZE, DURATION: The Environment and Reproductive Health (EARTH) Study is an on-going prospective cohort study which enrolls subfertile couples presenting at Massachusetts General Hospital (2005-2013). In total, 231 men provided 433 semen samples and 163 couples underwent 421 IVF or intrauterine insemination cycles. PARTICIPANTS/MATERIALS, SETTING, METHODS: Leisure time spent in physical and sedentary activities over the past year was self-reported using a validated questionnaire. We used mixed models to analyze the association of physical and sedentary activities with semen quality and with clinical pregnancy and live birth rates. MAIN RESULTS AND THE ROLE OF CHANCE: Men in this cohort engaged in a median of 3.2 h/week of moderate-to-vigorous activities. Men in the highest quartile of moderate-to-vigorous activity had 43% (95% confidence interval (CI) 9, 87%) higher sperm concentrations than men in the lowest quartile (P-trend = 0.04). Men in the highest category of outdoor activity (≥1.5 h/week) and weightlifting (≥2 h/week) had 42% (95% CI 10, 84%) and 25% (95% CI -10, 74%) higher sperm concentrations, respectively, compared with men in the lowest category (0 h/week) (P-trend = 0.04 and 0.02). Conversely, men who reported bicycling ≥1.5 h/week had 34% (95% CI 4, 55%) lower sperm concentrations compared with men who reported no bicycling (P-trend = 0.05). Paternal physical and sedentary activities were not related to clinical pregnancy or live birth rates following infertility treatment. LIMITATIONS, REASONS FOR CAUTION: The generalizability of the findings on live birth rates to populations not undergoing infertility treatment is limited. WIDER IMPLICATIONS OF THE FINDINGS: Certain types of physical activity, specifically weightlifting and outdoor activities, may improve semen quality but may not lead to improved success of infertility treatments. Further research is needed in other non-clinical populations. STUDY FUNDING/COMPETING INTERESTS: The authors are supported by NIH grants R01-ES009718, ES000002, P30-DK046200, T32-DK007703-16 and ES022955 T32-HD060454. None of the authors has any conflicts of interest to declare.

Dairy food intake in relation to semen quality and reproductive hormone levels among physically active young men.

STUDY QUESTION: Is increased consumption of dairy foods associated with lower semen quality? SUMMARY ANSWER: We found that intake of full-fat dairy was inversely related to sperm motility and morphology. These associations were driven primarily by intake of cheese and were independent of overall dietary patterns. WHAT IS KNOWN ALREADY: It has been suggested that environmental estrogens could be responsible for the putative secular decline in sperm counts. Dairy foods contain large amounts of estrogens. While some studies have suggested dairy as a possible contributing factor for decreased semen quality, this finding has not been consistent across studies. STUDY DESIGN, SIZE, DURATION: The Rochester Young Men's Study (n = 189) was a cross-sectional study conducted between 2009 and 2010 at the University of Rochester. PARTICIPANTS/MATERIALS, SETTING, METHODS: Men aged 18-22 years were included in this analysis. Diet was assessed via food frequency questionnaire. Linear regression was used to analyze the relation between dairy intake and conventional semen quality parameters (total sperm count, sperm concentration, progressive motility, morphology and ejaculate volume) adjusting for age, abstinence time, race, smoking status, body mass index, recruitment period, moderate-to-intense exercise, TV watching and total calorie intake. MAIN RESULTS AND THE ROLE OF CHANCE: Total dairy food intake was inversely related to sperm morphology (P-trend = 0.004). This association was mostly driven by intake of full-fat dairy foods. The adjusted difference (95% confidence interval) in normal sperm morphology percent was -3.2% (-4.5 to -1.8) between men in the upper half and those in the lower half of full-fat dairy intake (P < 0.0001), while the equivalent contrast for low-fat dairy intake was less pronounced [-1.3% (-2.7 to -0.07; P= 0.06)]. Full-fat dairy intake was also associated with significantly lower percent progressively motile sperm (P= 0.05). LIMITATIONS, REASONS FOR CAUTION: As it was a cross-sectional study, causal inference is limited. WIDER IMPLICATIONS OF THE FINDINGS: Further research is needed to prove a causal link between a high consumption of full-fat dairy foods and detrimental effects on semen quality. If verified our findings would mean that intake of full-fat dairy foods should be considered in attempts to explain secular trends in semen quality and that men trying to have children should restrict their intake. STUDY FUNDING/COMPETING INTEREST(S): European Union Seventh Framework Program (Environment), 'Developmental Effects of Environment on Reproductive Health' (DEER) grant 212844. Grant P30 DK046200 and Ruth L. Kirschstein National Research Service Award T32 DK007703-16 from the National Institutes of Health. None of the authors has any conflicts of interest to declare.

Intakes and sources of total and added sugars among 4 to 13-year-old children in China, Mexico and the United States.

BACKGROUND: Intakes of dietary sugars is a global concern, and many national and international organizations have set targets to limit consumption. However, it is unclear to what extent intakes of total and added sugars vary between geographies. OBJECTIVES: The aim of this study was to assess the differences in intakes of total and added sugars in 4 to 13-year-old children in China, Mexico and the United States. The secondary aim was to identify main sources of total and added sugars in the diets of these children. METHODS: Secondary data analysis was conducted using the 2011 China Health and Nutrition Survey, 2012 Mexican National Health and Nutrition Survey, and 2009-2012 US National Health and Nutrition Examination Surveys. Total and added sugar intakes were calculated using the US Food Patterns Equivalents Database. RESULTS: Mean intakes of total and added sugars were 26 and 9 g d-1 among Chinese children, 92 and 55 g d-1 among Mexican children, and 124 and 76 g d-1 among US children, respectively. The top food sources of total sugars were fruits among Chinese children, and sugar-sweetened beverages and milk-based beverages among Mexican and US children. CONCLUSIONS: These data highlight the heterogeneity of food patterns worldwide and the need for adapted country-specific public health recommendations on sugars.

Male soy food intake was not associated with in vitro fertilization outcomes among couples attending a fertility center.

Male factor etiology may be a contributing factor in up to 60% of infertility cases. Dietary intake of phytoestrogens has been related to abnormal semen quality and hormone levels. However, its effect on couple fecundity is still unclear. Intake of soy products was assessed in 184 men from couples undergoing infertility treatment with in vitro fertilization. Couples were recruited between February 2007 and May 2014 and prospectively followed to document treatment outcomes including fertilization, implantation, clinical pregnancy and live birth. Multivariate generalized linear mixed models with random intercepts, binomial distribution and logit link function were used to examine this relation while accounting for repeated treatment cycles and adjusting for potential confounders. Male partner's intake of soy foods and soy isoflavones was unrelated to fertilization rates, the proportions of poor quality embryos, accelerated or slow embryo cleavage rate, and implantation, clinical pregnancy and live birth. The adjusted live birth rates per initiated cycle (95% CI) for partners of men in increasing categories of soy food intake were 0.36 (0.28-0.45), 0.42 (0.29-0.56), 0.36 (0.24-0.51), and 0.37 (0.24-0.52), respectively. Soy food intake in men was not related to clinical outcomes among couples presenting at an infertility clinic. Data on the relation between phytoestrogens and male reproductive potential remain scarce and additional research is required to clarify its role in human reproduction.