Is Longevity Written in Our Genes?
Is living to 100 all about luck with your DNA – or is it a question of lifestyle and environment? For decades, scientists have wrestled with this puzzle and the answers are proving to be more complex than simple genetic inheritance.
Professor Veron Ramsuran, a high-impact researcher in the College of Health Sciences at UKZN, is one of the global voices shaping this conversation.
Research shows that while genetics account for about 25% to 30% of the variation in human lifespan, the rest depends largely on environment and lifestyle. Public health improvements such as access to clean water, nutrition, sanitation and medical care dramatically extended average life expectancy in the 20th century.
Now, researchers are studying why some people, particularly nonagenarians and centenarians, live significantly longer and healthier lives than others.
According to Ramsuran, who recently presented at the World Health Expo, there are two types of genetic information that matter. “The first is the DNA we inherit from our parents and grandparents. The second, and perhaps more influential, is epigenetics which are the changes that occur on top of our genes, driven by lifestyle and environment.”
In his presentation, Ramsuran used a simple analogy: “Think of your genes as the foundation of a house. You can’t change the number of rooms, but you can upgrade the lighting, plumbing, or décor. Those upgrades represent epigenetics.”
He emphasised that even individuals predisposed to conditions like diabetes or heart disease can defy the odds by adopting healthy habits such as exercising regularly, eating nutritious foods and managing stress. “It’s not about perfect genes,” he said. “It’s about making the most of the ones you’ve got.”
Indeed, experiments with mice have shown that altering certain epigenetic markers can extend lifespan significantly, offering hope that aging is not just inevitable decline but a process that can potentially be slowed or even reversed.
Ramsuran pointed out that much of the research on longevity has been conducted in Europe and North America, leaving a huge gap in understanding how African genomes contribute to human health and aging.
“Humankind originated from Africa, so studying the African genome is essential for understanding everyone else’s,” he explained. The lack of African representation in genetic studies has troubling consequences: medicines developed primarily on European genetic data often perform poorly or even dangerously in African populations.
South Africa, for example, has an adverse drug reaction rate of 25 percent, compared to just 0.09 percent in countries like Switzerland and Norway. “We’re applying a one-size-fits-all model to a world full of genetic diversity,” Ramsuran warned.
While the future may hold exciting breakthroughs in gene editing and personalised epigenetic therapies, Ramsuran urges people to focus on what they can control now such changing your diet, reducing stress and staying active “as these choices can profoundly shape how your genes are expressed and how long, and how well, you live.”
For him, longevity is not a genetic lottery ticket but a balanced equation between inheritance, choices and environment. His message is clear: Our DNA may load the gun, but our lifestyle pulls the trigger.
Words: MaryAnn Francis
Photograph: Supplied
