Restricting your daily calories to a healthy total will not just help you keep the pounds off. It just might help you live longer.
Researchers at Washington University School of Medicine in St. Louis have found a link between calorie consumption and a healthy heart. They say a key measure of the heart's ability to adapt to physical activity, stress, sleep and other factors that influence the rate at which the heart pumps blood, doesn't decline nearly as rapidly in people who have significantly restricted their caloric intake for an average of seven years.
The study is available online in the journal Aging Cell.
"This is really striking because in studying changes in heart rate variability, we are looking at a measurement that tells us a lot about the way the autonomic nervous system affects the heart," said Luigi Fontana, MD, PhD, the study's senior author.
There is a link, it turns out, between heart function, breathing and digestion.
"We would hypothesize that better heart rate variability may be a sign that all these other functions are working better too," she said.
The researchers hooked portable heart monitors to 22 people who restricted calories and who ate healthy diets but consumed 30 percent fewer calories than normal. Their average age was just over 51.
For comparison purposes, researchers also studied 20 other people of about the same age who ate standard Western diets. Heart rates were significantly lower in the calorie restriction group, and their heart rate variability was significantly higher.
"Higher heart rate variability means the heart can adjust to changing needs more readily," said lead author Phyllis K. Stein, PhD. "Heart rate variability declines with age as our cardiovascular systems become less flexible, and poor heart rate variability is associated with a higher risk of cardiovascular death."
Young at heart
The researchers say that, when looking at heart rate variability among people at different ages, they found that those who practice calorie restriction have hearts that look and function like they are years younger. They say they've seen this before.
Laboratory animals with a restricted calorie intake tend to live 30 percent to 40 percent longer than those that eat standard diets.
"Many humans who practice calorie restriction believe they also will live significantly longer, but that won't be known for several more years," Fontana said.
The daily calorie needs of individuals will vary. Obviously you should not begin a restricted calorie diet without determining how many calories a day you require and consulting with your doctor.