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Heart disease is the leading cause of disability and death in the world. In the United States, about 2,200 people die each day from cardiovascular problems, one every 40 seconds.
With that in mind, if you knew that you can help keep your heart healthy by eating a little less each day – about six calories of the standard size of Oreos – would you do it?
Researchers have found evidence that a simple reduction in our daily caloric intake could have protective effects on our heart, according to an article published this week in The Lancet Diabetes & Endocrinology.
The paper is based on data from the CALERIE study (Overall Assessment of the Long-Term Effects of Reducing Energy Consumption). This flagship project, supported by the National Institutes of Health, was one of the most in-depth efforts to measure the long-term effects of calorie restriction in humans. The researchers published numerous analyzes based on the two-year study data, examining various factors associated with life expectancy and longevity.
This paper, the latest to draw data, focuses on the impact of moderate caloric restriction on heart health and the potential for preventing age-related decline.
The experiment began with 218 participants, all of normal weight or slightly overweight, aged 21 to 50 years. Researchers implemented a diet that reduced their caloric intake by 145% by 143 participants; Another 75 were on a normal diet. In the end, 188 participants completed the study – 117 with caloric restriction and 71 without.
During the first four weeks of the study, members of the calorie cutting group were fed on-site in one of three clinical centers. During this time, they learned how to reduce their calorie intake and gradually fell into one of six dietary plans according to their preferences.
In the first six months, most people have very well adhered to their diet. On average, they reduce calories by about 20%. But they have not been better off for two years: overall, they reduced their caloric intake by an average of about 12% – about 300 fewer calories per person per day. .
Nevertheless, this relatively modest reduction in calories had a significant impact on participants who ate less: they lost about 16 kilograms on average and found improvements, including lower cholesterol and blood pressure, in the top six. factors associated with heart health risks. They also found an improvement in insulin resistance and metabolic rates.
"We expected that there would be [some] Improving cardiometabolic factors because of weight loss, "says William Kraus, lead author of the study and distinguished professor of Cardiovascular Genomics at Duke University. But … we did not expect the degree of improvement observed. "
And while the weight loss was relatively impressive, she was not responsible for the majority of heart benefits. After further analysis, the researchers determined that weight loss accounted for no more than 25% of the improvement in heart health measurements. Researchers say their findings suggest that caloric restriction may have health benefits beyond those normally associated with weight loss.
David Sinclair, a professor of genetics at Harvard Medical School, says the findings provide further evidence that calorie restriction can be beneficial in avoiding the negative effects of aging.
But, he says, the study also demonstrates an important problem related to the use of calorie restriction to improve human health: it's really hard to maintain even for motivated people. Of the 143 participants who initially started the restricted diet, 26 dropped out before the two years were up. (The small size of the sample was a limit of the study.) Many other people were excluded from the initial study group because of concerns related to their physical or mental health .
"You can not expect the elderly or frail people to follow this harsh diet," says Sinclair, who did not participate in the study. "We need alternatives, whether it's intermittent fasts or medicines mimicking a caloric restriction." He strives to understand how caloric restriction works at the molecular level so that he and others can offer drugs that provide the same benefits without pain or difficulty.
According to him, the goal of any research on caloric restriction is the reduction – and perhaps the elimination – of diseases related to aging.
"Aging is not considered a medical condition, it's just too common." Fortunately, in the near future, we will not accept it, "he says. "This is what caloric restriction proposes: it compresses the period of illness. It is hoped that people will live to age 90 in a healthy way and that they will die faster and longer. [less] painfully we are doing it now. "
Susie Neilson is an intern at NPR's Science Desk. Follow her on Twitter: @susieneilson.