Advertisements

Thirst: Our brains tell us when to stop drinking

When the water content of our blood drops, neurons in the brain tell us that we are thirsty. But how do we know when enough is enough?
Water

Water is essential to life. When we get deydrated, it can have serious consequences.

The water content in our body is tightly regulated. Dehydration can lead to dizziness, delirium, and unconsciousness. Drinking fluids restores this balance or homeostasis.

But it takes time for water to travel from our mouths through the body. We stop drinking a long time before this happens.

If we kept drinking during this delay, we would be at serious risk of water intoxication, or water poisoning, which is potentially deadly.

Scientists are beginning to unravel the sophisticated mechanisms that stop us from drinking too much water, and the answer lies in the brain.

What controls thirst?

The brain’s thirst control circuit is a small region in the forebrain called the lamina terminalis (LT).

Once the LT network is activated, we become thirsty. A study published last week in the journal Science demonstrated that thirst creates an uncomfortable feeling in mice, which is alleviated by drinking.

There is one other thing that triggers thirst: eating. As soon as we start to eat, our thirst is stimulated. This is known as prandial thirst.

Water is necessary for us to digest the food that we eat. It also stops electrolytes in food from disturbing homeostasis by balancing out the fluid levels.

Why do we stop drinking?

Zachary A. Knight, Ph.D. – from the Department of Physiology at the University of California, San Francisco – and his team reported in the journal Nature that neurons in the subfornical organ (SFO), which forms part of the LT, might be at the heart of things.

The authors explain that “much normal drinking behavior is anticipatory in nature, meaning that the brain predicts impending changes in fluid balance and adjusts behavior pre-emptively.”

For their study, the researchers used mice and restricted their access to water overnight. “When water was made available,” the authors write, “mice drank avidly and, surprisingly, [SFO] neurons were inhibited within 1 min.”

This drop in neuronal signaling happened much faster than the water was able to reach the blood.

“Drinking resets thirst-promoting SFO neurons in a way that anticipates the future restoration of homeostasis,” they add. This means that our brain anticipates how much water we need to drink to restore homeostasis.

Signals from the mouth to the brain

What is not yet clear is how the brain knows when we are drinking fluids. A recent study published in the journal Nature Neuroscience pointed the finger at receptors in our mouth.

The team – led by Yuki Oka, Ph.D., who is from the Division of Biology and Biological Engineering at the California Institute of Technology in Pasadena – showed that water changes the acid balance in the saliva, which activates acid-taste receptors.

So, what is the best way of quenching thirst? A study by Sanne Boesveldt, Ph.D. – from the Division of Human Nutrition at Wageningen University & Research in the Netherlands – and her team, which will be published in the October edition of the journal Physiology & Behavior, set out to answer this question.

The authors explain that cold drinks are already known to be more thirst quenching, as are sour, flavored, and carbonated drinks.

In their study, the team found that cold, flavored popsicles were significantly more thirst quenching than cold liquids. The most effective flavor was lemon.

So, while the days may be getting colder as fall gets underway in the Northern hemisphere, a lemon popsicle might still be a good option the next time thirst calls.

Advertisements

Lose weight by having sex with your partner

With more than half of the United States population on a diet, weight loss is clearly on our minds. But should you include sex in your weight management plan? We investigate.

sex and weight loss

Sex helps us burn calories. But the benefits don’t stop there.

A healthy weight is part and parcel of a healthy lifestyle. Keeping our pounds in check is good for our ticker, our bones, and our lungs. It might even keep cancer at bay, as we found out this week.

But a staggering 73.7 percent of men and 66.9 percent of women in the U.S. are overweight or obese. Perhaps it comes as no surprise, then, that 66 percent of us are currently on a diet.

Whether opting for a tried-and-tested Mediterranean diet or a relative newcomer, like intermittent fasting, as a nation we understand that our diet, our weight, and our health are intricately linked.

According to the U.S. Department of Health and Human Services (HHS), “physical activity is an important part of maintaining healthy weight, losing weight, and keeping extra weight off once it has been lost.”

The HSS recommend at least 150 minutes of moderate-intensity exercise every week, but less than 25 percent of adults manage to hit this target.

Where does sex fit into this?

Well, sex is good for our health, it burns calories, and it makes us happy. You are, of course, unlikely to burn as many calories between the sheets as during a heavy gym session, but exercise alone may not be the panacea for weight loss we give it credit for, according to a recent study.

