What is Gallic Acid & What are its Benefits, Downsides and Dosage?

Gallic acid is an antioxidant and phenolic acid that is found in plants and offers numerous health benefits.⁽¹⁾ Our body can get it from plants and as suggested by some sources it is available in supplement form as well. There are a variety of plants that contain Gallic acid and some of the best sources are:^{(2, 3)}

• Strawberry
• Blueberry
• Grape
• Banana
• Apple
• Walnut
• Cashew
• Blackcurrant
• Hazelnut
• Guava
• Red wine
• Avocado
• Green tea
• Mulberry
• Pomegranate

There are numerous studies that suggest that Gallic acid offers antimicrobial, anti-obesity, and antioxidant properties that play a role in improving cancer and brain health.

1. Gallic Acid and Antimicrobial Properties

   Gallic acid improves immune health and acts as a natural defense mechanism against microbial infection.⁽⁴⁾

   A study was performed in which Gallic acid was exposed to ultraviolet light to develop a light-enhanced antimicrobial treatment. Ultraviolet C is an invisible light emitted by the sun that is commonly used as a disinfectant. The microbial activity observed in this study was significant.⁽⁵⁾

   A lab study was conducted to look for the effect of Gallic acid on black truffles. It was found to improve the shelf life of fresh black truffles by fighting a bacterial contaminant called Pseudomonas.⁽⁶⁾

   There are numerous older studies that found Gallic acid to fight against food pathogens like Campylobacter, Escherichia coli, Listeria monocytogenes, and Staphylococcus aureus.^{(7, 8)} It also was found to fight against the bacteria found in the mouth called Streptococcus mutans.⁽⁹⁾

   All the above studies assure Gallic acid to be a useful additive in the food industry.

2. Has Anti-Obesity Properties

   There are a few studies that suggest the role of Gallic acid in reducing excessive fat storage in individuals by suppressing lipogenesis.⁽¹⁰⁾ Lipogenesis is the synthesis of fat from compounds like sugar in the body.

   It also helps in improving insulin signaling and reducing oxidative stress and inflammation.

   A study was conducted on overweight adults who were given an extract with Gallic acid daily for 12 weeks. It was observed that the mean waist circumference, body mass index, and belly fat were reduced significantly.⁽¹¹⁾

   Most of the studies have found mixed results and a few older ones have shown no benefit at all, while a few have shown the role of gallic acid in improving obesity and quality of life.^{(12, 13)}

3. Has Antioxidant Properties

   Gallic acid has strong antioxidant properties and helps in fighting oxidative stress that may otherwise damage cells and lead to numerous chronic diseases.^{(14, 15)}

   Research suggests that the antioxidant properties of Gallic acid may provide anti-cancer benefits and neuroprotective effects. It also protects brain structure and functions.^{(16, 17)}

   A lab study suggested mango peels have antioxidant and anticancer properties, which may be due to the Gallic acid content.⁽¹⁸⁾ This shows that Gallic acid may help prevent the growth and spread of cancer cells.

   Some research shows that Gallic acid can prevent the decline of brain function by reducing inflammation and oxidative damage. It may also help protect against stroke.⁽¹⁹⁾ Another animal study was done that found the role of Gallic acid in having protective effects on the brain after a traumatic brain injury.⁽²⁰⁾

   Despite the above studies, human studies are needed to know about the antioxidant properties of Gallic acid and its effect on human health.

Lack of human studies is a major downside of Gallic acid. It is best consumed through plant sources, which is due to the lack of approved and well-studied supplements. An animal study had a conclusion that Gallic acid can be non-toxic up to a dose of 2.3 grams per pound of body weight.⁽²¹⁾

More studies are needed to determine its use and dosage for humans.

Gallic acid is a phenolic acid that is found in plants especially fruits, nuts, wine, and tea. It is known for its antimicrobial, antioxidant, and anti-obesity properties. As it is not much researched those wanting to benefit from Gallic acid, it is best to focus on natural food sources till more research is conducted on its supplements.