Apple cider vinegar (ACV) is produced through a two-step fermentation process where yeast converts sugars in crushed apples into alcohol, and then bacteria transform the alcohol into acetic acid. This acetic acid, typically 5–6% of ACV, is the primary active component responsible for its distinctive taste and purported health properties. Historically used as a folk remedy, ACV has recently gained popularity with the belief that it can improve circulation and overall blood flow. Consumers often question whether scientific evidence supports the claim that ACV offers a direct benefit to the vascular system.
Proposed Mechanisms for Enhanced Blood Flow
The theoretical basis for ACV’s effect on circulation lies mainly with its acetic acid content and its potential interaction with the lining of blood vessels. Proponents suggest that acetic acid may influence the body’s production of nitric oxide, a compound that plays a direct role in regulating blood flow. Nitric oxide is a powerful vasodilator, signaling the smooth muscles within artery walls to relax and widen.
This widening, known as vasodilation, reduces resistance to blood flow, allowing blood to move more freely throughout the body. Certain studies have explored the possibility that the acetate component of vinegar may stimulate the activity of endothelial nitric oxide synthase (eNOS), the enzyme responsible for producing nitric oxide. Activating eNOS would, in theory, lead to enhanced flow-mediated vasodilation, directly improving blood vessel function.
Anecdotal claims also suggest that ACV acts as a general “detoxifier,” though this concept lacks specific scientific definition. Acetic acid may also indirectly affect blood flow by influencing electrolyte balance, which regulates muscle contraction, including the smooth muscle in vascular walls. These proposed actions offer a plausible biological mechanism for the belief that ACV can support better circulation.
Research Findings on Circulation and Heart Health
While direct, large-scale evidence tracking peripheral blood flow improvements from ACV consumption remains limited, existing research focuses on its effects on major cardiovascular risk factors. One promising area of study relates to the function of the endothelium, the thin membrane lining the heart and blood vessels. Research indicates that vinegar intake can enhance flow-mediated vasodilation in humans, linking this effect to the upregulation of endothelial nitric oxide synthase activity. This suggests a positive influence on the health and flexibility of blood vessel walls, which is foundational to good circulation.
Regarding blood pressure, a primary driver of poor circulation, the evidence is mixed. Some animal studies show that acetic acid can significantly reduce blood pressure levels. This effect is partly attributed to the proposed vasodilation mechanism, which would naturally lower the force exerted on arterial walls. However, conclusive, long-term human trials demonstrating a substantial blood pressure lowering effect from ACV alone are lacking.
The most consistent scientific findings involve ACV’s impact on lipid profiles and blood glucose, both significant risk factors for cardiovascular disease. Multiple systematic reviews and meta-analyses have found that ACV consumption can decrease total cholesterol and triglyceride concentrations, particularly in individuals with Type 2 diabetes. The reduction in these lipids, even if modest, contributes to reducing the risk of plaque buildup (atherosclerosis), which impedes healthy blood flow.
ACV has also been shown to improve glycemic control by reducing fasting blood glucose and hemoglobin A1C levels, especially in people with diabetes. Since uncontrolled high blood sugar damages blood vessels and impairs circulation, ACV’s ability to manage glucose levels represents an indirect, yet significant, benefit to long-term vascular health. ACV may support circulation by mitigating several related risk factors, even if it is not a direct, standalone treatment for flow issues.
Safe Usage and Associated Health Risks
If a person chooses to incorporate ACV into their routine, proper preparation is necessary to mitigate the risks associated with its high acidity. Undiluted ACV has a pH level that can damage tooth enamel and irritate the lining of the esophagus. To protect these tissues, ACV must always be diluted in water; a common recommendation involves mixing one to two tablespoons into a full glass of water.
Consuming the diluted mixture through a straw is also advisable to minimize contact with the teeth. Daily intake should be moderated, with most human studies using a total daily dose between 15 mL and 30 mL (about one to two tablespoons). Exceeding these amounts may increase the potential for adverse effects.
One concerning risk is hypokalemia, or abnormally low potassium levels, reported with long-term, high-dose use. This risk is amplified for individuals taking certain medications, as ACV can interact with diuretics (water pills) and insulin. Combining ACV with diuretics can cause potassium levels to drop too low.
When taken alongside insulin or other diabetes drugs, ACV may increase the risk of hypoglycemia, or dangerously low blood sugar. Anyone taking prescription medication should consult a healthcare provider before adding ACV to their diet.