New research published Thursday by the British Medical Journal shows that 80% of 50 to 90 years olds are sexually active and with that, cases of sexually transmitted diseases have more than doubled in this age group over the past 10 years."You never have to retire from sex," says clinical psychologist Judy Kuriansky. "But you should always behave as the 20-30 year-olds do. You need to be cautious about it."Numbers from the Centers for Disease Control and Prevention indicate that incidences of syphilis and chlamydia in adults aged 45 to 64 have nearly tripled over the past decade. Cases of Gonorrhea are up as well."In general, I would say that older people are really enjoying their sexuality," says Ian Kerner, sex therapist, CNNHealth.com contributor and founder of GoodInBed.com. "People can be sexual throughout their lives, until the day they die."Researchers are quick to point out that there's a huge lack of data on STDs in older populations. The authors of the BMJ editorial also note that older women are more vulnerable physiologically. "Post-menopausal changes to the vagina, such as thinning of the mucosa, narrowing and shortening of the vagina, and decreased lubrication leave women more vulnerable to minor genital injuries and microabrasions that facilitate the entry of pathogens," they write.With age, as parents teach their kids, comes responsibility. So why are parents exposing themselves to these avoidable risks?"They just don't think it can happen to them" says Kuriansky. "STIs (sexually transmitted infections) really started making news in the '80s and '90s. The fears and the warnings didn't hit their generation." They also didn't expect to be sexual. "It's the Jane Fondas of the world and men in their 80s like John Glenn, who divorced his wife and married a younger woman," she says.Kerner is quick to point out that the 50+ age group is one of the fastest-growing demographics for online dating. "They wouldn't even necessarily classify themselves as older," he says. "It's often the second time around for them. They've been married, have adult children, and they don't have the same concerns or the same stressors that other people might face."Interestingly, one study found that men aged 40+ who were taking drugs for erectile dysfunction were significantly more likely to be diagnosed with an STD in their first year of usage. However, that same study also found that those same men were significantly more likely to be diagnosed in the year prior to starting the medication. That suggests the drug doesn't so much alter the risk-taking behavior, but rather facilitates it.Older men can be wary of condom use because it can contribute to erectile dysfunction. Women assume since they're above child-bearing years that condoms are unnecessary."Just as we spend a lot of time advising kids to practice safer sex, we need to do the same things for ourselves and our parents," says Kerner.And perhaps even our grandparents.Experts purport more awareness from the media would go a long way. Kuriansky also suggests more questioning and counseling by physicians. "If you're really going to do something about it," she says, "you have to be tested for herpes and other viruses. Now, you have to request that. They're not in routine blood tests. [They] should make it routine."