What's known about aging well: an intriguing update

Host Amber Smith: Upstate Medical University in Syracuse, New York, invites you to be "The Informed Patient," with the podcast that features experts from Central New York's only academic medical center. I'm your host, Amber Smith.

As we age, our bodies change, but are those changes gradual or more abrupt? I'm talking about this with an exercise physiologist from Upstate. Dr. Carol Sames is also an associate professor of physical therapy education at Upstate.

Welcome back to "The Informed Patient," Dr. Sames.

Carol Sames, PhD: Thanks so much, Amber. It's great to be here.

Host Amber Smith: The journal Nature Aging published a study recently from a team of Stanford scientists that described waves of biomolecular shifts in the body that happen around ages 44 and 60. I wanted to ask you about this because I think a lot of us feel that aging is gradual.

This study suggests otherwise, though, right?

Carol Sames, PhD: Yeah, it was really an interesting study. So what they did was, they followed 108 individuals over a couple of years. They were a fairly diverse ethnic population, different ages, 25- to 75-year-olds, and they collected blood and stool and skin and oral and nose samples.

And they just wanted to look at a bunch of different molecules and see, do these molecules appear to age at the same rate?

And what they found: that there were some patterns that suggested that these molecules were changing at different rates, specifically around two times, around 44 years of age and 60 years of chronological age.

Host Amber Smith: So why 44 and 60? Why are these key points?

Carol Sames, PhD: So they're not exactly sure why. The authors even state that future research is clearly needed. They need a larger sample size. They didn't control for physical activity, and we certainly know that physical activity has a lot of positive benefits, on changing the slope of the line of aging.

And, they mentioned that future research could potentially lead to the development of early diagnoses and/or prevention strategies. So I think what they were trying to do is maybe tie the concept that aging is impacted by genetics and lifestyle choices, and we already have evidence that is suggestive of that.

Host Amber Smith: Can you define what aging is?

Carol Sames, PhD: Well, I can tell you what the World Health Organization defines aging as, and it's a biological process. It results in progressive and irreversible decline in physical function. It impacts most organ systems, and it puts individuals at risk for various age-related diagnoses and diseases.

That's the technical definition, but what we have found in the last 10 years are these two concepts. One is this idea of resilience, that when we get older, we tend to lose our physical resilience. And resilience is just the ability to resist or recover from a stress or a challenge. It could be an infection, surgery, medication, exposure.

But we know that with increasing age, people tend to lose that resilience, and that kind of ties into this new concept, or newer concept, of senescence, which is that as we get older, our body starts to accumulate damage. When you're young, you also can have damage, but it gets repaired, fairly quickly.

But with increasing age, that damage remains, and so we get what's called cellular senescence, and it's occurring throughout the body, and it certainly impacts body systems. One, for instance, is the musculoskeletal system, so we start to see issues with joints and cartilage and ligaments and tendons.

So I think those two concepts really do play into this World Health Organization definition of aging.

Host Amber Smith: So when we're born, we start growing. When do we start aging, or the cellular senescence? When does that start?

Carol Sames, PhD: Well, if we talk about when we age, we basically start aging on day two of life, because we have to get older, or we'd stay as infants. So there are changes that are going to occur. We generally identify, like, puberty as a big time-inflection point. But in terms of senescence, there's not a definite age because we know that aging is impacted by genetics and lifestyle changes.

And so some individuals, we could say, "Wow, they're aging well." And other individuals, we might say, "aging not as well."

There's not a defined date. There's a difference between chronological age, which is your specific age, and biological age. And biological age is more of an observable process that we can describe or define.

Host Amber Smith: Does aging differ based on gender or race or nationality?

Carol Sames, PhD: So if we look at, like, life expectancy as a way of kind of describing this, we know that in the U.S., Caucasian women live about two years longer than the total population and also live a few years longer than men.

If we look at African Americans, especially African American males, they have a life expectancy about 10 years less than Caucasian women.

If we look at the world, we see that Asian populations have the highest life expectancy, and the lowest life expectancy comes from American Indian and Alaskan native populations, and their life expectancy is 65 years.

