Benefits of a plant-based diet and considerations for the athlete.

Individuals may opt to follow a plant-based diet for a variety of reasons, such as religious practices, health benefits or concerns for animal or environmental welfare. Such diets offer a broad spectrum of health benefits including aiding in the prevention and management of chronic diseases. In addition to health benefits, a plant-based diet may provide performance-enhancing effects for various types of exercise due to high carbohydrate levels and the high concentration of antioxidants and phytochemicals found in a plant-based diet. However, some plant-based foods also contain anti-nutrional factors, such as phytate and tannins, which decrease the bioavailability of key nutrients, such as iron, zinc, and protein. Thus, plant-based diets must be carefully planned to ensure adequate intake and absorption of energy and all essential nutrients. The current narrative review summarizes the current state of the research concerning the implications of a plant-based diet for health and exercise performance. It also outlines strategies to enhance the bioavailability of nutrients, sources of hard-to-get nutrients, and sport supplements that could interest plant-based athletes.

Cycle-phase dependent associations between CRP, leptin, and reproductive hormones in an urban, Canadian sample.

OBJECTIVES: To assess the relationships among reproductive hormones, follicular development, inflammation, and adiposity in a sample of urban, Canadian women. MATERIALS AND METHODS: Participants (n = 41) had blood collected every 3 days through one interovulatory interval (IOI) to measure estradiol, progesterone, LH, FSH, leptin, and C-reactive protein (CRP). Participants underwent daily transvaginal ultrasound examinations during the IOI to quantify all follicles > 2 mm. CRP and leptin tertiles were used to compare conditions of high and low inflammatory processes and adiposity, respectively. RESULTS: Luteal phase estradiol, luteal phase LH, and follicular phase progesterone were lower among individuals in the highest CRP tertile (adjusted r(2) = 0.63, 0.70, 0.76, respectively). Luteal and follicular phase follicle diameter was greatest in the high CRP tertile (adjusted r(2) = 0.68, 0.71). Follicular phase progesterone was lowest among individuals in the highest leptin tertile, and follicular phase FSH was lowest among individuals in the lowest leptin tertile (adjusted r(2) = 0.54, 0.45). Luteal phase follicle diameter was highest among those in the moderate leptin tertile (adjusted r(2) = 0.49). DISCUSSION: This study is a first comprehensive assessment of the relationship between multiple ovarian function components and inflammatory biomarkers. The results are interpreted to mean that inflammatory and energetic stressors produce differential effects depending on population, adiposity, and cycle phase. Am J Phys Anthropol 160:389-396, 2016. © 2016 Wiley Periodicals, Inc.

Dominant follicle growth patterns and associated endocrine dynamics in anovulatory and ovulatory waves in women.

Growth patterns and associated endocrine profiles were compared between dominant anovulatory (ADF) and ovulatory follicles (OvF) developing from different waves within and between menstrual cycles in women. Follicular mapping profiles of 49 healthy women of reproductive age and blood samples were obtained every 1-3 days. Sixty-three dominant follicles were classified into wave 1 (W1ADF; n = 8) and wave 2 (W2ADF; n = 6) anovulatory follicles and wave 2 (W2OvF; n = 33) and wave 3 (W3OvF; n = 16) ovulatory follicles. Comparisons were made between W1ADF and W2ADF, W2ADF and W2OvF, and W2OvF and W3OvF. The waves were numbered 1, 2, or 3 based on when the waves emerged relative to the preceding ovulation. W1ADF emerged closer to the preceding ovulation, and W2ADF emerged in the late luteal or early follicular phase. The interval from emergence to maximum diameter was shorter for W2ADF than W1ADF and for W3OvF than W2OvF. Selection of W3OvF occurred at a smaller diameter compared to W2OvF. W1ADF regressed at a faster rate than W2ADF. Also, W1ADF were associated with lower mean FSH and higher mean estradiol than W2ADF. In contrast, W3OvF were associated with higher FSH and LH compared to W2OvF. However, W2OvF were associated with higher progesterone than W3OvF. This study contributes to the understanding of the physiologic mechanisms underlying selection of the dominant follicle, ovulation, and pathophysiology of anovulation in women, as well as optimization of ovarian stimulation protocols for assisted reproduction.

Ultrasound image attributes of human ovarian dominant follicles during natural and oral contraceptive cycles.

