Month: May 2023

Low sexual satisfaction in middle age may serve as an early warning sign for future cognitive decline, according to a new study.

The study, which tracked associations between erectile function, sexual satisfaction, and cognition in hundreds of men aged 56 through 68, found that declines in sexual satisfaction and erectile function were correlated with future memory loss.

The study, published in the journal Gerontologist, is the first to longitudinally track sexual satisfaction in tandem with sexual health and cognition, the researchers state, and its findings point to a potential new risk factor for cognitive decline.

“What was unique about our approach is that we measured memory function and sexual function at each point in the longitudinal study, so we could look at how they changed together over time,” says Martin Sliwinski, professor of human development and family studies at Penn State and coauthor of the study. “What we found connects to what scientists are beginning to understand about the link between life satisfaction and cognitive performance.”

The researchers explored the relationship between physical changes like the microvascular changes relevant for erectile function, and psychological changes, such as lower sexual satisfaction, to determine how the changes relate to cognition. They examined the shifts starting in middle age because it represents a transition period where declines in erectile function, cognition, and sexual satisfaction begin to emerge.

Sliwinski adds that while the team discovered a strong correlation between the three health factors, they can only speculate as to the cause.

“Scientists have found that if you have low satisfaction generally, you are at a higher risk for health problems like dementia, Alzheimer’s disease, cardiovascular disease, and other stress-related issues that can lead to cognitive decline,” he says.

“Improvements in sexual satisfaction may actually spark improvement in memory function. We tell people they should get more exercise and eat better foods. We’re showing that sexual satisfaction also has importance for our health and general quality of life.”

For the study, the researchers used survey data from 818 men who participated in the Vietnam Era Twin Study of Aging. Through neuropsychological tests, such as tests of memory and processing speed, they examined cognitive changes of participants over the 12-year span from age 56 to 68, adjusting for participants’ cognitive ability in young adulthood. Their erectile function and sexual satisfaction were measured alongside cognition, using the International Index of Erectile Function, a self-reported assessment for male sexual health. The researchers then built a statistical model to understand how the three variables changed as individuals aged.

“Research on sexual health has historically focused on quantifiable facets of sexuality like number of sexual partners or frequency of sexual activity,” says Riki Slayday, a doctoral candidate at Penn State and lead author of the study. “What we were interested in is the perception of that activity, how someone feels about their sex life, and how that influences cognitive function, because multiple people could be in the same situation physically but experience completely different levels of satisfaction.”

The researchers found that decreases in erectile function and sexual satisfaction were both associated with memory decline, which the researchers say points to a connection between psychological and physical health.

“When we mapped the relationship over time, we found increases or decreases in erectile function and sexual satisfaction were associated with concurrent increases or decreases in cognitive function,” Slayday says. “These associations survived adjustment for demographic and health factors, which tells us there is a clear connection between our sex lives and our cognition.”

Prior studies have found a link between microvascular changes and changes in erectile function over time. In fact, the active ingredient in Viagra (Sildenafil) was originally developed to treat cardiovascular problems, Sliwinski explains, so the connection between vascular health and erectile function is well understood. How erectile function connects to other aspects of health should be an area of focus for future research, he adds.

Increasing the assessment and monitoring of erectile function as a vital sign of health may help identify those at risk of cognitive decline before their 70s, he says. The researchers note that the older adult population in the US is expected to double over the next 30 years, which means twice as many people will likely enter their 60s and experience declines in erectile function and sexual satisfaction.

“We already have a pill for treating erectile dysfunction. What we don’t have is an effective treatment for memory loss,” Sliwinski says. “Instead of the conversation being about treating ED, we should see that as a leading indicator for other health problems and also focus on improving sexual satisfaction and overall well-being, not just treating the symptom.”

Additional coauthors are from of the University of California, San Diego and Boston University.

The National Institute on Aging at the National Institutes of Health supported the work.

Source: Penn State

Disparities in eight areas of life critical to health and well-being entirely explain why Black adults who live in the United States have a 59% higher risk of early death than white adults, researchers report.

The factors are called social determinants of health. They include employment, income, food security, education level, access to health care, quality health insurance, home ownership, and marital status.

Using data from the National Health and Nutrition Examination Survey, a CDC survey used to determine disease prevalence and risks across the country, the researchers modeled the impact of each factor on a person’s life expectancy. When all unfavorable social determinants were accounted for, the 59% mortality disparity was reduced to zero.

“It totally disappeared,” says Josh Bundy, an epidemiologist at Tulane University’s School of Public Health and Tropical Medicine and lead author of the paper published in The Lancet Public Health. “There’s no difference between Black and white premature mortality rates after accounting for these social determinants.”

While the mortality gap has been largely pinned on socioeconomic factors such as education level, income, and employment status in recent years, researchers have acknowledged that these factors only explained most of the gap, Bundy says.

“This is the first time that anyone completely explained the differences,” Bundy says. “We didn’t expect that, and we were excited about that finding because it suggests social determinants should be the primary targets for eliminating health disparities.”

