Intermittent Fasting: A Heart Healthy Dietary Pattern?

Abstract

Dietary patterns, such as the Dietary Approaches to Stop Hypertension (DASH) and the Mediterranean diet, have been shown to improve cardiac health. Intermittent fasting is another type of popular dietary pattern that is based on timed periods of fasting. Two different regimens are alternative day fasting and time-restricted eating. Although there are no large, randomized control trials examining the relationship between intermittent fasting and cardiovascular outcomes, current human studies that suggest this diet could reduce the risk for cardiovascular disease with improvement in weight control, hypertension, dyslipidemia, and diabetes. Intermittent fasting may exert its effects through multiple pathways, including reducing oxidative stress, optimization of circadian rhythms, and ketogenesis. This review evaluates current literature regarding the potential cardiovascular benefits of intermittent fasting and proposes directions for future research.

Keywords: Alternative day fast; Circadian; Diabetes; Dyslipidemia; Hypertension; Time-restricted feeding.

Figure 1.. Mechanisms of Intermittent Fasting

Proposed mechanisms of how intermittent fasting reduces cardiovascular risk factors. There are three main theories: Oxidative Stress Hypothesis, Circadian Rhythm and Ketogenic State. The Oxidative Stress Hypothesis postulates that fasting reduces stress leading to fewer free radical with less mitochondrial energy production ultimately lowering the body's oxidative stress. The Circadian Rhythm component focuses on syncing eating periods to the organ's circadian rhythm, optimizing glucose and fat utilization. The third mechanism, Ketogenic State, recognizes that Intermittent Fasting induces ketogenesis, which decreases blood pressure and adipose tissue.

Figure 2.. Similarities and di?erences between intermittent fasting and caloric restriction

Intermittent Fasting shares commonalities as well as differences with Caloric Restriction. Both have been shown to reduce cardiovascular risk factors including improving blood pressure, insulin sensitivity and dyslipidemia. In addition, it shares the common pathway of reducing stress response. Intermittent fasting revolves around defined periods of fasting syncing with the circadian rhythm while caloric restriction focuses on restricting overall calories. Thus far, intermittent fasting appears promising for overweight and obese individual and it remains to be seen if adherence is easier with intermittent fasting regimens.