BACKGROUND: Computer-assisted analyses were used to examine ultrasound image attributes of human dominant ovarian follicles that developed during natural and oral contraceptive (OC) cycles. We hypothesized that image attributes of natural cycle follicles would quantitatively differ from those in OC cycles and that OC cycle follicles would possess image attributes indicative of atresia. METHODS: Dominant ovarian follicles of 18 clinically normal women were compared using transvaginal ultrasonography for the 7 days before ovulation during a natural cycle (n = 9) or the 7 days before peak estradiol in women using OC (n = 11). Follicles were analyzed using region and line techniques designed to compare the image attributes numerical pixel value (NPV), pixel heterogeneity (PH) and area under the curve (AUC). RESULTS: NPV was higher in OC cycle follicles with region analysis and tended to be higher with line analysis (p = 0.005 and p = 0.06, respectively). No differences were observed in two other image attributes (AUC and PH), measured with either technique, between natural and OC cycle follicles. CONCLUSION: The increased NPV value of OC cycle follicles and lack of differences in PH and AUC values between natural cycle and OC cycle follicles did not support the hypothesis that OC cycle follicles would show ultrasonographically detectable signs of atresia. Image attributes observed in OC cycle follicles were not clearly indicative of atresia nor were they large enough to preclude preovulatory physiologic status in OC cycle follicles.

A new model for ovarian follicular development during the human menstrual cycle.

OBJECTIVE: To evaluate changes in ovarian follicle dynamics during the human menstrual cycle to test the hypothesis that folliculogenesis occurs in a wave-like fashion. DESIGN: Prospective longitudinal study. SETTING: Healthy volunteers in an academic research environment. PATIENT(S): Fifty healthy women of reproductive age (range 19-43 years) with a history of regular menstrual cycles not taking medications known to interfere with reproductive function were evaluated. INTERVENTION(S): Transvaginal ultrasonography was performed daily for one interovulatory interval (IOI). MAIN OUTCOME MEASURE(S): Changes in the diameter and number of follicles > or =5 mm were evaluated. RESULT(S): Sixty-eight percent of women exhibited two waves of follicle development during the IOI and 32% exhibited three waves. Waves were characterized by an increase and subsequent decrease in the number of follicles > or =5 mm occurring in association with the growth of > or =2 follicles to > or =6 mm. A day effect and day by wave interaction were detected in the mean diameter of the largest three follicles and the number of follicles > or =5 mm. CONCLUSION(S): The follicular wave phenomenon in women provides a new model for ovarian function during the menstrual cycle and will improve our understanding of the ovarian response to fertility and hormonal contraceptive regimens.

Magnetic resonance image attributes of the bovine corpus luteum during development and regression.

To determine whether magnetic resonance (MR) image attributes of the corpus luteum (CL) reflect its physiologic status at different phases of the bovine ovarian cycle, we analyzed the numerical pixel values (NPVs), relaxation rates, proton densities (PDs), and apparent diffusion coefficients (ADCs) from T(1)-, T(2)-, and diffusion-weighted in vitro images and maps of the CL acquired at defined phases of luteal function. Ovaries were removed and serum samples taken on days 3, 6, and 10, or >/=17 (day 0 = ovulation), representing metestrus (n = 10), early diestrus (n = 7), mid-diestrus (n = 9), and proestrus (n = 7), respectively. Regions of interest (ROIs) in each quadrant of the CL (which occupied at least 20% of the quadrant) were selected for analysis. Three MR image slices were analyzed: the slice with the greatest cross-sectional area of the CL, and the slices acquired immediately before and after that slice. The mean NPVs of the CL in T(1)-weighted images increased at each phase from metestrus (1,104 +/- 40 msec) to early diestrus (1,119 +/- 77 msec), to late diestrus (1,206 +/- 43 msec) and proestrus (1446 +/- 80 msec; P < 0.001). The mean NPVs in T(1)-weighted images were higher in regressing CL (proestrous) than in any other phase (P < 0.002). Grayscale heterogeneity of CL in T(1)-weighted images tended to increase during regression (P < 0.07). Regressing CL (proestrus) exhibited higher T(1)-weighted mean NPVs (P < 0.01) and tended to have greater heterogeneity (P < 0.06) than growing (metestrus) and mature (diestrus) CL, even though similar progesterone concentrations were observed. The increased brightness and heterogeneity of regressing CL in T(1)-weighted images appeared to be correlated with increased connective tissue and triglyceride content and decreased vascularity. It is anticipated that diagnostic markers for luteal viability and atresia in the in vitro bovine model will be applied to in vivo studies in women.

