Basil is a flavorful, leafy green herb that originated in Asia and Africa.

It’s a member of the mint family, and many different varieties exist.

Popular as a food seasoning, this aromatic herb is also used in teas and supplements which may provide a range of health benefits.

This article explains all you need to know about basil, its benefits and uses.

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The scientific name of the basil commonly purchased for cooking is Ocimum basilicum (abbreviated O. basilicum).

There are many different varieties of O. basilicum, including (1):

  • Sweet basil: The most widely grown, popular basil, renowned for its use in Italian dishes. Commonly sold dried in supermarkets. Has a licorice-clove flavor.
  • Bush or Greek basil: Has a strong aroma but mild flavor, so it can be substituted for sweet basil. Forms a compact bush with small leaves and grows well in a pot.
  • Thai basil: Has an anise-licorice flavor and is commonly used in Thai and Southeast Asian dishes.
  • Cinnamon basil: Native to Mexico. Has a cinnamon-like flavor and scent. Commonly served with legumes or spicy, stir-fried vegetables.
  • Lettuce basil: Features large, wrinkled, soft leaves with a licorice-like flavor. Works well in salads or tossed with tomatoes and olive oil.

The basil commonly used in supplements and herbal tea is holy basil — sometimes called tulsi — which is the O. tenuiflorum species, also known as O. sanctum. It is added to some Thai dishes because of its distinct flavor (1).

Summary Sweet basil is most widely used for cooking, but many other varieties — with slightly different flavor profiles — are available. The main type of basil for supplements and herbal tea is holy basil, which is a related but different species.

As recipes demand relatively small amounts of basil, this herb contributes few vitamins and minerals in typical diets.

Here is the most notable nutrient content of 1 tablespoon (around 2 grams) of sweet basil (2, 3):

Fresh leaves, choppedDried leaves, crumbled
Calories0.6 5
Vitamin A3% of the RDI4% of the RDI
Vitamin K13% of the RDI43% of the RDI
Calcium0.5% of the RDI4% of the RDI
Iron0.5% of the RDI5% of the RDI
Manganese1.5% of the RDI3% of the RDI

Though dried basil is more concentrated in nutrients, you use less in recipes compared to fresh. Therefore, neither is a significant source of most nutrients — except vitamin K.

Basil also supplies beneficial plant compounds that have antioxidant, anti-inflammatory and other health properties (4, 5).

In addition, these compounds give basil its “essence” — or distinct aroma and flavor. That’s why oils derived from basil and other plants are called essential oils (4).

Summary Because basil is generally used in small quantities, the only substantial nutrient it provides is vitamin K. Basil also supplies plant compounds, which contribute aroma, flavor and health benefits.

Basil is not only a popular folk remedy for ailments like nausea and bug bites but also widely utilized in traditional Chinese medicine, Ayurvedic medicine and other holistic medicine systems (4, 6, 7).

Today, scientists study potential medicinal benefits of basil. Extracts or essential oils of basil, which provide concentrated amounts of plant compounds, are typically tested instead of whole leaves (8).

Test-tube or animal studies are usually done to determine whether substances may be worth developing into medications and testing in people.

Potential Benefits of Sweet Basil

Below is a summary of potential benefits of extracts of sweet basil, primarily based on mouse and test-tube studies. Whether the same results would occur in people is uncertain.

Preliminary studies suggest sweet basil may:

  • Reduce memory loss associated with stress and aging (9, 10).
  • Reduce depression related to chronic stress (11, 12).
  • Reduce stroke damage and support recovery, whether given before or right after a stroke (13, 14).
  • Improve fasting blood sugar, cholesterol and triglycerides (15, 16, 17).
  • Reduce blood pressure in people with hypertension (18).
  • Relax blood vessels and thin your blood, similar to aspirin (19, 20).
  • Protect against aspirin’s damage to your gut, particularly preventing ulcers (21).
  • Prevent certain cancers, including of the breast, colon and pancreas (8, 22, 23).
  • Increase mental alertness when inhaled as aromatherapy (24, 25).
  • Inhibit the growth of bacteria that cause dental decay (26).
  • Improve food safety, such as if integrated into food packaging by manufacturers (8, 27, 28, 29).
  • Provide an alternative to antibiotics for infectious diseases, including combating antibiotic-resistant strains of bacteria (7, 30).
  • Repel insects, such as mosquitos and ticks (31, 32).

Mouse studies typically give 100–400 mg of basil extract per kg (220–880 mg per pound) of body weight. Appropriate human doses are unknown (4, 10, 15).

Potential Benefits of Holy Basil

Holy basil has a long history of use for many ailments, including many of those listed above. Though few human studies are available, their results are encouraging (33).

