Structured eating patterns, such as intermittent fasting (IF) and time-restricted feeding (TRF), involve cycling between periods of eating and voluntary fasting. These regimens have gained widespread attention for potential health benefits. A central question is whether this practice can directly address accumulated arterial plaque, a condition known as atherosclerosis. Researchers are actively investigating how fasting influences the development and potential reversal of plaque within the blood vessels.
Understanding Arterial Plaque Formation
Arterial plaque is the defining feature of atherosclerosis, often described as a hardening or thickening of the arteries. This buildup occurs when fatty substances, cholesterol, cellular waste products, and calcium accumulate within the innermost layer of the artery wall. The process begins with damage to the endothelium, the thin layer of cells lining the blood vessel, which triggers a localized inflammatory response. White blood cells migrate to the injury site and absorb oxidized lipids, transforming into foam cells, the earliest sign of plaque formation. As this fatty streak matures, it becomes a fibrous plaque that narrows the artery, restricting blood flow. Unstable plaque can rupture, leading to a blood clot that may cause a heart attack or stroke.
How Fasting Modulates Cardiovascular Risk Factors
Fasting influences several body-wide systems by shifting the body’s metabolism from using glucose to burning stored fat for energy. These systemic changes do not directly remove existing plaque but significantly reduce the conditions that encourage plaque formation and progression. Fasting protocols can improve the body’s response to insulin, reducing the chronic high blood sugar that damages the lining of blood vessels.
Lipid Profile Improvement
Fasting consistently improves the balance of circulating fats, known as dyslipidemia, a major driver of atherosclerosis. Studies demonstrate that various IF protocols reduce total cholesterol, low-density lipoprotein (LDL), and triglyceride levels in the blood. This reduction means less material is available to deposit within the artery walls. Fasting may also enhance the functionality of high-density lipoprotein (HDL). Research suggests fasting can increase HDL’s capacity to remove cholesterol from the arteries and transport it back to the liver for processing, a mechanism known as cholesterol efflux.
Metabolic Flexibility and Insulin Sensitivity
Periods of fasting enhance insulin sensitivity, meaning cells respond more efficiently to the hormone insulin. This improved response helps maintain lower fasting blood glucose levels and reduces circulating insulin. Chronic high insulin levels are associated with increased cell proliferation and inflammation that contribute to arterial wall thickening. By improving glucose regulation, fasting reduces a major stressor on the arterial wall environment. High blood sugar is known to damage the endothelial lining, creating entry points for cholesterol and initiating the atherosclerotic cascade.
Reduction in Systemic Inflammation
Atherosclerosis is fundamentally an inflammatory disease, and fasting has demonstrated an ability to lower systemic inflammation markers. Intermittent fasting can lead to a measurable reduction in C-reactive protein (CRP) and Tumor Necrosis Factor-alpha (TNF-α). This effect is most consistently observed in individuals with higher baseline inflammation or when fasting is combined with weight loss. Reducing this generalized inflammation is theorized to calm the inflammatory processes occurring locally within the artery wall. By dampening the signals that recruit immune cells, fasting may help stabilize or slow the growth of existing lesions.
Cellular Mechanisms: Autophagy and Vessel Wall Integrity
Fasting activates a cellular housekeeping process called autophagy, which translates to “self-eating.” This mechanism allows cells to break down and recycle damaged components and dysfunctional organelles. Autophagy is necessary for maintaining cellular health and is often impaired in aging or diseased tissues, including the blood vessels. Activating autophagy is theoretically beneficial for maintaining vessel integrity. It helps clear out accumulated debris and damaged mitochondria within smooth muscle cells and endothelial cells. This cellular cleanup strengthens the cells lining the arteries, making them more resilient to injury and less prone to the inflammatory process that starts plaque formation. Activating autophagy in macrophages, the immune cells that turn into foam cells, may help them process and clear the lipids they have engulfed, potentially preventing the formation of the plaque’s lipid-rich core.
Scientific Evidence on Plaque Reduction
The most direct research on plaque reduction has been conducted using animal models, which provide valuable but non-definitive insights for human biology. In several studies involving atherosclerosis-prone mice, intermittent fasting protocols have been shown to reduce the overall size of atherosclerotic lesions in the aorta. Fasting has also been observed to increase the stability of existing plaque by increasing the fibrous cap thickness and reducing the number of inflammatory macrophages within the lesion. However, the findings in animal studies are not uniform, highlighting the complexity and dependence on the specific fasting regimen used. Some research involving a different mouse model found that alternate-day fasting aggravated the development of atherosclerosis, possibly by negatively impacting certain cholesterol profiles.
In human trials, the evidence for fasting causing measurable regression of established plaque is still developing and largely indirect. While human studies strongly confirm the improvements in risk factors, direct evidence of plaque reversal often relies on surrogate markers. The current scientific consensus views fasting as a promising intervention for reducing the risk of developing plaque and for slowing the progression of existing atherosclerosis. However, it is not yet considered a proven standalone treatment for reversing severe, established plaque without conventional medical therapies. Individuals with diagnosed cardiovascular disease should view fasting as a complementary lifestyle tool, utilized under the guidance of a healthcare professional.