I've studied longevity for nearly 25 years: Here's what I prioritize to have a long, happy life

Dr. Andrea Maier is a health and longevity expert with nearly 25 years of experience in the field of geroscience, where she studied what aging is and why we age. Maier has spent the last 10 years bringing what she's learned into clinical practice.

As an internal medicine specialist in Singapore, she conducts tests on patients to determine their biomarkers of aging such as the health of their organs.

Using the results, Maier suggests practical solutions to increase a patient's chances of living longer: "That can be changing a diet based on the microbiome, together with doing certain physical activities, or changing sleep habits or taking supplements based on what that body at that moment needs."

Maier not only studies and doles out advice, she also follows some of it herself.

CNBC Make It interviewed Maier about her personal habits for longevity and what she does to stay happy and healthy.

This interview has been edited and condensed for clarity.

What a longevity expert does for a long, happy life

CNBC Make It: Is there anything you do specifically to help your brain be sharper and to improve your focus?

Maier: I think brain health is very underestimated. Knowing your brain capacity is important. Everybody [should] do brain tests, looking at what their short term memory or their long term memory is, what the capability of the brain is to multi-task.

There are also new, innovative approaches incorporating brain fitness at the gym. There is one [gym] in Singapore, it's called SPARKD, where you're on a treadmill, and then also being exposed to memory tasks, for example, and it's very exciting. You are training your brain while training your muscles, bones and your cardiovascular fitness.

Think about being on a treadmill and doing math. How good are you? How much do you slow down?

I think most important is simply using the brain. That's what I do constantly.

We also know that for longevity it's important to have and maintain positive relationships in your life. What's your own social fitness like?

I just came back from Paris and from Berlin. I had my quality time. Now it's time to work for a couple of days or weeks, and then there is [more] quality time [with others].

It's very important that individuals are being heard and being seen. It gives routine in life. Very often, if people do not have social interactions, and they don't have [a] purpose, or a job that can give them purpose, then that isolation is very detrimental because it induces bad habits.

First, measure how you feel at this moment in time. Do you feel isolated? Do you feel depressed? Do you feel worried? That's also what I apply to myself. Then, turn to social interactions [that are] meaningful. It's not just the time, but the quality and the meaning behind it.

Human beings are social animals, so we have to group together. It's also very important for the brain, because you can either stare at yourself in the mirror, or you can have lovely, lovely interactions.

What's your daily diet like? Is it important for you to eat with longevity in mind?

Very important. As a physician, I never had a lesson about diet, which is quite bad, but that was at that moment in time the curriculum. So nobody taught physicians of my age what to do.

I've been a vegetarian since I was three, for ethical reasons. But it also seems that it's quite healthy.

I leave out the red meat and the white meat and the fish. I'm 46, and still drinking Diet Coke.

I always skip, or very often skip, breakfast which, [and] I didn't know that 20 years ago or even 30 years ago, is related to intermittent fasting, or time-restricted eating.

I really start eating at two o'clock [p.m.], three o'clock. Sometimes my first meal is in the evening, and I'm fine. But these routines were actually in my lifestyle already, before I had the knowledge that there could be a positive benefit.

That does not mean everyone has to be vegetarian or vegan, and practice intermittent fasting.

Having good quality intake is very important, and watching, of course, the outcome [of your eating habits].

I'm interested in what the experts in your field are reading these days. What are you currently reading?

I spend at least one hour a day reading or just listening to the news. It's not only the BBC news podcast, but also different newspapers, for example, the New York Times.

We in the field have to stick to and really learn from a diversity of news [sources], because it's very important to see the engagement with health, with longevity, in a context. I think very often we see it out of the context.

We just say, 'Okay, life expectancy has to increase. Health expectancy has to increase' without realizing that we are living in an ecosystem where we have political influences, we have environmental influences, and we just have to also see what is important at this moment in time for certain societies, and where we can implement what.

A longevity expert's 4 daily habits

To sum up Dr. Maier's longevity practices, here's what she does to stay healthy and increase her happiness:

• For brain health: Using her brain often and being open to change
• For social fitness: Shuffling between quality time and work, depending on what she needs at the moment
• For her daily diet: Eating strictly vegetarian, no red meat, white meat or fish
• For her media diet: Staying up-to-date with the latest news

Want to earn more money at work? Take CNBC's new online course How to Negotiate a Higher Salary. Expert instructors will teach you the skills you need to get a bigger paycheck, including how to prepare and build your confidence, what to do and say, and how to craft a counteroffer. Start today and use coupon code EARLYBIRD for an introductory discount of 50% off through November 26, 2024.

Plus, sign up for CNBC Make It's newsletter to get tips and tricks for success at work, with money and in life.