Host Amber Smith: And do we know, does sedentary lifestyle versus active lifestyle, that has something to do with life expectancy, too, right?

Carol Sames, PhD: Absolutely, a very huge impact on life expectancy. If you just go through body systems and what being active can do to all major systems, we see that individuals that tend to be more active, they tend to have a longer life expectancy. It's certainly not a guarantee, because part of the equation is genetics, and we can't choose our parents, so we're always going to have that part. But lifestyle is considered about 65% of the equation, and genetics about 35% of the equation.

Host Amber Smith: This is Upstate's "The Informed Patient" podcast. I'm your host, Amber Smith.

I'm talking about aging with exercise physiologist and physical therapy associate professor Carol Sames.

I'd like to ask you what naturally we can expect as we age from, let's start with metabolism. Is it different for men versus women?

Carol Sames, PhD: The only difference would be that men usually have more muscle mass than women.

So as we age, we lose muscle mass. It's a natural occurrence. It happens in everyone, even individuals who are active. It's called sarcopenia. However, being active and engaging in resistance training can help change the slope of the line so that we lose less muscle mass.

And muscle mass is tissue that's very metabolically active. It needs energy. Muscle needs energy to contract and so that we can move. Fat mass sits there and takes up space, but it's not an active tissue. So when we lose muscle mass, we lose, essentially, calories that are burned off during the day, and so metabolism slows.

We also note that as individuals get older, if we look at activity levels, it starts to drop off. Like from 65- to 75-year-olds, only about 16 and a half percent of the population engage in regular activity.

When you get to 75- to 85-year-olds, they're down to about 10%.

And when you get over the age of 85 years old, we're down to less than 5% of the population, so we're moving less as we get older, and that certainly is going to impact metabolism.

Host Amber Smith: What about our skeletal system?

Carol Sames, PhD: So, as I mentioned, we lose muscle mass, even if we're participating in resistance training. However, as I mentioned, you can slow the slope of the loss, of that line. And we also know, with aging, we lose power. And power is really important to older adults. Power is how strong I am divided by time.

So we need power to get out of a chair. We need power to go upstairs. We need power to walk. And those fibers that are associated with power are fast-twitch fibers, and we start to lose those with age. Again, I can't change that, but I can maintain as much strength as possible. So that's really important.

We know that individuals who are inactive tend to have worsening effects of that sarcopenia. They also tend to have more falls, they tend to become frail, and they start to have more mobility concerns. You also get increases in hospitalizations, and you also have an increased risk of developing osteopenia and osteoporosis (weakened and brittle bones).

If you're not loading bone, we're going to lose bone.

Host Amber Smith: What about our stamina, just our ability to get through a workout?

Carol Sames, PhD: So that really ties into muscle, as we just mentioned. If I start to lose muscle mass, what happens is the muscle that's remaining is going to get used, but there's not enough of it. So it will require more oxygen so that when I start to move, I'm going to noticeably be short of breath, and I'm going to feel fatigued.

We also know that (regarding) the cardiovascular system, our arteries become stiffer. That's just a natural progression that occurs with age. That impacts blood flow to muscle, and muscle needs blood flow because it needs oxygen.

Also the amount of blood that is ejected from the heart, because the heart muscle gets stiffer, less blood comes out, and we naturally have an increase in blood pressure. And so that kind of prevents blood flow also. Maximum heart rate decreases with age, so that all contributes to that: "My muscle is weak. I'm not getting enough blood flow to muscle. I feel tired when I'm doing activity."

Host Amber Smith: Chronic conditions become more prevalent among older people. Are we able to predict or influence which ones are going to affect us?

Carol Sames, PhD: Again, what we can influence is not the genetic side, but we can really influence the lifestyle side. And so that's why it's so important that people remain active, that we engage in some kind of continuous, repetitive activity. Walking is fantastic or swimming or biking, just repetitive activity and also strength training.

And I think strength training really hasn't gotten out into the media. Most people kind of think, "I need to walk every day," and that is wonderful, but we also need to do some kind of strengthening. It doesn't require equipment. We have a body, A body weighs something. We can do body-weight exercises. Most of us have a chair, we have a wall. If you've been to physical therapy, you might have a couple of TheraBands (stretchy bands for exercise) lying around. So you can do strengthening activities and not require going to a facility or purchasing of equipment.

