Fermented Papaya Increases Immune Function and Detoxification

fermented papaya increased immune function

By Case Adams, Naturopath

Italian researchers have discovered that eating fermented papaya for six weeks significantly increases immune function and stimulates the body’s ability to detoxify through special enzymes such as superoxide dismutase.

The researchers, from Italy’s ReGenera Research Group for Aging Intervention Group in Milan, studied 90 healthy but sedentary human subjects. They divided the subjects into three groups by age (20-40 years old, 41-65 years old and over 65). They tested the subjects’ blood and saliva together with questionnaires prior to and after the papaya protocol.

The researchers then gave half of each of the subjects from each group either a placebo or nine grams per day of fermented papaya.

After the six weeks, the subjects were again tested and given a month break (washout period). Then the the placebo group was given the fermented papaya while the previous papaya group was given the placebo. This research method is called a crossover.

Before and after each testing period the researchers performed blood analysis on the patients, checked for white blood cells count, checked saliva flow rates and secretary IgA activity. They also checked lysozymes and redox gene expression for Phase II enzymes and superoxide dismutase secretion from upper airway cells.

Immunoglobulin-A is an antibody produced by the body to help identify invaders and guard the body from infections.

The researchers found that those taking the fermented papaya had significantly greater IgA (immunoglobulin-A) levels than the placebo groups.

The researchers also found that phase II enzymes and superoxide dismutase enzyme expression was significantly higher among the papaya groups.

While these responses were seen among all of the age groups studied, the salivary secretion rates increased significantly in the youngest group. This is another sign of increased immune function.

Why superoxide dismutase secretion is important

Superoxide dismutase secretion is extremely important to the nose and airways because it helps neutralize reactive oxygen species and reactive nitrogen species – both considered free radicals that will damage the body’s cells if they are not neutralized. Many toxins and pollutants – especially air pollutants containing mercury, sulfur and other reactive elements from air pollution – will convert to radicals in the presence of oxygen, damaging lung and airway cells.

Phase 2 enzymes include glutathione transferases and quinone reductases. These are important enzymes for preventing genetic mutations – and those preventing cancerous cells from forming.

The researchers confirmed that while further testing was required to confirm their findings, fermented papaya stimulates the immune system especially among the cells of the upper airways.

The fermented papaya concoction used by the researchers was produced by the Osato Research Institute from Gifu, Japan. The product was taken sublingually, which means it was put under the tongue, allowing the nutrients to be quickly absorbed into the bloodstream. This method of sublingual absorption works well for a number of nutrients, including vitamin B12.

Fermented papaya reduces damage from free radicals

Another study – this from French and Mauritius researchers – found that fermented papaya reduced the blood’s susceptibility to free radical damage. The study collected blood cells before and after the consumption of fermented papaya (six grams per day for 14 weeks). The researchers found that the fermented papaya significantly reduced blood cells’ rate of hemolysis (destruction) through contact from free radicals.

Other fermented foods have also been shown by other research to stimulate the immune system. These include kimchi, kefir, yogurt, sauerkraut and others.

It should be noted that many papayas grown in Hawaii are now genetically modified.

See an example of a fermented papaya product on Amazon.

Learn more about the health benefits of fermented foods.


Marotta F, Naito Y, Jain S, Lorenzetti A, Soresi V, Kumari A, Carrera Bastos P, Tomella C, Yadav H. Is there a potential application of a fermented nutraceutical in acute respiratory illnesses? An in-vivo placebo-controlled, cross-over clinical study in different age groups of healthy subjects. J Biol Regul Homeost Agents. 2012 Apr-Jun;26(2):285-94.

Somanah J, Bourdon E, Rondeau P, Bahorun T, Aruoma OI. Relationship between fermented papaya preparation supplementation, erythrocyte integrity and antioxidant status in pre-diabetics. Food Chem Toxicol. 2013 Dec 5;65C:12-17. doi: 10.1016/j.fct.2013.11.050.

Case Adams is a California Naturopath with a PhD in Natural Health Sciences, and Board Certified Alternative Medicine Practitioner. He has authored 26 books on natural healing strategies. “My journey into writing about alternative medicine began about 9:30 one evening after I finished with a patient at the clinic I practiced at over a decade ago. I had just spent the last two hours explaining how diet, sleep and other lifestyle choices create health problems and how changes in these, along with certain herbal medicines and other natural strategies can radically yet safely turn ones health around. As I drove home that night, I realized I needed to get this knowledge out to more people. So I began writing about health with a mission to reach those who desperately need this information. The strategies in my books and articles are backed by scientific evidence along with wisdom handed down through traditional medicines for thousands of years.” Case connects with the elements by surfing, hiking and being a beach bum.

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