In the old days, castor oil was used by some as a remedy and by others as a punishment. Parents often made misbehaved children swallow a spoonful of the thick, yellow oil. Also, this famous liquid has been used for medicinal purposes for centuries. Is castor oil good for inflammation or any other health problem, or is it all just a myth? Let’s find out.
Castor Oil is a vegetable oil that comes from the pressed seeds of the castor oil plant. Some of the earliest evidence of castor oil used for medicinal purposes goes back to the ancient Egyptians. In those days, they used the oil to treat eye irritation and for skin care. During the 1800s, Castor Oil was used as a home remedy for nearly any kind of sickness. Some even took a spoonful of the thick oil every day for its supposed general health benefits. Currently, India leads the world in castor seed and oil production.
Castor Oil is a triglyceride fatty acid, and most of its fatty acid content comes in the form of ricinoleic acid, which is believed to contain medicinal properties. This oil is most commonly used in the cosmetics industry since castor oil is believed to be healthy for the skin and hair. The oil is also used to make medications but not for the oil’s medicinal properties. Instead, Castor Oil is used as a drug delivery substance, that is, a medication is mixed with the oil to be sold or administered to patients.
How Does Castor Oil Work?
There are many diverse opinions about castor oil, but not many human-based studies. Still, a fair amount of animal research does exist. For instance, biologists at the Max Planck Institute for Heart and Lung Research in Germany decided to look into this age-old remedy. Because castor oil is rich in ricinoleic acid, the researchers looked at cell receptors that respond to this compound. What they discovered was pretty impressive.
They found that ricinoleic acid interacts with the EP3 and EP4 prostaglandin (PG) receptors. These receptors have important roles in your cells, such as in neuron and blood clotting functions. In the small intestine, castor oil activates receptors in the smooth muscle causing contraction. This is why castor oil is an effective laxative.
Other Potential Benefits of Castor Oil
Many sources claim that castor oil offers numerous benefits. For example, the oil might help:
- Prevent diabetes
- Treat inflammation
- Fight infections
- Provide antioxidant benefits
- Protect the liver
- Improve free radical scavenging
- Accelerate wound healing
To date, there are no human studies to support these claims. However, we might be able to draw some conclusions based on the action of ricinoleic acid on the PG receptors mentioned earlier.
In one animal study, EP3 and EP4 prostaglandin receptor signals facilitated wound healing. This is one of the oldest reported uses of castor oil as well. It might be helpful then, for example, to apply castor oil on minor burns or skin abrasions. If you use this remedy, make sure you keep the damaged skin out of the sun since the oil might increase the risk for sunburn.
In another study, published in Mediators of Inflammation, the authors noted that “Observational studies indicate that topical application of ricinoleic acid (RA), the main component of castor oil, exerts remarkable analgesic and anti-inflammatory effects.” Their animal experiments showed that when applied topically, ricinoleic acid appears to have an anti-inflammatory activity similar to capsaicin. Several studies show that capsaicin can help relieve conditions, such as:
- Joint pain due to rheumatoid arthritis and osteoarthritis
- Muscle sprains and strains
- Migraines and other headaches
Would it hurt to rub a bit of castor oil on your achy joints? How about a little on your lower back or shoulder to relieve muscle pain? According to the research, this might be effective, and it probably won’t cause any harm.
Other Actions of Prostaglandin EP3 and EP4 Receptors
Other animal studies dig even deeper into the potential benefits of castor oil. These animal studies were conducted by the Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences at Kyoto University in Japan. The results reveal some amazing properties of the PG receptors targeted by ricinoleic acid. These are:
EP3 receptor actions
- Mediates fever generation
- Suppresses type I allergy
- Inhibits angiogenesis associated with tumor and chronic inflammation (stops blood vessel growth in tumors and inflamed tissue)
- Lowers pain associated with virus infection
EP4 receptor actions
- Helps bone formation
- Protects against inflammatory bowel disease
- Facilitates Langerhans cell (special skin cells) migration and maturation
- Mediates joint inflammation in collagen-induced arthritis
Even though there are no confirmed human studies, the data above is impressive. It could mean that castor oil might help treat fevers, stop allergies, prevent cancer, relieve pain, improve skin health, and form healthy bones. Could it be that the old-time doctors were right all along?
Like many remedies that have survived over time, some actual medical science might support their use. Before you use castor oil, especially orally, make sure you consult with a doctor first. However, it might be worth a try to use castor oil externally, for example, on minor wounds or achy muscles and joints. It’s not a good idea, however, to use the oil on an open wound or surgical site.
The number of research studies about castor oil is on the rise. From 2010-2015, the number of research papers totaled 600, nearly double compared to the previous five-year period. Who knows? Maybe someday, we’ll be hearing that a spoonful a day of castor oil is good for you!
Castor Oil: Properties, Uses, and Optimization of Processing Parameters in Commercial Production. (n.d.). Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5015816/
Castor Oil Speeds Up Healing & Improves Your Immunity – Dr. Axe. (2018, May 15). Retrieved from https://draxe.com/castor-oil/
Effect of ricinoleic acid in acute and subchronic experimental models of inflammation. (n.d.). Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1781768/
Hosono K, et al. (n.d.). Signaling of Prostaglandin E Receptors, EP3 and EP4 Facilitates Wound Healing and Lymphangiogenesis with Enhanced Recruitment of M2 Macrophages in … – PubMed – NCBI. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/27711210
Just a spoonful of castor oil. (2014, October 31). Retrieved from http://www.sciencemag.org/news/2012/05/just-spoonful-castor-oil
Sugimoto, Y., & Narumiya, S. (2007, February 28). Prostaglandin E Receptors. Retrieved from http://www.jbc.org/content/282/16/11613.full.pdf