Clinical Research Supports Effectiveness of Ashwagandha to Boost Body's Immunity

An ancient herb, commonly known as Indian Ginseng, is found to increase the body’s first-line defense cells when combined with milk

PORTLAND, Ore. (August 13, 2008) — A team of Portland medical researchers has found that drinking whole cows’ milk with Ashwagandha, an herb used for more than 5,000 years in the practice of Ayurvedic medicine, can increase the body’s white blood cells, which help boost immunity.

This first-of-its-kind study was led by Heather Zwickey, Ph.D., director of the National College of Natural Medicine’s Helfgott Research Institute, with naturopathic medical students Jeremy Mikolai and Andrew Erlandsen. The team is presenting its findings at the 23rd annual meeting of the American Association of Naturopathic Physicians (AANP;, being held Aug. 13-16, 2008 in Phoenix, AZ. The full findings of the study will be published this fall.

According to Zwickey, three herbs – echinacea, astragalus and glycyrrhiza – have been extensively researched for their ability to stimulate the immune system. “I felt it was time to open the door a little wider and see what more we could find to use ancient medicine’s ability to heal the health disorders of today,” the immunologist said.

“Given that conventional medicine has a lot to offer for the treatment of bacterial infections, my lab is focusing on those products that can address viral disorders such as sinus infections, colds and the like.”


Zwickey says that Eastern and Oriental medicine practitioners have long known that Ashwagandha helps fight disease when used in combination with a liquid, known in Ayurvedic medicine as anupana. Anupana is derived from many different substances, from olive oil to beer.

“Each liquid is thought to have different properties, so an Ayurvedic practitioner selects an anupana that has the qualities that best fit a given situation,” she said. “Traditionally, one method of administering Ashwagandha and milk was to boil them together.”
According to Zwickey, investigations into herbal remedies rarely take into account how the herb has been administered throughout the tradition of the medicine’s life cycle, such as mixing it with water, tea, or oil. While many consumers today may consume the herb with water or no liquid at all, researchers know that Ashwagandha (Withania somnifera) has typically been taken with an anupana substance. It is believed to aid in the digestion and effectiveness of the plant.

To determine if an anupana substance would help enhance Ashwagandha’s immune properties, the research team used milk in a co-administered intervention along with the herb extract. Zwickey said that cows’ milk was chosen over other potential substances for the immunological study because Ayurvedic medicine considers it to be a strengthening, nutritive driver for medicines.


To measure the effects of the herb in humans, the researchers examined the impact the herb had on cell activation of lymphocytes. Lymphocytes are a type of white blood cell and come in four forms: (1) Natural Killer cells, which are a major component of the immune system and best known for their ability to respond to virally-infected cells and tumors; (2) B-cells, which make antibodies that bind to a virus or microorganism and then destroy it; (3) CD4+ T cells (also known as helper cells), which coordinate the immune system’s response; and (4) CD8+ T cells, which kill cells that become infected.

The research team took blood samples from five healthy volunteers (three female; two male; average age 27) to set a baseline for immune cell levels. They administered an alcohol and water extract of Ashwagandha totaling approximately two teaspoons (6mL) in eight ounces of cows’ milk. The liquids were consumed twice a day for four days. Blood work was drawn again at 24 and 96 hours post-baseline to look for differences in the cells.


The team found that consuming Ashwagandha with cows’ milk had the following effects on the human immune system:

  • There was a statistically significant overall increase in the level of white blood cell activation. Cell activation was most pronounced in the CD56+ Natural Killer cells. This is important, since these cells play a critical role in the body’s response to flu, mumps, or tumors.
  • There was a statistically significant increase in the number of CD4+ T helper cells. While both CD8+ T helper cells and B cells also increased, the amount was not significant.

Recommendations for Consumers

Zwickey recommends that those who use natural products consult a naturopathic practitioner or other alternative medicine specialist before purchasing herbal products. “The most expensive product does not always contain the best quality, and vice versa,” Zwickey says.

She recommends that the public wait until additional studies are complete before beginning a cows’ milk and Ashwagandha regime in earnest.

ABOUT NCNM: Founded in 1956, NCNM is the oldest accredited naturopathic medical school in North America. A non-profit college of natural medicine, NCNM offers four-year degree programs in Naturopathic Medicine and Classical Chinese Medicine. Its teaching clinics offer free and low-cost medical care throughout the Portland metropolitan area and treat more than 17,000 patients per year. NCNM’s Helfgott Research Institute is a non-profit research institute that conducts rigorous independent research to advance the science of natural medicine in order to improve clinical practice. Until July 2006, NCNM was known as the National College of Naturopathic Medicine.