So, get ready to look at the obvious and some of the more surprising reasons why sex should be firmly integrated into our plan to reach and maintain a healthy weight, regardless of whether you are a gym buff or not.

Sex is exercise

In 2013, Prof. Antony D. Karelis — along with colleagues from the Université du Québec à Montréal in Canada — studied exactly how many calories we burn when we get our groove on.

Prof. Karelis explains in his article in the journal PLOS ONE that only a handful of studies have attempted to shine the spotlight on the physiological effects during partnered sex with human subjects. All previous studies showed an increase in heart rate.

For his study, Prof. Karelis worked with 21 heterosexual couples, aged between 18 and 35.

The couples were asked to have sex once per week for a period of 4 weeks, while wearing an activity tracker that allowed the research team to calculate how much energy they spent each time.

A sexual encounter included foreplay, intercourse, and at least one orgasm by either partner, then “ended at the couple’s discretion,” as the authors explain.

Here is what the team found.

Men burned on average 101 calories and women 69 calories when they had sex. The average intensity was higher than walking but lower than jogging, Prof. Karelis explains, putting it firmly in the category of moderate-intensity exercise.

This means that each time we have sex, it counts toward our 150 minutes of weekly exercise recommended by the HSS.

If that’s not appealing enough, the data revealed more.

‘More pleasant’ than a gym workout

The range of calories burned during sex varied considerably. At the lower end, men burned 13 calories and women 11.6, while at the top of the range, men shifted 306 calories and women 164.

Let’s look at these numbers into the context of how long each sexual encounter lasted. While the average duration of foreplay, intercourse, and orgasm was 24.7 minutes, the actual time the couples spent having sex ranged from 12.5 to 36.9 minutes.

Whether the top calorie-burners had more vigorous sex or just took their sweet time isn’t clear from the data, but we can draw some conclusions. If we want to increase our calorie loss during sex, we can either get more actively involved, keep at it for longer, or a combination of both.

Prof. Karelis also compared sex with regular gym exercise. He found that men burned between 149 and 390 calories during a 30-minute, moderate-intensity session on the treadmill, while women burned between 120 and 381.

When asked to compare the two activites, all of the men and 95 percent of the women in the study said that sex was more pleasant than pounding the treadmill.

So, we are not only making considerable headway toward reaching our 150-minute weekly exercise goal when we have sex, we also stand to gain more pleasure than from a gym visit.

Exercise may not equal weight loss

While some may argue that a study on healthy, young individuals may not be representative of the general population, the participants included a wide spread of weight categories.

Body mass index (BMI) for men varied between 19.5 and 31, putting at least some of the men in the overweight and obese category. For women, the range was from 16.9 to 26.6, meaning some of the women were underweight and some were overweight.

The study doesn’t reveal anything about the participants’ weight during the 4 weeks they took part. But if you’re looking to shift some pounds, exercise alone may not be the answer to weight loss we once thought it was, as we reported last week.

Researchers from the University of Bangor in the United Kingdom found no discernible weight loss in women who had taken part in three sessions of circuit exercise training per week for either 4 or 8 weeks, despite burning around 3,400 calories in total during this time period.

On the contrary, the team identified changes in hormones that control appetite in overweight and obese study participants after exercise.

“[…] Someone undertaking more physical activity may experience increased appetite as a result,” senior study author Hans-Peter Kubis, Ph.D., explains.

Sex might fill a useful gap here because hormones released during our amorous experiences cause us to eat less.

Sex curbs food intake

The “love hormone” oxytocin is produced in the hypothalamus in our brain as well as in our gastrointestinal tract, and it has been accredited with key functions in sex, empathy, relationship-building, childbirth, and breast-feeding.

Oxytocin levels shoot up when we have sex – specifically, when we experience orgasm. But that’s not all the love hormone can do.

Dr. Elizabeth A. Lawson — from the Neuroendocrine Unit at Massachusetts General Hospital in Boston — explains in an article in the December edition of Nature Reviews Endocrinology that “experiments in rodents, nonhuman primates and humans consistently show that oxytocin reduces caloric consumption.”

She adds that men ate fewer calories, particularly in the form of fat, after receiving 24 international units (IU) of oxytocin in a nasal spray in one study.

