Intermittent fasting (also known as time-restricted eating) has been a “trend” for a while now. For those of you who aren’t familiar, it’s basically eating all of your meals within a set time frame. And there are different ways to do it.

For example, some forms of intermittent fasting involve eating whatever you’re going to eat that day for 8 to 5 hours, then fasting for the remaining 16 to 19 hours. Other intermittent fasting models alternate eating days with fasting days.

Proponents of intermittent fasting boast of its many benefits, including weight loss and lower insulin levels. When insulin levels remain too high for long periods of time, your risk of obesity, type 2 diabetes, and heart disease increases.

But while intermittent fasting seems to work in the short term, is it healthy and effective in the long term? March 18, 2024 American Heart Association Epidemiology and Prevention – Lifestyle and A new study presented at the Cardiometabolic Scientific Sessions 2024 suggests that may not be the case.

Before I share the details of the study, a quick note. These findings are presented as an abstract and have not yet been published in a peer-reviewed scientific journal. The AHA states: “Abstracts presented at the Society’s scientific conferences are not peer-reviewed, but are curated by an independent review committee and considered based on their potential to increase the diversity of scientific issues and views discussed at the conference. ” The findings are considered preliminary until published as a full manuscript in a peer-reviewed scientific journal. ”

What did this study find?

Researchers examined data on 20,000 U.S. adults from the National Health and Nutrition Examination Survey (NHANES) from 2003 to 2018, and data from the Centers for Disease Control and Prevention’s (CDC) National Mortality Index from 2003 to December 2019. The data were compared with those who had died up to that point. database.

The average age of participants was 49 years, approximately half of them were women, and they were of mixed racial and ethnic groups. They were followed for an average of 8 years and up to 17 years. Participants were 20 years of age or older and had completed at least two 24-hour dietary recall questionnaires within 1 year of enrollment.

The analysis found that people who followed a pattern of eating all their food during less than eight hours a day had a 91% higher risk of dying from cardiovascular disease.

For people with pre-existing cardiovascular disease, eating for 8 to 10 hours a day was associated with a 66% higher risk of death from heart disease or stroke.

“We were surprised to learn that people who followed an eight-hour time-restricted eating schedule were more likely to die from cardiovascular disease,” said study author Victor, professor and chair of the department. Dr. Wenze Zhong says: in epidemiology and biostatistics from Shanghai Jiao Tong University School of Medicine in Shanghai, China, said in a press release about the study. “While this type of diet was popular due to its potential short-term effects, our study showed that compared to the typical eating window range of 12 to 16 hours per day, It has been clearly shown that short meal times are not associated with longer lives.”

How does this apply to real life?

Zhong emphasizes a more personalized approach to eating that is also based on current recommendations, such as the 2020-2025 Dietary Guidelines for Americans.

“It’s important for patients, especially those with pre-existing heart disease or cancer, to be aware of the association between the eight-hour meal window and increased risk of cardiovascular death,” Zhong urges. “Our findings encourage a more careful and individualized approach to dietary recommendations, ensuring they are consistent with individual health status and the latest scientific evidence.”

Zhong also has a word of caution regarding the results. “Although this study identified an association between an 8-hour eating window and cardiovascular death, this does not mean that time-restricted eating causes cardiovascular death. ” Cardiovascular death. ”

In other words, the researchers could not prove that intermittent fasting caused death from heart disease. That said, it may explain the link between intermittent fasting and heart disease.

“Intermittent fasting is itself stressful for the body, and given our modern lives, which are already filled with chronic emotional, physiological, and environmental stressors, intermittent fasting is a good thing. It can do more harm than good,” said Gillian Greaves MPH, RD, LDN. eat well In a previous article. “Fasting increases cortisol, which over time can lead to dysregulated blood sugar levels, increased insulin resistance, decreased lean muscle mass, fatigue, and impaired thyroid function. Stimulating hormones may be lowered, but persistently elevated cortisol may reduce thyroid hormone conversion.”

Chronic stress is also a risk factor for heart disease, according to the CDC. Cortisol increases blood pressure, and high blood pressure is a direct risk factor for heart disease. People who are chronically stressed are also more likely to develop habits that can be harmful to their health, such as stress eating and excessive alcohol consumption. When you’re stressed, you tend to not get enough quality sleep, which only worsens your stress cycle.

conclusion

Researchers conducted this preliminary study because although there is evidence that intermittent fasting may have short-term benefits, there is little data on its long-term effectiveness and safety. is. And while this review suggests there may be a link between time-restricted eating and death from heart disease, whether or not you currently have heart disease, there are other possible links. Further research is required to flesh out the gender and details.

When practicing intermittent fasting, it’s important to be aware of its potential long-term risks. And if you’re going to do it, learn how to do it properly. When many of us “let it go,” our circadian rhythms can become disrupted, which has also been linked to an increased risk of heart disease. It is best to consult your doctor before making any changes to your current diet.