When 60 people with type 2 diabetes took 250 mg of holy basil extract alongside a diabetes drug each day before breakfast and dinner for three months, they had an 18% decrease in average blood sugar compared to those only taking the drug (34).

Additionally, in a study in 158 people with at least three symptoms of stress, taking 1,200 mg of holy basil extract daily for six weeks was 39% more effective at improving general stress symptoms than a placebo (35).

More human studies are needed to verify effectiveness and dosage.

Summary Both sweet and holy basil have a long history of medicinal use. A few studies in people suggest benefits for blood sugar and stress, though more research is necessary.

Though fresh basil gives stronger flavor, dried basil is less expensive and more convenient. You can also buy basil frozen into recipe-portioned cubes in the freezer section of stores.

Sweet basil is most widespread, but you may find other varieties at farmers markets or ethnic markets, such as Asian food stores. Alternately, try growing your own.

You can grow basil anywhere with nighttime temperatures above 60℉ (15.5℃) for at least two months. Basil is sensitive to cold and likes sun exposure all day.

You can cultivate basil from a seed planted in dirt or a stem cut from another plant that you put in water until roots start to grow. Basil will flourish in a garden or patio pot that drains well.

Harvest basil leaves as you need them, but don’t simply pluck them from your plants. To encourage proper growth, cut the stem toward the bottom so that only two to four leaves remain on the plant.

Put fresh basil stems in a jar with tap water to keep the leaves fresh for a few days. It’s debatable whether you should refrigerate fresh basil, as cold temperatures can discolor the leaves.

If you have a lot of fresh basil, you can dry the leaves and store them in a jar with a tight-fitting lid. Avoid crumbling the leaves until you need them, as this helps retain their essential oils, aroma and flavor.

Summary You can buy basil fresh, dried or frozen — though fresh basil has the best flavor. Try growing it yourself if you have at least a few months with warm night temperatures. To keep it for a few days, place the stems in a jar with water.

Basil gives zest to tomato dishes, salads, zucchini, eggplant, meat seasonings, stuffing, soups, sauces and more.

Pesto — a creamy, green sauce — is one of basil’s most popular uses. It’s typically made from crushed basil, garlic, parmesan cheese, olive oil and pine nuts, though dairy-free options are also available. Try it as a dip or sandwich spread.

Basil complements other herbs and spices such as garlic, marjoram, mustard, oregano, paprika, parsley, pepper, rosemary and sage.

If you have fresh basil, take only the leaves — not the stem. It’s generally best to add fresh basil at the final step of cooking because heat can diminish the flavor and bright green color (36).

If a recipe calls for fresh basil but you only have dried, use just 1/3 of the measurement, as dried is more concentrated.

If you’re cooking without a recipe, use the following amounts per 1 pound (450 grams) of food as a general guide (2, 3):

Dried basil Fresh basil
Vegetables, grains or legumes1.5 teaspoons2 tablespoons
Meat, poultry or fish2 teaspoons2.5 tablespoons
Baked goods1.5 teaspoons2 tablespoons
Summary Basil enlivens many dishes, including pastas, salads and sauces. If using fresh basil, add it toward the end of cooking since heat subdues its flavor and color. Use about 1/3 of the amount of dried basil compared to fresh.

Basil is generally safe when consumed in small amounts, but a few precautions are warranted.

Basil leaves are high in vitamin K, which helps blood clot. High intakes could interfere with blood-thinning drugs, such as warfarin (37).

If you’re taking a blood thinner, aim to consume consistent amounts of vitamin K daily so that your doctor can regulate your medication. Eating foods made with a lot of basil — such as pesto — could make this difficult (37, 38, 39).

In contrast, basil extracts — such as those found in supplements — can thin your blood, leading to problems if you have a bleeding disorder or an upcoming surgery (40, 41).

Additionally, people taking blood pressure-lowering drugs or diabetes drugs should use caution with basil supplements since they may lower blood pressure and blood sugar. Your doctor may need to decrease your drug dose (18, 34).

Avoid holy basil if you’re pregnant or trying to get pregnant. Animal studies suggest that holy basil supplements may negatively affect sperm and trigger contractions in pregnancy. Risks during breastfeeding are unknown (42, 43).

Though basil allergies are rare, a few cases have been observed in people who reacted to pesto (44).

Summary Basil is generally safe when ingested in small amounts, but certain health conditions and drugs necessitate caution. Holy basil supplements should be avoided by couples seeking pregnancy.

Basil comes in many varieties. While this herb may not contribute significant nutrients to your diet, it can spice up your meals.

Though holy basil is typically added to herbal teas and supplements, studies suggest that sweet basil may provide similar health benefits, such as stress reduction and blood sugar control.

Keep in mind that more studies in humans are needed on both types of basil.

Try growing basil on your own and add it to sauces, salads and soups — your taste buds will thank you.