Apple Cider Vinegar: Benefits, Myths, and Side Effects
Apple cider vinegar has been touted as a useful and effective natural remedy for centuries, with claims of its ability to cure or treat numerous ailments and health conditions. The first known people to use apple cider vinegar as a remedy were the ancient Babylonians, dating back to around 5,000 BCE. They used it for medicinal purposes as well as for food preservation and flavoring. The ancient Greeks and Romans also incorporated apple cider vinegar into their medical practices. As with many traditional remedies, the actual scientific evidence for these claims varies, with some being supported by research and others lacking scientific bases [1].
Active constituents in apple cider vinegar
Apple cider vinegar contains several components that may contribute to its purported medicinal effects:
- Acetic acid: The primary active component in any vinegar, acetic acid is produced during the fermentation process. It is responsible for the sour taste and pungent smell of vinegar. Acetic acid has antimicrobial properties and may help control blood sugar levels [2, 3].
- Malic acid: This organic acid found in apple cider vinegar and contributes to its sour taste. Malic acid has been associated with potential benefits, such as improved digestion and reduced muscle pain [4].
- Tartaric acid: This organic acid is also found in apple cider, and some studies have linked it to lower blood pressure [5].
- Polyphenols: Apple cider vinegar contains various polyphenols, such as chlorogenic acid, which are plant-based compounds with antioxidant properties. These antioxidants are reported to help protect cells against oxidative stress and may reduce the risk of chronic diseases [6, 7].
- Enzymes: The raw, unfiltered version of apple cider vinegar contains enzymes that are suggested to support digestion and promote a healthy gut, including amylase, protease, lipase, pectinase, and cellulase [7].
Separating Myths from Scientific Facts
No single food or supplement can cure or prevent all illnesses, and apple cider vinegar is not a panacea. There is little scientific evidence to support the claim that apple cider vinegar can dissolve or prevent kidney stones. Kidney stones are often composed of calcium oxalate, which does not dissolve in acetic acid. While apple cider vinegar has been anecdotally used for kidney stone relief, it is essential to consult a healthcare professional for proper diagnosis and treatment [8].
The idea that apple cider vinegar can help “detoxify” the body is largely a myth. The human body has natural mechanisms for removing toxins, primarily through the liver and kidneys. There is little scientific evidence to suggest that consuming apple cider vinegar can enhance or replace these processes. Maintaining a healthy lifestyle, including a balanced diet, regular exercise, and proper hydration, is a more effective approach.
This is not to say there is no evidence; for example, a 2022 study found that mulberry vinegar attenuates the effects of inflammatory responses induced by lipopolysaccharide, a very potent endotoxin, on C6 glial cells. It is not clear whether acetic acid, a defining constituent of all vinegars, or the potent antioxidant anthocyanins found in mulberries were responsible for this effect [9]. Furthermore, this was an experiment in a dish with cells, which is very different from a clinical trial. Such experiments seldom translate to effective use in humans.
Blood sugar, weight loss, and antimicrobial properties
One of the most scientifically supported benefits of apple cider vinegar is its ability to help regulate blood sugar levels. Multiple studies have demonstrated that it can improve insulin sensitivity and reduce blood sugar spikes, particularly when consumed before or with a high-carbohydrate meal. This effect may be particularly beneficial for people with type 2 diabetes or those at risk for developing the condition [3, 10-13].
Apple cider vinegar has been linked to modest weight loss in some studies. It has been reported to increase feelings of fullness, thereby reducing overall calorie intake. However, it is not a magic weight loss solution. Combining apple cider vinegar with a balanced diet and regular exercise is the most effective approach to achieve and maintain a healthy weight [14-17].
Apple cider vinegar has been found to possess antimicrobial properties due to its acetic acid content. This has led to its use as a natural preservative and in the treatment of minor skin infections or irritations. However, it should be used with caution on the skin, as it can cause irritation or burns if not appropriately diluted [2, 18-22].
Cardiovascular health and cancer
While some studies have suggested that apple cider vinegar may have a positive impact on cardiovascular health, such as reducing blood pressure and improving cholesterol levels, the evidence is limited and inconsistent. More research is needed to determine the extent of these potential benefits and the optimal dosage and duration of its consumption.
