fresh star anise spice

Health Benefits of Star Anise vs. Side Effects of Poisoning

[toc]What is star anise? Also known as badiam, its pods look liked star-shaped pine cones and actually, they do come from a type of evergreen. However the Illicium verum tree does not have needles, but rather leaves which stay on year ‘round. That’s why it requires a subtropical climate (USDA Zones 8 through 11) and natively grows in the warm southern portions of China and Vietnam.

You don’t eat the outer shell of the Chinese star anise. Each of the star’s eight arms has a seed inside and those are the parts you eat. They tastes like bitter licorice.

Ground to a fine powder, it’s used sparingly in meats like pork and duck in South Asian cuisine. Some recipes for Indian curries use it.

Unlike the vast majority of spices and herbs which are considered entirely healthy, star anise may not always be good for you. It’s a dichotomy because on one hand, there may be medical benefits. On the other, possibly serious side effects to weigh.

In short, Japanese star anise is toxic and Chinese star anise is not. Since both look almost identical when dried, there is a widespread practice of selling the Japanese and trying to pass it off as the Chinese type.

This is why you don’t want to cut corners when you shop for it. Make sure you buy a trustworthy brand like this, rather than some brand you’ve never heard of.



Chinese pork spiced with aniseThis is actually good or bad, depending on how you want to interpret it.

Yes, there are antioxidants in it. The ORAC value of star anise is 11,300.

That may sound great if you were comparing it to a red apple at 4,275. Though ORAC is based not on serving size, but a standard weight of 100 grams (about 3.5 ounces).

One large apple weighs over twice that amount. With how sparingly star anise is used, how many dozens or hundreds of dishes would you need to cook in order to use that much?

Relative to other spices, it actually ranks quite low on the ORAC scale.


Unlike the antioxidant content, the indirect antiviral benefits of a star anise compound are not disputed. We say indirect because on its own it’s not an antiviral, but it is used to make something that is.

Tamiflu packagingThe active ingredient in Tamlifu is shikimic acid.

Guess what makes up 7% of the star anise pod by weight? You guessed right and it happens to be the highest natural source of shikimic acid. Pine needles are around 3% and the sweet gum tree is as low as 1.7%.

How else can you can make shikimic acid is through fermentation using genetically modified bacteria. However that method is considered even less economical than the complicated ten stage process of extracting it from the spice.

Though to be clear, shikimic acid on its own is not antiviral.

Shikimic acid is used as base material for making Tamiflu (oseltamivir). So those alternative medicine folks peddling a star anise flu remedy are just plain wrong. This spice can’t prevent or treat the influenza virus.

However the spice might have direct antiviral properties, for other viruses.

It is not approved for medical treatment of any disease. The limited research has only taken place in Petri dishes, not human bodies. With such very preliminary findings, there is zero proof that it actually works for any viral disease.

For the herpes simplex virus type 1 (HSV-1) certain compounds in star anise essential oil were found to reduce viral infectivity by up to 99% in laboratory experiments (in vitro) (1) (2).

At least one major health website has claimed that the University of Heidelburg researchers who conducted those studies have said it’s “effective against several types of viruses, including the herpes virus” but we have been unable to verify if that claim was actually made.

Lastly, to dispel another myth, there is no evidence or research about star anise for the COVID-19 coronavirus. While you may come across articles suggesting anti-viral effects against COVID-19, there is zero research to support that. Do NOT use this or any other spice for the treatment, prevention or cure of COVID-19.


It has been known for at least two decades that the antimicrobial, as well as antifungal activities, are largely due to a compound in the seed called anethole (5). It makes up 80 to 90% of the star anise essential oil extract.

In just 20 minutes, one experiment found that it killed 100% of drug-resistant strains of Vibrio cholerae, which is the cause of cholera (6). Another study found (7):

“…extracts of Illicium verum showed substantial antibacterial activity against 67 clinical drug-resistant isolates [infections]”

Currently there are no medications which make use of its antimicrobial properties, but one of the research papers suggested it should be developed into antibiotics.


bacteria and fungus in petri dishAgain, this is another benefit which might exist but is not certain or medically proven.

Can it help your pet? Microsporum canis is a fungal infection which infects cats. Italian researchers used a mixture which included essential oils from the star anise – along with other plants – and they were successful in treating 4 out of the 7 cats which were infected (3).

Meanwhile in humans – especially women – one of the most prevalent and problematic fungal infections is candida overgrowth.