“The authors found that oxytocin reduced consumption of a postprandial snack, particularly chocolate cookies,” Dr. Lawson explains.

It’s important to note that oxytocin doesn’t stick around in our bodies for very long. Within 2–8 minutes of being released, half of hormone will be gone.

The after-effect of a single sexual encounter on our food intake will therefore only ever be transient. Still, every little helps, and a temporary curb on eating after sex is sure to contribute to overall weight loss.

Sex and weight management

Now that we’ve looked at the benefit of sex when it comes to burning calories and temporarily putting a halt on eating, how likely is it that we are going to lose weight by having sex?

That probably depends on how easy it is to incorporate sex into your personal schedule. Finding time to be romantic sounds easy, but the stark reality of busy lives make it less tenable for some.

However, it is worth reminding ourselves that sex has a plethora of health benefits, and, unlike a gym visit, you don’t have to stray far from your bedroom — or other location of personal preference — to make it happen.

So, if you are looking to shed a few pounds in the lead up to the peak holiday season, why not make the time to spend with your partner, enjoy sharing some intimate moments, and bask in the full effect that all that oxytocin and calorie loss will hopefully have on your scales.

You might find that your 2018 diet plan will easily accommodate sex as an indispensable component.

Health benefits of sex

Type “sexual health” into a search engine, and it is likely that you will be bombarded with pages of articles covering anything and everything, from sexual norms and advice on relationships, birth control, and pregnancy, to information about STDs and how to avoid them. What is less often discussed, however, is the abundant physical and psychological health benefits of sex. We have put together a list of the top health benefits of sex, as backed up by science.

[man and woman in bed looking intimate]

Sex has numerous physical and psychological health benefits.

In exploring just how sex affects the mind and body, the list of potential benefits appears to be endless.

Aside from reproduction, pleasure, and intimacy, sex seems to have a positive impact on many life areas, including work, physical and cognitive performance, marriage, and happiness into our senior years. Sex may also have a positive effect on certain organs and conditions, as well as a preventive effect on some diseases.

For example, a recent study published in the Journal of Management found that maintaining a healthy sex life at home might boost job satisfaction and engagement at work.

Sex may also play a fundamental role in preserving a happy marriage, according to research published in Psychological Science. Partners are suggested to experience a sexual “afterglow” that lasts for up to 48 hours following sexual intercourse. This afterglow is associated with higher levels of long-term relationship satisfaction.

Sex is also considered a significant form of exercise. Sex burns around 85 calories, or 3.6 calories per minute, according to a study published in PLOS One.

These few examples are a drop in the ocean of the numerous health benefits of sexual activity and masturbation that are presented in studies from around the globe. Medical News Today provide the low-down on the top evidence-based health benefits of sex.

1) Improves immunity

Participating in sex one to two times per week appears to be the optimum frequency to boost the immune system, according to research published in Psychological Reports.

Scientists can test how tough our immune systems are by measuring levels of an antibody called immunoglobulin A (IgA) in saliva and mucosal linings.

Study authors Carl Charnetski, from Wilkes University in Pennsylvania, and his colleague Frank Brennan found that people who had sex once or twice per week had a 30 percent increase in IgA. However, the same results were not seen in individuals who had sex more or less frequently.

Clifford Lowell, an immunologist at the University of California-San Francisco, says that people who are sexually active are exposed to more infectious agents than individuals who are not sexually active. The immune system responds to these infectious agents by producing more IgA, which may protect against colds and flu.

For those of you who have sex more or less frequently than the optimal amount, fear not. According to another study by Charnetski, petting a dog can also significantly raise IgA.

2) Good for the heart

Physical activities that exercise the heart are good for your health, and this includes sex. Being sexually aroused increases heart rate, with the number of beats per minute peaking during orgasm.

[red heart and cardiogram]

Men who have regular sex are 45 percent less likely to develop heart disease.

Men, in particular, have been shown to benefit from the effect of sex on the heart. A study published in the American Journal of Cardiology, involving men in their 50s, suggested that men who have sex at least twice per week have a 45 percent reduced risk of heart disease, compared with men who have sex less frequently.

The American Heart Association say that heart disease should not affect your sex life. Heart attacks or chest pain caused by heart disease rarely happen during sex and, for the most part, it is safe to have sex if your heart disease has stabilized.

