Your Genes Aren’t Your Destiny. Here’s How to Outsmart Your DNA to Live a Healthier Life

Your Genes Aren’t Your Destiny. Here’s How to Outsmart Your DNA to Live a Healthier Life

Most of us go through life thinking we’re blessed—and dinged—by the genes we’ve inherited. Maybe you got your mom’s gorgeous eyes but also her astigmatism, or you scored the tall-and-slender genes from your father’s side of the family but worry that you also have their predisposition to Alzheimer’s.

Though we cannot change our genetic makeup, we can positively influence how our DNA gets expressed, says Brandon Colby, M.D., the author of Outsmart Your Genesand a clinical geneticist in Beverly Hills. “You can think of your genes like a road map of possible routes,” explains Dr. Colby. “While your genes may mean your road map has paths that go toward heart disease or Alzheimer’s, those paths aren’t set in stone—they’re just possibilities laid out by your genes.”

And there are a number of things you can do to program your genetic GPS so it takes you down a road toward health. “Most diseases are determined by a combination of genetic and nongenetic factors, which means you can make changes that will minimize—and maybe even eliminate—your chances of contracting diseases for which your genes put you at risk,” says Dr. Colby. “It’s empowering.”

Taking what we know about our own genetic predisposition, how can we reroute ourselves so we’re on a path toward better health and maybe even sidestep issues our parents and grandparents faced? While the majority of our insight comes from genetic research, we are starting to get some guidance from the tens of thousands of studies in the emerging field of epigenetics, which looks at how lifestyle and environment can modify the ways genes function.

Before you take steps that can tweak your gene expression for the better, it’s important to have a basic understanding of what genes are and how they work beyond giving you traits like eye and hair color.

Here’s a fact that will bring you back to Biology 101: Despite how vastly different humans seem from one another, we all inherit the same 20,000-plus genes, all made up of DNA. In every single one of the trillions of cells in your body, your DNA is organized into pairs of chromosomes. While both chromosomes in any given pair contain the same genes, the genetic code within those genes may be slightly different, says Dr. Colby. And when a cell divides, gene mutations—also known as variants—can come about. “Differences within our genetic code are responsible for everything from what we look like to our personality traits to our predisposition to disease,” says Dr. Colby.

A rare mutation that occurs in one of the cells that combine to form an embryo, either the egg or the sperm, becomes a new genetic variant that neither parent has, but the child will. That child can then pass it along to future offspring. Sometimes this is a great thing: The fact that our genes have mutated over time is the reason humans have evolved to be smarter and live longer.

On the flip side, sometimes a change in a gene can cause it to wreak havoc, explains Dr. Colby, which is why particular genes are associated with particular diseases. Some changes are prompted by factors such as too much sunlight, poor diet, smoking, and other environmental and lifestyle choices—which can lead to diseases like cancer. Other mutations occur as a result of aging or because of occasional mistakes made as the body’s cells go through their normal process of dividing and multiplying. However, these generally don’t pose any health risks. “Luckily, your body detects and corrects most errors—and even if it doesn’t, many gene mutations are harmless and won’t affect your health,” says Dr. Colby. “However, some mutations are harmful—and those are the ones we can now detect and try to outsmart.”

Joshua Selsby, Ph.D., a muscle physiologist and a professor at Iowa State University, likes to compare our 20,000 genes to recipes in a big cookbook. “While we get our genetic makeup (DNA) from our parents, with fixed ingredients, through lifestyle choices we can exert control over how often we make certain recipes. And while you can’t change your cookbook, you can decide which recipes you cook the most.”

Say, for example, you exercise regularly. That healthy lifestyle choice is like making a good-for-you recipe over and over again—so many times that your cookbook will automatically open to the page for that recipe, says Keith Baar, Ph.D., a professor of molecular exercise physiology at the University of California, Davis. “When it comes to the genes you use a lot, it’s as if you’re pushing on your genome like you’d push down the pages of the recipes you use repeatedly,” he says. That’s a great thing if what you’re doing is something positive like exercising or eating 12 servings of fruits and veggies a day, choices that change your genes in helpful ways.

The converse is also true. Things like smoking and sitting for 12 hours a day can push on genes you don’t want turned on. “How you move, what you eat, and a number of other factors will affect your DNA,” says Selsby, which means you can favor the genes that will help you live a long, healthy life and work to suppress the ones that put you at increased risk for disease: “While you can’t control your genetics, you can impact what you do with those genetics,” Selsby says.

With advances in genetic testing, it’s possible to understand your specific gene mutations—information that can help doctors, say, predict your risk of certain diseases and more precisely prescribe medication (you could even be offered truly targeted nutritional recommendations). Yet even most geneticists agree that genetic testing isn’t a must for most people, especially because most clinicians won’t know how to support you with this kind of precision medicine.

However, a handful of strategies will work across the board to “turn on” your health- promoting genes and “turn off” ones that could cause problems. Below are several ideas for how to start.

