Is it true that oysters can be an aphrodisiac? Here’s the science.

The question:

Is it true that oysters are an aphrodisiac?

The science:

For centuries, people have considered oysters an aphrodisiac, with at least one legendary lover, Giacomo Casanova, reportedly attributing his sexual prowess to eating dozens of them at a time.

Experts say these briny mollusks do contain elements that may enhance sex drive, though there is no scientific evidence showing a direct link to a more robust libido.

Raw oysters are high in zinc — a 3.5-ounce serving contains more than five times the recommended daily amount for an male adult and more than seven times for a female adult. Zinc is associated with improved testosterone levels, which influences male and female sex drives, and is essential for male fertility, research shows.

Zinc also boosts dopamine, a neurotransmitter involved in pleasure and reward-seeking behaviors and may influence sexual responses in men and women, said Julia Zumpano, a registered dietitian for the Center for Human Nutrition at the Cleveland Clinic.

Oysters also contain an amino acid called D-aspartic acid, which, research suggests, may support testosterone production, at least in animals. A review of 23 animal studies and four human studies showed that D-aspartic acid enhanced testosterone levels in male animals. Results, however, were inconsistent for humans.

There’s another explanation as to why oysters may bring out a romantic side: the placebo effect, said Waguih William IsHak, a professor of psychiatry at Cedars-Sinai and the University of California at Los Angeles, who edited a textbook on sexual medicine and co-wrote a chapter on aphrodisiacs.

Meta-analyses on placebo treatments for male and female sexual dysfunction have shown that people given a placebo reported an improvement in sexual functioning — in some studies, at a rate as high as 50 percent.

The placebo effect is meaningful and “has to always be raised with sexual functioning,” IsHak said.

What else you should know:

There is no set number of oysters needed to potentially produce an aphrodisiac effect, but for those who want to test the concept, experts recommend about four to six.

Experts differ on whether people should eat cooked or raw oysters, but if you try them raw, know that uncooked seafood can lead to a rare but serious infection with vibrio vulnificus, a pathogen carried by water and food.

There may be other ways you can enhance your sexual desire or performance, said Deb Laino, a board-certified sex and relationship therapist.

• Watermelon, beets and strawberries can be aphrodisiacs, too, because of their amino acids, vitamins and minerals, she said.
• Eating light is advised before a romantic encounter. A heavy meal, particularly with a lot of carbohydrates, may make you sleepy and kill the mood.
• Don’t drink too much alcohol. One or two glasses of wine is plenty, Laino said.

The bottom line:

There’s no scientific evidence proving oysters increase sex drive in humans. But some experts hypothesize that the mollusk contains elements that may be associated with greater sexual desire and functioning.