A team of researchers from the Jackson Laboratory in the U.S., led by Professor Gary Churchill, claims that the secret to a long life lies primarily in our genes, rather than in fasting.
This conclusion emerged from a large-scale experiment involving nearly 1,000 female mice. The study also demonstrated that while fasting can contribute to longevity, reducing caloric intake may not benefit everyone.
Previous research has indicated that consuming fewer calories correlates with a longer and healthier life. Scientists have shown, for instance, that a 25 percent reduction in calories can slow aging by 3 percent.
What the Researchers Discovered
During the study, the researchers examined the effects of intermittent fasting and caloric restriction using nearly 1,000 female mice. The rodents were divided into five groups based on the type of diet provided by the scientists.
The first group was allowed to eat freely at any time, while the second and third groups received 60 and 80 percent of the baseline caloric intake, respectively. The mice in the last two groups fasted for one or two days each week, but on other days, they could eat as much as they wanted.
The researchers monitored the mice throughout their lives, analyzing around 200 indicators, including body weight, fat content, and sugar levels.
The team found that mice with unrestricted diets lived an average of 25 months. Those practicing intermittent fasting lived an average of 28 months. Mice receiving 80 percent of their food intake lived to about 30 months, while those on a 60 percent diet reached an average of 34 months.
The researchers noted that in many cases, caloric restriction indeed contributed to increased lifespan. However, within each group, the lifespan varied significantly. For example, in the group consuming the fewest calories, lifespans ranged from a few months to four and a half years.
Upon analyzing the reasons for such a wide range, the scientists discovered that genetic factors had a greater impact on lifespan than diet. Although fasting often promoted longevity, as reported by the Independent, it was not the sole factor.
Professor Churchill pointed out that this research highlights the importance of genetic resilience: “The strongest animals maintain their weight even under stress and caloric restriction, and they are the ones that live the longest.”
He also suggested that a moderate level of caloric restriction could help “balance long-term health and lifespan.”
Key Takeaways
According to the study’s authors, genes play a “crucial role in how diet affects an individual’s health trajectory.”
Professor Churchill even joked about it: “If you want to live a long time, there are things you can control throughout your life, like your diet, but really, you need a very old grandmother.”
He added, “While caloric restriction is generally beneficial for longevity, our data show that weight loss during caloric restriction can actually be detrimental to lifespan.”
Thus, according to the professor, when individuals lose weight and improve their metabolism during trials for longevity-enhancing drugs, it doesn’t necessarily indicate their future longevity.
The team emphasized the need for further research on humans to clarify the impact of restrictive diets on lifespan, including intermittent fasting and caloric restriction while maintaining adequate nutrient intake.