As people who study aging often say, the best thing you can do to extend your life is to choose good parents. After all, it has long been recognized that people who live longer tend to have longer parents and grandparents, suggesting that genetics influences longevity. How lifestyle and genetics play a role is an open question, but a recent study published in the journal Nature has shed new light. Also read | Don’t expect average human lifespan to grow any further, we’re reaching a plateau: researchers say
However, complicating the situation is that lifestyle, especially the sum of diet and exercise, is also known to have a significant impact on health and longevity in later life.
Learn more about the research
Scientists have long known that reducing caloric intake can help animals live longer. In the 1930s, it was noted that rats that ate reduced calories lived longer than rats that ate as much as they wanted. Similarly, physically active people tend to live longer. However, linking a single gene specifically to longevity was controversial until recently.
Cynthia Kenyon, who was studying the lifespan of tiny worms, Caenorhabditis elegans, at the University of California, San Francisco, discovered that small changes to genes that control how cells detect and respond to nutrients in their surroundings can shorten the lifespan of worms. I discovered that this led to doubling the amount. This raises new questions. If we know that genetics and lifestyle influence lifespan, which is more important? And how do they interact?
A new study published in the journal Nature examined various models of calorie restriction in 960 mice to tease out the effects of genetics and lifestyle. In particular, the researchers found that calorie restriction (eating 20 percent or 40 percent fewer calories than control mice) or intermittent fasting, which consists of 1 to 2 days of no food (intermittent fasting may be useful for people seeking positive effects), Due to its popularity, we focused on the classic experimental model. benefits of calorie restriction).
The researchers used particularly genetically diverse mice because we now know that small genetic variations can affect aging. This is important for two reasons. First, laboratory studies in mice are typically conducted on genetically very similar mice, which allows researchers to uncover the effects of both diet and genetic variables on longevity. I did.
Second, humans are so diverse that studies on genetically nearly identical mice are unlikely to lead to high genetic diversity in the human race.
Diet is important, but genes are even more important.
The headline finding was that genetics appears to play a larger role in longevity than dietary interventions. The long-lived mice still lived longer despite the change in diet.
And although short-lived mice showed improvement as a result of dietary restriction, they were unable to catch up with long-lived mice. This suggests that the joke about “choosing good parents” is true.
The caloric restriction model still extended lifespan in all types of mice, with the 40% restriction group having increased mean and maximum lifespans compared to the 20% group.
And 20 percent of the groups showed improvements in both the group’s average lifespan and maximum lifespan compared to the control group. The effect of genetics was simply greater than the effect of dietary intervention.
All caloric restriction models increased the lifespan of mice on average, but in the most extreme caloric restriction model tested (40 percent less group), changes that would be considered physical harm were observed.
These include decreased immune function and reduced muscle mass, which can impact health and longevity outside of a predator- and bacteria-free laboratory environment. There are some important caveats to such studies. First, it is unclear whether these results apply to humans.
As with most calorie restriction studies in mice, the restricted-feeding group ate 20 or 40 percent less than the control group, who ate as much as they wanted. In human terms, it’s like believing that eating from a bottomless buffet every day is “normal.” And people who don’t eat the food on their endless trays are “restricted eaters.” It’s not exactly the same as how humans live and eat.
Second, although exercise was not controlled in any way in this study, most groups ran a similar amount on a wheel in a cage, except for the 40 percent group that underwent calorie restriction, which ran significantly more. I went for a run.
The researchers suggested that this extra exercise in the 40% group was due to the mice constantly hunting for more food. However, this group exercised much more than the other groups, which may mean that this group also saw the positive effects of increased exercise along with calorie restriction.
What you need to know
So while we can’t choose our parents or change the genes we inherit from them, it’s important to know that certain genetic variations play an important role in the maximum age we can aspire to. That’s interesting.
The genetic cards we are dealt determine how long we will live. But just as important as this study, lifestyle interventions such as diet and exercise aimed at extending lifespan should be effective regardless of the genes we carry.
Disclaimer: This article is for informational purposes only and is not a substitute for professional medical advice. Always seek the advice of your doctor with any questions you may have regarding a medical condition.
