Apple cider vinegar: The “mother” of cures?

Abstract

Apple cider vinegar (ACV) is one of the most popular natural health products available. Commonly used in salad dressings, sauces, and food preservation, ACV has recently gained acceptance as a dietary supplement. It has been touted as an appetite suppressant, digestive health aid, and immune system boost and studied in treatment of obesity, diabetes, and problems related to hair and skin, among many other conditions. But are these health claims backed by science? ACV is made from the fermented juice of crushed apples and its cloudy appearance is from “the mother” of vinegar, which is the combination of yeast and bacteria. ACV contains probiotics, various minerals (e.g., potassium, magnesium, and calcium), vitamins (e.g., B vitamins and vitamin C), and dietary fiber. Fruit vinegars in general can increase antioxidant and antimicrobial capacities because the fermentation process produces organic and acetic acids. ACV is high in acetic acids which, in concert with phenolic compounds, may be responsible for lowering blood glucose levels, regulating lipid abnormalities, and changing how foods are absorbed from the gut. There are multiple studies suggesting that ACV might positively affect blood glucose levels and insulin response among people with diabetes and improve cholesterol levels and weight loss among obese individuals. Studies involving people with and without diabetes suggest that adding two teaspoons of vinegar to water or a meal may improve blood glucose control, decreasing fasting glucose concentrations after a meal containing starches. A 2019 randomized controlled clinical trial in Clinical Nutrition ESPEN assessed the efficacy of ACV on fasting blood glucose, insulin, and blood pressure. Patients with type 2 diabetes and hyperlipidemia were randomly assigned to an intervention or control group to assess the effect of 20 mL ACV per day over the course of the 8-week study. Researchers found significant improvement in fasting blood glucose but no significant effect on blood pressure was observed. ACV may promote weight loss due to acetic acid's impact on appetite, insulin function, and metabolism. Acetic acids in vinegar are thought to inhibit lipogenesis and stimulate fatty acid oxidation. A highly cited parallel-group, randomized, double-blind, placebo-controlled 2009 trial published in Bioscience, Biotechnology, and Biochemistry evaluated the effects of vinegar intake on the reduction of body fat mass in 175 obese patients, ranging in age from 25 to 60. During the 12-week treatment period, patients ingested 500 mL daily of a beverage containing either 15 mL of vinegar, 30 mL of vinegar, or 0 mL of vinegar (placebo). The researchers confirmed that body weight, BMI, visceral fat area, waist circumference, and serum triglyceride levels were significantly lower in both vinegar intake groups compared to placebo and reductions in body weight and BMI were found to be dose dependent. No adverse effects were reported. This finding was confirmed in a 2020 systematic review published in European Journal of Nutrition that assessed the effect of ACV on metabolic parameters and body weight. Investigators identified 487 studies and confirmed there may be beneficial health effects from the consumption of ACV while the risk of adverse effects in recommended quantities was unremarkable. ACV is available in your local grocery store. ACV dietary supplements are usually sold as capsules, tablets, gummies, or powders, often paired with ginger and cayenne. In general, 1-2 tablespoons (15-30 mL) of ACV daily, with a meal or diluted in liquid, significantly reduces blood glucose levels after eating and aids in weight loss. Overall, fruit vinegars are natural sources of dietary antioxidant polyphenols and organic acids and ACV is generally considered safe. Large amounts over the long term might lead to low levels of potassium and ACV may interact with certain supplements or drugs, including diuretics and insulin. Take care to monitor blood glucose closely if combining ACV with diabetes medications. Caution patients not to consume ACV straight as it can irritate or even burn the esophagus. ACV may be unsafe when applied to skin and has been associated with skin irritation and chemical burns. Advise patients to compare labels as the range of contents and acidity levels may vary per product.