Study Finds Intermittent Fasting May Lead To A 91% Higher Risk Of Death From Heart Disease

Intermittent fasting has long remained a popular dietary approach among people aiming to lose weight and live a generally healthier life, including parents. This diet, which essentially means limiting the period of eating to a certain number of hours, maintains its appeal with its simplicity and promise of significant health benefits, including weight loss and improved metabolic health. However, recent findings presented at the American Heart Association’s Epidemiology and Prevention | Lifestyle and Cardiometabolic Health Scientific Sessions 2024 bring to light possible long-term health implications associated with the 8-hour time-restricted eating pattern.

Key findings from the study

The research scrutinized dietary patterns of over 20,000 U.S. adults and discovered the following main points:

• Increased cardiovascular risk: Participants following an 8-hour eating schedule exhibited a 91% higher risk of dying from cardiovascular diseases than those who ate over a more traditional 12-16 hour period.
• Vulnerable populations: The study highlighted an increased risk of cardiovascular mortality among individuals with pre-existing heart disease or cancer, suggesting that intermittent fasting might not be suitable for everyone.
• Long vs. short eating windows: Interestingly, an eating window of more than 16 hours was associated with a lower risk of cancer mortality among those with cancer, indicating the complex effects of fasting on different health outcomes.
• Contrast between short-term and long-term effects: Despite the short-term benefits of intermittent fasting, such as improved cardiometabolic health measures, the study revealed significant long-term risks, specifically an increased risk of cardiovascular mortality.

The study’s senior author, Victor Wenze Zhong, Ph.D., highlighted the unexpected nature of these results, pointing out the contrast between the known short-term health improvements and the newly discovered long-term risks associated with this diet.

“It’s crucial for patients, particularly those with existing heart conditions or cancer, to be aware of the association between an 8-hour eating window and increased risk of cardiovascular death. Our study’s findings encourage a more cautious, personalized approach to dietary recommendations, ensuring that they are aligned with an individual’s health status and the latest scientific evidence,” Zhong emphasized.

“Although the study identified an association between an 8-hour eating window and cardiovascular death, this does not mean that time-restricted eating caused cardiovascular death,” he clarified.

Moreover, Christopher D. Gardner, Ph.D., FAHA, the Rehnborg Farquhar Professor of Medicine at Stanford University in Stanford, California, and chair of the writing committee for the Association’s 2023 scientific statement, Popular Dietary Patterns: Alignment with American Heart Association 2021 Dietary Guidance, highlights the need to learn other details involved in the study. He mentioned, “Overall, this study suggests that time-restricted eating may have short-term benefits but long-term adverse effects. When the study is presented in its entirety, it will be interesting and helpful to learn more of the details of the analysis.”

“One of those details involves the nutrient quality of the diets typical of the different subsets of participants. Without this information, it cannot be determined if nutrient density might be an alternate explanation of the findings that currently focus on the window of time for eating,” he added. “Second, it needs to be emphasized that categorization into the different windows of time-restricted eating was determined on the basis of just two days of dietary intake.”

Dr. Kenneth Mukamal, a primary care doctor at Beth Israel Deaconess Medical Center and a professor of medicine at Harvard Medical School in Boston, who was not involved in the study said that it’s too soon to conclude that intermittent fasting is harmful. “This was a reasonable effort to look at long-term effects of time-restricted eating. At first glance, it does not suggest this is likely to be of cardiovascular benefit and indeed it was harmful. But there could be health reasons to eat in a time-restricted manner that would make this appear harmful, when it’s not,” Dr. Mukamal said.

“At this point, if people want to eat over a shorter duration and it's easier for them to maintain their weight that way, I would not use this as a reason not to do it,” he further emphasized.

What is intermittent fasting?

Intermittent fasting involves cycling between periods of eating and fasting, with various approaches defining different windows for eating and abstaining from food. The 16:8 method, one of the most popular forms, restricts food intake to an 8-hour period each day, followed by 16 hours of fasting. This method has been hailed for its ability to facilitate weight loss, improve metabolic health, and simplify meal planning.

Why parents are drawn to intermittent fasting

• Simplicity: Intermittent fasting offers a straightforward approach to dieting that eliminates the need for calorie counting or meticulous meal planning.
• Weight management: Many turn to intermittent fasting as a tool for weight loss, attracted by its promise of burning fat by extending the nightly fasting period.
• Health benefits: Preliminary studies have suggested that intermittent fasting can improve various health markers, including blood pressure, blood glucose levels, and cholesterol profiles.
• Lifestyle flexibility: Intermittent fasting provides a flexible dieting approach that easily appeals to busy parents. It’s adaptable to hectic schedules, potentially making healthy eating more attainable.

What does this study’s findings mean for parents?

Given these findings, here are a few factors parents should consider before adopting any diet or lifestyle, including intermittent fasting:

Consult healthcare professionals: Before making significant changes to dietary habits or lifestyle, especially for those with pre-existing health conditions, it’s best to consult a healthcare professional.

Consider individual health needs: The study’s findings highlight the importance of personalizing dietary approaches to align with each family member’s specific health needs and conditions.

Explore other, proven diets: For parents reconsidering intermittent fasting, here are some well-established dietary patterns that promote heart health and balanced nutrition:

• DASH Diet: Targets hypertension reduction through a diet rich in fruits, vegetables, whole grains, and lean proteins, with limited sodium intake.
• Mediterranean Diet: Emphasizes fruits, vegetables, nuts, whole grains, fish, olive oils, and moderate wine consumption, with minimal red meat.
• Pescetarian Diet: Combines a vegetarian diet with the inclusion of seafood, offering a rich source of omega-3 fatty acids beneficial for heart health.

As dietary trends continue to evolve, staying informed and prioritizing dietary choices based on both short-term benefits and long-term health implications will ensure the well-being of families.

Read here to learn why some diets might not be working out for you.