Intermittent fasting and cardiovascular risk – What science says


Intermittent fasting has garnered attention as a potential weight loss tool and health enhancer, but recent research presented at the American Heart Association’s scientific sessions raises concerns about its impact on cardiovascular health.

While intermittent fasting may offer benefits like lowered blood pressure and weight loss, this analysis suggests a stark contrast – a 91% higher risk of cardiovascular death for those with restricted eating windows. Let’s delve into the nuances of this study and the potential health risks associated with intermittent fasting.

The Shanghai Study Unveiled:


Researchers from Shanghai Jiao Tong University School of Medicine analysed data from the CDC’s National Health and Nutrition Examination Survey spanning 2003 to 2018. Their findings challenge previous notions of intermittent fasting’s cardiovascular benefits. Contrary to expectations, individuals limiting eating to less than eight hours daily faced a significant increase in cardiovascular mortality over an eight-year period compared to those with wider eating windows.

Unpacking the Risks:

While intermittent fasting may yield short-term benefits such as weight loss and improved cardiometabolic health, caution is advised for prolonged adherence. The study suggests that restricting eating to narrow time frames could potentially harm cardiovascular health over time. Factors like nutrient deficiencies, disrupted hormonal balance, and heightened stress hormones may contribute to this heightened risk.

Expert Perspectives:

Health experts weigh in on the implications of this research. Dr. Benjamin Horne highlights the potential stress-induced risks associated with fasting, particularly in vulnerable groups like the elderly or those with chronic conditions. While acknowledging potential long-term benefits, he underscores the importance of understanding the short-term risks.

Nuances of Implementation:

Intermittent fasting regimens vary widely, from daily time-restricted feeding to the popular 5:2 diet. However, the study emphasises the importance of understanding individual responses to fasting. Dr. Francisco Lopez-Jimenez suggests that meal timing may influence outcomes, cautioning against skipping breakfast due to its association with increased heart disease risk.

Considerations and Limitations:

While the study provides valuable insights, experts note its limitations. The reliance on self-reported dietary data and the absence of nutritional quality assessment pose challenges in drawing definitive conclusions. Dr. Pam Taub highlights the individual benefits her patients have experienced with intermittent fasting but urges a cautious approach in light of this new research.

Intermittent fasting continues to captivate interest for its potential health benefits, but emerging research underscores the need for careful consideration. While intermittent fasting may offer short-term advantages, the Shanghai study suggests a potential link to increased cardiovascular risk over time. As research unfolds, individuals are encouraged to approach fasting regimens with caution, mindful of potential risks and benefits. Consulting healthcare professionals and staying informed can help navigate the complexities of intermittent fasting for optimal health outcomes.