What You Need to Know About Phenolic Acids

Parabens, which are commonly used as preservatives in cosmetic products, are actually derived from a phenolic acid known as 4-hydroxybenzoic acid.

Phenolic acids are basically plant metabolites. They are considered to be a type of phytochemical known as polyphenols. Along with flavonoids and stilbenes, they are major polyphenols that naturally occur in plants. Phytophenols are often produced by plants to defend themselves against pathogens. Phenolic acids also act as signaling molecules and play an important role in plant growth and reproduction.

Phenolic acid can be found in a large number of vegetables and fruits, especially in their skin and seeds. In recent times, they have been widely studied, and some of these studies have revealed that these plant polyphenols can have beneficial effects on human health. Here is a brief discussion about the various aspects of phenolic acids and their health benefits.

There are several categories of phenolic acid, out of which hydroxybenzoic and hydroxycinnamic acids are the most widely distributed. The chemical formula of hydroxybenzoic acid is C₇H₆O₃, and it is derived from benzoic acid.

Salicylic acid, gallic acid, gentisic acid, phloroglucinol carboxylic acid, and protocatechuic acid are some common examples of hydroxybenzoic acid.

On the other hand, some common cinnamic acid derivatives include caffeic acid, cichoric acid, coumaric acid, chlorogenic acid, coumarin, and ferulic acid. The cinnamic acid derivatives are more common than the benzoic acid derivatives.

Phenolic compounds, including phenolic acids and flavonoids, belong to the class of secondary metabolites and bioactive compounds synthesized by plants. They basically act as signaling molecules in the interaction between plants and microbes. In fact, they play a crucial role in initiating the symbiotic relationship between plants and useful microorganisms.

For example, flavonoids secreted by leguminous plants stimulate the nitrogen-fixing bacteria, Rhizobia, to secrete nod factors. Nod factors are signaling molecules secreted by Rhizobia before forming nodules on the roots of leguminous plants. Leguminous plants can recognize these signaling molecules, and so, produce several changes in response to their secretion. This eventually paves the way for the formation of a symbiotic relationship between them.

Apart from this, sometimes phenolic compounds are produced by plants to defend themselves against harmful microorganisms that can cause diseases. Some phenolic compounds, such as salicylic acid, are essential for plant growth, development, photosynthesis, while others play an important role in reproduction. For example, flavonoids are essential pigments for flower coloration, which help attract pollinators.

Phenolic compounds, including phenolic acids, have been a subject of several biological, medical, and agricultural studies. Some of these studies have highlighted the protective role of phenolic acids against oxidative damage. So, it is believed that the consumption of foods that contain these compounds can have several health benefits, as discussed below.

Protection Against Free Radicals
Phenolic compounds have been found to exhibit strong antioxidant properties in several studies. So, these compounds can help protect body cells from the damaging effects of free radicals, and in the process reduce the risk of certain diseases, like cancer and heart disease.

Reduce Inflammation
Some phenolic acids can have anti-inflammatory properties, for which they may provide relief in inflammatory conditions, like arthritis. Gallic acid, a type of hydroxybenzoic acid, is known to control the expression of chemicals, like histamines and cytokines, that are responsible for producing an inflammatory or allergic response. So, this phenolic acid can help control allergic reactions.

Fight Harmful Microorganisms
Several phenolic compounds, including phenolic acids, have been found to possess antimicrobial properties. Plants produce some phenolic compounds to destroy pathogens, and so, it is believed that they may offer the same benefit to humans as well. For example, cichoric acid has antiviral properties, while gallic acid has been found to exhibit antifungal and antiviral properties.

Other Benefits

Apart from these, some phenolic acids, such as gallic acid, ellagic acid, rosmarinic acid, and caffeic acid, have cosmetic benefits as well. Phenolic acids, like salicylic acid and 4-Hydroxybenzoic acid, also found industrial and medical uses. 4-Hydroxybenzoic acid is used to derive paraben, a common preservative used in the cosmetic industry.

On the other hand, salicylic acid is an important ingredient in products that are used for treating dandruff, psoriasis, acne, and warts. Presently, phenolic acids are being studied for replacing synthetic antioxidants, like BHT (Butylated hydroxytoluene) and BHA (Butylated hydroxyanisole) in foods.

Phenolic acids can be found in many foods, of which some of the good sources are:

✦Citrus fruits
✦ Aloe vera
✦ Apples
✦ Artichokes
✦ Grapes

✦ Pomegranate
✦ Strawberries
✦ Blueberries
✦ Pineapples
✦ Mangoes
✦ Plums
✦ Cherries
✦ Pears

✦ Rice
✦ Oats
✦ Corn
✦ Basil
✦ Thyme
✦ Oregano
✦ Echinacea
✦ Mushrooms
✦ Peanuts
✦ Tea
✦ Coffee
✦ Red wine

Phenolic acids are abundantly found in fruits, vegetables, and whole grains. Supplements of phenolic acids are also available in the market, especially in the form of grape seed extract and green tea extract.

However, it is always better to rely on a balanced diet to get the required amount of phenolic acids. These plant phytonutrients are readily absorbed in our intestine, and so, you will get plenty of them by simply following a diet that includes whole grain products, fresh vegetables, and fruits.

Disclaimer: This story is for informative purposes only, and should not be treated as a substitute for professional medical advice.