You already know that working out is one of the best things you can do for your health, and research shows that exercise—specifically, weight training—can actually change your genes so they mimic those of someone much younger. In a study, men and women older than 65 did twice-weekly resistance training for six months. Researchers then compared their muscle tissue to that of a group of 20-somethings, and they found a real change: The older adults’ genetic fingerprint had actually reversed, reaching levels similar to those seen in the younger adults.

Cardio workouts are still important too; in fact, when it comes to risk of breast cancer, exercise has been shown to have a significant and positive effect. Doing four or more hours per week of cardio exercise lowers the risk of breast cancer by about 30%, and experts think this is due to changes in the genes themselves. Also, an interesting study on breast cancer survivors suggested that increasing physical activity might affect genes that suppress tumors, which could boost survival outcomes.

“Think back to when you were a kid—you probably sprinted as fast as you could, pulled yourself up on the jungle gym, and tried to lift or push heavy things, and all this activity turned certain genes on,” says Baar. “Doing strenuous activity as an adult sparks your epigenetic memory, prompting those genes that respond well to exercise to respond again.”

Keep in mind that the key to triggering this reaction is to stress your body. That means that a couple of times a week you should do activity that goes beyond brisk-walk-around-the-block intensity, adds Baar. “If you really push yourself, the genetic response will be bigger.”

What we eat serves as an epigenetic signal that can actually prompt changes—and these changes adjust important chemical tags on DNA, potentially influencing our health for better or worse.

For example, a diet loaded with refined grains and lacking in fruits and veggies has been linked to DNA changes that stifle gene expression and cause disease. On the other hand, polyphenols (found in fruits, vegetables, green tea, coffee, and red wine) have been shown to reduce DNA damage, ultimately protecting against disease. “It’s also important to eat foods you enjoy, be conscious of what you’re eating, and maintain a caloric intake at or slightly below what you need,” Baar says.

When it comes to outsmarting gene mutations that might lead to cognitive decline, exercising your mind on a regular basis is especially important. This has been shown to stimulate the growth of new brain cells and strengthen the synapses between those cells—two things that keep you sharp as you age. And mental exercises you really enjoy have the added benefit of reducing stress, also key when it comes to programming your genetic GPS.

“Playing card games or chess, doing puzzles, attending lectures, learning a new language, and starting a new hobby all count,” Dr. Colby says. “And the best types of mental exercises appear to be those involving social interaction. A strong social network of friends has also been associated with a protective effect against Alzheimer’s, possibly because it helps ease stress.” Aim to do any of those brain-boosting activities for about an hour three or more times a week.

Many geneticists believe that whole-genome sequencing as a regular part of health care is the wave of the future and that this will ultimately help health care practitioners create a precise personalized medical plan for every patient. But until then, there’s still a lot you can do to alter, minimize, and even entirely avoid your current genetic destiny, says Dr. Colby.

“You don’t have to wait until illness appears and then try to treat it,” he says. “The best way to defeat disease will always be to prevent it, and we’re learning how to do that by studying our genetic code and using the information it provides.”

These are three of the biggies, and the gene mutations to be aware of for each.

What we know: The BRCA1 and BRCA2 mutations are inherited from your mother or father and can increase your risk of developing breast cancer by 70%. The PIK3CA gene mutation isn’t inherited and is more likely to tell docs how a patient might respond to cancer treatment.

What we know: The APOE4 gene variation is the main genetic risk for the disease; it can lead to the buildup of harmful deposits in the brain that can compromise the function of brain cells. One study found that this variation also caused Alzheimer’s disease to manifest earlier in life, with memory decline before age 60.

What we know: Many of us have genetic variants that increase our risk of cardiovascular disease no matter what our lifestyle. For example, the APOE gene plays a role in how the body processes cholesterol, and variants within this gene are associated with increased risk of premature death. The SCN5A gene is associated with heart arrhythmias, a risk factor for stroke.

Cells from your body (typically via your saliva if it’s an at-home test, or from blood if it’s a test your doc ordered) are collected and sent to a lab, which looks at the DNA within those cells. The amount of genetic info reviewed can be small (for example, a test might look only for the APOE gene for Alzheimer’s disease) or huge (your entire genome may be sequenced). The resulting info goes to a geneticist, who analyzes it and creates a report. Here’s where genetic counselors can be incredibly helpful: They’re trained to look at your specific gene mutations and help you tailor personalized prevention strategies.

In 2008, Congress made it illegal for, say, an insurance company to increase your premiums or refuse you coverage based on genetic info—but it’s still a good idea to verify that test results will remain confidential, especially when using a personal genomics company such as 23andMe or one of its competitors. “Your name and any other identifying info shouldn’t be linked to your genetic information,” Dr. Colby says. “That way, even if a third party somehow managed to access your genetic info, there’d be no way to associate it with you.”

Doctors and patients are concerned about the potential for that. But Dr. Colby says that while your anxiety may go up in the days and weeks after you learn you’re at increased risk of disease, research shows that it’s likely to return to baseline. Still, think this through and consider your mental health before making the decision.

This article originally appeared in the March 2021 issue of Prevention.

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