A study conducted on rats found that acetic acid, a primary component of apple cider vinegar, may help reduce blood pressure by inhibiting the enzyme responsible for constricting blood vessels [23, 24]. In a more recent study, Tartaric acid, another acid present in apple cider vinegar, has also been shown to lower blood pressure [5]. However, more research, particularly in humans, is needed to confirm these findings and determine if there is an optimal consumption for blood pressure management [25].
Some animal studies have shown that apple cider vinegar may improve cholesterol levels by reducing low-density lipoprotein (LDL) “bad” cholesterol and increasing high-density lipoprotein (HDL) “good” cholesterol. However, the evidence in humans is limited, and more research is needed to confirm these effects and establish appropriate dosages and guidelines for use in managing cholesterol levels [6, 7, 26].
Apple cider vinegar contains polyphenols, including chlorogenic acid, which are known to have antioxidant properties. Antioxidants can help protect cells from damage caused by free radicals, which are believed to contribute to the development of cardiovascular disease. However, the direct impact of apple cider vinegar’s antioxidant properties on cardiovascular health remains unclear and requires further investigation.
In vitro studies have demonstrated that acetic acid, the primary component of apple cider vinegar, may slow the growth of some cancer cells. However, these studies were conducted on isolated cells in a laboratory setting, so the results cannot be directly applied to humans [7, 27].
In summary, apple cider vinegar has been shown to improve control over blood sugar, promote modest weight loss, and possess antimicrobial properties. However, many other claims about the efficacy of apple cider vinegar in treating various ailments have not been scientifically validated. This does not mean all of those claims are invalid. Scientific validation of medicinal claims requires a significant expenditure of money, which is often not available for unpatentable or natural products.
Literature
[1] Johnston, Carol S., and Cindy A. Gaas. “Vinegar: medicinal uses and antiglycemic effect,” Medscape General Medicine 8.2 (2006): 61.
[2] D. Yagnik, V. Serafin, and A. J. Shah, “Antimicrobial activity of apple cider vinegar against Escherichia coli, Staphylococcus aureus and Candida albicans; downregulating cytokine and microbial protein expression,” Sci Rep, vol. 8, no. 1, Dec. 2018
[3] C. S. Johnston, C. M. Kim, and A. J. Buller, “Vinegar improves insulin sensitivity to a high-carbohydrate meal in subjects with insulin resistance or type 2 diabetes,” Diabetes Care, vol. 27, no. 1, pp. 281–282, Jan. 2004
[4] J. R. Ifland et al., “Functional foods in the treatment of processed food addiction and the metabolic syndrome,” Nutraceuticals and Functional Foods in Human Health and Disease Prevention, pp. 43–60, Jan. 2015
[5] M. Kousar, U. Salma, T. Khan, and A. J. Shah, “Antihypertensive Potential of Tartaric Acid and Exploration of Underlying Mechanistic Pathways.,” Dose Response, vol. 20, no. 4, p. 15593258221135728, Oct. 2022
[6] S. Meng, J. Cao, Q. Feng, J. Peng, and Y. Hu, “Roles of Chlorogenic Acid on Regulating Glucose and Lipids Metabolism: A Review,” Evidence-Based Complementary and Alternative Medicine, vol. 2013, p. 11, 2013
[7] N. H. Budak, E. Aykin, A. C. Seydim, A. K. Greene, and Z. B. Guzel-Seydim, “Functional Properties of Vinegar,” J Food Sci, vol. 79, no. 5, pp. R757–R764, May 2014
[8] A. Joshi et al., “Complementary and Alternative Medicine Use in First-time and Recurrent Kidney Stone Formers,” Urology, vol. 156, pp. 58–64, Oct. 2021, doi: 10.1016/J.UROLOGY.2021.05.084.