The heart’s response to sex is comparable with mild to moderate effort encountered in daily activities, according to research published in the European Heart Journal. If you can take part in activities that have a similar impact on the heart – such as walking up two flights of stairs – without chest pain, then you can usually assume that it is safe to have sex.

More research is currently needed to draw connections between specific cardiovascular conditions and sex, particularly for women and older adults.

3) Lowers blood pressure

Research conducted by Michigan State University and published in the Journal of Health and Social Behavior found that sex in later years might reduce the risk of high blood pressure – at least for women.

Women in the study aged between 57 and 85 years who found sex pleasurable or satisfying were less likely to have hypertension. However, male study participants who had sex once per week or more were twice as likely to experience heart problems than men who were sexually inactive.

In another study published in Behavioral Medicine, researchers found that the act of hugging can help a person to maintain a healthy blood pressure.

According to the American Heart Association, high blood pressure increases the risk of heart attack and stroke and can also affect your sex life. High blood pressure has an impact on blood flow throughout the body and can prevent enough blood flowing to the pelvis.

In men, high blood pressure can lead to erectile dysfunction and in women, high blood pressure can lower libido and reduce interest in sex. It is considered safe to have sex if you have high blood pressure. However, if you are concerned or are having problems in the bedroom, seek advice from your doctor.

4) Relieves pain

headache may often be used as a reason to avoid sex. However, before you reach for the painkillers, neurologists have found that sexual activity can relieve head pain associated with a migraine or cluster headache in some people.

[woman in bed with migraine]

Sex has been shown to ease the pain associated with migraines and cluster headaches.

The research was conducted by the University of Munster in Germany and published in Cephalalgia. In individuals with a migraine, 60 percent of people reported an improvement in pain after sexual activity, while 37 percent of people with a cluster headache reported an improvement.

The University of Munster researchers explain that sex triggering the release of endorphins is the mechanism behind the pain relief. Endorphins are the body’s natural painkillers and are released through the central nervous system, which can reduce or eliminate pain the experienced with a headache.

In other research published in Pain, women were found to experience reduced pain sensitivity and had an increased pain tolerance threshold when experiencing pleasure through vaginal self-stimulation.

5) Reduces the risk of prostate cancer

Men who frequently ejaculate could be protected against prostate cancer, the most common cancer among men in the United States.

Research led by Michael Leitzmann, from the National Cancer Institute in Bethesda, MD, and published in JAMA, discovered that men who ejaculated 21 times per month or more were a third less likely to develop prostate cancer than men who ejaculated between four and seven times per month.

Leitzmann and team have a number of theories as to why increased ejaculation may help to prevent prostate cancer.

The first theory is that frequent ejaculation may allow the prostate gland to clear out carcinogens, and materials that may orchestrate the development of carcinogens. Another theory suggests that regular drainage of prostate fluid stops crystalloid microcalcifications – which are associated with prostate cancer – from developing in the prostate duct.

Men who have more than 12 ejaculations per month may also benefit, although the researchers note that at this point, the research would not warrant recommending men to change their sexual behavior.

6) Improves sleep

Do you have trouble getting to sleep at night? Sexual activity could be just what the doctor ordered.

[woman sleeping on man's chest]

Some of the chemicals released during sex may help you to fall asleep more easily.

Insufficient sleep is a public health problem, according to the Centers for Disease Control and Prevention (CDC). Around 50 to 70 million adults in the U.S. have a sleep disorder.

Sex could be the answer to help you achieve the recommended 7 to 9 hours of sleep per night.

During sex and orgasm, a cocktail of chemicals are released in the brain, which includes oxytocin, dopamine, and a rush of endorphins. Oxytocin, also known as the “cuddle hormone,” facilitates closeness and bonding, and it surges during sex and orgasm in both men and women.

After orgasm, it is thought that the effect of oxytocin, combined with the release of the hormone prolactin (which is linked to the feeling of satiety and relaxation), makes you feel sleepy.

In women, a rise in estrogen levels during sex has been shown to enhance their REM cycle, according to a study published in the Journal of Women’s Health.

In men, the prefrontal cortex – the area of the brain associated with alertness, consciousness, and mental activity – “switches off” after orgasm. According to a study published in Neuroscience & Biobehavioral Reviews, this process is connected with the release of oxytocin and serotonin, both of which have sleep-inducing effects.

