By Dr. Mercola
Coriander is an aromatic annual plant that grows all over the world, although it's native to the Mediterranean and western Asia. In the U.S., coriander leaves are commonly referred to as cilantro, although they're also known as Chinese parsley when used in Asian cuisine.
Coriander is unique in that it's both an herb (the leaves) and a spice, the latter coming from coriander seeds, which are dried and used in whole or ground powder form.
If you have a choice, choose whole coriander seeds, as the powder loses flavor quickly (and the whole seeds are easy to grind yourself using a mortar and pestle).
As a spice, coriander is often used in Indian cuisine, although it can be added to salad dressings, meat rubs, beverages and much more. Cilantro is commonly used in Asian and Spanish cooking, where it makes a prominent appearance in foods like guacamole and pico de gallo.
Coriander Was Traditionally Used to Support Digestive Health
Both coriander seeds and leaves have traditionally been used to reduce gas in the stomach and intestines, stimulate digestion and treat spasms of smooth muscle, such as your stomach.
In both traditional Chinese medicine and Ayurvedic medicine, coriander seeds are often combined with caraway, cardamom, fennel and/or anise seeds to treat digestive complaints.
The leaves, meanwhile, have traditionally been regarded as an appetite stimulant and they were also eaten or applied externally to the chest to treat chest pain and cough.1 According to the American Botanical Council (ABC):2
"Coriander was used by Hippocrates (ca. 460 — 370 BCE) and other Greek physicians and was later introduced to Britain by the Romans. It has been widely used around the world, from Africa to northern Europe, where the seeds were mixed with bread.
In the East, coriander has been used as an ingredient in curry. In traditional Chinese medicine, coriander was used to treat stomachache and nausea.
Coriander has been approved by the German Commission E for internal use in dyspeptic complaints (disturbed digestion) and loss of appetite.
It is also used as a treatment for complaints in the upper abdomen such as a feeling of distension (uncomfortable fullness), flatulence (excessive gas) and mild cramps.
The fruits [seeds] are still used to relieve gas and in laxative preparations to prevent griping (bowel or stomach spasms)."
Coriander Seeds Contain Powerful Antioxidants and Have Anxiety-Reducing Effects
Coriander seeds and herbs have been actively investigated for their beneficial properties, including antimicrobial, antioxidant, hypoglycemic, hypolipidemic, anxiolytic, analgesic, anti-inflammatory, anticonvulsant and anti-cancer activities, among others.3
In one study of eight herbs, coriander (as well as basil) contained the highest levels of beta-carotene, beta-cryptoxanthin, and beneficial lutein and zeaxanthin.4
Coriander seed oil also contains up to 70 percent linalool, a terpenoid that has powerful cellular antioxidant properties and is responsible for coriander's pleasant smell.5
Linalool also has sedative and anxiety-reducing properties, which explains why the seeds have also been valued for treating mild anxiety and insomnia. The American Botanical Council reported:6
"In Iranian traditional medicine, coriander seed was primarily used to treat anxiety and insomnia. The traditional dose of seed powder is from 1 g to 5 g, three times per day.
This translates to a 14 to 71 mg/kg dose, three times per day, for a 150-pound individual."
Coriander seed oil is popular in aromatherapy and may have stress-relieving effects when inhaled.
The diluted essential oil can also be used topically to treat minor skin infections, and it contains compounds called aldehydes that are effective against yeast, salmonella and other bacteria. Research has also linked coriander seed and its extract to:7
Decreased blood sugar Reduced insulin resistance Lower cholesterol levels Better heart health Lower triglycerides Increased HDL ("good") cholesterol
Cilantro: Powerful Antioxidant and Anti-Inflammatory Benefits
The leaves are also a treasure trove of beneficial flavonoids, polyphenols and phenolic acids. This includes antioxidant and anti-inflammatory kaempferol and quercetin. Quercetin is an antioxidant that many believe prevent histamine release — making quercetin-rich foods "natural antihistamines."
Kaempferol, meanwhile, may help fight cancer and lower your risk of chronic diseases including heart disease. The phenolic acids and other nutrients in cilantro are equally impressive. As noted by ABC:8
"These secondary plant metabolites have attracted interest and study for their potential protective role against oxidative damage and its associated diseases, including coronary heart disease, stroke, and cancers.
