The Tears of Chios

As wildfires blaze across the island this week, are the iconic mastic groves of Chios once again at risk?

Jun 26, 2025

Image of the dried resin of the mastic tree, also known as mastic gum or tears of Chios.

As wildfires blaze across the Aegean island of Chios, Greece this week—not only are local homes and businesses at risk, but also the iconic source of the “Tears of Chios”, also known as mastic (Greek name: Μαστίχα). Mastic is a plant resin used in cooking, cosmetics, oral health, digestive health, and in skin care products. It is also chewed as a natural gum, with the hard resin softening in the mouth and shifting in flavor from slightly bitter to notes of pine and cedar.

Mastic is harvested from a special tree in the Anacardiaceae plant family—the same family as mangoes, poison ivy, pistachios, and cashews. The scientific name of the mastic tree is Pistacia lentiscus L.

One woman on Chios has been arrested so far for lighting one of several fires across the island when she discarded a lit cigarette. This isn’t the first time the mastic groves have been at risk on Chios. In 2012, another wildfire on the island wiped out more than half of the mastic tree population.

While the mastic harvest is largely concentrated in Chios, I’ve also spotted this species at many other sites in the wild across the Mediterranean, especially in Sardinia and Sicily.

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What is mastic?

Mastic is a liquid resin excreted by the mastic tree through its resin glands. When the tree’s bark is injured or cut, the resin seeps out. On the island of Chios, the harvest takes place from July through early October. To collect the resin, small incisions are made in the bark, prompting the resin to flow out as a cloudy, milky liquid. Over the course of 2–3 weeks, it dries and hardens into clear "tears" on the trunk. These tears are then carefully collected by hand, cleaned to remove any sand, sorted, and sold on the international market. The process is regulated by the Mastic Growers’ Association, a cooperative that ensures production meets strict quality standards.

This gum has played an important role in the history of trade in the region, worth its weight in gold in some periods of history. Use of mastic for the treatment of gastrointestinal disorders and inflammation dates back to at least 2000 years ago by the Greeks and Romans. More recently, according to a market report, mastic was valued at 350 million USD in 2022, and is expected to reach 645 million by 2032. I found this excellent video that demonstrates the production process for mastic. It is 7 minutes long and well worth the watch:

Chemical Makeup

To date, around 120 compounds have been identified in mastic gum, which is composed mainly of three substance categories: the polymer fraction, volatile essential oil, and triterpenes. Triterpenes are the dominant constituents, accounting for 65–70% of the resin’s weight, and include both acidic (e.g., oleanonic acid, moronic acid, 24Z-isomasticadienonic acid) and neutral forms (e.g., tirucallol, dammaradienone). The essential oil, comprising about 3% of the gum’s dry weight, is made up primarily of monoterpene hydrocarbons, oxygenated monoterpenes, and sesquiterpenes, with α-pinene, myrcene, and β-pinene being the major components. These volatiles are typically obtained through steam or water distillation, though supercritical fluid extraction offers a low-temperature, green alternative that preserves thermally sensitive compounds. The polymer fraction makes up 25–30% of the dry weight and is mainly composed of poly-β-myrcene in the cis conformation. Mastic gum also contains minor components such as phenolic acids (e.g., tyrosol, gallic acid) and α-tocopherol, though polyphenols are present only in trace amounts. Its high triterpene content and poor water solubility contribute to the challenges of chemical analysis and handling.

Pharmacology

Chios mastic gum (CMG) has been evaluated in many scientific studies in animal models and clinical trials. Here, I summarize some key findings:

Inflammatory Bowel Diseases

According to a 2023 review article, CMG has shown promising anti-inflammatory and antioxidant activity in the treatment of inflammatory bowel diseases (IBD), including Crohn’s disease and ulcerative colitis. Experimental studies in animal models and small-scale human trials suggest mastic can modulate key pathways involved in IBD, particularly through the regulation of inflammatory cytokines, oxidative stress, intestinal barrier function, and the gut microbiome. Its complex chemical composition (e.g., terpenes, polyphenols, and fatty acids) appears to act synergistically to alleviate intestinal inflammation and support gut health. While evidence points to potential benefits in reducing disease activity and maintaining remission, current clinical data remain limited, underscoring the need for larger, well-controlled trials.

Cardiometabolic Disorders

According to another 2023 review article, CMG has emerged as a promising botanical supplement for managing cardiometabolic disorders, including dyslipidemia, insulin resistance, hypertension, and non-alcoholic fatty liver disease (NAFLD). Human and animal studies demonstrate its potential to improve lipid profiles, modulate hepatic and cardiovascular markers, and influence metabolic inflammation and microbiota composition. It appears to exert these effects through multiple mechanisms, including antioxidant activity, regulation of pro-inflammatory pathways, and modulation of gene-nutrient interactions. While the greatest benefits are observed with higher doses, longer treatment durations, and in individuals with severe obesity or existing cardiometabolic disease, its safety profile has remained consistently favorable across trials.

Oral Health

In another 2023 review article (a popular year in the literature for mastic!), CMG is reported to exhibit potent antimicrobial, anti-inflammatory, and anticancer properties that make it a promising natural agent for maintaining oral health. Research highlights its efficacy in reducing dental plaque, inhibiting pathogenic oral bacteria, supporting gum health, and potentially preventing oral cancers. Mastic gum’s unique combination of bioactive compound (particularly its essential oils and triterpenes) contributes to its broad-spectrum antibacterial effects and ability to enhance natural immunity in the oral cavity. While much of the data is preclinical, findings strongly support further investigation into CMG as a safe, plant-based adjunct or alternative to conventional oral care treatments.

The Takeaway

As wildfires threaten the groves of Pistacia lentiscus on Chios, they put at risk more than just trees. They endanger a unique botanical resource with deep historical roots and modern therapeutic promise. Revered since antiquity, mastic gum has served as both a medicine and a valuable trade commodity. Today, scientific research is validating traditional uses, revealing mastic’s potential in treating inflammatory bowel disease, managing cardiometabolic risk, and supporting oral health. With its complex chemical makeup and broad pharmacological activity, mastic stands out as a remarkable example of how natural products can connect the wisdom of the past with the innovations of the future—if we can succeed in protecting them.

Yours in health, Dr. Quave