Having frequent sex throughout a woman’s monthly cycle boosts her immune system and increases the chance of conception. No mention of whether men benefit from more sex, but I’m going to guess yes.
The researchers also found that during the follicular phase of the menstrual cycle—the period of time before ovulation—Type 1 T-cell count surged in sexually active. This helps the body safeguard against illnesses and infections that could ultimately inhibit a woman’s chance of becoming pregnant.
The second paper looked at immunoglobulin antibody levels in women who were sexually active and compared them to the levels in those who were not. These antibodies are produced by white blood cells and are critical to fighting off bacteria, viruses and other microbes. The researchers found that sexually active women had higher levels of certain antibodies at different times of their cycle, and the pattern reflected the body’s efforts to ramp up its protective defense to prepare for the potential for pregnancy. The researchers did not observe the same fluctuations in T-cell counts and immunoglobulins in non–sexually active women.
Short version: have more sex if you want to get sick less or are trying to conceive.