Apple cider vinegar: The science and the trends

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Apple cider vinegar is rapidly gaining popularity in consumer health media. Online influencers are touting it as a home remedy for everything from warts to weight loss, and market research firms like Mordor Intelligence expect the global apple cider vinegar market to grow at a 5.4% CAGR through to 2024.¹ But are the purported benefits of apple cider vinegar (ACV) scientifically proven? And if so, which ACV products are expected to see the most growth? Here are some of the emerging scientific findings and product sales trends in the ACV space.

Probiotic Support for Gut Health

Apple cider vinegar is made from fermented apples, making it rich in probiotics. Nicole Avena, PhD, (New York, NY), a research neuroscientist who studies food addiction and early-life nutrition, says that apple cider vinegar’s main role is in supporting gut health.

“We’re able to deduce that fermented products like apple cider vinegar are beneficial for gut health because of past studies on probiotics,” Avena says. “Apple cider vinegar is one of those things that has been touted as a cure-all for everything, but the biggest health benefit that I see is that it’s a probiotic.”

According to the Canadian Digestive Health Foundation, because apple cider vinegar is only loosely strained rather than extensively filtered, many of the other nutrients present in apples are also present in apple cider vinegar, including probiotic bacteria.² One 2016 in vitro study isolated 168 strains of bacteria present in apple cider vinegar,³ including Acetobacter pasteurianus. Other bacteria in the Acetobacter genus have exhibited characteristics of probiotics in gene sequencing studies,⁴ which indicates that the bacteria in apple cider vinegar could have probiotic properties as well.

Liquid Shots Dominate, but Other Formats Grow

Rikka Cornelia, product manager for the Martin Bauer Group (Secaucus, NJ), says that apple cider vinegar is most commonly sold in liquid form and consumed directly in small amounts or diluted into other liquids. However, as more brands are entering the ACV space, this trend is beginning to change.

“We’re seeing more innovative delivery vehicles being launched due to the recent availability of powders, such as Martin Bauer Group’s unfiltered organic apple cider vinegar powder,” Cornelia says. “The most popular applications for apple cider vinegar powder are gummies and capsules.”

Brands like EBYSU Nutrition (Champlain, NY) and New Nordic (Malmö, Sweden) are now offering apple cider vinegar products in the form of vegetarian capsules and gummies. Meanwhile, Vermont Village (York, ME) is currently selling RTD apple cider vinegar shots in single-serving packets, and functional drink brand Squeeze Dried (Carlsbad, CA) offers two flavors of freeze-dried ACV powder stick packs. As the ACV market continues to grow, expect product formats to diversify further.

New Nordic’s apple cider vinegar gummy supplements. Photo from New Nordic.

Source and Filtration Method Determine Quality

Avena says that quality control is an important consideration. While the fact that ACV is fermented does help to destroy some natural contaminants, she notes, consumers want to know that the product they’re buying doesn’t contain impurities.

“For brands, choosing organic apple cider is important because that allows you to eliminate a lot of impurities and mitigate problems,” Avena says. “It’s also important to consider where the apples are being harvested. If they’re coming from the United States or from another country with high standards, and if they’re coming from an organic farm, that’s helpful because consumers can take confidence in that. And certainly, the filtration process is important.”

Consumers perceive apple cider vinegar to be natural, familiar, and pure, Avena notes, but the products on the market don’t always meet consumer expectations regarding quality. One 2005 product testing study carried out in response to a report of an adverse event involving apple cider vinegar tested eight tablet brands for pH level, component acid content, and microbial growth. The study authors found that pH level, acid content, and tablet size varied widely across brands. They also found that several products had inaccurate labels, made inconsistent dosing recommendations, and touted unsubstantiated health claims. The study concluded that the quality of the products tested is questionable.⁵ For brands seeking to offer ACV products, quality control, substantiation of health claims, and product standardization should be important priorities.

ACV Products Can Vary in Acid Type and Concentration

Cornelia says that spiking can introduce other acids and compounds into apple cider vinegar products, including non-naturally derived acids. She notes that common assay methods are not enough to validate the integrity of apple cider vinegar products. A more robust identity testing process is needed for ACV that includes full testing of both the source vinegar and other ingredients.

“Common titration methods don’t provide specific enough data to differentiate which acids are actually in an ACV powder,” Cornelia says. “We [at Martin Bauer Group] tested a batch of apple cider vinegar powder with 9.7% acetic acid by the titration method, when, in fact, other acids were present.”

Martin Bauer Group’s analysis used high-performance liquid chromatography to determine that the sample in question contained 7.2% acetic acid. Furthermore, the chromatography test detected trace amounts of malic acid that the titration method missed. The actual acid content determined by chromatography was 7.4%, compared to the 9.7% acid content determined through titration.

Cornelia says that brands looking to do identity testing on ACV should use high-performance thin-layer chromatography (HPTLC) in addition to an HPLC assay technique to derive an accurate chemical profile of incoming raw ACV. This combination of techniques can determine whether an ACV product has been fortified with other acids.

“HPTLC is an FDA-recommended method for verifying the identity of incoming raw materials. It should be more widely used to identify and separate components of a mixture, such as vinegar, and to confirm the vinegar is actually derived from apples and not synthesized from methanol, acetaldehyde, or ethylene,” says Cornelia.

More Clinical Trials Are Needed

Avena says that the media hype around ACV has run ahead of the science, and further research is needed to support health claims that are often made about it. Apple cider vinegar has been promoted in consumer health media and by brands as a weight loss stimulator, a natural remedy for diabetes, a blood pressure modulator, a gut health supplement, an immune support product, and even a skincare ingredient. There are a few small-scale studies that provide a limited degree of substantiation to some of these health claims, but Avena says that there are no major research papers, no landmark clinical trials, that push ACV over the top. While consumer media has given ACV a “health halo” that has resulted in consumers using it for everything from acne to warts, Avena says the best scientific support for ACV indicates that it may have probiotic properties. Until more clinical trials have determined ACV’s actual health benefits, brands would be wise to stay within the bounds of science and position ACV responsibly.

References

1. Mordor Intelligence. “Apple Cider Vinegar Market – Growth, Trends, and Forecast (2020-2025).” Published online December 24, 2019. Accessed at: https://www.mordorintelligence.com/industry-reports/apple-cider-vinegar-market​
2. Canadian Digestive Health Foundation website. Cook D. “Apple Cider Vinegar for Digestion. What’s the Deal?” Published online October 15, 2018. Accessed at: https://cdhf.ca/health-lifestyle/apple-cider-vinegar-for-digestion-whats-the-deal/​
3. Stornik A et al. “Comparison of cultivable acetic acid bacterial microbiota in organic and conventional apple cider vinegar.” Food Technology & Biotechnology, vol. 54, no. 1 (March 2016): 113-119
4. Haghshenas B et al. “Potentially probiotic acetic acid bacteria isolation and identification from traditional dairies microbiota.” International Journal of Food Science & Technology, vol. 50, no. 4 (April 2015): 1056-1064
5. Hill LL et al. “Esophageal injury by apple cider vinegar tablets and subsequent evaluation of products.” Journal of the Academy of Nutrition and Dietetics, vol. 105, no. 7 (July 2005): 1141-1144