Sassafras trees are large trees native to North America. These beautiful trees can grow 100 feet tall, and beautiful aromatic flowers smell just like root beer when they bloom.
For generations, sassafras was widely available and approved in the United States as a flavoring for beverages and candies and as a tea. However, in 1976, the U.S. Food and Drug Administration (FDA) banned sassafras oil as a food additive.
This came after multiple studies in the 1960s indicated that safrole causes cancer. Safrole is a chemical compound found in high-levels in sassafras and to lesser extents in nutmeg and anise. In addition, safrole is found in high levels in the betel nut of Asia.
In China and other parts of Southeast Asia, the betel nut is commonly chewed because of its stimulating effects. This is due in part to its high levels of safrole. This has led researchers to study potential safrole dangers, and multiple studies have linked safrole to oral cancer and hepatocellular cancer, a cancer of the liver.
Today, in the United States, many natural health practitioners point to the fact that sassafras tea has been consumed in many areas of the country for centuries—without an increase in cancer rates. This statement, however, has not been backed by verifiable research.
What has been determined is that a single cup of sassafras tea made from 2.5 grams of sassafras (which is less than 0.10 of an ounce) contains 200 milligrams of safrole, or 4 1/2 times as much sassafras as researchers consider “poisonous.”
Many of these same natural health personalities point to studies that indicate sassafras “kills cancer cells.” And yes, sassafras has been studied, quite extensively, in the fight against cancer. However, it is essential to understand the details of the trials.
Sassafras and Safrole in Cancer Research
It is true that safrole has been studied as both a cancer-causing agent and a cancer-fighting agent. Let’s take a look at some of the research examining safrole’s cancer-fighting potential
Lung cancer: In a study published in the journal Experimental Lung Research, researchers state that synthesized safrole oxide may kill lung cancer cells. This opinion was based on in vitro studies, which literally means “in glass” in Latin. Please note that the findings were not based on human or animal trials but rather on human lung cancer cells in test tubes.
Oral cancer: In another in vitro study published in the Journal of Dental Research, safrole was shown to kill human oral cancer cells. What is particularly interesting about this study is that it seems to contradict previous studies that found safrole causes oral cancer.
Liver cancer: In addition to oral cancer, safrole has been indicated in the development of liver cancer. However, an in vitro study published in the International Journal of Clinical and Experimental Pathology found that at the molecular level safrole could suppress liver tumor cell growth. This study demonstrated that safrole stimulates or induces apoptosis, which is defined as cell death.
Breast cancer: Researchers from Chile studied the effect of catechols that had been synthesized from safrole on breast cancer cells. In this in vitro study, the catechols inhibited cell growth in two types of breast cancer—MCF-7 and MDA-MB-231. The most exciting finding of this study is that the catechols did not appear to cause toxicity in surrounding healthy cells.
Prostate cancer: In another in vitro study published in the Journal of Receptors and Signal Transduction researchers found that the “carcinogen safrole” can decrease prostate cancer cell viability at the molecular level.
Osteosarcoma: Osteosarcoma is one of the most devastating cancers, as it often strikes children. In this in vitro study, safrole was tested against human osteosarcoma cells, and researchers found safrole can cause cell death. This was a very targeted study that looked at a variety of concentrations, syntheses of safrole, and the time in which safrole was exposed to cells.
There are several more studies that have looked into safrole’s effect on different types of cancer, but it is vital to recognize that these studies are very preliminary. The studies highlighted above are from the 2000s and this decade, and yet, even with some of the in vitro studies showing possibility, there are currently zero clinical trials ongoing, recruiting, or completed in the United States.
Sassafras and Safrole in Medical Research
While safrole is most often studied outside the United States in regards to cancer, there are other medical conditions for which it, and sassafras, have been researched.
Diabetes: Researchers in India have conducted an animal trial on safrole and diabetes. After 30 days of receiving safrole orally, researchers found that a dose of 100 milligrams and 200 milligrams significantly improved the diabetic condition of the rats in the study. It is important to note here that, as mentioned above, 200 milligrams is over four times the amount considered poisonous to humans.
Leishmaniasis: Leishmaniasis is a tropical parasitic disease. In a study published in the journal Natural Product Communications, researchers found that sassafras bark extract shows excellent activity against leishmaniasis protozoa. This animal trial also found that the compound that successfully fought the parasites was sesamin, a chemical that is also found in sesame oil.
Alzheimer’s disease: One of the more promising preliminary reports on sassafras is that researchers from China have identified two compounds in sassafras known as AChE inhibitors. AChE inhibitors are currently used in Alzheimer’s care, schizophrenia, glaucoma, and more.
As mentioned, the primary phytochemical in sassafras that is concerning is safrole. In the 1960s comprehensive studies found safrole to be a carcinogen that can cause oral, esophageal, and liver cancers.
Additionally, safrole is classified as a “watched substance” because it is the ingredient used to synthesize the illegal drug MDMA (Ecstasy and Molly).
If you have heart disease, speak to your cardiologist before drinking sassafras tea or consuming other sassafras products. A preliminary study indicates that safrole can compromise plaque in the arteries and cause a stroke.
Pregnant women should avoid all sassafras products, as sassafras can cause a spontaneous miscarriage.
Sassafras Side Effects
Drinking small amounts of sassafras tea, particularly those that are sold “safrole-free” is generally well tolerated. However, sassafras tea can cause the following side effects:
- Excessive sweating
- Hot flashes
- High blood pressure
- Skin rashes (when applied topically)
Sassafras is considered unsafe for:
- Women who are pregnant or breastfeeding
- Women with a UTI
- People taking sedative medications
Sassafras drug interactions can be serious. Speak to your physician before adding any sassafras product to your diet. If you have a surgery scheduled within the next two weeks do not consume sassafras, as doing so can interfere with multiple cardiac and blood-clotting functions.
Sassafras tea has been consumed for hundreds of years in some regions of the United States. Many natural health practitioners promote sassafras’s ability to kill cancer cells. However, it is essential to understand that the trials that show sassafras’s anti-cancer potency are very preliminary and not conducted on humans—they are in vitro studies that are the jumping off point for further research.
It is also important to understand that the safrole used in the majority of the trials mentioned was synthesized and injected directly into cancer cells. You just cannot expect the same results from drinking sassafras tea.
As with all natural and synthetic health products, do your research and make the best decision for you.