On May 9, 2024 – Were you born with family genes that predict a short life? Don’t worry; it turns out that possessing such genes is not a death sentence, but an opportunity.
In fact, new findings indicate that adopting and maintaining a combination of lifestyle changes could be one of the key ways to defy these „bad“ family genes.
The study, which was published in late April, examined the combined effects of lifestyle and genetics on human lifespan based on records of over 350,000 individuals of European descent who were observed for an average of 13 years.
After categorizing the individuals in the study into three groups based on predicted life expectancy (long, medium, and short), researchers found that those with a high genetic risk for a short life had a 21% increased risk of early death compared to those with low genetic risk, regardless of lifestyle. Furthermore, individuals with unhealthy habits had a 78% increased risk of dying early. However, a healthy lifestyle seemed to alter genetic odds by up to 62% and extend life by 5.2 years.
„We have identified an optimal combination of four lifestyle factors that offer better benefits for extending human life: currently not smoking, regular physical activity, adequate sleep duration, and a healthy diet,“ said Xue Li, PhD, co-author of the study and Professor of Big Data and Health Sciences at Zhejiang University School of Medicine in Hangzhou, China. „Our advice is to focus on building and maintaining healthy habits, regardless of what your genes may suggest.“
Early Bird Catches the Worm
For the study, researchers used an index called Polygenic Risk Score (PRS) to determine an individual’s overall genetic tendency toward a short or long life. The score combines multiple DNA changes (variants) that influence life expectancy. Li stated that using this tool alongside screening and genetic counseling could help individuals make informed decisions about their health.
However, replicating this approach could be challenging; PRS is not part of routine clinical practice, and genetic counseling is not routinely offered. Additionally, tests through private companies can be costly. But take heart; there are still many steps you can take.
„There is an enormous body of literature exploring lifestyle and longevity, as well as genes and longevity,“ said Pam Factor-Litvak, PhD, Professor of Epidemiology at the Mailman School of Public Health at Columbia University in New York City. She explained that gene expression can be altered by environmental factors (e.g., smoking or diet). Factor-Litvak also noted that markers for healthy aging, called telomeres (DNA and protein structures responsible for cell division), are also influenced by lifestyle factors. A healthy lifestyle lengthens telomeres, extending cell lifespan and division capacity, while an unhealthy lifestyle shortens them, leading to cell death and tissue aging.
„The earlier one begins with a healthy lifestyle, the better off they will be,“ she said.
According to Factor-Litvak, the threshold used in the study was 40 years. The results showed that individuals with good genes for life expectancy and healthy lifestyle habits had an average life expectancy of 6.69 years, compared to those with genes for good life expectancy and unfavorable lifestyle habits.
But even older adults can benefit; like dominos, 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, North Carolina, shared that he has treated many individuals in their 70s and 80s who feel better and become stronger when adding one of the four lifestyle factors mentioned in the study: healthy diet.
„They are more energetic, grow stronger, and are less prone to injury or falls; they experience quite immediate benefits,“ he said. „And of course, there are some long-term benefits in the following years depending on the changes they make.“
Yancy also pointed out that as individuals age, they are able to prioritize their health, which helps them maintain a healthier lifestyle.
Selvi Rajagopal, MD, MPH, Assistant Professor of Medicine at Johns Hopkins University School of Medicine and specialist in obesity medicine in Baltimore, mentioned that she has also seen older patients benefit from lifestyle changes, especially in terms of strength and resistance training. „We know that falls are one of the major risk factors for early mortality,“ she said.
Bad Behaviors Stick Together
One bad habit tends to lead to another, which leads to another, and so on.
„That is one of the reasons why the combination of the big four – smoking, physical activity, sleep, and healthy diet – is greater than the individual effects,“ said Factor-Litvak.
The study authors referred to these habits as „the optimal lifestyle combination.“
Interestingly, according to the study results, these big four also provide better benefits for longevity than other combinations. But just as bad behaviors stick together, so do healthy behaviors.
„When people typically lose 10 to 15% of their original body weight, they notice significant improvements in their mobility and joint function. Therefore, they are more likely to engage in physical activity, which has a truly positive cascade effect,“ said Rajagopal.
The challenge lies in the fact that few people are able to maintain a healthy lifestyle like the one tested in the study. „To my recollection, about 25% of people practice all of these healthy lifestyle practices simultaneously,“ said Yancy. To that end, starting small can be beneficial.
„For someone in the modern era with many life commitments and stressors, it is unrealistic and unsustainable to get everything right. Instead, start with a few small, meaningful, and achievable things you can do. Then make it a part of you (usually takes 8 to 10 weeks for a habit to develop),“ said Rajagopal.
Then? „Once you have succeeded, check off the next step and have an accountability partner who can accompany you on this journey,“ she said.