Lemon juice can both hurt and help male fertility, depending on how it is used. The nutrients in this juice -- including vitamin C and thiamin -- may boost fertility, although applying it directly to sperm may have deleterious effects. Do not consume lemon juice to treat male infertility without consulting your health-care provider.
About Male Fertility
The Mayo Clinic reports that 15 percent of couples are unable to conceive a child because one or both of them experience fertility problems. Male infertility may occur for any number of reasons, including damage to or malformation of the testicles, malformed sperm, small amounts of sperm, infections that attack sperm, tumors and hormonal imbalances. Diet may also influence the quality of sperm.
Getting adequate amounts of vitamin C through lemon juice and other foods in your diet may improve male fertility. A study published in the July 2011 issue of "Reproductive Biology and Endocrinology" investigated the effect of vitamin C on hyperglycemic rats and found it decreased the amount of abnormal sperm and boosted testosterone levels, both of which may contribute to male infertility. More research is needed to confirm this finding in humans. A 100-gram portion of lemon juice contains 77 percent of the daily recommended intake of vitamin C if you follow a 2,000-calorie diet.
Consume a serving of lemon juice, and you take in 3 percent of the thiamin you need each day. This thiamin may contribute to a protective effect when it comes to testicular injury. Research featured in the February 2009 "Journal of Huazhong University of Science and Technology" indicates that thiamin consumption -- in conjunction with vitamin C -- benefits sperm count and motility in male rats with impaired fertility triggered by lead exposure. Additional research is required to confirm that thiamin from lemon juice and other foods helps with fertility in human males.
Use as Birth Control
Despite the usefulness of lemon juice nutrients in boosting sperm quality and fertility, it can also be used to kill sperm. A study in the May 2006 "Fertility and Sterility" journal evaluated the effect of direct application of lemon juice to sperm. The acidity of lemon juice killed all sperm movement within one minute of exposure, leading researchers to theorize that lemon juice may serve as a natural contraceptive agent after additional research since it effectively dampens male fertility.