Eating fewer calories can lead to a longer, healthier life, according to a new study based on 30 years of research on monkeys.
The study shows rhesus monkeys that eat a calorie-restricted diet live several years longer – and remain healthier – than rhesus monkeys that eat as much as they want.
As Science Alert explains, this research “is a big deal”. It’s not based on one brief study: it’s based on an unprecedented, 30 year data set collected from rhesus monkeys over the years.
For over 30 years, two competing research teams have debated the effects that calorie restrictions have on rhesus monkeys.
On the one side, one research team was arguing that calorie restriction would have a significant impact on the health and longevity of the monkeys, while the other research team was taking the opposite approach.
Eventually, the two research teams decided to work together to reach a consensus.
How The Study Worked
Starting in the 1980s, researchers in the United States set up long-term experiments with rhesus macaque monkeys.
The fact that researchers used rhesus monkeys is important: these monkeys share 93% of the human genome. They also age in a similar way to us: they get grey hair, they go bald, and they experience cognitive decline as they get older. That’s why this research could have a profound impact on science’s current understanding of human longevity.
The two experiments were based at the University of Wisconsin-Madison (UW-Madison) and the US National Institute on Ageing (NIA) in Maryland. After 30 years of research, several of the monkeys have already celebrated their 40th birthday. To put that number in perspective, the average age of a rhesus monkey in captivity is about 26 years.
Together, researchers gathered data from a total of 200 monkeys. Over the years, the two research teams have come to different conclusions from their research.
Does Eating Fewer Calories Lead To A Longer Life?
Researchers had previously come up with differing conclusions from their research.
In 2009, for example, the Maryland group published results that showed no difference in survival rates between calorie-restricted monkeys and the group of monkeys that ate a normal number of calories.
The UW-Madison team, on the other hand, published conflicting results.
This latest study, however, involved a collaboration between the two research teams, where they came up with similar conclusions. Those conclusions included all of the following:
Animals in the two concurrent studies had their diets restricted at different ages. In one group, monkeys had their diets restricted at a younger age, while in the other group, monkeys had their diets restricted at a later age.
- Researchers found that calorie restriction was more beneficial in adult and older primates instead of younger primates.
- Monkeys in the control group at the NIA ate fewer calories than the UW-Madison control group, which made the difference between the two groups of monkeys less pronounced.
- Diet composition was significantly different across the two studies, with the NIA monkeys eating naturally-sourced foods and the UW-Madison monkeys eating processed foods high in sugar content
- The two groups of monkeys also had different genetic codes, with the NIA monkeys coming from China and India, while the UW-Madison monkeys came from India
- Female monkeys benefited from calorie restriction less than male monkeys, leading researchers to conclude that female primates were less at risk for the downsides of excess calorie consumption
- UW-Madison monkeys were fatter overall at the end of the study
What Does This Mean For You?
How can you use this research to be smarter about your diet? Here are some of the things you can learn from this latest study:
Calorie restriction in monkeys tends to lead to monkeys with longer, healthier lives. Monkeys on a calorie restricted diet, according to the data produced by this 30 year study, tend to live 3 years longer than monkeys not on a calorie restricted diet.
Researchers claim this data isn’t just important for monkeys:
“Taken together, these data confirm that health benefits of calorie-restriction are conserved in monkeys and suggest that calorie-restriction mechanisms are likely translatable to human health”, said the researchers in Nature Communications.
Should You Eat Fewer Calories To Live Longer?
It’s no secret that eating fewer calories can help you lose weight. This research shows that, in certain primates, eating fewer calories can also help you live longer.
This could correspond to a similar effect in humans – although more research needs to be done on humans to confirm that these results translate from rhesus monkeys to humans.
Nevertheless, this is an important first step that could have a significant impact on our knowledge of human longevity, human health, and the benefits of calorie restriction.