[King:] For the first time in our country's history, both candidates for president facing accusations, they are in mental decline. Dr. Sanjay Gupta explores.
[Dr. Sanjay Gupta, Cnn Chief Medical Correspondent:] Regardless of who wins the election in November, a record will be broken either 74-year-old Donald Trump will become the oldest second term president in U.S. history or 77-year-old Joe Biden will be the oldest first term president. And questions of age, health, and most notably cognition, have started to emerge.
[Unidentified Male:] If I may start respectfully, in the "Fox" poll, they asked people, who is more competent? Who's got whose mind is sounder? Biden beats you in that.
[Donald Trump, President Of The United States:] Well, I tell you what, let's take a test. Let's take a test right now. Let's go down. Joe and I will take a test. Let him take the same test that I took. But I guarantee you that Joe Biden could not answer those questions.
[Joe Biden , Presumptive Democratic Nominee For President:] I've been testing and constantly testing. Look, all I got to do is watch me and I can hardly wait to compare my cognitive capability to the cognitive capability of the man I'm running against. [voice-over]: Biden's advisors say he was referring to the everyday rigors of being on the campaign trail. But according to researchers, it is true that the average person's acquired skills, memory, and knowledge, known collectively as crystallized abilities tend to improve until we're about 60 years old, and then plateau till about age 80. But they also caution to not read too much into age alone.
[Unidentified Male:] I don't think it's responsible or entirely factual to just use age as a decision point on whether or not someone has a true cognitive impairment. [voice-over]: And of course, neither candidate is your average person. Americans have seen these two candidates aged, not just over the last several years, but over the last several decades, watching their careers play out on the national stage.
[Unidentified Female:] Campaigning for Eric
[Trump:] The first time that I've been involved in a convention.
[Biden:] Got to bounce that ball.
[Unidentified Male:] T.V. star.
[Trump:] I never thought this was going to happen. [voice-over]: But lately, these are the moments that are getting a lot of attention. No collusion, no obstruction. I hope they now go and take a look at the oranges, the oranges of the investigation.
[Biden:] We tried it in Iraq is not working. So now we're going to try, I mean in Iran, excuse me. We tried in Ukraine.
[Trump:] We've performed 1.87 million tests today. So that's 1,870,000 tests.
[Biden:] All men and women are created by go, you know, the, you know, the thing. [voice-over]: It is true that everyone's sharpness changes a bit day to day could be a poor night's sleep, being distracted, low blood sugar, dehydration.
[Unidentified Male:] It's very dangerous to over interpret mental slips when you see it in an older person. We know that there are many factors that affect our mental acuity. They may look like they're not functioning as well cognitively, but they may be perfectly normal. [voice-over]: And as much as we think we know them, to diagnose a true cognitive problem is quite challenging even for a professional. The way that a physician makes a clinical diagnosis is to have a clinical relationship is to do a very comprehensive medical workup to order specific imaging, brain imaging when needed. And then order specific cognitive assessments, a more, you know, elaborate battery of cognitive tests in order to really have any degree of accuracies. [voice-over]: So then, what do we really know about Donald Trump and Joe Biden's health. Based on the medical records released by the White House, President Trump is on a Statin medication to manage his cholesterol. He is clinically obese. In 2018, the White House said Trump scored a 30 out of 30 on the Montreal Cognitive Assessment, which doctors use to screen for mild cognitive dysfunction. That same year, White House records indicate the President underwent a coronary calcium CT scan and scored 133, indicating that plaque is present and that he has a common form of heart disease. This past December, Biden released a summary of his medical history, which noted that he also takes a Statin to lower his cholesterol and triglyceride levels. And he also takes Eliquis to prevent blood clots. He has an irregular heart rhythm known as non-valvular atrial fibrillation or AFib. And he is of normal weight. Most notably, in 1988, Biden suffered a brain bleed due to a ruptured cerebral aneurysm and underwent two separate brain operations. His doctors say he hasn't had any recurrence of aneurysm since.
[Biden:] I got hospitalized years ago with cranial aneurysm. I was hospitalized the couple of times. They took the top of my head off the second time, said they could not find my a brain the first time. [voice-over]: It's worth remembering there is no requirement for a presidential candidate to release any of their medical history. So we may never have a complete picture of their overall physical and cognitive health. It's the campaign itself that is the ultimate test, leaving the voters to decide whether or not age really matters.
[Unidentified Male:] Even if it's in the most powerful position in the land, what I would say is you have to pick the best person for the job.
[Gupta:] Well, John, no one knows campaigns better than you. But I think even you'd be surprised that how much cognitive health has become an issue in this campaign. It's not like we haven't heard about this sort of thing before, but it's really become something that both candidates are talking about quite a bit. We'll see how this sort of turns out. I do want to point to this Montreal Cognitive Assessment, that's the test that I think President Trump was talking about. Take a look at, John, you may have seen some of these images before. But it's a fairly simple test, a 10-minute test, it's 30 questions. You're looking at visual spatial relations, you're looking at fluency of speech, you're looking at attentiveness, and then just plain memory. You're asked to remember five objects that are recited to you and you have to recite them back at some point later in the test. It's really considered more of a screening test, John. As you heard, it's very difficult to actually do a diagnostic test that requires time and requires a lot more sophisticated understanding of these tests. So there you have it, John, we'll see how much of an issue this continues to be, but clearly, both candidates talking about it for now. John?
[King:] Dr. Sanjay Gupta, appreciate the detailed look there. I like any test that has a rhinoceros on it. Thanks for joining us today. I hope to see you back here same time tomorrow. Brianna Keilar picks up our coverage right now. Have a great day.