Low-calorie diet may be key to longer life at any age, according to a fruit fly study

It’s never easy to start a new diet, and elderly people might feel that there’s not much use for them anymore. However, a recent study from the University of Connecticut indicates that dietary modifications can greatly enhance health and lengthen life expectancy even in later years.

It’s crucial to remember that the research used to reach this conclusion used fruit flies. How on earth would that apply to people? About 75% of the genes that cause diseases in humans are also present in fruit flies, despite the fact that they are very different from humans. Because of their genetic resemblance, these genes can be studied to learn more about how different human diseases and health conditions are caused by them.

Obesity, which is becoming a global health concern, may be the biggest threat to human health. Numerous metabolic illnesses, such as diabetes and heart disease, are associated with it. Previous research on animals has consistently demonstrated that calorie restriction can increase longevity without causing malnutrition. Less food consumption has also been linked to improved health in human trials, especially in obese people, though the relationship with longevity has been more difficult to determine.

Geneticist Blanka Rogina of the Institute for Systems Genomics and Department of Genetics and Genome Sciences at UConn led the team. They concentrated on fruit flies that were fed a diet that resembled a processed modern diet and was high in calories, sugar, and protein. These flies showed metabolic alterations similar to those seen in obese people. It’s interesting to note that these flies’ lifespans were significantly extended and their metabolisms significantly changed when they were put on a low-calorie diet later in life.

Fruit flies normally don’t live very long—those fed a high-calorie diet can only survive for about 80 days, while those fed a low-calorie diet can live up to 120 days. The effects of diet modifications on juvenile and adult male flies were investigated in this study. The lifespan of young flies that changed from a high-calorie to a low-calorie diet at 20 days of age was equal to that of those that had always eaten low-calorie foods.

After Following a Low-Calorie Diet, Older Flies Show Amazing Improvement
The real surprise, though, was revealed with the older flies. Individuals who were fed a high-calorie diet as children had higher levels of body fats and needed more energy to fight oxidative stress. In addition, their death rate was higher than that of people following a low-calorie diet. However, the metabolisms and lifespans of these older, high-calorie diet flies significantly improved when they were switched to a low-calorie diet at 50 or even 60 days.

“Our studies were performed in flies aged on a high calorie diet, akin to obese individuals, suggesting that late-life diet shift in obese humans might have remarkable beneficial impact on health,” Rogina said in a statement.

The group also examined gene expression in these flies, with Brent Graveley, chair of the genetics and genome sciences department at UConn School of Medicine, participating. The genes governing physiological and metabolic adaptations were found to differ significantly between flies fed a high-calorie diet and those fed a low-calorie diet. Gravely states, “The remarkable finding of this study is that flies can gain the benefits of life span extension by simply switching to a low calorie diet, even after living a significant portion of their lives on a high calorie diet.”

The findings of this study, which were published in PNAS, provide a fresh perspective on how to treat obesity and the health problems it causes in people, raising the possibility that improvement can always be made at any time.