Eating right increases male fertility
Infertility, defined as the failure to achieve pregnancy after one year of unprotected intercourse, affects 10 to 20 percent of couples. At least 40 percent of the time, the woman is unable to conceive because her male partner has a physical problem. As with female fertility, male fertility is affected by what foods and nutrients are eaten–although some of the specifics are different. Following is a review of the fertility factors that seem most important for men.
*Alcohol is a male reproductive tract toxin. Consumed in a large enough quantity over a long enough period of time, alcohol can cause infertility.1 Fortunately, findings from animal research suggest that the damage alcohol causes to sperm is at least partially reversible if males infertile from alcohol avoid drinking it for a “moderate” period of time.2
*Vitamin B12 deficiency also plays a role in fertility. Here’s how: Intrinsic factor is a substance necessary for the proper absorption of B12. When an aging stomach lining fails to secrete enough intrinsic factor, a B12 deficiency results causing serious or pernicious anemia. Eventually, this condition can cause infertility in both men and women. In one study, infertility caused by pernicious anemia was shown to be reversible with vitamin B12 injections.3
It is not necessary to obtain symptomatic or laboratory evidence of vitamin B12 deficiency because, among infertile men, even those without evidence of a B12 deficiency may respond to supplementation. For example, in one double-blind study 375 infertile men received daily injections of 1,5006,000 mcg of mecobalamin, a common form of the vitamin, although none of the participants had been evaluated for vitamin B12 deficiency. However, more than half of the men whose sperm counts were very low responded with increased sperm production.4
*Vitamin C has long been important to fertility. In recent years, we have become increasingly aware of the destructive effects of free radicals, which contribute to the development of many disorders. Vitamin C helps protect sperm against free radical damage.5
Several studies have found vitamin C supplementation not only increases sperm counts but improves various measures of sperm health.6 The vitamin’s therapeutic effects are not limited to changes seen in the laboratory. In one study, two months after 30 infertile but otherwise healthy men began receiving 1 g of the vitamin daily, all of their wives had become pregnant, whereas none of the wives of a similar group of men who received a placebo had become pregnant.7
*Zinc is among the most important nutrient minerals in regards to male fertility. Zinc levels in the seminal plasma (the fluid in which the sperm exist) are directly related to sperm mobility,8 and dietary zinc restriction reduces both sperm count9 and seminal plasma volume.10 Moreover, infertile men with azoospermia (absence of living sperm),11 as well as those with oligospermia (low sperm count),12 may have decreased seminal zinc levels.
Several clinical trials have found zinc supplementation to be an effective fertility treatment. In one study, 14 infertile men with unexplained low sperm counts (below 40 million/mL) received 220 mg of zinc sulfate daily. After four months, there were significant improvements in sperm count and in the number of progressively motile and normal spermatozoa–and the wives of two men conceived.13
The results of other studies suggest treatment of a low initial plasma testosterone14 or surgical correction of a varicocele (abnormal dilation of spermatic cord veins) prior to zinc supplementation15 increase the chances of success. In this latter study, of the entire group of infertile men who received zinc, only those who had a varicocelectomy prior to starting zinc supplementation had significant improvements in sperm counts and mobility; in other words, sperm did not improve unless the men had both surgery and zinc supplementation.
*L-arginine, a testosterone precursor, in adequate dietary amounts is necessary if a man is to maintain a normal sperm count.16 Adequate L-arginine is also important for sperm mobility, both because it is the precursor in the synthesis of polyamines17 and because it is the precursor to nitric oxide.18 The polyamines putrescine and spermidine are organic components important to sperm movement. Nitric oxide within spermatozoa also appears to be necessary for adequate sperm mobility. In fact, pathospermia (abnormal sperm) sometimes seems to be caused by abnormal arginine metabolism.19
Arginine aspartate, 9 g daily, has been effective in some cases of asthenospermia (reduced sperm mobility).20 Also, L-arginine, 4 g daily, has been shown to improve sperm counts in men with oligospermia, especially those with counts between 20 million and 50 million sperm per ejaculate.21
Because these simple, inexpensive and safe nutritional interventions can often transform an infertile couple into proud parents, they should be routinely considered in all infertility treatment programs.
