Black Pepper and Turmeric: Why They're Paired

Black pepper is paired with turmeric because piperine, the compound that makes pepper hot, has been shown to raise how much curcumin from turmeric reaches the bloodstream. The best-known human study used concentrated supplement doses, so it says little about a pinch of pepper in a curry. In the kitchen, the pair is a long-standing combination that tastes good, nothing more mysterious than that.

Why does curcumin need help?

Curcumin is the best-studied compound in turmeric and gives it much of its yellow colour. Taken by mouth on its own, very little of it shows up in the blood. It's poorly absorbed and the body breaks it down quickly.

That's the reason supplement makers look for ways to improve its bioavailability. The US National Center for Complementary and Integrative Health (NCCIH) lists combining curcumin with piperine as one of those ways.

What the key study found

The study most often quoted was published in 1998 in the journal Planta Medica. Human volunteers took 2 g of curcumin, either alone or with 20 mg of piperine. With piperine, the researchers reported that bioavailability of curcumin went up by about 2000%, or roughly twenty times, compared with curcumin alone.

The proposed explanation is that piperine slows the processes in the gut and liver that break curcumin down, so more of it stays in circulation for a while.

What that research doesn't tell us

• The doses were not kitchen doses. 2 g of pure curcumin is far more than you'd get from the turmeric in a day's cooking.
• It measured blood levels, not health outcomes. Higher levels in the blood is a separate question from whether anything changes in the body.
• It was a small study. Later work has explored other ways to improve absorption, and results vary between products.

So the fair summary is: piperine can raise curcumin absorption from supplements. Claims that a pinch of pepper turns turmeric into a treatment go well beyond the evidence.

A note on supplements and safety

NCCIH advises anyone taking medicine to talk with their doctor before using herbal products, because some herbs and medicines interact. It also notes reports of liver problems linked to some turmeric and curcumin supplements, especially highly absorbable forms. If you're considering a turmeric or piperine supplement, check with your doctor first. Using both spices in food is a different matter from taking concentrated doses.

How Indian kitchens already use the pair

Turmeric and black pepper turn up together in plenty of everyday cooking, long before anyone measured curcumin:

• Rasam and many sambars
• Pepper-based meat dishes such as Kerala pepper chicken, where turmeric goes into the marinade alongside pepper
• Fish fry masalas
• Manjal paal (turmeric milk), often with a pinch of pepper

Most of these dishes also use coconut oil, ghee or milk. Curcumin dissolves in fat rather than water, which is one more reason the traditional recipes hold together.

A simple turmeric and pepper milk

1. Warm 1 cup of milk in a small pan.
2. Stir in ¼ teaspoon turmeric, a small pinch of freshly crushed black pepper and ¼ teaspoon ghee.
3. Simmer gently for 2 minutes, stirring so the turmeric doesn't settle.
4. Take it off the heat and sweeten with jaggery or honey if you like.

Keep the pepper small. More than a pinch makes the milk sharp rather than warming.

Does it matter what pepper and turmeric you use?

For flavour, yes. Piperine is fairly stable, so even older pepper keeps its heat, but freshly crushed whole pepper smells far better. With turmeric, colour and aroma vary a lot between grades. Our guide to turmeric grading explains what to look for.

We don't sell turmeric yet, though we plan to add it. Our whole Kerala black pepper is grown in Idukki and packed whole, ready to crush as you need it.

Sources

• PubMed: Shoba et al. (1998), Influence of piperine on the pharmacokinetics of curcumin
• NCCIH: Turmeric, usefulness and safety