7) Relieves stress

Stress can cause all kinds of health problems, from headaches, problems sleeping, muscle tension, and upset stomach, to more severe conditions, including a weakened immune system and chronic depression.

Evidence published in Psychosomatic Medicine demonstrated that physical or emotional intimacy in couples is associated with reduced stress levels.

A study published in Biological Psychology found that people who engaged in penetrative sex experienced lower stress-related blood pressure when public speaking than individuals who had masturbated or had non-coital sex. Participants in the study who abstained from sex had the highest blood pressure levels triggered by stress.

Stuart Brody, a psychologist at the University of Paisley in the United Kingdom, hypothesized that the calming effect might be caused by the release of the “pair-bonding” hormone, oxytocin.

8) Boosts brain power

Research published in the Archives of Sexual Behavior suggests that frequent sex may improve women’s memory. Results from a computerized word-memory task found that women who had penetrative sex had better memory recognition of abstract words.

[man holding a lightbulb]

Frequent sex may improve a woman’s ability to memorize words.

The researchers note that at this stage, it is unclear whether sex improves memory or if better memory leads to more sex. However, they say that sex may improve memory by stimulating the creation of new neurons in the hippocampus – the region of the brain that is involved in learning and memory.

Another study, by the University of Amsterdam in the Netherlands and published in Personality and Social Psychology Bulletin, found that thinking about love or sex has different effects on our brains.

Thinking about love activates long-term perspective and global processing, which promotes creative thinking and interferes with analytical thinking. However, in contrast, thinking about sex triggers short-term perspective and local processing, which then promotes analytical thinking and interferes with creativity.

9) Increases lifespan

Do you want to live longer? Sexual activity could hold the key to a longer life.

A study published in The BMJ concluded that sexual activity might have a protective effect on men’s health.

The researchers tracked the mortality of almost 1,000 men aged between 45 and 59 over the course of 10 years. They found that risk of death was 50 percent lower in men who frequently had orgasms than men who did not regularly ejaculate.

Other research also concluded with similar results. A 25-year study published in The Gerontologistdetermined that in men, frequent intercourse was a significant predictor of longevity, whereas in women, those who reported past enjoyment of sex lived longer.

10) Boosts self-esteem

In addition to all the physical benefits, having frequent satisfying sex may improve emotional wellness.

[woman with arms open in the sunset]

People who enjoy casual sex tend to report higher self-esteem and well-being.

Research published in Social Psychology and Personality Science found that among college students, those who enjoyed casual sex reported higher well-being and self-esteem levels, compared with students who did not have casual sex.

On the other side of the coin, according to a study published in the Journal of Adolescent Health, women with higher self-esteem reported having more satisfying sex, including having more orgasms.

These are just some of the many benefits that sex can have for your health. While sex can be a pleasurable and exciting activity, it is important to remember that practicing safe sex can reduce the risks of contracting STDs, as well as helping to avoid unplanned pregnancies.

How does sex affects our brains?

Sex! Sex! Sex! Having sex can flavor our nights, and days, with sweet pleasure and excitement, relieving stress and worry. And, of course, sex has been key to ensuring that the human race lives on. In this article, we ask, “How does sex impact what happens in the brain?”

thirdone-890x395

Sexual intercourse is known to impact the way in which the rest of our body functions.

Recent studies have shown that it can have an effect on how much we eat, and how well the heart functions.

As we have reported on Medical News Today, sex has been cited as an effective method of burning calories, with scientists noting that appetite is reduced in the aftermath.

Also, a study published in the Journal of Health and Social Behavior in 2016 found that women who have satisfying sex later in life might be better protected against the risk of high blood pressure.

Many of the effects of sex on the body are actually tied to the way in which this pastime influences brain activity and the release of hormones in the central nervous system.

Here, we explain what happens in the brain when we are sexually stimulated, and we look at how this activity can lead to changes in mood, metabolism, and the perception of pain.

Brain activity and sexual stimulation

For both men and women, sexual stimulation and satisfaction have been demonstrated to increase the activity of brain networks related to pain and emotional states, as well as to the reward system.

This led some researchers to liken sex to other stimulants from which we expect an instant “high,” such as drugs and alcohol.

The brain and penile stimulation

A 2005 study by researchers at the University Medical Center Groningen in the Netherlands used positron emission tomography scans to monitor the cerebral blood flow of male participants while their genitals were being stimulated by their female partners.

