- Researchers say reducing calorie intake seems to help slow the aging process, at least in healthy adults.
- Experts say the findings are intriguing, but more research needs to be done to determine if other factors are involved.
- They note that you can eat healthily by sticking to a healthy diet pattern, focusing on nutrient-dense foods, and avoiding foods with high sugar content.
Researchers, led by the Butler Columbia Aging Center at Columbia University Mailman School of Public Health in New York, used DNA analysis from blood samples to measure the rate of aging and reported that calorie restriction slowed the aging process.
Participants included 220 healthy men and women in three different sites in the United States. The participants either continued with their regular diet or had a 25% reduction in their consumed calories.
The scientists followed the participants’ diet and health for two years and took blood samples at the start of the study and again at 12 months and 24 months.
The researchers reported a slowing aging process based on three DNA markers.
They said these results could provide a sense of what effects scientists can look for when completing trials for specific weight interventions, such as intermittent fasting.
“This study teaches us that keeping a person’s body at a lean weight helps decrease the molecular changes on a cellular level that happen in response to aging,” said Dr. David Selzer, an internal medicine specialist at NYU Langmore Medical Associates in West Palm Beach and Delray Beach in Florida who was not involved in the study. “With that noted, life is not a test tube. People age for multifactorial reasons such as stress and anxiety, not just their diet.”
“I agree that calorie restriction plays a role on the molecular level,” Selzer told Healthline. “However, I think finding a healthy balance between caloric intake and daily exercise is more likely to lead to a longer lifespan.”
The researchers are currently completing a follow-up study to see if calorie restriction has a long-term effect on healthy aging.
“The results make sense to me,” said Dr. Raphael Kellman, an internist and functional medicine physician at Kellman Wellness Center in New York City. “However, nutrition studies are notoriously difficult to conduct, particularly long-term, as people naturally have trouble adhering to diets.
“I think you should take into consideration a few things,” Kellman told Healthline. “One, what kind of diet was the control group on vs. the calorie-restricted group? If the control group is overeating or eating a lot of unhealthy foods and the calorie-restricted group is eating a healthier diet, are the results due to the calorie restriction, or would just eating a healthier diet also have a positive impact?”
“Also, it is hard to know whether people are truly adhering to a diet unless their food is strictly controlled and monitored,” Kellman added. “Clearly, if this study was conducted over two years, people are out living their lives, how do we know for sure that they have stuck to a 25 percent restricted diet that entire time, if at all, given how hard it is for most people to track portion size and calories on most normal diets truly? I think this study is valid and has some interesting results, requiring further study.”
Caroline Thomason, RD, CDCES, a nutrition expert, offers some caveats to calorie-reduction diets.
“Short-term calorie restriction can be advantageous; long-term calorie restriction harms our metabolism, energy levels, and general well-being,” she told Healthline. “People who should not be in a calorie deficit intentionally or for very long include individuals with eating disorders, those with osteopenia or osteoporosis (specific to the older population), those who are underweight, and people trying to gain weight.”
“In general, it’s essential to focus on various foods and a healthy balance before cutting calories,” Thomason added. “Focus on the basics first: getting a serving of protein in each meal, eating a variety of whole grains, fruits and vegetables, and some healthy fats. Other healthy behaviors include getting enough sleep, being regularly active, and managing stress. These factors are also crucial for healthy aging.”
The U.S. Departments of Agriculture and Health and Human Services jointly publish the
The current guidelines suggest the following:
- Follow a healthy dietary pattern.
- Customize your eating based on your preferences, cultural traditions, and budgetary considerations.
- Focus on nutrient-dense foods and beverages. These provide vitamins and minerals without added sugars, saturated fats, and sodium.
- Limit foods with high added sugars, saturated fat, and sodium, and limit alcoholic beverages.
“It is best to eat low carbohydrates and increased protein to keep muscle strength and weight at an ideal level,” Selzer said. “As patients age, it is important to find the right amount of caloric intake depending on their exercise and movement capabilities.”
Another option is intermittent fasting, Kellman noted.
“This is relatively easy to do and can aid with weight loss, has been shown to aid in the regulation of blood sugar, and there are studies that show that it may provide other health benefits, such as supporting healthy aging,” he said.