Erectile dysfunction is simply the inability to maintain an erection long enough to have sex. Formerly referred to as impotence, erectile dysfunction is a serious problem, affecting more than 80 million men worldwide. While it may be uncomfortable for a man to discuss sexual problems with his doctor, many times erectile dysfunction is a symptom of a more serious health problem, and it should be brought to a physician's attention. While there are several popular drugs on the market to treat erectile dysfunction, a few dietary changes may also have a similar effect.

Watermelon

The main premise behind Viagra, or any drug used to treat erectile dysfunction, is its ability to allow blood vessels to relax, making it easier for blood to fill the penis. A similar effect occurs after eating watermelon, according to Texas A&M’s Dr. Bhimu Patil, who heads up the university's Fruit and Vegetable Improvement Center in College Station.

Watermelon contains citrulline, which is converted to arginine by enzymes in the body. Arginine helps increase nitric oxide, which is beneficial to increased blood circulation.

Cold-Water Fish

Cold-water fish include salmon, tuna, mackerel and sardines. These fish are high in zinc content, and zinc plays an important role in the production of testosterone.

Pomegranate

Pomegranate appears to have several beneficial elements related to sexual performance, including increased sperm amounts and improved erections. A study that appeared in the April 2007 issue of International Journal of Impotence Research showed that 47 percent of the men who consumed pomegranate juice over 2 four-week periods with a two-week interruption in between reported improved erections.

Researchers from the University of California, Los Angeles, and The Male Clinic in Beverly Hills, Calif., attributed the improvement to the antioxidant properties of pomegranate, which help with blood circulation.