Trent Lott, a Mississippi Republican, could tell the president of the United States couldn't place him.
It was 1988, and he'd approached President Ronald Reagan in the Cabinet room at the White House. The president had made it a habit to meet almost weekly with Lott and other lawmakers whenever Congress was in session.
"I never will forget the look in his eyes," Lott said. "He looked at me almost like: 'I don't understand what you're saying. Who are you?'"
Lott said such an exchange happened only once. Reagan, who would have been about 77 at the time, could have been having an episode of forgetfulness that's normal for people with advanced age, scientists say. Maybe he was just short on sleep.
Or maybe Lott, who said Reagan was his favorite president to work with, was observing a change in cognitive function that only people close to the president could have noticed.
It's hard to know for sure, experts on aging told Insider. The public is generally in the dark when it comes to presidential health. US presidents aren't required to disclose such details, and any medical records they do make public are ones they've approved voluntarily.
Without making objective, detailed assessments from doctors public, presidents have opened themselves up to politicized speculation. People scoffed at the glowing hourlong media conference that President Donald Trump's White House doctor gave about his health. President Joe Biden hasn't once subjected his longtime doctor to questions from the press, breaking with decades of precedent.
What's left is rumors and what both laypeople and experts observe publicly.
When Lott approached Reagan in 1988, he was the minority House whip, someone responsible for rounding up votes who was therefore regularly in touch with the world's most powerful man.
He said the interaction stuck with him as "the first indication that I got that he was beginning to lose it."
Reagan publicly announced he had Alzheimer's disease five years after he left the White House. Anecdotes aside, historians haven't found evidence Reagan had dementia during his presidency that would have affected his ability to make decisions. Moreover, diseases causing dementia can take many years to damage the brain enough for symptoms to start showing regularly.
The Reagan years introduced the nation to the idea that a president didn't have to be middle-aged. In 2017, Trump surpassed Reagan as the oldest president at the time elected, at age 70.
Then, last year, Biden finally realized his lifelong quest to become president, at 78 years old. Reagan was 77 when he left the White House.
Meanwhile, the three top Democrats in the House — Speaker Nancy Pelosi, Majority Leader Steny Hoyer, and Majority Whip James Clyburn — are all in their early 80s. Senate Minority Leader Mitch McConnell is 80. Senate Majority Leader Chuck Schumer is 71. And the average age of a member of Congress is 61.
Four months in the making, Insider's "Red, White, and Gray" series explores the costs, benefits, and dangers of life in a democracy helmed by those of advanced age, where issues of profound importance to the nation's youth and future — technology, civil rights, energy, the environment — are largely in the hands of those whose primes have passed.
The nearly 330 million Americans affected by these leaders' decisions cannot, of course, get inside their heads. But science on how the brain changes over time has a story to tell.
Our ever-shrinking brains
The outward signs of aging are easy to see.
You get wrinkles and gray hair. The older you get, the more likely you are to develop conditions such as hearing loss and arthritis. Injuries can take longer to heal.
Then there are the changes inside the brain, the most complex organ in the human body. They start to happen earlier in life than many people might expect.
People start to have trouble remembering words for things when they're in their 30s, S. Jay Olshansky, a leading expert on aging at the University of Illinois Chicago, told Insider. It's a familiar experience for many people, having a word on the tips of their tongues while trying to jog their memories.
There's a biological explanation: During our 30s and 40s, our brains have already begun to shrink.
The parts of the brain responsible for cognitive functions shrink more than other parts. And the wrinkled outer part of the brain thins. These changes generally increase in speed when people are in their 60s.
As you get older, it subtly and gradually becomes harder to recall where you parked your car or put your phone. Retaining information after people tell you their name or give you their phone number becomes more difficult.
Recalling facts or things that happened to you becomes a greater challenge. You don't sleep as well or as deeply. Multitasking and paying attention for long periods of time taxes your energy.
"We tend to process things slower," Dr. G. Michael Harper, the president of the American Geriatrics Society, said. "It takes more time to learn new things."
These are changes that might, for example, affect lawmakers' performance in Congress.
They regularly fly or drive from their districts to Washington, DC, and give floor speeches, meet with constituents and lobbyists, and conduct hearings. Votes can sometimes run until 2 a.m., and House hearings can last for hours.
And fundraising is an intrinsic part of the job — whether it's at a crowded gala in Palm Beach, Florida, or during back-to-back phone calls to donors at the Democratic National Committee office just a few blocks from the US Capitol.
Members of Congress do have the option of leaning on their staff, but voters didn't elect legislative aides to represent their interests in Washington.
Redefining 'normal'
Among the most obvious differences between an average person in their 50s and someone in their 80s can be seen during a memory test, Emily Rogalski, an associate director of the Mesulam Center for Cognitive Neurology and Alzheimer Disease at Northwestern University, said.
Doctors read a list of 15 unrelated words to patients. About 30 minutes later, they'll ask patients to repeat the words.
It's perfectly normal for someone in their 50s or 60s to remember nine of those words, Rogalski said. And it's considered normal for someone in their 80s to remember only five of them.
"What we call average or normal adjusts with age," she said.
Having trouble with name recall is typical in aging and has "nothing to do with cognitive function," Dr. Nir Barzilai, the director of the Institute for Aging Research at the Albert Einstein College of Medicine, said.
"You have to separate those," he said. "Slowness is also part of aging, but it's not part of cognitive function."
But normal cognitive decline can progress into what's known as mild cognitive impairment, a condition that can stay the same, improve, or lead to dementia. People can forget important events, lose their train of thought, or become more impulsive. They might feel overwhelmed by making decisions — and their friends and family tend to notice the changes.
The risk for dementia starts to increase after 65, then doubles every five years, according to the Centers for Disease Control and Prevention. By 85 and up, the chances are about one in two that you'll have either mild cognitive impairment or dementia, Harper said.
