Previous studies have indicated that our dietary choices and specific eating patterns can positively influence aging and longevity. A recent study conducted on mice has revealed that while reducing caloric intake may contribute to a longer lifespan, those mice that achieved the greatest longevity did not experience significant weight loss on a calorie-restricted diet.
Researchers from The Jackson Laboratory in Bar Harbor, ME, and Calico Life Sciences in South San Francisco, CA, found in their study that genetic factors could play a more crucial role in determining lifespan than dietary habits. The findings were published in the journal Nature.
The study examined various diets, including the Mediterranean diet, intermittent fasting, and caloric restriction, all known for their potential to enhance longevity. For this research, 960 genetically diverse female mice were divided into five diet groups:
- Caloric intake limited to 60% or 80% of their baseline needs
- Fasting for one or two consecutive days each week without caloric limits
- Unlimited access to food
Senior author Gary Churchill, PhD, from The Jackson Laboratory, explained that the aim was to determine if lifespan-enhancing interventions like caloric restriction or intermittent fasting were universally beneficial or effective only for specific individuals. Using a genetically diverse mouse model allowed for more comprehensive insights.
Andrea Di Francesco, PhD, lead author of the study, highlighted that while caloric restriction has been known to extend lifespan in rodents since the 1930s, the mechanisms behind this phenomenon are still not completely understood. Recent studies have also suggested that the timing of food intake may significantly affect its benefits.
At the end of the study, the results showed that mice allowed to eat freely lived an average of 25 months, while those on intermittent fasting diets enjoyed an average lifespan of 28 months. Mice on a caloric restriction diet had the longest lifespans, averaging 30 months for those consuming 80% of their baseline calories and 34 months for those consuming only 60%.
Churchill noted their surprise at the significant lifespan extension observed with the more extreme 40% caloric restriction, especially without any indication that it negatively affected the lifespan of any mouse. The study’s design, featuring a genetically diverse population, provided unique insights into this phenomenon.
Additionally, researchers discovered that genetic factors, including resilience, may be more influential on longevity than dietary choices. Di Francesco emphasized that the variability seen in lifespans suggests that while diets can improve average lifespans, they do not guarantee longevity for every individual.
The researchers found that mice maintaining stable body weight and healthy immune responses during calorie reduction and stress lived the longest. This challenges the notion that caloric restriction extends lifespan solely by reducing obesity and prediabetes traits; rather, it appears that greater longevity was associated with maintaining a higher body weight.
Mir Ali, MD, a bariatric surgeon, expressed intrigue over the study’s conclusion that reducing caloric intake can enhance lifespan without necessarily leading to weight loss, which he described as counterintuitive. He emphasized the need for further research to determine how these findings in mice translate to humans.
Monique Richard, MS, RDN, LDN, a registered dietitian nutritionist, noted that the study aligns with emerging knowledge about cellular function and optimal health benefits from lower-calorie diets and fasting.
In light of the findings, individuals are encouraged to focus on factors that can enhance their longevity, recognizing that while genetics play a crucial role, maintaining a healthy lifestyle is essential. Ali advised against obesity and unhealthy eating habits, emphasizing the need to support one’s genetic potential through proper nutrition and weight management.
Richard added that the body operates best when provided with adequate nutrients, which support cellular functions and promote longevity. She recommended consulting with a registered dietitian to tailor dietary approaches to individual needs, as there is no universal solution for everyone.
