He’s known for carrying out wacky experiments on himself, from blasting his pelvic floor with electromagnetic pulses to receiving blood plasma infusions from his teenage son, and biohacker Bryan Johnson is clearly leaving no stone untouched in his quest for eternal youth.
The 45-year-old American billionaire and software entrepreneur has previously declared that he has no intention of dying and has been obsessed with improving his biological age.
With dozens of tests being conducted on every part of his body, from his gums to his bowels, Johnson’s latest headline-making move has been something called nocturnal penile tumescence testing (NPT), which tracks the length of his night-time erections during deep sleep. With his current readings of two hours and 12 minutes equating to a biological age of 49, he aims to boost this to three and a half hours, the night-time average of an 18-year-old.
“All men experience uncontrolled erections during sleep,” explains Professor Asif Muneer, consultant urology specialist at HCA Healthcare and The Princess Grace Hospital in London. “That’s just physiological. The autonomous nervous system, which controls erections, gets fired off without suppression during a certain part of your sleep. It’s a good measure that they’re functioning normally as it’s supposed to occur.”
NPT is often conducted by specialists in a sleep lab, but devices are also available that allow people to measure their night-time erections at home. The most accurate method uses a special electronic device connected to two rings, one placed at the tip of the penis and the other at the base.
The penis as a barometer of heart health
While urologists most commonly use this test as a way of assessing cases of erectile dysfunction, measuring the length and frequency of erections can also be a vital indicator of heart health.
“The penis is an excellent barometer of your physical health,” says Tobias Köhler, Professor of Urology at the Mayo Clinic in Rochester, Minnesota. “And if it’s not working, it could be a sign of impending doom.”
According to medical experts, healthy men can experience as many as three to five erections per night, lasting up to 20 or 30 minutes at a time, while research has found that regularly waking up with “morning wood” is also a sign of good circulation and a well-functioning heart.
It is normal to have fewer erections as you age, particularly beyond 50, but last year, a study of 1800 middle-aged and older men in Belgium published in the journal Age and Ageing found that those who regularly woke up erect were 22 per cent less likely to have a heart attack or stroke in the following three to five years.
While measuring erection length at night using NPT can be one way of assessing your health, Köhler says that any cases of erectile dysfunction during sexual activity are the biggest warning sign that something is amiss, especially for younger and middle-aged men who still have relatively healthy levels of the hormone testosterone which helps drive erections. Bouts of erectile dysfunction which do not stem from psychological problems or factors such as excessive pornography consumption can be an indicator of serious internal health issues.
“In young men, it’s one of the more powerful predictors of cardiac events that we have,” Köhler says. “On average, for men with certain types of erectile dysfunction, the first heart attack occurs three to five years after the first problems in the bedroom. The severity of erectile dysfunction predicts both the severity of heart attacks and degree of heart blockage.”
A narrowing of the arteries in the penis
This is because erectile problems can stem from a condition known as atherosclerosis, which refers to narrowing of the arteries in the body, making it increasingly difficult for blood to flow through. It is caused by a build-up of plaque in the inner lining, which is made from deposits of fatty substances, cholesterol, calcium and cellular waste, and can result from years of smoking, not exercising regularly and consuming a diet high in ultra-processed foods. People with atherosclerosis are at a higher risk of both heart problems and stroke.
Köhler explains that the symptoms of atherosclerosis are first experienced in the penis where the blood vessels are just one to two millimetres wide, while those in the heart are two to three millimetres. The carotid arteries which deliver blood to the brain are five to six millimetres wide and the femoral vessels in the thigh are one centimetre.
“People accumulate narrowing of vessels in a systematic fashion, everywhere at the same time,” he says. “So first comes the erectile dysfunction, then comes the heart attack and the stroke, and finally comes the problems of pain while walking because the femoral artery is the biggest blood vessel that you’re blocking.”
Improving erectile health
So how can you improve your erectile health? “Anything that is good for the heart is good for the penis, and vice versa,” says Köhler. “Things like quitting smoking, eating more fruits and vegetables, reducing stress, getting a slimmer waistline and exercising – if exercise were a drug, it would be a trillion-dollar drug.”
Johnson completes high-intensity exercise three times per week, and attempts to keep to a regular sleeping schedule, which are both important for promoting heart health. Like Johnson, we should all aim for at least 150 minutes of moderate- to high-intensity exercise, and try to increase the fibre content of our diet by adding in more wholegrains and vegetables. Plant chemicals in lentils, mushrooms, nuts and seeds can help mop up artery-blocking cholesterol. Losing weight will also help with erectile (and heart) health if you’re carrying a few extra pounds.
One solution for both erectile problems and heart issues could be drugs such as Viagra and Cialis. Köhler points out that while Viagra is well-known for enhancing sexual performance, research also appears to indicate that taking it can have protective effects for heart disease.
“The mechanisms are not entirely clear, but there are different theoretical reasons,” he says. “One which has been speculated that these drugs protect the inner layers of the blood vessels. A recent study in the United States looking back at men who are on a consistent regime of these drugs found that they had a much lower heart attack risk, something like 60 per cent lower. It’s preliminary but the signals seem to be very strong that there is some protective nature of these drugs for heart disease.”
While Johnson’s methods may seem wacky, Köhler applauds his dedication to optimise his health. “You want to think about your health now so that you can live well when you’re in your eighties,” he says.
“It’s not only living a long time, but it’s living long well, so you have to do everything in your power to be in the top percentile in strength, flexibility, waistline in your fifties. Because as Father Time rolls the calendar by, we all have a pre-programmed loss of muscle and hormone production. So anything that you can do to optimise your fitness in the forties and fifties will pay you back many fold in years to come.”