Ovarian follicular development during the use of oral contraception: a review.

Over the past 40 years, alterations to the composition of oral contraceptives (OCs) have been made in attempts to reduce adverse effects and to improve patient compliance while maintaining contraceptive efficacy. However, there is growing evidence to indicate that reducing the estrogen dose to minimize adverse effects may have compromised the degree of hypothalamo-pituitary-ovarian suppression, particularly during the hormone-free interval (HFI) or following missed doses. Follicle development during OC use appears to occur in association with a loss of endocrine suppression during the HFI. This information provides a rationale for reducing or eliminating the HFI in OC regimens. There is also evidence for an increased risk of follicle development and ovulation in women who use delayed OC initiation schemes, such as the "Sunday Start" method. It is not currently known why some follicles ovulate during OC use while others regress or form anovulatory follicle cysts. Continued research about follicle development during OC use would provide insight into understanding the precise mechanisms of action underlying combined OCs, as well as those of continuous OC formulations and emergency contraceptive regimens.

Systemic inflammation is associated with ovarian follicular dynamics during the human menstrual cycle.

BACKGROUND: Ovarian processes and the timing of ovulation are important predictors of both female fertility and reproductive pathology. Multiple waves of antral follicular development have been documented during the menstrual cycle in women. However, the mechanisms underlying the development of follicular waves and their clinical significance are not fully understood. The objective of this study was to examine the relationship between C-reactive protein (CRP) and follicular waves in healthy women. We wanted to determine whether follicular wave dynamics influence systemic inflammation, as ovarian activity increases local inflammatory processes and blood flow. We tested the hypothesis that women with 3 follicular waves would have higher CRP concentrations than those with 2 waves. We further hypothesized that a greater number of major waves (those with a dominant follicle) would be positively associated with CRP. METHODS/PRINCIPAL FINDINGS: Thirty-nine healthy women underwent daily transvaginal ultrasound examinations for one interovulatory interval, as part of an earlier study. Serum was collected every 3 days during the interovulatory interval (IOI). Enzyme-linked immunosorbent assays were conducted to quantify serum CRP concentrations. Women with 3 waves had higher average log CRP concentrations (n = 14, -0.43±0.35) over the IOI than those with 2 waves (n = 25, -0.82±0.47, p = 02). Average log CRP concentrations were greater in women with 3 (0.30±0.31) versus 1 (-0.71±0.55) or 2 (-0.91±0.47) major waves (p = 0.03). Greater average CRP over the IOI was attributed to greater CRP in the follicular, but not the luteal phase, of the IOI. CONCLUSIONS/SIGNIFICANCE: A greater number of total antral follicular waves, in particular major waves, corresponded to greater serum concentrations of CRP. These findings suggest that women with a greater number of follicular waves exhibit greater tissue remodeling and therefore greater local and systemic inflammation.

Ovarian antral folliculogenesis during the human menstrual cycle: a review.

BACKGROUND Ovarian follicles undergo dynamic morphologic and endocrinologic changes during the human menstrual cycle. The physiologic mechanisms underlying recruitment and selection of antral follicles in women are not fully elucidated. METHODS A comprehensive review of >200 studies was conducted using PubMed. The objective was to compare and contrast different perspectives on human antral folliculogenesis. RESULTS Antral folliculogenesis has been studied using histologic, endocrinologic and/or ultrasonographic techniques. Different theories of antral follicle recruitment include: (i) continuous recruitment throughout the menstrual cycle; (ii) recruitment of a 'cohort' of antral follicles once in the late-luteal phase or early-follicular phase of each cycle and (iii) recruitment of two or three 'cohorts' or 'waves'  during each cycle. Generally, a single dominant follicle is selected in the mid-follicular phase of each cycle and this follicle ovulates at mid-cycle. However, a dominant follicle may also be selected during anovulatory waves that precede the ovulatory wave in some women. CONCLUSIONS There is increasing evidence to indicate that multiple waves of antral follicles develop during the human menstrual cycle. Ovarian follicular waves in women are comparable with those documented in several animal species; however, species-specific differences exist. Enhancing our understanding of the endocrine and paracrine mechanisms underlying antral follicular wave dynamics has clinical implications for understanding age-related changes in reproductive function, optimizing hormonal contraceptive and ovarian stimulation regimens and identifying non-invasive markers of the physiologic status of follicles which are predictive of oocyte competence and assisted reproduction outcomes.

Growth rates of ovarian follicles during natural menstrual cycles, oral contraception cycles, and ovarian stimulation cycles.

