It’s been long known that both your diet and your genes have a lot to do with how long you will live. But which has the greater influence? A new study answers that question, and the finding might surprise you.
The study, published in Nature, sheds a new light on the debate of lifestyle versus genetics when it comes to human lifespan, apparently concluding that genes make the bigger difference.
To try to tease out the effects of genetics versus lifestyle, the study examined different models of caloric restriction in 960 mice. The researchers specifically looked at classical experimental models of caloric restriction (either 20% or 40% fewer calories than control mice) or intermittent fasting of one or two days without food since intermittent fasting is popular among people looking to see the positive benefits of caloric restriction.
Because we now know that small genetic variations affect aging, the researchers specifically used genetically diverse mice. This is important for two reasons. First, as laboratory studies on mice are normally performed on genetically extremely similar mice, this allowed the researchers to isolate the effects that both diet and genetic variables would have on longevity.
Second, humans are highly diverse, meaning that studies on genetically near-identical mice don’t often translate into humanity’s high genetic diversity.
The key takeaway?
Genetics appeared to play a larger role in lifespan than any of the dietary restriction interventions. Long-lived types of mice were still longer lived despite dietary changes.
And while shorter-lived mice did show improvements as a result of dietary restrictions, they didn’t catch up to their longer-lived peers. This suggests that there’s truth to the old joke among longevity experts, who like to say, “The best thing you can do to increase how long you live is to pick good parents.”
This is not to say that diet does not matter and you should go run down to McDonald’s. Blessed with good genes or not, caloric restriction still increased lifespans across all the types of mice, with the 40% restriction group having improved average and maximum lifespans compared with the 20% group.
Another factor to point out is that although exercise wasn’t controlled in any way in this particular study, most groups did similar amounts of running in their in-cage running wheels except the 40 percent caloric restriction group, who ran significantly more.
The researchers suggested that this extra exercise in the 40% group was the mice constantly hunting for more food. However, as this group did so much more exercise than the others, it could also mean that positive effects of increased exercise were also seen in this group alongside their caloric restriction.
You can read the complete study by following this link.
