Want to influence your genes to crack the longevity code? Health (like wealth) comes down to making the right choices and following a few simple rules.

One of the most common arguments against embracing a growth mindset -- the perspective that we can be what we work to become -- is genetics: That we are what we are, and no matter what we do or hard we try, we will never really be able to change.

Sometimes that's true, especially where certain physical attributes are concerned.

But also not.

Take longevity, something that is important to all of us not because we all want to live long, healthy lives, but also because -- just ask Warren Buffett -- longevity is an important component of success. (And also because the older you are, the more likely you are to be able to start a thriving business.)

As Dr. Michael Roizen writes in the new book The Great Age Reboot: Cracking the Longevity Code for a Younger Tomorow, 40 percent of premature deaths (premature meaning before you turn 75) are related to lifestyle choices.

By the time you turn 60 years old, 75 percent of your health outcomes are determined by your choices.

If that sounds depressing, there's good news: Your choices can influence approximately 1,200 of the 1,500 genes that are switched "on," and likely influence the estimated 21,000 that are switched "off."

One example Roizen cites is prostate cancer; after men improved their diet, level of physical activity, and ability to deal with stress, genes associated with prostate cancer growth switched off, while a gene that produces a protein causing cancer cells to self-destruct switched on. The same applied to breast cancer: Lifestyle changes switched off genes that promote cancer, and switched on genes that fight it.

As for longevity, every healthy thing you do helps turn off genes that cause you to age, and helps turns on "youth-promoting" genes.

The result is a virtuous cycle: Turning off bad genes and turning on good genes causes more bad genes to switch off and good genes to switch on.

The result is a genetic version of a growth mindset: Sure, genes are genes, but the choices we make influences how those genes function.

In short: you are what you are, but you can become more of what you want to be.

But You Don't Have to Be Perfect

According to Roizen, longevity depends on what you do most of the time.

Eat poorly and don't exercise and your risk of heart disease, lung cancer, stroke, diabetes, and dementia skyrockets. Enjoy an occasional cheat day? Miss a couple days of workouts? Once a year, eat a quart of ice cream in one sitting? (Okay, maybe that's just me.)

Over the long haul, no big deal.

The key is to consistently -- not perfectly, but consistently -- make healthy choices that help prevent chronic disease and set you up for a long life. Don't smoke. Don't drink to excess. Get a good night's sleep. Eat a healthy diet. Exercise a few times a week.

Simple stuff. You know what to do. The key is actually doing it.

But how do you know if what you're doing is working? How can you tell that what you're doing will help promote greater longevity? Focus on 6 + 2

Roizen's barometer for health success is "6 Normals + 2." I recently had a physical and blood work, so for fun I'll include my results.

Here are the "Normals."

1. Regain and maintain normal blood pressure. The target is 110/75. Mine is 118/78. So I'm a tad high, but not worryingly so. (And my resting heart rate is 52, so I've got that going for me, which is nice.)

2. Regain and maintain a healthy level of LDL cholesterol. The target is 100 mg per deciliter. Mine was 101. Yep: A tad high. (Bummer.)

3. Regain and maintain a healthy fasting blood glucose level. The target is 100 mg/dL or below. Mine is 104. (Double bummer.)

4. Maintain a healthy weight for your height. Here's where it gets tricky. Most people use body mass index (BMI) to determine a "healthy" weight. But muscle, or lack of, matters. A 6' tall NFL cornerback who weighs 215 pounds has a BMI of 29.2. That puts him at the high end of the "overweight" category, even though by any objective measure he's incredibly fit. (My BMI is 22.5, and I like to think I'm reasonably fit.)

Your body fat percentage is probably a better indication of whether you're maintaining a healthy weight. Mine is 19, which puts me at the upper end of the "lean" category. (I definitely have some squishy areas I don't like but haven't committed to eliminating. Again, knowing what to do doesn't automatically mean doing it.)

Even so, start with BMI. It's at least directionally accurate, especially if you fall on the farther ends of the spectrum.

5. Practice ongoing stress management. Roizen's target is to "sleep well and feel at ease in your own skin." I typically get 8 hours, so I'm good on sleep. And I feel reasonably comfortable in my own skin, although that's situational.

But don't just think of sleep in terms of longevity; a 2018 study found that lack of sleep correlates with tension, anxiety, and lower overall mood. Sleep is good for you later, and good for you now.

As for stress? Here are three science-backed ways to better deal with stress.

6. Have no primary, secondary or tertiary smoke from tobacco in your body. If you aren't familiar, tertiary smoke involves pollutants that settle indoors when tobacco is smoked. Think couches, curtains, bedspreads, etc. Roizen's target? Declare yourself a smoke-free zone.

I don't smoke. I'm occasionally around people who smoke, but that only happens when I'm outdoors. So my smoke-free zone isn't perfect... but it's close enough.

Now for the "Plus 2."

1. Get a full body check up. You are what you measure, and you can't know your numbers -- and if necessary work to improve them -- until you get your numbers.

2. Keep your vaccinations up to date. Roizen recommends that everyone get an annual flu shot since it can decrease flu and lung problems as well as reduce the risk of heart attack and stroke. He also recommends people aged 50-plus get the shingles vaccine, and those 65 and over get the pneumonia vaccine.

I kinda suck here. My "normal" vaccinations are up to date, but I never get a flu shot. And I haven't gotten the shingles vaccine. Work to do there.

Where Should You Start?

Roizen's advice is pretty simple.

Diet? Eliminate saturated fats. Ditch added sugars. Eat whole grains, seven to nine servings of vegetables and fruits, and stick to lean proteins like fish and chicken. (Yep: Think Mediterranean diet.) Consider taking a multivitamin, too.

For exercise, walk the equivalent of 10,000 steps a day and do strength training two or three times a week for 20 minutes per session. As for stress, get seven to eight hours of sleep a night, consider meditating, get out in nature once in a while, and spend time with your family and friends.

And don't smoke, and avoid second- and third-hand smoke as best you can.

I fall a little short on fruits, and shorter on vegetables. (I'm working on that.) I've grown to dislike red meat, so eating lean proteins is easy. I get plenty of sleep, and nature is right outside the door.

Exercise is where I score better. I lift weights an average of six days a week for about an hour each session. I do cardio three or four times a week. I work on construction projects four or five days a week, on average for three to four hours a day. Activity isn't a problem.

And, while it's nearly impossible to exercise your way to significant weight loss, or exercise enough to maintain a healthy weight regardless of what you eat, that likely contributes to my BMI as well as some of my test results. Exercise helps improve your cardiovascular system, lower your blood pressure, lower harmful LDL cholesterol and triglycerides, raise healthy HDL cholesterol, strengthen muscles and bones, reduce anxiety, and improve overall well-being.

And that, in a nutshell, is the real takeaway. It's hard to be perfect, whether in every aspect or on a consistent basis. You may eat really healthy, but fall a little short on exercise. You may get plenty of sleep, but spend significant time around people who smoke. No one is great at everything.

The key is to focus on doing more of what is good for you, and do it more often.

That's approach is not only good for improving your health and longevity, but also for achieving anything worthwhile.

Because we are what we are... but with consistent effort over a period of time, we can also become what we hope to become.

Inc