OBJECTIVE: To compare growth rates of ovarian follicles during natural menstrual cycles, oral contraception (OC) cycles, and ovarian stimulation cycles using standardized techniques. DESIGN: Prospective, comparative, observational, longitudinal study. SETTING: Healthy volunteers in research trials and infertility patients undergoing treatment at an academic institution. PATIENT(S): Women were evaluated during natural cycles (n = 50), OC cycles (n = 71), and ovarian stimulation cycles (n = 131). INTERVENTION(S): Serial transvaginal ultrasonography was performed to measure follicle diameter. Day-to-day growth and regression profiles of individual follicles were determined. Mean growth rates were calculated for ovulatory follicles. Mean growth and regression rates were calculated for anovulatory follicles. MAIN OUTCOME MEASURE(S): Follicle growth rate (in millimeters per day). RESULT(S): Mean follicular growth rate was greater during ovarian stimulation cycles (1.69 +/- 0.03 mm/day) compared to natural (1.42 +/- 0.05 mm/day) and OC cycles (1.36 +/- 0.08 mm/day). The interval from dominant follicle selection to ovulation was shorter during stimulation cycles (5.08 +/- 0.07 days) compared to natural cycles (7.16 +/- 0.23 days). CONCLUSION(S): Follicles grew faster during ovarian stimulation therapy compared to natural cycles or OC cycles. Greater follicular growth rates in stimulation cycles were associated with shorter intervals from selection to ovulation. The biologic effects of increased follicular growth rates and shorter intervals to ovulation on oocyte competence in women undergoing assisted reproduction remain to be determined.

Effects of oral contraceptives administered at defined stages of ovarian follicular development.

OBJECTIVE: To elucidate the effects of initiating oral contraceptives (OC) at defined stages of ovarian follicle development. DESIGN: Prospective longitudinal study. SETTING: Healthy volunteers in an academic research environment. PATIENT(S): Forty-five healthy women between the ages of 18 and 35 years, randomized to initiate OC when a follicle diameter of 10, 14, or 18 mm was first detected. INTERVENTION(S): The OC administration at defined stages of dominant follicle development. MAIN OUTCOME MEASURE(S): Fates of all dominant follicles and serum concentrations of E(2)-17beta, LH, and P before and after initiating OC. RESULT(S): No ovulations (0/16) were observed when OC use was initiated at a follicle diameter of 10 mm, 4/14 (29%) follicles ovulated when OC were initiated at 14 mm, and 14/15 (93%) ovulated when OC were initiated at 18 mm. When ovulation did not occur, follicles regressed or became anovulatory cysts. Peak LH and E(2) levels were lowest in the 10-mm group, moderate in the 14-mm group, and greatest in the 18-mm group. Peak endocrine levels in all treatment groups were lower than the historic reference group. CONCLUSION(S): Follicular development, ovulation, and endocrine concentrations were not suppressed effectively when OC were initiated at late stages of dominant follicle development.

Characterization of ovarian follicular wave dynamics in women.

A wave phenomenon of ovarian follicular development in women has recently been documented in our laboratory. The objective of the present study was to characterize follicular waves to determine whether women exhibit major and minor wave patterns of follicle development during the interovulatory interval (IOI). The ovaries of 50 women with clinically normal menstrual cycles were examined daily using transvaginal ultrasonography for one IOI. Profiles of the diameters of all follicles >or=4 mm and the numbers of follicles >or=5 mm were graphed during the IOI. Major waves were defined as those in which one follicle grew to >or=10 mm and exceeded all other follicles by >or=2 mm. Minor waves were defined as those in which follicles developed to a diameter of <10 mm and follicle dominance was not manifest. Blood samples were drawn to measure serum concentrations of estradiol-17beta, LH, and FSH. Women exhibited major and minor patterns of follicular wave dynamics during the IOI. Of the 50 women evaluated, 29/34 women with two follicle waves (85.3%) exhibited a minor-major wave pattern of follicle development and 5 women (14.7%) exhibited a major-major wave pattern. Ten of the 16 women with three follicle waves (62.5%) exhibited a minor-minor-major wave pattern, 3 women (18.8%) exhibited a minor-major-major wave pattern, and 3 women (18.8%) exhibited a major-major-major wave pattern. Documentation of major and minor follicular waves during the menstrual cycle challenges the traditional theory that a single cohort of antral follicles grows only during the follicular phase of the menstrual cycle.