Question: What effect does lifestyle have on fertility?
Answer: Relatively little is known about dietary interventions that improve fertility; however, it is recognized that men who eat more vegetables and fruit tend to have better sperm production than men who have more meat and fat in their diet.
Similarly, excess exercise can actually increase body heat and decrease sperm production, and men who are very sedentary tend to have more fat in their body and somewhat lower sperm production. So, moderate exercise—meaning exercises less than an hour and a half per day—is probably beneficial for sperm production, but excess exercise may actually be somewhat detrimental.
Question: Does the use of supplements help improve male fertility?
Answer: Personally, I’ve had concerns about the use of male infertility supplements that have herbal components because it’s hard to quantify which herbal components are present or to identify all of their effects. A Cochrane meta-analysis looking at the use of antioxidants suggests that antioxidants could improve sperm production and improve fertility for men, either with or without assisted reproduction.1 Exactly which agents that are most effective is not clear, as all different antioxidants that have been used in trial were analyzed together in that meta-analysis. However, it appears that trace elements such as zinc, antioxidants including CoQ10 and acetyl-l-carnitine, and at least trace amounts of selenium maybe helpful in enhancing fertility.
Question: Is a varicocele an important factor in infertility, and is varicocele repair worthwhile?
Answer: A recent Cochrane meta-analysis documented that men who have impaired semen parameters and infertility with a clinical varicocele will have improved fertility after varicocele repair.2 And most studies taken together suggest that the baseline fertility rate of about 16% would be at least doubled after varicocele repair, thus suggesting that clinical varicoceles, meaning varicoceles that can be palpated or that are > 3 mm on ultrasound, may be repaired with improvement in male fertility for men who have abnormal semen parameters.
Question: What is the potential effect of sperm defects on assisted reproduction?
Answer: The current recommendations of the American Society of Reproductive Medicine3 indicate that detailed sperm function testing, such as DNA fragmentation analysis, is not required prior to the use of assisted reproduction because, although abnormal sperm DNA fragmentation affects the results of assisted reproduction, it doesn’t affect IVF success rates enough not to have IVF treatment. In addition, the treatments for abnormal sperm DNA fragmentation are relatively limited. However, sperm DNA fragmentation analysis can be very helpful in identifying the reason for recurrent spontaneous miscarriages or multiple failed IVF cycles. So, it certainly can be a useful test to evaluate a man who has IVF failure with his female partner.
Question: How does obesity affect male fertility?
Answer: Certainly, it is recognized that men who are overweight tend to have more conversion of testosterones to estrogens. They have more local heat effects around the testicle; and men with lower body mass index tend to have better sperm production than men with elevated body mass index and obesity. Even though the overall trend to have better fertility with lower weight is relatively clear in multiple publications, it is also evident that men who have very rapid weight loss, at least rapid weight loss because of gastrointestinal bypass or surgery, tend to have a decrease in sperm production with an increased FSH level, even though the loss of weight is associated with an improved serum testosterone level. We don’t currently understand the mechanism by which this weight loss results in damage to the testes or decreased sperm production, but it is of concern that this has occurred, and this is observed now in several different studies.
- Showell MG, Brown J, Yazdani A, et al. Antioxidants for male subfertility. Cochrane Database Sys Rev. 2011 Jan 19;1:CD007411. doi: 10.1002/14651858.CD007411.pub2.
- Kroese AC, de Lange NM, Collins J, Evers JL. Surgery or embolization for varicoceles in subfertile men. Cochrane Database Syst Rev. 2012 Oct 17;10:CD000479. doi: 10.1002/14651858.CD000479.pub5.
- Male Infertility Best Practice Policy Committee of the American Urological Association; Practice Committee of the American Society for Reproductive Medicine. Report on optimal evaluation of the infertile male. Fertil Steril. 2006;86(5 Suppl 1):S202-S209.
Peter N Schlegel MD, FACS