This applies to women, but I am sure there would be equivalent health problems for men too. The more sex partners (over 10!) a woman has the greater the cancer risk:
https://cancer.news/2020-07-28-study-finds-women-with-10-sexual-partners-greater-risk-of-cancer.html#
“Now, according to an alarming study published in the journal BMJ Sexual & Reproductive Health, researchers have discovered that women who have multiple sexual partners are also more likely to be diagnosed with cancer.
Women’s health and cancer risk
In the study, researchers examined data from 2,537 men and 3,185 women over 50. All the volunteers took part in the English Longitudinal Study of Ageing, which tracks long-term changes in a number of people.
The volunteers were asked to state the number of sexual partners they have had during their lifetime. Additionally, they were asked to give a “self-rated health and self-reported limiting long-standing illness, cancer, coronary heart disease, and stroke.”
Upon examining data from the volunteers, the researchers found that:
• Out of the male participants, 29 percent reported one or zero sexual partners, 29 percent had two to four, 20 percent had five to nine and 22 percent reported having 10 or more.
• Out of the female volunteers, just under 41 percent had one or zero sexual partners, 36 percent reported two to four partners, 16 percent reported five to nine partners and eight percent said they had 10 or more.
Unlike women who reported one partner or none, female participants who reported 10 or more were 91 percent more likely to have been diagnosed with cancer. On the other hand, men with 10 or more partners were 64 percent more likely to have been diagnosed with cancer, unlike other male volunteers who only had one partner or none. Dr. Lee Smith, one of the co-authors of the study, explained that this could be due to a stronger link between certain STDs and cancer in women like HPV (human papillomavirus) and cervical cancer, unlike HPV and penile cancer in men.
Greater exposure to STDs
Smith – who is also the director of research at the Cambridge Centre for Sport and Exercise Sciences at Anglia Ruskin University in England – said that having many sexual partners also increases your risk of getting STDs. The study suggests an association, but it didn’t prove that having more sexual partners throughout one’s lifetime was directly responsible for the greater likelihood of developing cancer. But data indicates a link between “a more promiscuous lifestyle” and other behaviors that may increase your risk of being diagnosed with cancer. For example, male and female volunteers with more sexual partners were often younger and unmarried. They were also more likely to smoke and consume alcohol frequently. Robert Edwards, a professor of obstetrics, gynecology and reproductive sciences at the University of Pittsburgh School of Medicine, said that habits like smoking and alcohol consumption both increased the risk for cancer, along with certain STDs. Smith also offered a suggestion for people with very active sex lives, saying that those who have had “risky sexual encounters” must consult their health care providers to get checked for potential STDs and discuss how to minimize this risk. Smith concluded that using “appropriate protection” is one of the most effective methods of lowering your risk of related cancers.”
No, the best form of “protection” is not to be having promiscuous sex in the first place, and for society to abandon the flawed libertarian philosophy of the 1960s, ands return to traditional values, such as no sex before marriage.