The scans demonstrated that stimulating the erect penis increased blood flow in the posterior insula and the secondary somatosensory cortex in the right hemisphere of the brain, while decreasing it in the right amygdala.

The insula is a part of the brain that has been tied to processing emotions, as well as to sensations of pain and warmth. Similarly, the secondary somatosensory cortex is thought to play an important role in encoding sensations of pain.

As for the amygdala, it is known to be involved in the regulation of emotions, and dysregulations of its activity have been tied to the development of anxiety disorders.

An older study from the same university — which focused on brain regions that were activated at the time of ejaculation — found that there was an increase in blood flow to the cerebellum, which also plays a key role in the processing of emotions.

The researchers liken the activation of the cerebellum during ejaculation to the pleasure rush caused by other activities that stimulate the brain’s reward system.

"Our results correspond with reports of cerebellar activation during heroin rush, sexual arousal, listening to pleasurable music, and monetary reward."

The brain and the female orgasm

In a study of the female orgasm that was conducted last year, scientists from Rutgers University in Newark, NJ, monitored the brain activity of 10 female participants as they achieved the peak of their pleasure — either by self-stimulation or by being stimulated by their partners.

The regions that were “significantly activated” during orgasm, the team found, included part of the prefrontal cortex, the orbitofrontal cortex, the insula, the cingulate gyrus, and the cerebellum.

These brain regions are variously involved in the processing of emotions and sensations of pain, as well as in the regulation of some metabolic processes and decision-making.

Another study previously covered on MNT suggested that the rhythmic and pleasurable stimulation associated with orgasm puts the brain in a trance-like state. Study author Adam Safron compares the effect of female orgasms on the brain to that induced by dancing or listening to music.

“Music and dance may be the only things that come close to sexual interaction in their power to entrain neural rhythms and produce sensory absorption and trance,” he writes.

“That is,” he adds, “the reasons we enjoy sexual experiences may overlap heavily with the reasons we enjoy musical experience, both in terms of proximate (i.e. neural entrainment and induction of trance-like states) and ultimate (i.e. mate choice and bonding) levels of causation.”

Sex and hormonal activity

So what does this all mean? In essence, it means that sex can impact our mood — normally for the better, but sometimes for the worse.

couple kissing in bed

Having sex has repeatedly been associated with improved moods and psychological, as well as physiological, relaxation.

The reason behind why we may feel that stressimpacts us less after a session between the sheets is due to a brain region called the hypothalamus.

The hypothalamus dictates the release of a hormone called oxytocin.

Higher levels of oxytocin can make us feel more relaxed, as studies have noted that it can offset the effects of cortisol, the hormone linked with an increased state of stress.

Not only does oxytocin make us calmer, but it also dampens our sense of pain. A study from 2013 found that this hormone could relieve headaches in individuals living with them as a chronic condition.

Another study from 2013 suggested that a different set of hormones that are released during sexual intercourse — called endorphins — can also relieve the pain associated with cluster headaches.

Can sex also make us feel down?

The answer to that, unfortunately, is “yes.” While s3x is generally hailed as a great natural remedy for the blues, a small segment of the population actually report an instant down rather than an instant high after engaging in this activity.

This condition is known as “postcoital dysphoria,” and its causes remain largely unknown. One study conducted in 2010 interviewed 222 female university students to better understand its effects.

Of these participants, 32.9 percent said that they had experienced negative moods after sex.

The team noted that a lifelong prevalence of this condition could be down to past traumatic events. In most cases, however, its causes remained unclear and a biological predisposition could not be eliminated.

“This draws attention to the unique nature of [postcoital dysphoria], where the melancholy is limited only to the period following sexual intercourse and the individual cannot explain why the dysphoria occurs,” the authors write.

Sex may lead to better sleep

Studies have shown that sexual intercourse can also improve sleep. After an orgasm, the body also releases higher levels of a hormone called prolactin, which is known to play a key role in sleep.

Researchers from Central Queensland University in Australia also hypothesized that the release of oxytocin during sex may act as a sedative, leading to a better night’s sleep.

In the case of men, ejaculation has been found to reduce activity in the prefrontal cortex, which is a brain region known to benefit particularly from a good night’s sleep.

In sleep, the prefrontal cortex exhibits the slowest brainwave activity compared with other brain regions, which supports the proper execution of cognitive functions during the daytime.