The leaves of the plant are high in vitamins A, K, and C, as well as calcium."
Cilantro leaves may also help reduce pain in people with arthritis, a benefit attributed to the vitamins A and C, phenolic acids and polyphenols they contain. One phenolic component, ethanolic extract, was also shown to protect against liver damage in an animal study.9
Why Cilantro and Seafood Make an Especially Good Combination
Cilantro is often promoted as a tool for chelation, or removal of heavy metals, including mercury, from your body. Research to support this is scarce, but there is evidence showing that eating cilantro along with foods that contain heavy metals may reduce the metals' absorption and toxicity in your body.10
Since heavy metals often accumulate in seafood, cilantro-seafood dishes may be a perfect match, both flavor wise and for your health. According to ABC:11
"Some pre-clinical evidence does suggest that concomitant use of coriander leaf while consuming foods considered high in heavy metals can reduce the absorption of toxins and potential toxic effects, but does not support the theory that coriander can remove heavy metals already present in the body.
Consuming coriander leaf-based pesto, salsa, or chutney at the same time as foods often laden with mercury, like seafood, could potentially decrease the absorption of heavy metals in the body."
Coriander May Reduce Cancer-Causing Cooking Byproducts
If you enjoy the flavor of coriander, there's good reason to use it liberally in your cooking, especially as a rub, spice or marinade for meats and burgers. Heterocyclic amines (HCAs) are formed when food is cooked at high temperatures, and they're linked to cancer.
However, adding spices including coriander seeds, to your food can significantly reduce the formation of HCAs.12 It's easy to blend coriander into burgers and meatloaf, or use it as part of a marinade, dressing or spice rub.
Cilantro: Love It or Hate It?
Most people either love cilantro or hate, and there may be a genetic basis for this. Aldehyde chemicals in cilantro give it a pungent soapy smell, but it's balanced by pleasant grassy, citrusy notes. It's thought that people who dislike cilantro may only be able to sense the soapy scent and not the pleasant ones, leading to a dislike of the beneficial herb.
Behavioral neuroscientist Charles J. Wysocki, Ph.D. of the Monell Chemical Senses Center in Philadelphia has conducted research on twins that shows identical twins tend to either both like or both dislike the herb — but the same does not hold true in fraternal twins. Wysocki told NBC News:13
"[The findings] suggest very strongly that whatever it is that … underlies the preference is genetically determined … What we think might be happening is the person who hates cilantro is, in fact, detecting the soapy odor. But what they seem to be missing is the nice, aromatic, green component.
… It's possible that they have a mutated or even an absent receptor gene for the receptor protein that would interact with the very pleasant smelling compound."
Cilantro Is Easy to Grow and Use
Cilantro has been implicated in a number of recent foodborne illness outbreaks, including a Cyclospora outbreak linked to Mexican-grown cilantro in 2015. Fortunately, cilantro is easy to grow at home and can even be grown in pots indoors, ensuring you'll have a fresh supply at your fingertips year-round.
A little goes a long way, for both coriander seeds and cilantro leaves, so you'll only need to devote a small area of your garden or planting space. As mentioned, cilantro works well when added to fresh dips, salad dressings and salsas. You can also add it to your vegetable juice. For a delicious, fresh-tasting condiment that will brighten up your meals and aid in digestion, try the recipe that follows, which was shared by Hannah Bauman in ABC's HerbalEGram.14
- 1 cup fresh mint leaves, chopped
- 1 cup fresh cilantro leaves, chopped
- 1 small green chili, such as serrano, stem and seeds removed (optional)
- ½-inch piece of fresh ginger, peeled and roughly chopped
- 1 teaspoon ground cumin
- 1-2 tablespoon fresh lemon juice, to taste
- 1-2 tablespoons of water, as needed
- Kosher or black salt, to taste
- In a food processor, combine all ingredients except for salt and blend until the mixture forms a smooth paste. Add water to create a thinner consistency, if necessary.
- Mix salt into chutney.