Intermittent Fasting: A Heart Healthy Dietary Pattern?

Although cardiovascular mortality rates have improved, the decline in mortality has recently ceased, and there has been an increase in mortality in 35- to 64-year-old males and females in the United States. Obesity along with poor diet are important, modifiable contributors to the rise of cardiovascular disease with an estimated attributable risk of 13% to cardiovascular mortality. There are several dietary interventions that have been shown to improve cardiovascular risk, including caloric restriction, which involves limiting calories consumed during a given period. Caloric restriction is linked to improvement in weight, blood pressure, and insulin sensitivity in humans.

Intermittent fasting is a dietary intervention similar to caloric restriction, as it uses the principle of restricting food intake. However, intermittent fasting focuses on the timing of when one can consume meals either within a day or a week. Two overarching types of intermittent fasting are alternative day fasting and time-restricted fasting. In alternative day fasting, a subset may consist of 24-hour fasts followed by a 24-hour eating period that can be done several times a week such as a 5:2 strategy when there are 2 fast days mixed into 5 nonrestrictive days. For time-restricted fast programs, variations include 16-hour fasts with 8-hour feeding times, 20-hour fasts with 4-hour feed times, or other similar versions. Although both caloric restriction and intermittent fasting may result in overall decreased caloric intake, this is not integral to intermittent fasting. Intermittent fasting has been linked to better glucose control in both humans and animals. However, long-term adherence to caloric restriction is low, whereas adherence to intermittent fasting may be more promising.

Given the similarity between these 2 diets, it is plausible that intermittent fasting could confer cardiovascular benefits as well. This dietary pattern has also shown potential benefit in slowing the progression of neurodegenerative diseases like Alzheimer and Parkinson diseases. In this review, we explore the potential benefits of intermittent fasting for improving cardiovascular health.