What is piperine?
Piperine is one of the most important active ingredients in pepper, especially black pepper. The plant substance is responsible for the hot taste of the pepper, but also for most of the health-promoting effects typical of pepper.
Piperine belongs to the alkaloids, a group of substances that the plant usually uses to defend itself against predators. Because alkaloids often taste bitter or – like piperine – very pungent. Another alkaloid you may be familiar with is capsaicin from chili. Caffeine is also an alkaloid or theobromine from cocoa.
Which pepper contains the most piperine?
Black and white peppercorns contain the most piperine – up to 7.4%. Piperine levels of up to 5.6% were measured in green pepper, and levels of up to 4.3% in red P. In addition, the spice contains many other substances, e.g. B. piperettin, piperanine, flavonoids (quercetin, kaempferol, rhamnetin), phenols, amines and between 1 and 3% essential oil (2) (3) (4).
The effects and properties
Piperine has numerous properties that we can use very well for our health:
Antioxidant and anti-inflammatory effect
For example, as an antioxidant, it protects against damage caused by oxidative stress by inhibiting the formation of free radicals. In addition, piperine showed strong anti-inflammatory properties. In mouse studies, the substance reduced various inflammatory markers such as tumor necrosis factor, prostaglandin-2 and interleukin-10 ( 1 ). These values are increased in many chronic inflammatory diseases, e.g. B. in rheumatic diseases, chronic inflammatory bowel diseases or psoriasis.
Improving the bioavailability of other active ingredients
Piperine also increases the bioavailability of curcumin, quercetin, beta-carotene, selenium and resveratrol as well as vitamin A, vitamin B6 and vitamin C and is therefore added to a number of dietary supplements, especially preparations with curcumin.
Piperine increases the absorption of the substances mentioned, for example, by promoting blood flow in the digestive tract and increasing the permeability of the intestinal mucosa. There are also many other mechanisms of action, not all of which have been studied (5) (14).
A study published in 1998 in the journal medical plant published showed that taking piperine and curcumin together increased the bioavailability of curcumin by 2000% (i.e. 20-fold). The subjects had taken 20 mg piperine and 2000 mg curcumin (i.e. 1 percent piperine).
This increased the concentration of curcumin in the blood serum from 0.006 (without piperine) to 0.18 µg per ml (with piperine). This effect occurred within three quarters of an hour after ingestion – but after an hour the concentration of curcumin decreased again ( 6 ).
Another study (2007) is often cited to show that piperine’s increase in curcumin bioavailability is not very reliable or consistent. Because in this study, piperine was only able to double the bioavailability of curcumin. But although the participants here also received 2000 mg of curcumin, they only received 5 mg of piperine, not 1 percent but 0.25 percent, which makes a difference ( 20 ).
Possible side effects of piperine
Piperine is toxic in large quantities. The lethal dose when taken orally is 330 mg per kg body weight in mice and 514 mg per kg body weight in rats.
Doses of up to 100 mg per kg of body weight are considered harmless. However, dosages used in animals must be appropriately converted to humans. Rat doses must first be divided by 6.2, mouse doses by 7.4.
Nevertheless, the amount of piperine taken with a dietary supplement (10 to 30 mg per day, i.e. not per kg of body weight) is only a fraction of even the maximum amount that is still considered harmless.
Piperine and Leaky Gut Syndrome
If you know about Leaky Gut Syndrome (LGS), then perhaps alarm bells went off when you read in the penultimate section that piperine can increase the permeability of the intestinal mucosa. Because the LGS describes an overly permeable intestinal mucosa – and an overly permeable intestinal mucosa can promote the development of a wide variety of diseases, especially allergies and autoimmune diseases.
However, if a substance like piperine makes the intestinal mucosa a little more permeable for a short time, then this cannot be equated with a permanently and pathologically permeable intestinal mucosa.
There are even initial animal studies showing that piperine does not damage the gut lining, but on the contrary can help with inflammatory bowel disease (15) (16) and even colon cancer (17) (18) (19).
Piperine could z. B. to reduce the symptoms of ulcerative colitis (diarrhea, bloody stool), lower inflammatory markers and had an anti-cancer effect on colon cancer cell lines while not harming healthy cells. All of these observations would not be possible if piperine resulted in a damaged and diseased intestinal lining.
Interactions of isolated piperine with drugs
Piperine not only increases the bioavailability of dietary supplements, but may also increase that of some medications, which is why that too Federal Institute for Risk Assessment (BfR) People who take drugs recommends consuming no more than 2 mg of piperine per day from supplements (12) (13). Interactions with piperine are particularly possible with the following drugs:
- Antiepileptic drugs (treatment of epilepsy, e.g. carbamazepine) (7)
- Antiallergics (treatment of allergies, e.g. fexofenadine) (8)
- Cancer therapeutics (treatment of tumors, e.g. tamoxifen) (9)
- Analgesics (painkillers, e.g. diclofenac) (10)
- Antiemetics (used to treat nausea and vomiting, such as domperidone) (11)
However, piperine could also be used to advantage in medicines: as soon as piperine has been sufficiently researched, the substance could be added to some medicines to increase their bioavailability.
This could contribute to the medication being able to be dosed in lower doses and thus lead to fewer side effects. Interactions with pepper are not to be feared, only with isolated piperine.
Piperine supplements during pregnancy
Pregnant women should be loud Federal Institute for Risk Assessment avoid piperine supplements. Animal studies have shown that isolated piperine damages embryos and impairs the reproductive capacity of the animals. However, the studies examined by the BfR are not specified, let alone the level of the piperine dose examined.
The current data situation is summarized in a review from 2021: In an animal study, doses of 75 mg per kg body weight did not show any negative effects on the offspring. In other studies, on the other hand, doses of between 5 and 10 mg per kg of body weight and a dose of 10 mg had a negative effect on fertility in rats – even in male rats. To be on the safe side, do not take piperine supplements during pregnancy (13).