Socioeconomic factors were still found to play a major role, accounting for approximately 50% of the Black-white difference in mortality in the study.

However, the other nearly 50% of the difference was explained by marital status, food security, and whether someone has public or private health insurance, softer indicators that can speak to a person’s social support network, stability, or job quality.

Unfavorable social determinants of health were more common among Black adults and were found to carry enormous risk.

Having just one unfavorable social determinant of health was found to double a person’s chances of an early death. With six or more, a person has eight times higher risk of premature mortality.

Corresponding author Jiang He, chair of epidemiology, says these results “demonstrated that race-based health disparities are social, not biological, constructs.”

Bundy agrees, adding that the findings explain how “structural racism and discrimination lead to worse social risk factors, which may lead to premature death.”

“So how do we eliminate the structural differences between races?” Bundy says. “And regardless of race, if you have six or more of these factors, you’re at a really high risk. How do we address these issues for everyone?”

As a concept, social determinants of health is a relatively new framework being emphasized by the CDC’s Healthy People 2030 initiative.

Going forward, Bundy hopes the concept gains more traction and that policymakers use these findings to address the race-based mortality gap.

“These social determinants of health are the foundation of health problems,” Bundy says. “They need to be a top priority going forward and it’s going to take policy, research, and a multi-disciplinary approach to tackle these issues.”

Source: Tulane University

The same neural circuitry involved in habit formation underlies binge eating disorders, according to a new study.

Habits are like shortcuts for our brains. Once we form a habit—say, putting on a seat belt whenever we get into a car—the behavior becomes almost automatic in the right context. But habit formation isn’t always a boon.

Using brain imaging, researchers saw differences in the neural circuitry that promotes habit formation in people with binge eating disorders, which involves consuming excessive amounts of food in a short time period.

The differences were more pronounced in those with more severe disorders. The habitual element of these conditions, the researchers say, could be part of the reason they are so hard to treat.

“A habit is a learned association. Maybe initially the behavior started to achieve a goal, but eventually you’ve done it so many times that you do the action without thinking about the outcome,” says Allan Wang, a medical student at the Stanford School of Medicine and lead author of the study, which appears in Science Translational Medicine.

“We were interested in whether habit formation in the brain might be involved in a complicated behavior like binge eating,” Wang says.

Binge eating disorders seem to have the hallmarks of habits. Episodes can be triggered by context, whether external, like the smell of food or an enticing advertisement, or internal, like feelings of sadness or frustration. People with these disorders also report feeling a loss of control over the behavior, which happens in maladaptive habits ranging from nail biting to drug addiction.

It wasn’t known, however, whether these disorders stemmed from the neural circuitry of habits.

To find out, the researchers first analyzed MRI scans from the Human Connectome Project, a large-scale venture that the National Institutes of Health sponsors, to map the brain circuits that underlie human behaviors. They focused on a region called the striatum, previously implicated in habits, and a particular part of the striatum called the sensorimotor putamen, which connects to brain regions that govern sensation and movement. Based on these connections, they hypothesized that the sensorimotor putamen would be key to habitual behavior.

Next, the researchers collected fMRI data, which measures brain activity, from 34 people who had been diagnosed with a binge eating disorder and from 22 healthy controls. All the participants were female. They answered questions about the frequency of their binges and whether they were driven by external or internal factors.

Compared with healthy controls, people with binge eating disorders had notable differences in the sensorimotor putamen’s neuronal connections with several brain regions—confirming the researchers’ hypothesis. They had stronger connections with the motor cortex, which is involved in movement, and the orbitofrontal cortex, involved in evaluating reward value, such as how good a food tastes. They had weaker connections with the anterior cingulate cortex, which regulates self-control.

The extent of the deviations reflected the severity of their disorder, regardless of whether the binges were externally or internally driven.

“Possibly, there’s some loss of self-regulation of this behavior,” Wang says. “At the same time, there’s increased strength of circuits involved in the motor behavior of binge eating.”

Further imaging studies revealed that patients with more altered habit circuitry also had less dopamine binding, or sensitivity to dopamine, in these brain regions. That hints at a mechanism underlying these abnormalities: The sensorimotor putamen uses dopamine, a neurotransmitter, to communicate with the cortex, so changes to dopamine sensitivity can alter these connections, Wang says. And decreased dopamine sensitivity can result from prolonged high levels of dopamine during repeated exposure to rewarding stimuli.

“Our findings suggest that the more dopamine exposure these patients have had in the context of binge eating, the more altered their overall habit circuit connectivity is,” he says.

It’s likely that the habit circuitry is also a factor in addiction and other psychiatric disorders, Wang says. Understanding how neuronal connections go awry in these conditions could guide targeted therapies, such as deep brain stimulation, which uses electric currents applied to the brain to alter neural activity.

“I think there’s also some mental benefit for patients in being able to reframe these behaviors as rooted in habit,” Wang says. “Eating disorders are not a fault of their personality. They’re related to physical changes in the brain.”

Whether people with binge eating disorders are more inclined toward other habits, good or bad, is an open question. “But it’s interesting to think about,” he says.

Source: Stanford University