Herb safety

Herb safety: read this before a daily cup

Dried herbs are sold as food, and most of what we carry is ordinary kitchen fare. A few herbs on our shelves carry real cautions, and you deserve to know them before you buy.

Four rules that apply to every herb

• If you are pregnant or nursing, ask your doctor before you drink any herbal tea regularly. Many herbs have never been tested in pregnancy.
• If you take a prescription medicine, ask your pharmacist about a herb before it becomes a habit. Some herbs change how medicines work.
• Tell your surgeon about the herbs you drink if you have an operation coming.
• Do not give herbal teas to young children without asking their doctor.

Pots and clay

A cocimiento can simmer for a quarter of an hour or more, so the pot matters. The California Department of Public Health warns that leaded glaze on some imported or handmade pottery can pass lead into food cooked or stored in it. Boil herbs in a steel or enamel pot, and keep glazed clay for serving only if you know it is lead-free.

Herb by herb

Hoja de guanábana

Memorial Sloan Kettering lists soursop (graviola) as able to lower blood sugar and blood pressure, so it may not be safe next to medicines that do the same. It can affect PET scan results, and laboratory and animal studies have raised nerve-toxicity concerns. It also states plainly that there is no proof graviola helps people with cancer.

Cardo mariano

The NIH notes that milk thistle can cause allergic reactions, especially in people allergic to related plants such as ragweed, chrysanthemum, marigold and daisy, and that the most common side effects are digestive.

Hierba de San Juan

The NIH warns that St. John's wort can interact in dangerous, sometimes life-threatening ways with many medicines, and can weaken some antidepressants, birth control pills and transplant drugs. Large amounts can make skin react to the sun.

Pasiflora

The NIH advises against passionflower during pregnancy. It names drowsiness, dizziness and confusion as side effects, and asks you to tell your doctor if you take it within two weeks of surgery.

Canutillo

Mormon tea is a plant of the genus Ephedra. The FDA banned dietary supplements containing ephedrine alkaloids in 2004, and the NIH links ephedra to high blood pressure, heart attack, seizure and stroke, even at low doses.

Flores de caléndula

Memorial Sloan Kettering advises against calendula during pregnancy or breastfeeding and for people allergic to plants of the daisy family.

Palo de víbora y quina roja

Quina roja is red cinchona bark. Federal food rules allow red cinchona bark as a flavoring in beverages only, with no more than 83 parts per million of total cinchona alkaloids in the finished drink.

Chapulines adobados

The California Department of Public Health lists chapulines among imported foods that have been found to contain lead, and warns that leaded glaze on imported or handmade pottery can pass lead into food cooked or stored in it.

Polen de abeja

Bee pollen carries the pollen of the plants the bees visited. A case reviewed in the medical literature describes a severe allergic reaction to one tablespoon in a man with seasonal pollen allergy. If you have hay fever or a pollen allergy, ask your doctor before you try it.

Cal para nixtamal

Cal is calcium hydroxide, also called slaked or hydrated lime. NIOSH lists it as an irritant that can burn eyes and skin and irritate the airways: measure it dry with a spoon, keep it out of eyes and away from children, and rinse it off skin.

This is general information about a dried herb, not medical advice. If you are pregnant or nursing, take a prescription medicine or live with a condition, ask your doctor or pharmacist before you drink any herbal tea regularly.