The list of side effects is long, including digestive issues like abdominal cramps, gas and bloating, skin issues, headaches, and much more. Two of the most common are frequent vaginal yeast infections and urinary tract infections.

Researchers at Korea University in Seoul wanted to see if any of the medicinal herbs used in their culture exhibited antifungal properties against this nasty infection (4). They concluded that extracts from the spice “could be a candidate for a new antifungal agent for candidiasis and other fungal disease.” The specific extract was a real mouthful; 1-methoxy-4-(2-prophenyl) benzene.

Herbal remedies

All of these are unproven of course, but here are some of the things people have been known to use it for:

  • Sleep – It is known to have a sedative side effect, which might be a good thing for insomnia.
  • Digestion – Star anise tea is commonly consumed after meals in Southeast Asia because it is believed to help with forms of indigestion, such as gas and bloating.
  • Lactation – In China, many believe it boosts how much milk the mother produces. There might be something to this since the spice is a phytoestrogen. In a 2015 study, lactating pigs which were fed the spice and the results suggested that it increased their milk production (8).
  • Skin and hair – It is applied topically as a remedy for head lice and acne.
  • Back and joint pain – Some claim using star anise for rheumatoid arthritis is helpful.
  • Male libido – This herbal remedy claims that each night, men should drink crushed seeds mixed in a glass of water.

To reiterate, these remedies are all unproven. Most have zero research.

Anticancer or causes cancer?

In a laboratory experiment using a breast cancer cell line (MCF-7), it was said that the cell cultures treated with various spice extracts “showed inhibitory activity against nicotine-induced cell migration” (9). The eight-pointed star was just one of the nine spices tested.

graph of how spices affect cancer
The effects of the spices on the cancer cells in vitro.

Just because that happened in a Petri dish, it doesn’t mean the same thing occurs in the human body. You could dump bleach on a tumor in a test tube and kill it, but obviously that doesn’t mean bleach is an an anti-cancer treatment.

There was a study with rats suggesting “anti-carcinogenic potential” by reducing stress on the liver (10).

Aside from a couple studies like these, there is very little research suggesting the possibility of cancer benefits from star anise. In fact, some research suggests the opposite; it contains a compound which may cause cancer.

As a naturally occurring compound, a tiny amount of safrole is in star anise. This compound is considered to be:

  • Genotoxic and carcinogenic, according to the European Commission on Health and Consumer Protection (11).
  • Reasonably anticipated to be a human carcinogen, ever since the 2nd edition (1981) of the U.S. government’s Annual Report on Carcinogens (12).

For these reasons, safrole is banned from being used as a food additive and for cosmetics.

sassafras leaves
Root beer was originally made out of sassafras, but not anymore.

Sassafras is the highest food source of safrole, which is why root beer no longer uses it. Dietary use of sassafras is still permitted, but it first must go through processing to remove the safrole.

Other spices that contain it include ginger, cinnamon, nutmeg, mace, white and black pepper (though not red pepper, your hot sauce is safe). How much safrole there is in spices is so low, it’s not considered to cause cancer.

Plus if these spices are washed, dried, and irradiated, the safrole degrades significantly (13). Keep in mind that USDA certified organic spices are not irradiated.

Is it bad for you?

“People are being advised not to consume teas brewed from star anise after the FDA determined that such beverages have been associated with illnesses in people and infants.”

emergency roomThat was a warning that came straight from the FDA back in 2003, after reviewing over 40 cases from a two year period (14). The side effects seen included:

  • vomiting
  • rapid eye movement
  • jitteriness
  • seizures

Some speculate that other sources of anise might have played a part in those cases.

Japanese star anise vs. Chinese

visual differences between true Chinese and Japanese star anise
As you see, the Japanese (top) and Chinese (bottom) can look practically the same when dried. Photos taken by Tshwane University of Technology, South Africa (15)

There is a big difference between these two types.

  • Chinese star anise (Illicium verum) – Also called true star anise, it is generally recognized as safe (GRAS). When you buy the spice at the supermarket, the bottle is supposed to only contain this type.
  • Japanese star anise (Illicium anisatum) – This is not edible. It contains a poisonous substance called sikimitoxin, which causes inflammation of the kidneys and digestive organs. It also contains a neurotoxin called anisatin.

The problem is that once the Japanese and Chinese anise are dried, you can’t tell them apart. Their taste is also not noticeably different, especially when they’re mixed.

