Important points
- A new study published by the American Heart Association found that people on a 16:8 intermittent fasting diet have an increased risk of cardiovascular death.
- This study has not been published or peer-reviewed.
- Doctors said more robust research was needed.
Intermittent fasting has come under scrutiny since the American Heart Association (AHA) released information earlier this week about research linking this dietary pattern to an increased risk of death from heart disease. The findings have been controversial because they have not been peer-reviewed or published.
The study collected two days of dietary data from more than 20,000 adults as part of a national survey conducted from 2003 to 2018, according to an AHA press release. The researchers compared this information with data collected from people who died in the United States. From 2003 to December 2019.
Researchers found that people with an 8-hour daily eating window (which mimics the common 16:8 intermittent fasting diet pattern) had lower heart rate compared to those who ate more than 12 to 16 hours a day. They concluded that they were 91% more likely to die from the disease. , which is a more typical eating pattern.
The study also found that people who already had cardiovascular disease and who spent less than 10 hours a day eating had a 66% higher risk of dying from heart disease or stroke. Overall, the study results showed that no form of time-restricted eating pattern reduced the risk of death from any cause.
Dr. Joseph Daibes, an interventional heart specialist at Northwell Health, encourages people to look into the details of the study before making any major conclusions.
“I do not believe the American Heart Association did justice by publishing this incomplete and poorly designed summary, knowing it would be controversial,” Duives said. told Berrywell. “We get calls from patients asking if they should stop eating and change their lifestyle. There is no reason to do so based on these findings.”
There are red flags to address
The study has not yet been published, the AHA has only shared a press release about it, and it has not been peer-reviewed.
“Peer review is an important part of the medical publication process to ensure accurate scientific research and dissemination of research findings in a methodologically sound manner,” said Megan Kamath, M.D., a cardiologist at UCLA Health in Berry. told Well.
This data is also based on just two days of dietary intake.
“Two days of dietary data is a limited amount of time when considering outcomes such as cardiovascular disease and all-cause mortality,” Kamath said. He also noted that there is “limited information” about what people ate during mealtimes. “It will help us analyze this type of study as well as other complications that these patients have,” she said.
The study was based on survey data, where people filled out information about their eating habits. This is difficult in science because people are not always completely honest about what they ate, and may not fully remember what and how much they had to eat. There are cases, Dybes said.
This study lacks information on other lifestyle risk factors for cardiovascular disease, such as physical activity levels and tobacco and alcohol use.
Duybes suggested viewing these findings as “preliminary data for a study that could one day be large-scale.”
There teeth Data supporting intermittent fasting for health
One of the study's researchers said in an AHA statement that they were “surprised” by the results, given that most data supports the use of intermittent fasting for heart health. .
“There is data showing that intermittent fasting and time-restricted eating are beneficial to health for a variety of reasons,” Dive said.
A meta-analysis of human and animal studies published in 2019 found that restricting eating windows is associated with an array of benefits, including lower blood pressure, weight loss, and improved longevity. .
Data also shows that while intermittent fasting can help you lose weight, it is less effective than traditional calorie restriction. One study of 139 obese adults in China found that those who followed an intermittent fasting diet lost about the same amount of weight as those who counted their calories and had improved cardiovascular health after one year. It turned out to be equivalent.
A randomized controlled trial of 116 people published in 2020 also found that between those who didn't eat anything from 8pm until noon the next day (16:8 diet) and those who didn't do intermittent fasting. No significant difference was found in weight loss. diet.
Dybes said intermittent fasting may indirectly help heart health by limiting the amount of insulin spikes during the day.
“It really helps your metabolism. Baseline blood sugar levels are more stable during the day,” he said.
Dybes added that intermittent fasting is also a helpful tool for weight management for some people, as maintaining a healthy weight is associated with cardiovascular health.
Does breakfast make a difference?
Some schools of thought say it's best not to skip breakfast for heart health when following an intermittent fasting diet, but Professor Kamath said that was still under consideration.
“This is an area of discussion in the medical field as well,” she says. “Most of the ideas about not skipping breakfast center around the theory that breakfast boosts your metabolism and that people who eat breakfast have healthier eating habits, but these have not been proven in large studies. Not.”
Dybes agreed that the data is inconclusive as to whether skipping breakfast is a bad thing. However, “breakfast should be your most caloric meal, and subsequent meals should be low in calories and not heavy,” he said.
Ultimately, the doctors said more robust research is needed to investigate the potential benefits and drawbacks of following an intermittent fasting diet for cardiovascular health.
“We have seen previous studies showing potential benefits. [of intermittent fasting] Regarding the management of obesity, blood pressure and diabetes, however, further research is needed to better understand this,” Kamath said. “This is an area of medicine, and we are still trying to understand what is best, and more research needs to be done before we can make formal recommendations in this area.”
How to practice intermittent fasting in a healthy way
Dybes said it's important to maintain a healthy diet during mealtimes.
“Time-restricted eating needs to be done the right way,” he says. “You can't say, 'You can eat whatever you want for those eight hours.'”
He recommends eating a balanced diet that is primarily plant-based, with plenty of vegetables and white meat and fish.
“The Mediterranean diet has been proven time and time again to be optimal for improving cardiovascular disease,” he says.
If you're planning an intermittent fasting diet, Kamath recommends talking to your doctor first to “consider your individual medical condition and long-term health goals.”
If your budget allows, it may be helpful to consult a registered dietitian to make sure you're eating well during mealtimes, says Duybes.
“I send quite a few of my patients to a dietitian to discuss what their dietary intake should be,” he said.
what this means to you
Although research into the potential health benefits of intermittent fasting is ongoing, doctors stressed that the latest findings are weak and inconclusive. If you're concerned about your heart health and have questions about your diet, talk to your health care provider for personalized guidance.
