A lack of interest in sex may indicate an increased risk of premature death among men living in Japan, according to newly published research.
The exact relationship between mortality and libido is something researchers will need to disentangle, although researchers speculate that decreased sex drive may be a more visible sign of subtle health issues.
The data came from 20,969 people (8,558 men and 12,411 women) aged 40 or older who underwent annual medical examinations for six years in Yamagata Prefecture, a mountainous region of Japan famous for its hot springs, temples and natural beauty.
A team of researchers from Yamagata University looked at the self-reported level of sexual interest in an initial questionnaire and in a follow-up survey conducted many years later. Of the original 20,969 subjects, 503 died during this time.
Researchers found that cancer mortality and all-cause mortality were significantly higher for men who reported a lack of interest in sex.
The association held even when they controlled for factors such as age, high blood pressure, diabetes, smoking, alcohol consumption, BMI, education, marital status, frequency of laughter, and psychological stress.
“While sexual activity and sexual satisfaction are believed to be beneficial for mental health and well-being in older groups, the relationship between sexual interest and longevity has not been studied,” the researchers write.
“This study is the first to prospectively examine the associations between sexual interest and all-cause mortality and mortality from cardiovascular disease and cancer in a local population.”
The study found that women were more likely than men to report a lack of interest in sex – 16 percent of women in their sample did so, compared to 8 percent of male volunteers – but no significant association was found between lower libido and mortality in women as in men.
Because this is a purely observational study, there is no way to tell which, if any, factor is cause and which is effect.
It’s possible that a lack of sexual interest among men could be linked to an “unhealthy lifestyle,” researchers suggest.
“In addition, if we assume that sexual interest is associated with positive psychological factors,” they write, “lack of interest can influence a range of inflammatory, neuroendocrine, and immune responses.”
More research will be needed to understand what exactly is going on, but just revealing such a potential link is an important step, the researchers add.
Several important caveats should also be noted in the study. A person’s lack of sexual interest was determined by one question from the initial core questionnaire: “Currently, are you interested in people of the opposite sex?”
Even if everyone understands what the question is about, it excludes people who are attracted to people of the same sex, as the researchers admit.
“Any person who answered ‘no’ was defined as having no sexual interest. Thus, same-sex sexual interest would be considered “no sexual interest” in this study, they write.
The researchers estimate that their sample may have included around 200 LGBTQ participants, and due to the narrow question used in this study, there is therefore reason to doubt at least some of this data. The authors of the study call for this to be taken into account in future studies.
The new study also did not take into account certain “medically significant elements known to affect sexual function and longevity,” the authors wrote, such as neurological conditions or medications taken by the subjects, because it was not part of the main study.
Nevertheless, maintaining sexual interest can have a positive effect on longevity. Despite the limitations of the study, the researchers advocate raising awareness of sexual interest as a public health factor among older populations in Japan.
“The Canadian government has started to advocate sexual activity as part of its ‘well aging’ program through its public health materials. In Japan, there are more prejudices about sex among the elderly than in the Western world, the authors of the study write.
“We hope our findings will help promote public health by promoting sexuality in Japan.”
The study was published in the journal PLOS One.