Now consider these three things…

1. China grows 90% of it

Whether it’s the spice or tea, almost all comes from China (16). A place where sellers aren’t exactly known for taking pride in the quality of what they sell, to put it nicely.

Chinese farmers processing dried anise
At this star anise farm in Guangxi, China, notice how the crop is dried and processed right next to other spices, making it prone to cross contamination. Might that be Japanese anise on the right? photo credit: fuzheado on Flickr

2. Majority of crop is used for Tamiflu

While their government doesn’t disclose the exact number, an estimated 66% of their crop is estimated to be used for the financially lucrative Tamiflu. Some years they have a shortage, like during the swine flu outbreak.

3. Japanese anise is cheap and only has one use

Since it is not edible, it only has a very niche use – burning it as incense.

Conclusion = too much incentive to cheat

After considering those things, you may wonder if your true star anise is really the true kind, right?

With teas, some have been found to contain the real deal but were “watered down” with the toxic Japanese variety (17).

There are other poisonous types too, like the Illicium floridanum which grows in the Southeast United States.

Liver failure? Seizures?

mulled wine in pot on stovePublished in 2016, a medical paper discusses a tragic outcome which resulted from giving a baby star anise (18).

The parents were giving their 4 month old infant a daily mixture of star anise and green anise (Pimpinella anisum). The latter is not toxic. It’s the much more expensive anise spice, which is what star anise was actually named after because it has a similar flavor (they each come from a completely different family of plants).

Why were they giving this to their baby? Because some believe the star anise can be used to treat baby colic (infantile colic), which is defined as crying for more than 3 hours each day.

What a disastrous idea, because it had a poisoning effect, which caused the baby to have liver failure. If contamination from another species was to blame, it was not stated in the abstract.

There was actually research in the 90’s which claimed that compounds isolated from Illicium verum (the true kind) were shown to cause lethal toxicity in mice. Reportedly it contains convulsants (19). The compounds were sesquiterpenoids, veranisatins A, B and C.

Even at doses as low as 0.1 mg per kg of body weight, locomotor activity was said to be affected (20).

Though to be clear, the scientific community’s consensus is that the Chinese variety is safe for adult consumption.

In another case report on an infant, it was clearly stated that contamination from the Japanese variety was to blame. That case occurred in Virginia and involved a 3 month old infant being rushed to the ER, due to star anise poisoning symptoms, which were gastrointestinal and neurological in nature (21).

As mentioned, the neurotoxin anisatin (in the Japanese type) is known to cause epileptic seizures and apparently the frequency of them occurring can be high. In the Netherlands, one bad shipment of tea put 22 adults in the hospital (22). Of those who were hospitalized, over 70% (16) experienced seizures.

Is it safe during pregnancy?

pregnant woman with husbandTo be on the safe side, even 100% verified authentic star anise during pregnancy should probably be avoided. There is not sufficient data one way or another to conclude if it is safe or dangerous to the fetus.

On that note, the same advice holds true for breastfeeding moms. Sure, some followers of alternative medicine believe it might increase milk production, but even if it really works for that, they don’t know if it’s safe for the baby (who may be getting it from the breast milk).

Given the risk of contamination, with pregnancy it seems even Chinese star anise is a gamble that’s not worth taking.

If you do choose to avoid it during that time, keep in mind that some chai tea formulations contain it.

Does Starbucks chai tea have star anise? Yes and no. The Oprah Cinnamon chai does not list it in the ingredients, but their Chai Latte does. While shopping for tea at the grocery store, you will experience similar hits and misses.

What about everyone else?

The true Chinese star anise is considered to be safe for adults.

However the reason grown men and women are worried about its safety is because of the very real risk of not receiving the pure form.

In 2004, the prestigious Journal of the American Medical Association (JAMA) had an article which analyzed samples that were obtained from 3 infant episodes. Determining what the chemical composition of the Chinese variety was proved to be quite difficult (23):

“Microscopic examination of the samples did not prove suitable for a definitive determination of L. anisatum adulteration due to inherent variation observed in the hundreds of L. verum fruits examined.”

If even a microscopic examination isn’t useful in discerning between them, then how can we be 100% confident in the purity of this spice?

Unlike other spices such as turmeric, there are really no health benefits proven for anise. Considering the pros (mediocre taste?) and cons (dangers of getting a fake?) many are choosing to say búyào xièxie – which in Mandarin means no thanks – to using this spice.