How Food Choices Impact on Male Fertility

PURPOSE OF REVIEW

Increasing evidence on the significance of nutrition in reproduction is emerging from both animal and human studies, suggesting an association between nutrition and male fertility. Here, we have highlighted the impact of the various food groups on reproductive hormones and on spermatogenesis, and the effects of classical and latest dietary patterns such as Mediterranean diet, Western diet, intermittent fasting, ketogenic diet, and vegan/vegetarian diet on male fertility.

RECENT FINDINGS

Nutrients are the precursors of molecules involved in various body's reactions; therefore, their balance is essential to ensure the correct regulation of different systems including the endocrine system. Hormones are strongly influenced by the nutritional status of the individual, and their alteration can lead to dysfunctions or diseases like infertility. In addition, nutrients affect sperm production and spermatogenesis, controlling sexual development, and maintaining secondary sexual characteristics and behaviors. The consumption of fruit, vegetables, fish, processed meats, dairy products, sugars, alcohol, and caffeine importantly impact on male fertility. Among dietary patterns, the Mediterranean diet and the Western diet are most strongly associated with the quality of semen. Nutrients, dietary patterns, and hormonal levels have an impact on male infertility. Therefore, understanding how these factors interact with each other is important for strategies to improve male fertility.

Efficacy of Pomegranate Seed Powder on Glucose and Lipid Metabolism in Patients with Type 2 Diabetes: A Prospective Randomized Double-Blind Placebo-Controlled Clinical Trial

INTRODUCTION

Pomegranate is known as a functional food which has multiple health-promoting activities. It has been assessed for patients with metabolic syndrome. Specifically, an antidiabetic activity of its juice and plausible mechanisms for its action have been shown in multitudinous studies. The aim of this study was assessing the effects of complementary treatment with pomegranate seed powder (PSP) oral supplementation on patients with type 2 diabetes mellitus (T2DM).

METHODS

Sixty patients were treated for 8 weeks by 5 g PSP or placebo, twice daily. Fasting blood glucose (FBG), glycated hemoglobin (HbA1c), total cholesterol, and triglyceride (TG) were recorded as the outcome measures at the beginning and after the intervention. The findings were analyzed using the independent t test and Mann-Whitney U test.

RESULTS

After 8 weeks, the mean differences of FBG, HbA1c, cholesterol, and TG were significantly decreased in the PSP group when compared with the placebo group (p value <0.05). In addition, post-intervention values of FBG and HbA1c were significantly lower in patients treated with PSP compared to the placebo group (p values = 0.02 and 0.01, respectively). However, the latter comparison regarding cholesterol and TG showed no significant differences (p values = 0.51 and 0.26, respectively).

CONCLUSION

It seems that complementary treatment with PSP may have beneficial effects on FBG and HbA1c of patients with T2DM. However, its effect on TG and cholesterol was equivocal.

Effects of natural polyphenol-rich pomegranate juice on the acute and delayed response of Homocysteine and steroidal hormones following weightlifting exercises: a double-blind, placebo-controlled trial

BACKGROUND

Maximal strength-speed exercise is a powerful stimulus to acutely increase concentrations of circulating steroid hormones and homocysteine [Hcy]. There is some evidence that antioxidant beverages rich in polyphenols can attenuate [Hcy] levels and modulate endocrine responses in favor of an anabolic environment. Polyphenols-rich pomegranate (POM) have been reported to possess one of the highest antioxidant capacities compared to other purported nutraceuticals and other food stuffs. Studies focused on proving the beneficial effect of POM consumption during maximal strength exercises have only measured physical performance, muscle damage, oxidative stress and inflammatory responses, while POM effects on [Hcy] and hormonal adaptations are lacking. The aim of the present study was to investigate the effect of consuming natural polyphenol-rich pomegranate juice (POMj) on the acute and delayed [Hcy] and steroidal hormonal responses to a weightlifting exercises session.

METHODS

Nine elite weightlifters (21.0 ± 1 years) performed two Olympic-weightlifting sessions after ingesting either the placebo (PLA) or POMj supplements. Venous blood samples were collected at rest and 3 min and 48 h after each session.

RESULTS

Compared to baseline values, circulating cortisol [C] decreased (p < 0.01) and testosterone/cortisol [T/C] ratio increased immediately following the training session in both PLA and POMj conditions (p = 0.003 for PLA and p = 0.02 for POM). During the 48 h recovery period, all tested parameters were shown to recover to baseline values in both conditions with significant increases in [C] and decreases in [T/C] (p < 0.01 for PLA and p < 0.05 for POMj) from 3 min to 48 h post-exercises. Compared to PLA, a lower level of plasma testosterone [T] was registered 3 min post exercise using POMj supplementation (p = 0.012) and a significant decrease (p = 0.04, %change = - 14%) in plasma [Hcy] was registered during the 48 h recovery period only using POMj. A moderate correlation was observed between [Hcy] and [T] responses (p = 0.002, r = - 0.50).

CONCLUSION

In conclusion, supplementation with POMj has the potential to attenuate the acute plasma [T] response, but did not effect 48 h recovery kinetics of [Hcy] following weightlifting exercise. Further studies investigating androgen levels in both plasma and muscular tissue are needed to resolve the functional consequences of the observed acute POMj effect on plasma [T].

TRIAL REGISTRATION

Clinical Trials.gov, ID: NCT02697903. Registered 03 March 2016.