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People who research aging love to quip: The best thing you can do to extend your lifespan is to choose good parents. After all, it has long been believed that people who live longer have longer-lived parents and grandparents, which suggests that genetics influence longevity. What lifestyle versus genetics contributes is an open question on which a recent study in Nature sheds new light. Read this also Don’t expect human life expectancy to increase much, we’re reaching a plateau: researcher says
However, what complicates the picture is that we know that your lifestyle, especially the combination of diet and exercise, also has a significant impact on your health in old age and how long you live.
More information about the study
Scientists have long known that reducing calorie intake can help animals live longer. In the 1930s, it was observed that rats that ate fewer calories lived longer than rats that could eat as much as they wanted. Similarly, people who are more physically active live longer. But specifically linking a single gene to longevity was controversial until recently.
While studying the lifespan of the tiny worm C. elegans at the University of California, San Francisco, Cynthia Kenyon discovered that small changes in the genes that control the way cells detect and respond to nutrients around them can lead to the worms’ lifespan. Lifespan is doubled. This raises new questions: If we know that genetics and lifestyle affect how long you live, which is more important? And how do they interact?
To try to understand the effects of genetics versus lifestyle, the new study in Nature examined different models of calorie restriction in 960 mice. The researchers specifically tried calorie restriction (either 20 percent or 40 percent fewer calories than control rats), or intermittent fasting of one or two days without food (because intermittent fasting is popular in those Those who want to see the positive) looked at the classical experimental model. Benefits of calorie restriction).
Because we now know that small genetic variations affect aging, the researchers used specifically genetically diverse mice. This is important for two reasons. First, since laboratory studies on mice are typically conducted on genetically very (very!) identical mice, this allows researchers to explore the effects of both diet and genetic variables on longevity.
Second, humans are highly diverse, meaning that studies on genetically nearly identical mice often do not translate into humanity’s high genetic diversity.
Diet matters, but genes matter more
The main finding was that genetics play a larger role in lifespan than any dietary restriction intervention. Long-lived mice lived longer despite changes in their diets.
And while the short-lived mice showed improvement as a result of dietary restrictions, they couldn’t keep up with their longer-lived peers. This turns out there’s some truth to the “choose good parents” joke.
The calorie restriction model still increased the lifespan of all types of mice, with the 40 percent restriction group having improved average and maximum lifespan compared to the 20 percent group.
And the 20 percent group showed improvements in both the group’s average and maximum length of life compared to the control group. It’s just that the effect of genetics was larger than the effect of dietary interventions.
While all calorie restriction models resulted in an average increase in lifespan in mice, the most extreme calorie restriction model tested (40 percent less group) saw changes that could be seen as physical harm.
These include decreased immune function and loss of muscle mass, which can affect health and longevity outside of a predator- and germ-free laboratory environment. There are some important caveats to such studies. First, it is not known whether these results apply to humans.
As with most calorie restriction research in rats, the restricted food groups fed 20 percent or 40 percent less than the control group who ate as much as they wanted. In humans, it would be like assuming that people eating every meal at a bottomless buffet every day is “normal.” And those who do not eat from the unlimited tray of food are “restricted eaters”. This is not exactly parallel to the way humans live and eat.
Second, although exercise was not controlled in any way in this study, most groups ran similar amounts of time on their in-cage running wheels, except for the group with 40 percent calorie restriction who ran significantly more.
The researchers suggested that this extra exercise in the 40 percent group of rats was causing them to constantly seek out more food. But since this group exercised so much more than the others, it could also mean that the positive effects of increased exercise were seen in this group as well as calorie restriction.
what you should Know
So, while we can’t choose our parents or change the genes we get from them, it’s interesting to know that specific genetic variations play an important role in the maximum lifespan we can aspire to.
The genetic cards we are given determine how long we can expect to live. However, just as important as this study found, lifestyle interventions such as diet and exercise, aimed at improving lifespan, should be effective regardless of the genes we have.
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 about a medical condition.
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