Intermittent Fasting Linked to Increased Cardiovascular Death Risk

A recent analysis has raised concerns about the long-term safety of intermittent fasting, suggesting that the popular dieting method may be linked to a higher risk of cardiovascular death. The study, which has yet to be peer-reviewed, was presented at the American Heart Association’s scientific sessions in Chicago and is based on data from the Centers for Disease Control and Prevention.

Intermittent fasting, which involves alternating periods of eating with periods of fasting, has gained significant popularity over the past decade as a strategy for weight loss and health improvement. Proponents have claimed benefits ranging from extended lifespan to reduced risk of chronic diseases. However, the new research from Shanghai Jiao Tong University School of Medicine in China indicates that the practice might not be without risks.

The researchers analyzed dietary data from around 20,000 adults in the U.S., who recorded their food intake over at least two days. They then examined the subsequent deaths from cardiovascular disease over a median follow-up period of eight years. The findings revealed that individuals who restricted their eating to less than eight hours per day had a nearly doubled risk of dying from cardiovascular disease compared to those who consumed food over a 12 to 16-hour period.

Dr. Victor Wenze Zhong, a co-author of the analysis, cautioned that while short-term intermittent fasting, such as over a period of three months, may lead to benefits like weight reduction and improved metabolic health, long-term fasting for years should be approached with caution.

The study also found that people with existing cardiovascular conditions or cancer who followed a time-restricted eating pattern had a 66 percent higher risk of cardiovascular death. In contrast, cancer patients who ate over a period of more than 16 hours had a lower risk of dying from cancer.

Experts not involved in the study, such as Dr. Kenneth Mukamal from Beth Israel Deaconess Medical Center, have urged caution in interpreting these findings. Mukamal pointed out that the study is observational and does not necessarily prove causation. He also noted that the reasons behind individuals choosing a time-restricted eating pattern were not known, which could influence the results.

Despite these findings, intermittent fasting may still offer benefits for some individuals, particularly in the short term. However, this study suggests that more research is needed to fully understand the long-term effects of such dietary patterns, especially for those with pre-existing health conditions.

As the scientific community continues to explore the implications of intermittent fasting, this study serves as a reminder that dieting trends should be considered carefully and personalized to individual health needs. It also underscores the importance of consulting with healthcare professionals before making significant changes to one's eating habits, particularly for those with underlying health issues.