[9] S. I. Bang, H. Y. Kim, W. T. Seo, A. Y. Lee, and E. J. Cho, “Mulberry vinegar attenuates lipopolysaccharide and interferon gamma-induced inflammatory responses in C6 glial cells,” J Food Biochem, vol. 46, no. 8, p. e14197, Aug. 2022
[10] T. Fushimi et al., “Acetic acid feeding enhances glycogen repletion in liver and skeletal muscle of rats,” J. Nutr., vol. 131, no. 7, pp. 1973–1977, 2001
[11] H. Liljeberg and I. Björck, “Delayed gastric emptying rate may explain improved glycaemia in healthy subjects to a starchy meal with added vinegar,” Eur. J. Clin. Nutr., vol. 52, no. 5, pp. 368–371, 1998
[12] J. N. Hunt and M. T. Knox, “The slowing of gastric emptying by four strong acids and three weak acids,” J. Physiol., vol. 222, no. 1, pp. 187–208, Apr. 1972
[13] E. Östman, Y. Granfeldt, L. Persson, and I. Björck, “Vinegar supplementation lowers glucose and insulin responses and increases satiety after a bread meal in healthy subjects,” European Journal of Clinical Nutrition 2005 59:9, vol. 59, no. 9, pp. 983–988, Jun. 2005
[14] T. Kondo, M. Kishi, T. Fushimi, S. Ugajin, and T. Kaga, “Vinegar intake reduces body weight, body fat mass, and serum triglyceride levels in obese Japanese subjects,” Biosci. Biotechnol. Biochem., vol. 73, no. 8, pp. 1837–1843, 2009
[15] K. H. Kim and Y. Park, “Food components with anti-obesity effect,” Annu. Rev. Food Sci., vol. 2, pp. 237–257, 2011
[16] H. Yamashita, “Biological function of acetic acid-improvement in obesity and glucose tolerance by acetic acid in type 2 diabetic rats,” Crit Rev Food Sci Nutr., vol. 56, pp. S171–S175, Jul. 2015
[17] B. K. Beh et al., “Anti-obesity and anti-inflammatory effects of synthetic acetic acid vinegar and Nipa vinegar on high-fat-diet-induced obese mice,” Scientific Reports 2017 7:1, vol. 7, no. 1, pp. 1–9, Jul. 2017
[18] F. D. Halstead et al., “The antibacterial activity of acetic acid against biofilm-producing pathogens of relevance to burns patients,” PLoS One, vol. 10, no. 9, p. e0136190, Sep. 2015
[19] Y. Dong, J. Hu, L. Fan, and Q. Chen, “RNA-Seq-based transcriptomic and metabolomic analysis reveal stress responses and programmed cell death induced by acetic acid in Saccharomyces cerevisiae,” Sci Rep, vol. 7, Feb. 2017
[20] D. Yagnik, M. Ward, and A. J. Shah, “Antibacterial apple cider vinegar eradicates methicillin resistant Staphylococcus aureus and resistant Escherichia coli,” Scientific Reports 2021 11:1, vol. 11, no. 1, pp. 1–7, Jan. 2021
[21] D. Yagnik, V. Serafin, and A. J. Shah, “Antimicrobial activity of apple cider vinegar against Escherichia coli, Staphylococcus aureus and Candida albicans; downregulating cytokine and microbial protein expression” Scientific Reports |, vol. 8, p. 1732, 2018
[22] A. Saqib, “Antimicrobial Activity of Apple Cider Vinegar,” Mapana – Journal of Sciences, vol. 16, no. 2, pp. 11–15, Apr. 2017
[23] L. Na et al., “Vinegar decreases blood pressure by down-regulating AT1R expression via the AMPK/PGC-1α/PPARγ pathway in spontaneously hypertensive rats,” Eur J Nutr, vol. 55, no. 3, pp. 1245–1253, Apr. 2016
[24] S. Kondo, K. Tayama, Y. Tsukamoto, K. Ikeda, and Y. Yamori, “Antihypertensive effects of acetic acid and vinegar on spontaneously hypertensive rats,” Biosci Biotechnol Biochem, vol. 65, no. 12, pp. 2690–2694, Dec. 2001
[25] H. Kanouchi et al., “Association of blood pressure and dietary intake of Sunomono, Japanese vinegared side dishes, in community-dwelling Japanese: A cross-sectional study.,” Heliyon, vol. 8, no. 5, p. e09505, May 2022
[26] Z. Beheshti et al., “Influence of apple cider vinegar on blood lipids,” 2012
[27] C. S. Johnston and C. A. Gaas, “Vinegar: Medicinal Uses and Antiglycemic Effect,” Medscape General Medicine, vol. 8, no. 2, p. 61, 2006
