Studies have shown that intermittent fasting can almost double the risk of dying from cardiovascular disease

New research shows that a preferred weight reduction strategy that limits the hours at which calories are consumed can nearly double the long-term risk of death from cardiovascular disease, especially amongst individuals with cardiovascular disease or cancer.

But the query stays how time-restricted eating, which limits calorie intake to parts of the day, affects the risk of heart disease and stroke. Previous research has suggested that weight loss program can reduce cardiovascular risk aspects in the short term.

While latest research is compelling, the reasons participants selected this eating style are unknown, said Dr. Kenneth Mukamal, a primary care physician at Beth Israel Deaconess Medical Center and a professor of medicine at Harvard Medical School in Boston. Mukamal was not involved in the study, which was presented Monday at the American Heart Association’s Epidemiology, Prevention, Lifestyle and Cardiometabolic Health conference in Chicago.

“It was a reasonable attempt to look at the long-term effects of time-restricted eating,” he said. “At first glance, this does not suggest that it would be beneficial to the cardiovascular system, in fact it was harmful. However, there may be health reasons to eat in a time-restricted way that makes it seem harmful when it is not.”

Mukamal said it’s too early to say that people should avoid time-restricted eating if it helps them achieve their weight reduction goals. “At this point, if people want to eat for shorter periods of time and it’s easier for them to maintain their weight that way, I wouldn’t use that as a reason not to do it,” he said.

Time-restricted eating, a sort of intermittent fasting, typically limits caloric intake to a window lasting 4 to 12 hours. Previous research has shown that it can be an efficient weight reduction strategy, especially when combined with calorie restriction. Research also suggests it can quickly lower blood pressure and other key markers of cardiovascular disease in obese people.

In the latest study, researchers analyzed dietary data from a nationwide survey of 20,078 U.S. adults with a mean age of 49. They recalled twice all the food and drinks that they had consumed in 24 hours.

People who limited eating to lower than eight hours a day were almost twice as prone to die from cardiovascular disease, including heart disease and stroke, over a median follow-up of eight years, compared with those that ate meals . inside 12-16 hours. The eight-hour eating window was related to higher cardiovascular mortality in the general population, in addition to in individuals who had pre-existing cardiovascular disease or cancer.

Time-restricted eating doesn’t appear to have an effect on the risk of death from all causes combined, especially cancer. However, in individuals with cancer, eating greater than 16 hours a day was related to a lower risk of dying from cancer.

The results are considered preliminary until the full results are published in a peer-reviewed journal.

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Principal investigator Dr. Victor Wenze Zhong, professor and chair of epidemiology and biostatistics at the School of Public Health at Shanghai Jiao Tong University in China, said the findings surprised his team.

“Limiting daily eating time to a short period, such as eight hours, has gained popularity recently because it appears to help people lose weight and improve cardiometabolic health,” Zhong said. “We therefore expected that long-term adoption of eight-hour food restriction would be associated with a lower risk of cardiovascular death and even death from any cause. We were surprised to find out (it wasn’t true).”

Mukamal, nonetheless, said many aspects remain unexplained.

“It’s important to note that these are people who choose to eat this way,” he said, noting that it was an observational study, not a randomized one, by which people were asked to eat at different times for comparison. For example, individuals with cancer may struggle with loss of appetite and due to this fact eat for a shorter period of time, but their life expectancy could also be shorter.

“Some of what seems harmful may be due to why people choose to eat this way,” Mukamal said.

However, even amongst people in the general population who selected to eat during restricted periods, “no clear cardiovascular benefits were found,” he said. “This leaves quite open the question of whether time-restricted eating can improve cardiovascular health in the long term.”

While research continues, people in search of healthier eating patterns should follow those proven to enhance heart health, Mukamal said. DASH (Dietary Approaches to Stop Hypertension), pescetarian and Mediterranean weight loss program scored highest for heart healthin line with the AHA scientific statement.

“At least for now, focusing on what people eat is more important than focusing on the time they eat,” Mukamal said.