Is Edible Castor Oil for Constipation?

Castor oil has been used in folk and conventional medicine for centuries, and it has many purported uses for treating a range of ailments. At least one of the claims, that drinking castor oil benefits constipation, is true. This is due to a fatty acid it contains called ricinoleic acid.

Castor oil comes from the beans of the castor oil plant, a perennial flowering shrub native to eastern tropical Africa and Ethiopia, according to the Master Gardener Program at the University of Wisconsin-Madison. Growing to a height of 40 feet, it generates prodigious amounts of seeds contained in vivid, spiny pods the size of golf balls.

About 50 percent of the seed's weight is a viscous oil that is yellowish or almost colorless. In ancient times, the oil was used as lamp fuel. Today, castor oil is used in paints, varnishes, water-resistant coatings, motor oil, inks, soaps and plastics. It is also used as a lubricant in some laxatives, reports the U.S. National Library of Medicine.

Castor oil laxative effects are due to a compound called ricinoleic acid, a fatty acid pulled from castor oil by intestinal enzymes, according to a report published in June 2012 in the Proceedings of the National Academy of Sciences of the United States of America. The authors explain that the molecular mechanisms aren't well understood, but that it may activate smooth muscle cells in the intestine, therefore increasing motility.

The effects are so powerful that they can even help induce labor in pregnant women, potentially preventing the necessity for Cesarean section. Authors of a retrospective study published in the Journal of Maternal-Fetal and Neonatal Medicine in August 2018 found that the oil can be a safe pharmacological method for inducing labor when medically necessary.

Read more: 6 Common Foods That May Cause Excessive Bowel Movements

The seeds of the castor oil plant are severely toxic, warns the University of Wisconsin-Madison. They contain the toxin ricin, which is among the deadliest toxins found in nature. In fact, it is approximately 6,000 times more poisonous than cyanide and 12,000 times more poisonous than a rattlesnake's venom.

Ricin is not present in purified castor oil. When taken in the amounts included in laxative supplements, it poses no health risks. However, the U.S. National Library of Medicine warns that consuming large amounts of castor oil can be harmful. Symptoms may include abdominal cramps, chest pain, diarrhea, dizziness, fainting, nausea, shortness of breath, skin rash and tightness of the throat.

If you are taking castor oil, be sure to only take the amount recommended on the label or by your health care provider.

Laxatives in general are not safe for long-term use. Excessive use of laxatives can result in physical and psychological dependence, warns Cornell Health. Constipation can be a side effect of laxative abuse because the intestines lose muscle and nerve response and require higher and higher doses. Diarrhea and gas are other side effects, as are dehydration, electrolyte imbalances, bloody stools and rectal prolapse.

Laxatives should only be used occasionally for a very limited period, if at all. Talk to your doctor about other ways to treat constipation that have a lower risk of side effects. One of the first steps to combat constipation is to increase your intake of dietary fiber, found in fruits, vegetables and whole grains, as well as fluids. Fiber increases stool bulk and helps stools move through the intestine, while water helps keep stools soft and easy to pass.

Read more: 19 High-Fiber Foods — Some May Surprise You!