African blue basil

What is African blue basil?

African blue basil is a garden herb grown for cooking, for scent and for bees. It is a modern hybrid basil, not a classic medicinal plant. There is no good human research showing it treats any illness.

It is a cross between camphor basil (Ocimum kilimandscharicum) and a dark purple sweet basil. The plant is sterile, so it sets no seed and is grown from cuttings. New leaves come in purple, and the flower spikes stay purple through the season.

The smell is sharper than sweet basil. People describe it as basil with a camphor or menthol edge, plus a little clove. Cooks use the leaves fresh or dried in small amounts, much like other basil.

Long use of a herb in the kitchen is not proof that it works as a medicine, and it is not proof that larger or stronger doses are safe. That point applies to everything on this page.

How does African blue basil work?

No mechanism has been shown for this plant in people. What follows comes from lab work on its oil and on its parent plants.

In test tubes, basil oils rich in camphor and linalool slow the growth of some bacteria and fungi. Whether that does anything in a human body is not known.

In laboratory tests, the same oils mop up free radicals, which are reactive by-products of normal cell chemistry. That is a chemistry-dish result, not a health claim.

In insect studies, camphor basil oil repels mosquitoes and some stored-grain pests. This is the best-supported action of the parent plant, and it is about insects, not people.

Eugenol, a clove-scented compound in many basils, slows platelet clumping in cell studies. Platelets are the blood cells that form clots. No trial has tested whether eating the herb changes clotting in a person.

What forms does African blue basil come in?

Most people meet this plant as a living plant, not a product. Common forms:

- A potted or garden plant, sold at nurseries and bought for pollinators. - Fresh leaves, used in cooking. - Dried leaves, used as a kitchen herb.

- A simple leaf tea or infusion, made at home. - Infused oil or vinegar, made at home for food use. - Essential oil, which is uncommon and sold mainly for scent.

Standardised capsules and tinctures of this specific hybrid are rare. Products labelled "basil extract" are usually sweet basil or holy basil, which are different plants with different chemistry.

The essential oil is a very concentrated product. It is not the same thing as the leaf, and it should not be treated as food.

Where it comes from:

This plant has no deep folk tradition, because it is recent. It was found as a chance seedling in a US nursery in the early 1980s and spread through the garden trade.

Its parents do have longer records. Camphor basil was grown in East Africa and India, where it was used as an insect repellent and in local folk remedies for colds, fevers and skin complaints. Sweet basil carries its own long history in Mediterranean and South Asian cooking and folk practice.

Gardeners adopted African blue basil mainly for its long flowering season and its appeal to bees. Writers who recommend it today usually borrow claims from its parents rather than from any record of its own use.

None of that history has been tested in people for this hybrid, and it is not a reason to use it as a treatment.

What does African blue basil help with?

• Flavouring food: This is the use that holds up. The leaves are a kitchen herb, like other basils. Food use is not a health claim.
• Attracting bees and other pollinators: Because the plant is sterile, it flowers for months instead of setting seed. Gardeners report heavy bee traffic. This is a garden benefit, not a health one.
• Repelling insects: The camphor basil parent repels mosquitoes in lab and field tests. African blue basil itself has not been tested this way. A growing plant on a patio is unlikely to clear an area of mosquitoes.
• Easing a blocked nose (claimed, untested): Camphor and 1,8-cineole smell cooling, and steam from any hot drink can make a nose feel clearer for a while. No trial has tested this plant for congestion. Any relief is likely short and mild.
• Settling mild stomach upset (claimed, untested): Folk use of related basils for wind and indigestion is old and widespread. It has not been tested for African blue basil in people. Treat it as unproven.

Which foods are rich in African blue basil?

African blue basil is itself a food herb. You will not find it as a nutrient in other foods. Its close kitchen relatives are sweet basil, Thai basil, holy basil and camphor basil.

What are the side effects of African blue basil?

• Allergic reaction in people sensitive to mint-family plants
• Mouth or throat irritation from strong tea
• Nausea or stomach upset from large amounts
• Skin rash or burning from the undiluted essential oil
• Headache or dizziness from heavy exposure to the oil's vapour

Good to know:

In normal food amounts, side effects are rare and mild. Basil is eaten by millions of people daily with few problems.

The risk sits almost entirely with the concentrated essential oil. Swallowed camphor oils can cause vomiting, confusion and seizures, and small children are most at risk.

There is no safety data for this hybrid in pregnancy, in breastfeeding, or in children beyond ordinary food use.

How much African blue basil should you take?

• Recommended daily: No medicinal dose is established, because no human trial has set one. As a kitchen herb, it is used in the amounts you would use any basil: a few fresh leaves, or a pinch of the dried herb, in a dish. No amount is given here for the essential oil. Camphor-rich oils can be dangerous if swallowed, and this page will not suggest a figure. Keep the oil for scent only, and keep it away from children.
• Best time of day: Time of day does not matter for a culinary herb. Use it when it suits the meal.
• With or without food: It is usually eaten as part of food, which is the gentlest way to take it. A strong tea on an empty stomach may feel harsh. There is no evidence that food changes how it works.
• Time to effect: For flavour, it works at once. For any health effect, there is no reliable answer, and it may do nothing at all. If you try a cup of the tea and nothing changes, that is the expected result.
• How long to take it: As food, it is eaten whenever you cook with it, with no time limit. No safe length of use has been studied for stronger forms such as daily strong tea or oil. Because the oil is camphor-rich, long daily use of concentrated forms is not supported.