Researchers say that sex may lead to better cognitive functioning in older age, protecting people from memory loss and other cognitive impairments. Studies have shown that “older men who are sexually active […] have increased levels of general cognitive function.”

For women, being sexually active later in life appears to sustain memory recall, specifically. These effects may be due to the action of hormones such as testosterone and oxytocin, which are influenced by intercourse.

So, next time you’re about to slip between the sheets with that special someone, just know that this moment of passion will spark a whole neural firework show, releasing a special hormonal cocktail that will, at its best, charge a whole set of biological batteries.

Does sex enhance older brains?

New research found that older adults who reported having sex at least once each week got better scores on certain cognitive tests than those who reported having sex only once per month or not at all.

Senior couple in bed together.

Researchers have discovered that older couples who have sex at least once weekly perform better on certain tests of cognitive ability.

The study – by researchers at Coventry University and the University of Oxford, both in the United Kingdom – is published in the Journals of Gerontology, Series B: Psychological and Social Sciences.

Learn about the THINGS YOU MUST KNOW ABOUT YOUR PENIS

The research builds on earlier work, which found that sexually active older adults performed better on some tests of mental ability than those who were not sexually active.

However, it is not clear why such a link exists. The authors refer to other studies that have found that older adults who are physically active and also have busy social lives are likely to perform better on tests of mental function.

These might suggest that the link between sexual activity and cognitive function is just a reflection of the social and physical elements of sexual activity.

Lead author Dr. Hayley Wright, from the Centre for Research in Psychology, Behaviour and Achievement at Coventry University, and colleagues argue that sexual activity is a complex phenomenon with the potential to transcend not only its social and physical components, but also the emotional, psychological, and biological aspects.

They proposed that more frequent sexual activity may be linked with improved cognition, in the same way as such a link exists for other activities. Thus, they designed a study using a broader range of cognitive tests to investigate the link.

 

Study used range of cognitive tests

For their investigation, the team recruited 73 participants (28 men and 45 women) between 50 and 83 years of age, aged 62 on average.

The participants filled in a questionnaire that asked general questions about health and lifestyle, as well as how often they had engaged in sexual activity in the past 12 months. They were asked to respond with: once per week, once per month, or never.

Sexual activity was defined as “engagement in sexual intercourse, masturbation, or petting/fondling.”

The participants also underwent tests of mental ability. One of these – the Addenbrookes Cognitive Examination III – includes assessment of memory, verbal fluency, language, attention, and visuospatial ability, which is the ability to visualize objects and the spaces between them.

The verbal fluency test involves naming as many animals as possible in 60 seconds, and then to say as many words starting with the letter “F” as possible. The visuospatial ability test includes drawing a clock face from memory and copying a complicated design.

In their analysis, the researchers adjusted the results to account for gender, age, number of years of formal education, and cardiovascular health. They took heart health into account as this might influence frequency of sex and brain function.

Frequency of sex linked to cognitive scores

The results showed that frequency of sexual activity did not change with age, education, cardiovascular health, marital status, quality of life, and other factors.

More participants reported having had sex once each week than once per month or never in the last 12 months.

Participants who reported never having sex scored lower on average for overall cognitive function and verbal fluency compared with participants who reported having sex every week.

Also, participants who reported having sex once every month scored lower on average for verbal fluency and marginally lower on visuospatial ability, compared with those who reported having sex at least once weekly.

The team found no link between frequency of sexual activity and attention, memory, or language ability.

Because of its design, the study cannot prove that more frequent sex increases brain function; it can only establish a link and its strength. However, the researchers claim that it does shed more light on the association.

As Dr. Wright argues, “Every time we do another piece of research we are getting a little bit closer to understanding why this association exists at all, what the underlying mechanisms are, and whether there is a ’cause and effect’ relationship between sexual activity and cognitive function in older people.”

She and her colleagues suggest that further studies should investigate the biological aspects of the link and examine, for instance, the roles of dopamine and oxytocin.

People don’t like to think that older people have sex – but we need to challenge this conception at a societal level and look at what impact sexual activity can have on those aged 50 and over, beyond the known effects on sexual health and general well-being.”

Dr. Aubry Brain

Things you must know about your penis

Although many of us men are relatively familiar with our penis and its antics, there’s more to our appendage than meets the eye. In this feature, we discuss 10 interesting things that you probably didn’t know about your genitals.
Statue of David with close up on the penisWhat do you call yours?

