Effects of Dietary Glucose on Serum Estrogen Levels and Onset of Puberty in Gilts

Sugar-sweetened beverage intake in relation to reproductive parameters in young men

BACKGROUND

There has been a decrease in sperm concentration in recent years. Concurrently, there were important dietary changes, including an increase in sugar-sweetened beverage intake (SSB). The relation between SSB and male reproduction functions in humans are barely described in the literature.

METHODS

Cross-sectional study with 209 participants (18-23 years old) recruited during one year in Murcia, Spain. All men provided semen and blood samples the same day. SSB consumption was evaluated using a 101-item validated food frequency questionnaire. Reproductive hormones were analysed from serum samples, obtaining levels of follicle-stimulating hormone, inhibin B, luteinizing hormone, estradiol, and testosterone. The evaluation of semen analysis followed the WHO guidelines and consisted of seminal volume, sperm concentration, total sperm count, percentage of morphologically normal sperm, and percentage of motile sperm. SSB intake association with semen parameters and hormone levels were examined using multiple linear regression.

RESULTS

Men in the highest quartile of the SSB intake had a higher percentage of morphologically normal sperm, 37.4% [6.1, 68.3] (p, trend=0.047) and higher estradiol levels (9.5% [-3.5, 22.5] (p, trend=0.047) than those in the first quartile. SSB intake was unrelated to other semen quality parameters or reproductive hormone levels.

CONCLUSIONS

Our results indicate that sperm morphology and estradiol levels may be associated with sugar-sweetened beverage intake. These findings might be explained by physiological metabolism homeostasis, though more studies are required to confirm these results and draw conclusions in other male populations.

Diet and Nutrition in Gynecological Disorders: A Focus on Clinical Studies

A healthy lifestyle and a balanced diet play a paramount role in promoting and maintaining homeostatic functions and preventing an array of chronic and debilitating diseases. Based upon observational and epidemiological investigations, it is clear that nutritional factors and dietary habits play a significant role in gynecological disease development, including uterine leiomyoma, endometriosis, polycystic ovary syndrome, and gynecological malignancies. Diets rich in fruits and vegetables, Mediterranean diets, green tea, vitamin D, and plant-derived natural compounds may have a long-term positive impact on gynecological diseases, while fats, red meat, alcohol, and coffee may contribute to their development. Data regarding the association between dietary habits and gynecological disorders are, at times, conflicting, with potential confounding factors, including food pollutants, reduced physical activity, ethnic background, and environmental factors limiting overall conclusions. This review provides a synopsis of the current clinical data and biological basis of the association between available dietary and nutritional data, along with their impact on the biology and pathophysiology of different gynecological disorders, as well as an outlook on future directions that will guide further investigational research.

Exploring the Impact of a Low-Protein High-Carbohydrate Diet in Mature Broodstock of a Glucose-Intolerant Teleost, the Rainbow Trout

Sustainable aquaculture production requires a greater reduction in the use of marine-derived ingredients, and one of the most promising solutions today is the augmentation in the proportion of digestible carbohydrates in aquafeed. This challenge is particularly difficult for high trophic level teleost fish as they are considered to be glucose-intolerant (growth delay and persistent postprandial hyperglycemia observed in juveniles fed a diet containing more than 20% of carbohydrates). It was previously suggested that broodstock could potentially use carbohydrates more efficiently than juveniles, probably due to important metabolic changes that occur during gametogenesis. To investigate this hypothesis, 2-year old male and female rainbow trout (Oncorhynchus mykiss) were either fed a diet containing no carbohydrates (NC) or a 35%-carbohydrate diet (HC) for an entire reproductive cycle. Zootechnical parameters as well as the activities of enzymes involved in carbohydrate metabolism were measured in livers and gonads. Fish were then reproduced to investigate the effects of such a diet on reproductive performance. Broodstock consumed the HC diet, and in contrast to what is commonly observed in juveniles, they were able to grow normally and they did not display postprandial hyperglycemia. The modulation of their hepatic metabolism, with an augmentation of the glycogenesis, the pentose phosphate pathway and a possible better regulation of gluconeogenesis, may explain their improved ability to use dietary carbohydrates. Although the HC diet did induce precocious maturation, the reproductive performance of fish was not affected, confirming that broodstock are able to reproduce when fed a low-protein high-carbohydrate diet. In conclusion, this exploratory work has shown that broodstock are able to use a diet containing digestible carbohydrates as high as 35% and can then grow and reproduce normally over an entire reproductive cycle for females and at least at the beginning of the cycle for males. These results are highly promising and suggest that dietary carbohydrates can at least partially replace proteins in broodstock aquafeed.

Effects of supplying omega-3 polyunsaturated fatty acids to gilts after weaning on metabolism and ovarian gene expression

Omega-3 PUFA may benefit sow reproductive performance, but effects on weaned gilts are unknown. This study evaluated the effects of supplementing omega-3 PUFA to gilts after weaning on growth, metabolic markers, and gene expression of steroidogenic enzymes and hormone receptors. For 52 d, gilts in the control group were fed 100 g/d of regular diets, whereas gilts in the omega-3 group were fed 75 g/d of such diets plus 25 g/d of the microalgae Schizochytium sp. (3.5 g/d of omega-3 PUFA; n = 8 gilts/group). Blood samples were collected at day 0, day 21, and day 52. Total serum cholesterol levels were lower for the omega-3 group than for the control group (P < 0.05), but high-density lipoprotein-cholesterol levels were reduced at day 52 for both groups (P < 0.05). Gilts in the omega-3 group presented lower feed intake, better feed conversion, and less-intense immunolabeling for leptin and its receptor in the cytoplasm of oocytes included in primordial/primary follicles than gilts in the control group (P < 0.05). The expression of genes coding for cholesterol side-chain cleavage and aromatase enzymes and the LH receptor in follicular cells was lower for supplemented gilts (P < 0.05). Compared with controls, supplemented gilts presented decreased serum cholesterol levels and better feed conversion, but leptin presence and gene expression for steroidogenic enzymes and for the LH receptor were lower at ovarian level.