Is it true?  Sex Affects Intelligence let see.

New research says sexual activity can grow brain cells. Keeping them may be another matter.

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Forget mindfulness meditation, computerized working-memory training, and learning a musical instrument; all methods recently shown by scientists to increase intelligence. There could be an easier answer. It turns out that sex might actually make you smarter.
Researchers in Maryland and South Korea recently found that sexual activity in mice and rats improves mental performance and increases neurogenesis (the production of new neurons) in the hippocampus, where long-term memories are formed.
In April, a team from the University of Maryland reported that middle-aged rats permitted to engage in sex showed signs of improved cognitive function and hippocampal function. In November, a group from Konkuk University in Seoulconcluded that sexual activity counteracts the memory-robbing effects of chronic stress in mice. “Sexual interaction could be helpful,” they wrote, “for buffering adult hippocampal neurogenesis and recognition memory function against the suppressive actions of chronic stress.”

So growing brain cells through sex does appear to have some basis in scientific fact. But there’s some debate over whether fake sex—pornography—could be harmful. Neuroscientists from the University of Texas recently argued that excessive porn viewing, like other addictions, can result in permanent “anatomical and pathological” changes to the brain. That view, however, was quickly challenged in arebuttal from researchers at the University of California, Los Angeles, who said that the Texans "offered little, if any, convincing evidence to support their perspectives. Instead, excessive liberties and misleading interpretations of neuroscience research are used to assert that excessive pornography consumption causes brain damage.
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