Whatever you happen to call it — todger, wang, willy, or dangler — the penis is an odd-looking bit of kit. But beyond the japes and sniggers, it is, of course, vital to the survival of our species.

When you consider the penis as an evolutionary adaptation, it has done remarkably well.

We can all say without too much doubt that our father’s penis worked, as did our grandfather’s, and his father’s, and so on, right back through successive generations until we reach far beyond the birth of humanity.

The penis is ancient. Just in case you were wondering, the oldest known penis dates back 425 million years, and its fossilized remains belong to an arthropod dubbed Colymbosathon ecplecticos, which means “amazing swimmer with a large penis” in Greek.

It’s worth reflecting on its role in our species’ survival next time you are surprised by how easily your penis is “activated.” As far as reproduction is concerned, a false arousal is better than a missed opportunity.

As the author Mokokoma Mokhonoana once wrote, “Even the world’s greatest actor cannot fake an erection.” This leads us on to the first penis fact of the day.

1. Your first erection

Penises are born ready. It is common for babies to exit the womb with an erection. Even before the moment of birth, ultrasound scans sometimes show a fetus with a fully formed erection.

According to a study from 1991, fetal erections occur most commonly during random eye movement (REM) sleep. And, they can happen a number of times each hour. No one is quite sure why, but it might just be our body’s way of testing things out and keeping them running correctly.

2. Your penis is twice as long as you think

A lot of men might take solace in this fact: our penises are longer than they look. In fact, around half of its entire length is housed inside of our bodies.

Diagram of the penisAn internal view of the male genitalia.

You might be thinking, “Well, it’s no good to me up there,” but it needs to remain connected to the rest of your anatomy, so it’s probably best that it stays put.

As you can see from the diagram here, the mass of pink erectile tissue — which comprises the so grandly named corpus cavernosum and corpus spongiosum — extends well into the pelvic region, forming a sort of boomerang shape.

I wouldn’t use any of the above as a pick-up line, though.

3. The shoe size myth

Let’s lay this one to rest, shall we? According to a study published in the journal BJU International, there is no correlation between shoe size and penis length.

Although an older study — which was published in 1993 — did find that penile length was related to both height and foot length, it was a weak relationship, and the authors concluded, “Height and foot size would not serve as practical estimators of penis length.”

Also, the International Journal of Impotence Research published an Iranian study looking at other correlations. They concluded that “penile dimensions are significantly correlated with age, height, and index finger length,” but not foot size.

4. ‘Morning wood’

Most men have 3–5 erections every single night — mostly during REM sleep, as with the in utero boys.

A wooded area at sunrise

Morning wood isn’t as poetic as it sounds.

Also called nocturnal penile tumescence, it’s still not clear why it happens. However, one theory is that it might help to prevent bed-wetting; an erection inhibits urination.

A full bladder is known to stimulate nerves in a similar region to those involved in erections. But because females experience something similar — nocturnal clitoral tumescence — bed-wetting prevention is probably not the entire answer.

Another potential explanation is that REM sleep is linked with switching off cells that produce noradrenaline in the locus coeruleus, which is in the brainstem. These cells inhibit the tone of the penis. So, by reducing the inhibition, the penis becomes erect.

Whatever the reason behind nocturnal erections, they can be useful as a diagnostic tool. If a man has difficulty achieving an erection when awake but becomes erect when he sleeps, it is an indication that there is a psychological issue, rather than a physical one.

However, if he does not get erections during sleep, the issue may be physical.

5. One final erection

So, we’ve established that we can get erections in the womb and during sleep, but this is perhaps even more surprising: the death erection. Also called angel lust or terminal erection, it happens in the moments after death.

Most commonly, it occurs in men who have died from hanging; scientists believe that it may be due to pressure from the noose on the cerebellum. However, it has also been reported following death by a gunshot wound to the head, damage to major blood vessels, and poisoning.

6. You can break your penis

As I’m sure you are aware, there is no bone in your penis, which is fairly unusual for mammals. However, it is still possible to break your penis. It most commonly occurs during vigorous sex, although it has been documented to happen to men who fell out of bed with an erection.

Penile fracture, as it is known, is actually the rupture of the fibrous covering of the corpora cavernosa, which is the tissue that becomes erect when engorged with blood.

Up ↑

%d bloggers like this: