May 9, 2024 – Were you born with family genes that predict a short life? Fear not; it turns out that having such genes is not a death knell but an opportunity.
In fact, new findings suggest that adopting and sticking to a combination of lifestyle changes may be one of the most important ways to defy these “bad” family genes.
The study, which was published in late April, looked at the combined effect of lifestyle and genetics on human lifespan based on the records of over 350,000 people of European ancestry who were followed for an average of 13 years.
After dividing the people in the study into three groups based on predicted lifespan (long, intermediate, and short), the researchers found that those who had a high genetic risk for short lifespans faced a 21% increased risk of early death, compared with those with low genetic risk, regardless of lifestyle. Moreover, people with lifestyle habits considered unhealthy had an increased risk of dying early by 78%. But following a healthy lifestyle appeared to change the genetic odds by as much as 62% and add 5.2 years to life.
“We identified an optimal lifestyle combination of four lifestyle factors that offered better benefits for prolonging human lifespan: no current smoking, regular physical activity, adequate sleep duration, and a healthy diet,” said Xue Li, PhD, a study co-author and professor of big data and health science at the Zhejiang University School of Medicine in Hangzhou, China. “Our advice is to focus on building and sticking to healthy habits, no matter what your genes say.”
The Early Bird Gets the Worm
For the study, the researchers used an index called the polygenic risk score (PRS) to arrive at a person’s overall genetic tendency to have a short or long life. The score combines multiple changes in DNA (known as variants) that influence life expectancy. Li said using this tool with screening and genetic counseling might help people make informed decisions about their health.
But it might be difficult to mimic this approach; not only is the PRS not part of routine clinical practice, but genetic counseling is also not routinely offered. And testing through private companies can be costly. But take heart; there’s still a lot of steps you can take.
“There’s an enormous amount of literature that has looked at lifestyle and longevity and genes and longevity,” said Pam Factor-Litvak, PhD, a professor of epidemiology at the Columbia University Mailman School of Public Health in New York City. She said that gene expression can be changed by environmental factors (for example, smoking or diet). Factor-Litvak also explained that markers of healthy aging called telomeres (DNA and protein structure responsible for cell division) are also impacted by lifestyle factors. A healthy lifestyle lengthens telomeres and prolongs a cell’s life and ability to divide, and an unhealthy one shortens them, causing the cells to die and tissues to age.
“The earlier you start a healthy lifestyle, the better off you are,” she said.
To Factor-Litvak’s point, the cutoff used in the study was 40 years, with findings showing that people with good lifespan genes and healthy lifestyle habits had an average gain of 6.69 years of life expectancy, compared with people with bad lifespan genes and unfavorable lifestyle habits.
But older adults can still benefit; like dominoes, the effects of lifestyle changes add up.
William Samuel Yancy Jr., MD, an internist and medical director of the Duke Lifestyle and Weight Management Center in Durham, NC, said that he treats a lot of people in their 70s and 80s who start to feel better and become stronger when they add one of the four lifestyle factors cited in the research: healthy eating.
“They’re more energetic, get stronger, and are less likely to get injured or have falls; you get pretty immediate benefits,” he said. “And obviously, there are some long-term benefits over the following years, depending what kind of changes they make.”
Yancy also said that as people age, they are able to make their health a priority, which helps them stick to healthier lifestyles.
Selvi Rajagopal, MD, MPH, an assistant professor of medicine at the Johns Hopkins University School of Medicine and an obesity medicine specialist in Baltimore, said she’s also had older patients who’ve benefited from lifestyle changes, especially when it comes to strength and resistance training. “We know that falls are one of the major risk factors for early mortality,” she said.
Bad Behaviors Go Together
One bad habit tends to lead to another, which leads to another, and so on.
“That’s one reason why the combination of the big four – smoking, physical activity, sleep, and healthy diet – is bigger than the individual effects,” said Factor-Litvak.
The study authors referred to those for habits as “the optimal lifestyle combination.”
Notably, these big four were also shown to convey better benefits for a longer lifespan than other combinations, according to the study results. But just as bad behaviors go together, so do healthy ones.
“Typically, when people lose 10% to 15% of their initial body weight, they start to experience significant improvements in their mobility and joint function. And so, they feel more inclined to engage in higher levels of physical activity, where there’s a really positive cascade effect,” Rajagopal said.
The challenge is that few people are able to stick with a composite healthy lifestyle like the one tested in the study. “My recollection is that about 25% of people are doing all of these healthy lifestyle practices simultaneously,” said Yancy. Toward that end, there may be something to be gained by starting small.
“It’s unrealistic and unsustainable for someone in the modern age with lots of life commitments and stressors to do all of the things right. Instead, start with a few small, meaningful, actionable items that you can do. Then make it part of who you are (it usually takes 8 to 10 weeks to form a habit),” said Rajagopal.
Then? “Once you’ve nailed it, make a checkbox for the next thing, and have an accountability partner who can walk this journey with you,” she said.