Host Amber Smith: Well, the million-dollar question: What can we do to slow the aging process?

Carol Sames, PhD: So back to activity, back to strength training.

And the other thing that's big that people don't realize is reducing sedentary behavior. So I can be active, I could have gotten up this morning and done a walk, and then I can sit in my chair for the next eight hours. And that sedentary behavior in some ways negates some of the benefits that I got from getting up and walking this morning.

So it's really important to monitor how many hours we are sitting, and this is awake time, it's not sleep time. The exact number is not known. We're thinking it's around 10 hours a day. And you'd be surprised how easily you could accumulate 10 hours, especially, like, if after dinner people sit down and maybe watch television for a couple of hours. You can get to 10 hours pretty quickly.

Making sure that you seek regular medical care, again, because maybe things can get diagnosed as they're starting, as opposed to when they become more of a chronic condition.

Making sure that people get a healthy amount of sleep.

Staying cognitively challenged. Engaging in activities, engaging in social activities, monitoring chronic stress because chronic stress leads to chronic inflammation, and we're learning a lot more that inflammation affects everybody's system.

Moderate alcohol, not too much alcohol.

If you're smoking, really try to quit smoking.

Controlling cholesterol, managing blood sugars, not gaining too much weight.

All really important things that can help with those lifestyle impacts on aging.

Host Amber Smith: So I know that sedentary behavior is not healthy for us, but does that accelerate aging? If you lie around on the couch all day, are you aging faster?

Carol Sames, PhD: So what we know from the research is there seems to be a relationship, not a cause and effect, but a relationship, with cognitive decline and hours of sedentary behavior. More and more research keeps getting published, and so, that certainly is an aging process because we know that there are brain changes with age. We do lose gray matter. Our brains actually get a little smaller, and neurotransmitters don't work as well as they had previously.

But when we think of what exercise can do as a beneficial thing, when we exercise, we have an increase in blood flow to the brain. When we're sedentary, we're not using muscle. Blood flow's still occurring, but not at a greater rate.

So just the idea of just getting up every hour and moving for a couple of minutes, it kind of breaks that lengthy sedentary behavior. And I think probably within the next one or two years, we will see that added as a risk factor for cardiovascular disease. It isn't there yet, but with the amount of research that's being published, population-wide research following people for years, I think that will be an addition to a risk factor, along with chronic inflammation. That's probably the next one also to join the "risk factor parade," I guess you could say.

Host Amber Smith: So it sounds like we have really no control over this, but there are some things that we can do that might make it slow a little bit.

Carol Sames, PhD: Yeah, absolutely. I mean, there is no reason why we cannot, besides the genetic component, why we cannot age and be active. I think in the past we did a disservice to older adults. We were like, "Let me do that for you. Oh no, you shouldn't be doing this." In some ways we probably forced older adults to be inactive.

As I was saying in class today, I don't want to be older and just be concerned with performing activities of daily living. I want to be older and doing fun activities. And being active to me is my defense, of trying to be as strong as I can, trying to get sleep, trying to eat a balanced diet, because certainly that's a lifestyle indication.

I want to make sure that I'm not eating a whole lot of ultra-processed foods, Once in a while, fine, but not on a daily basis. So I think there are a lot of lifestyle changes that we can make, and they don't have to all be made at once, but just being active, you're just going to feel better.

I mean, that's physiology. So just trying to get people to move a little bit more and not sit as much and try to engage in some aerobic, continuous activity and some strength training can do a world of wonders for our bodies.

Host Amber Smith: Well, Dr. Sames, thank you so much for making time for this interview.

Carol Sames, PhD: My pleasure. Thank you so much for inviting me.

Host Amber Smith: My guest has been Dr. Carol Sames. She's an exercise physiologist and associate professor of physical therapy education at Upstate.

"The Informed Patient" is a podcast covering health, science and medicine, brought to you by Upstate Medical University in Syracuse, New York, and produced by Jim Howe.

Find our archive of previous episodes at upstate.edu/informed.

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