Good Genes vs. Good Habits: Which Impacts Your Longevity More?

Reference Lab

JAN 02, 2021
Upd: APR 27, 2023

Was your grandma still dancing on tables well into her 90s? Is your dad hiking every day, even in his early 80s? If so, you might partially have signs of good genes to be thankful for: studies have shown that people who live long lives in good health often share similar genetic markers, which means grandma and dad might have passed some of their good health onto you. But don’t worry if it doesn’t seem like longevity genes run in your family: recent research has revealed that only 20-30% of our longevity is influenced by our genetics. The other 70-80% is not about who we’re related to but how we live–and the conscious steps we take throughout our lives to take care of our mental, physical and emotional health. Let’s take a closer look at the research to uncover the secrets behind longevity.

Genetic inheritance plays a role in how a person develops, and we can see many physical traits that are inherited from our parents or family members. Common traits that may be inherited are:

• Hair color
• Eye color
• Blood group
• Dominant hand
• Skin tone

Our baseline genetics and whether each gene is dominant or recessive ultimately determine what traits are available to be expressed, but the environmental factors around us can influence the level of expression of these genes and their subsequent visible traits. The Leiden Longevity Study, published more than a decade and a half ago, found that the people who have centenarians in their families have lower chances of developing age-related diseases and exhibit more youthful metabolism and age-related inflammation markers than other people around their age.

While scientists are still looking into the exact genetic factors behind this phenomena, it appears clear that there is a genetic connection. A study that compared the DNA of 800 people between the ages of 95 to 119 against random controls found specific genetic polymorphisms that were associated with the longevity group.

However, not everyone with exceptional longevity shares the exact same polymorphisms. In fact, recent findings suggest that there are likely a number of gene variations – some of which have yet to be identified–that act together to minimize the chances of age-related diseases like cancer, dementia, alzheimer's disease, and heart disease.

So what does that mean for you? If you’re from an exceptionally long-lived family, you might have ‘signs of good genes’ and some genetic advantage, including a lower risk of age-related diseases. But because only 20-30% of your longevity is determined by your genetics, there’s no guarantee that you’ll follow in grandpa’s footsteps. In fact, your daily habits and environmental factors may have a lot more to do with your health profile in old age. If scientists now know that 70-80% of our longevity lies not in our genes but in our daily habits, the logical next question is simple: what habits help some people live longer than others?

To get to the bottom of it, scientists have studied areas of the world where people tend to live longer. One of the most notable high-longevity regions of the world is Japan, with an estimated life expectancy of nearly 85 years. In addition to a robust healthcare system, a lower risk of obesity and cardiovascular disease, and a traditionally healthy diet, Japan is also home to one of the world’s Blue Zones, or areas where the population has a life expectancy that’s much higher than the global average.

Okinawa, a string of islands along Japan’s southernmost end, is home to a large population of centenarians, including the world’s longest lived women. While there may be some baseline genetic factors at play, scientists think that Okinawans mostly have lifestyle factors to thank for their incredible longevity.

This may, at least in-part, be due to the effects of lifestyle habits on epigenetics, which dictate which genes are expressed.7 Not only that, but those epigenetic modifications can be passed down to future generations, therefore your lifestyle habits, even in your younger years, can impact the genetic expression of your offspring.

Let’s take a closer look at some traditional Okinawan lifestyle practices and the scientific research that backs them up. While there is no guaranteed formula for exceptional longevity, studies have shown that common habits in Blue Zones like Okinawa are tied to living longer. In particular, these three activities have been shown across multiple studies to support longevity.

1. Eating Plant-Based: Okinawans eat a largely plant-based diet that’s particularly high in nutrient-dense sweet potatoes.⁷ Eating a diet that’s high in vegetables, fruits, whole grains, beans and nuts and low in red meat is proven to decrease cardiovascular mortality. A 2020 study in the journal Gut found that following a Mediterranean diet–which is generally high in veggies–for just one year slowed the development of age-related inflammatory processes.⁷ Another study showed that eating three servings of nuts a week reduced the participants’ risk of premature death by 39%.⁷
2. Nurturing Your Social Life: In Okinawan tradition, people form a moai, or tight knit group of lifelong friends. Residents describe this network as an essential safety net in times of need, alleviating stress through community support. A 2019 study found that social relationships like moai significantly increase longevity in older adults and a long-running Harvard study showed that healthy friendships appear to have a protective effect on the brain. ⁷
3. Staying Active: Older Okinawans are active gardeners and walk almost every day. Regular exercise can add years to your life, according to countless studies — and even small doses count. A 2015 review observed that even a small amount of moderate-to-vigorous exercise every week was associated with a 22% lower risk of early death.⁷

When it comes to a healthy lifestyle, it’s equally as important to avoid bad habits as it is to adopt good ones. Particularly, the big three: insufficient sleep, high stress, and cigarette smoking.

1. Not Getting Enough Sleep: Researchers consistently say that getting seven to nine hours of sleep per night can mitigate your risk of age-related disease. According to one Harvard study, getting less than 5 hours of sleep per night increases mortality risk from all causes by 15%. ⁷
2. Stressing Out: While it’s normal to go through periods of stress throughout our lives, chronic stress can tax the body and lead to higher levels of systemic inflammation. This can have very real impacts on our physical health. In fact, a recent study of 30-year-olds showed that being under heavy stress shortened the life expectancy of women by 2.3 years, and men by 2.8 years.⁷
3. Smoking Cigarettes: Cigarette usage is a major cause of premature death around the world. But just how much time does this bad habit cut off our life expectancy? Quite a lot! Compared to people who have never smoked, smokers are expected to die a whole decade earlier. It’s not all bad news: quitting before you turn 40 reduces the risk of death associated with smoking by about 90%.⁷

If you dream of still being active well into your 90s, there’s a lot that you can do to increase your chances now. While your genetics play a role, your longevity profile is not set in stone. Even small lifestyle changes can make a big difference when it comes to improving your healthspan.

• Signs of ‘good genes’ can have a positive impact on longevity, but only to a certain extent; good habits actually play a much larger role in extending your lifespan. Researchers are now finding that this may be due to the effects of lifestyle habits on epigenetics.
• When it comes to genetic longevity factors, there is no single gene that all long-lived people have in common. Instead, scientists think many genetic longevity markers interact to minimize the risk of age-related diseases.
• About 70-80% of longevity is likely due to lifestyle factors, and there may be clues in Blue Zones, areas of the world with a higher concentration of centenarians.
• These areas often have a plant-based diet, rich social networks, and active lifestyles. Research has shown these practices have validated impacts on your overall longevity.
• Getting enough sleep, managing your stress levels, and avoiding cigarettes are also important in supporting your overall lifespan.

Sources:

1. https://www.scientificamerican.com/article/genetic-factors-associated-with-increased-longevity-identified/
2. ​​https://www.researchgate.net/figure/Overview-of-the-Leiden-Longevity-Study-sample-for-participants-and-first-degree_tbl1_324053256
3. https://www.scientificamerican.com/article/genetic-factors-associated-with-increased-longevity-identified/
4. https://www.tandfonline.com/doi/full/10.1080/13102818.2018.1532317
5. https://ourworldindata.org/life-expectancy
6. https://www.bluezones.com/explorations/okinawa-japan/
7. https://www.sciencedaily.com/releases/2022/09/220926200451.htm