Biden would end his second term at 86. What could that mean for his brain and body?

Biden is “a healthy, vigorous 80-year-old male,” according to a February report from the White House physician, Dr. Kevin O’Connor. Although he was recently treated for basal cell carcinoma, a common and slow-growing skin cancer, Biden has no major medical problems, doesn’t smoke or drink and exercises at least five days a week.

“The spectrum of health at older ages varies so widely,” said Dr. Holly Holmes, a professor and the chair in gerontology at the University of Texas Health Science Center at Houston. “As we get older, we are more and more unlike our peers, and it becomes harder to generalize what a ‘typical’ 80-year-old would be like.”

Dr. R. Sean Morrison, a professor and the chair in geriatrics at the Icahn School of Medicine at Mount Sinai in New York, added that the changes that occur during aging happen to different people at different times. Some 85-year-olds have healthier bodies than some 65-year-olds, and much of the variation comes down to genes and a person’s lifestyle before the age of 60.

Yet, as people enter their 80s and even their mid- to late 70s, some standard age-related shifts tend to occur, like muscle loss and a drop in bone strength, that make people more prone to disease and injury.

Here’s a head-to-toe snapshot of the body and mind of an octogenarian and the potential problems doctors look out for.

Brain

Most healthy people in their 80s don’t have trouble performing complex cognitive tasks such as problem-solving and planning, Morrison said, but they may find it harder to multitask and learn new things. Some may struggle to remember words. Reaction time can also slow, but usually only slightly — on the order of fractions of a millisecond, Morrison said.

Scientists don’t know exactly why these changes happen, but the brain does get slightly smaller with age because of brain cell loss, so that could be playing a role, said Dr. Scott Kaiser, director of geriatric cognitive health at Pacific Neuroscience Institute in Santa Monica, California. Interestingly, certain cognitive skills — such as vocabulary and abstract reasoning — may stay constant or even improve with age, also for unknown reasons, he said.

Dementia does become more common with age, but it still only affects a minority of adults in their 80s. According to the National Health and Aging Trends Study, 10.9% of adults ages 80 to 84, and 18.7% of adults ages 85 to 89, dealt with dementia in 2019. “These conditions are not a normal or inevitable part of aging,” Kaiser said.

Eyes and Ears

Vision tends to worsen over time. Octogenarians often need reading glasses and become more sensitive to glare, Morrison said. Nearly 70% of adults older than 80 have cataracts, a clouding of the lens of the eye, but the condition can be treated effectively with surgery, he said.

Age-related hearing loss is another common problem. First, people lose the ability to hear high-frequency sounds such as bird chirps and alarm clocks; this can start early, even in a person’s 30s or 40s. Low-frequency changes, affecting the ability to hear men’s voices and bass sounds in music, come later. Hearing loss can be treated with hearing aids — now available over the counter — or other devices, and it’s crucial to do so: “We have increasing data now that suggests that people who go longer with untreated hearing loss and don’t get hearing correction are more likely to develop dementia or diseases like Alzheimer’s disease,” Morrison said.

Heart and Lungs

As a person ages, heart rate slows slightly, and the heart can’t beat as fast during physical activity, which can make aerobic exercise more challenging. That said, an aging healthy heart typically “functions quite well,” said Dr. Lona Mody, a geriatrician at Michigan Medicine.

Doctors monitor for heart disease in their octogenarian patients. “Blood vessels become stiffer with age, and this leads to higher blood pressure,” Mody said, which can increase the risk of high blood pressure and heart disease. According to the American Heart Association, 83% of men and 87% of women aged 80 and older have heart disease, sometimes requiring the use of medications or surgery. Biden has asymptomatic atrial fibrillation — an irregular heartbeat — and takes apixaban (Eliquis), an anticoagulant drug that is often prescribed to help prevent blood clots and strokes. He also takes rosuvastatin (Crestor) to lower his cholesterol.

Lung capacity often slightly drops with age because of changes in the strength and elasticity of the lung tissue and diaphragm, which can make breathing a bit harder, Mody said. One disease doctors look out for is chronic obstructive pulmonary disease, an inflammatory lung disease seen in just under 11% of people 65 and older.

Bones and Joints

Bones become more brittle with age. The body starts to reabsorb the minerals that strengthen them, such as calcium and phosphate, in part because the intestines can’t absorb what is needed from food as effectively as they used to. For women, this degeneration is accelerated by the drop in estrogen after menopause, which reduces bone density.

Decreased bone density puts older people at an increased risk for bone fractures and osteoporosis. In 2020, when Biden was the president-elect, he had a hairline fracture in his foot, requiring him to wear a walking boot as he healed. The bone injuries that doctors worry about most are hip fractures, which hospitalize more than 300,000 Americans older than 65 every year. “Hip fractures are one of the most common reasons for hospitalization among people 85 and over,” said Dr. Susan Wehry, a geriatrician at the University of New England. Recovery is often difficult because of complications such as infections, sometimes picked up at the hospital, and internal bleeding, or because conditions such as heart disease slow healing.

Joints can also become more painful because the bones and cartilage that make up the joints start to wear down. According to the Centers for Disease Control and Prevention, nearly half of all Americans older than 65 have been diagnosed with osteoarthritis, which causes joint pain and stiffness. Biden has been diagnosed with osteoarthritis of the spine, which has stiffened his gait.

Strength and Balance

Most healthy people in their mid-80s can and should engage in physical activity, and many remain strong and agile, Holmes said. She encourages patients to participate in aerobic exercise and weight training a couple of days a week and to stretch at least once a week but sometimes recommends modifications for patients with pain, orthopedic problems or cardiac issues.

Adults “start to lose muscle mass and start to gain fat” as they get older, Morrison said. Between 42% and 62% of people in their mid-80s have sarcopenia, a disease characterized by loss of muscle mass and strength. Common symptoms include difficulty walking, ascending stairs and holding shopping bags.

In addition, the spaces between the spinal vertebrae dry and compress, causing people to lean forward, which can affect their balance, Morrison said. People in their 80s tend to walk slowly and have a short gait, which also worsens balance, he added.

In some older adults, the insulating layer that surrounds nerves and helps them communicate with one another, called myelin, starts to break down. This can slow reflexes and make people clumsy, Kaiser said.

“One important consequence of these age-related changes to the brain and overall nervous system — along with changes to other systems and a broad range of other factors — is an increased risk of falls,” Kaiser said, which in turn can become more dangerous because bones are weaker and break more easily.

Still, it’s important to remember that everybody ages differently and that age does not define a person’s health. Many people in their 80s are healthier than people 20 years younger, Mody said, and the choices they make late in life matter, too: Research suggests that adopting healthy behaviors even in the ninth decade can extend one’s life.

Many octogenarians, Holmes said, are “quite resilient.”