“There’s nothing in our genetics that tells us to age or die.”

At 44 years old, renowned fitness and nutrition expert Jillian Michaels defines aging gracefully.

To some, she even makes the process look easy.

In fact, she took for granted the healthy lifestyle choices she makes daily until she started listening to others’ views on getting older.

“It was conversations with my peers that confused me,” Michaels tells Healthline. “A woman recently said to me, ‘I’m 40 and I started waking up with aches and pains.’ And I said, ‘Well, I’m 44 and I had to break into my house the other day. I had to jump over things, climb onto the roof, jump off the roof, and slide into the window. It felt like parkour training, yet I had zero issues with it.’”

Conversations like these prompted Michaels to contemplate the reasons why she (and others) age well, and why some people don’t.

“I’m not a genetic outlier,” Michaels says. “I look at someone 80 years old running a marathon and someone dropping dead of a heart attack at 42. It’s not as straightforward as it seems. So I wondered, what are the massive discrepancies in how people age? That’s when I began studying what it is that literally makes us age.”

Michaels’ findings are detailed in her latest book, “The 6 Keys: Unlock Your Genetic Potential for Ageless Strength, Health, and Beauty.”

Based on interviews with leading geroscientists and more than a thousand studies on longevity, genetics, and more, Michaels outlines a lifestyle to reverse aging and add years of vitality and optimal health.

“There’s nothing in our genetics that tells us to age or die,” she explains. “There are six body processes that can work for you or against you, and how you live affects those six keys.”

The first part of Michaels’ book details each of the six factors that scientists and doctors have identified as major age inciters.

“These are the six body processes that either make us old or help keep us young,” Michaels says. “They all work in unison like a symphony. When all the different instruments play in unison, it’s a beautiful song. If one is out of whack, they are [all affected].”

Strong-arming your stress

While many people think stress is bad, Michaels says stress is actually good when managed correctly.

“Stress is what makes people stronger physically and emotionally when you look at something called the stress adaptation response,” she explains.

For example, lifting weights is recommended for people who have osteoporosis or osteopenia because exercise stresses bones, which causes the bones to have an inflammatory response. The inflammation initiates bone cells to remodel the bone, which in turn makes the bone denser.

“But when stress becomes chronic, be it emotional, psychological, sociological, physical, and so on, that’s when stress literally becomes counterintuitive and a killer… if you aren’t giving your body the opportunity to adapt and rebuild and repair the damage the stress has done, [this is when] it impacts the other five keys in a negative fashion,” Michaels says.

Owning inflammation

As Michaels points out with stress, inflammation can have a positive role too, particularly to fight conditions like the common cold and repair injury.

“You work out, you get swollen, your muscles rebuild and repair. Now when your inflammation becomes chronic, it can cause a host of things, including chronic stress. When the inflammation gets out of control, your army of immune cells — little white blood cells that are meant to go after the bad guys — start to go after the [good guys],” she says.

When this occurs, autoimmune conditions, such as rheumatoid arthritis, can develop.

The book discusses how inflammation works for and against you and how you can turn inflammation in the right direction versus the wrong.

Managing your metabolism

As we age, Michaels says our metabolism changes, and when we eat — and what we don’t eat — begins to matter more.

“[It’s about] the timing of the foods you’re eating — when to do intermittent fasting so it’s effective and [understanding] how it can be counterintuitive,” Michaels explains.

While your metabolism slows with age, eating fewer calories isn’t necessarily the answer. As Healthline previously reported, “Older adults also tend to have a lower appetite, which may decrease calorie intake and slow metabolism.”

In addition to managing your diet with more protein-rich foods and making sure you eat enough food, resistance training and high-intensity interval training (HIIT) are also helpful in maintaining a healthy metabolism.

Engineering your epigenetics

Epigenetics is the study of changes in organisms caused by modification of gene expression.

“The epigene’s job is to be a really overbearing parent for your DNA,” Michaels says. “Your cells all share the same genetic material, but how a cell knows to become a bone cell and another to become hair or skin cells [is epigenetics]. When we make claims in the back of the book about how you can help your children fight cancer in the future with their genetics, it’s with epigenetics.”

While there’s still a great deal of research being done in this area, some level of evidence has linked certain diseases and behaviors to epigenetic mechanisms. These include many cancers, thinking ability, and various health conditions, ranging from respiratory and cardiovascular disease to reproductive and mental health issues.

Mastering your macromolecules

Macromolecules are cells that consist of fat, carbs, protein, and nucleic acid.

Understanding macromolecules can help keep your cells healthy, says Michaels.

“The way your cells communicate, the way your cells are being reproduced, etc., all of this is about keeping the cells healthy top to bottom,” she says.

Tackling your telomeres

Telomeres are a compound structure at the end of a chromosome. Michaels compares their role to that of the plastic cap at the end of a shoelace. The cap’s purpose is to keep the laces from unraveling.

“Every time your cells divide, you shave off a tiny bit of those telomeres, which is a pretty big deal,” she says. “When the telomere is gone, that’s when your DNA is exposed and a host of bad things can happen.”

For instance, she says that depression is linked to shorter telomeres.

“We want to maintain the length and health of our telomeres to protect our DNA,” Michaels explains.

While conducting research for the book, Michaels says two themes jumped out at her.

“One was a holistic approach and appreciating how everything is interconnected,” she explains. “The second thing is balance. If you have too much or too little of anything (sleep, vitamins, etc.,) that’s bad.”

With those two principals in mind, Michaels addresses the following five areas to tackle for anti-aging purposes:

1. Lifestyle. From your relationships to the way you manage your stress (physically and emotionally), lifestyle choices can impact the six keys.

2. Mind-body intervention. The way we live, think, and feel changes the chemistry and shape of certain parts of our brain. Michaels says, “Something as simple as five minutes of meditation a day can literally add years of quality to your life.”

3. Eating. Determining what you eat and how much of it you should eat in order to get the proper amount of vitamins, minerals, probiotics and more is key.

4. Exercise. Examining how often you train, how intense you train, and what techniques you use to train is an essential part of anti-aging.

5. Environment. Consider how the environment you live in provides toxicity (from UV rays and air quality to products you put on your body and the cookware you use). “Having houseplants and opening windows and having an air purifier can make a massive difference,” Michaels says.

So, is it ever too late to start crafting a longer life? Michaels clearly thinks not. She says “The 6 Keys: Unlock Your Genetic Potential for Ageless Strength, Health, and Beauty” is for everyone, at any age.

“Most scientists believe that the first person to live to 200 is alive right now. Now, that’s probably not you or me,” she laughs. “But the sooner we turn things around, the less damage we do over the decade, and the better we’re going to be. Plus, the sooner you jump on [these changes], the better and easier it will be to maintain. With that said, it’s never too late to make changes.”

That said, Michaels also encourages everyone to use the book’s insights in a way that suits their own lifestyle and personal goals.

“This can be as skin deep as you want it to be. It can be that you want to look good at 50, or it can be that you want to live to 100 and meet your great-grandchildren. The reality is both will happen, but in order for that, you have to take the necessary steps, because anything worth having does require work and sacrifice,” she says.

“This is a book to help you live your best life, be it looking your best, feeling your best, or living your longest.”

Cathy Cassata is a freelance writer who specializes in stories around health, mental health, and human behavior. She has a knack for writing with emotion and connecting with readers in an insightful and engaging way. Read more of her work here.