Cordyceps or worm grass is well known in Thailand as “Tang Shao”. It is a famous Chinese medicine with diversity of at least 680 types (1) according to the difference of worms and mushroom spores that grow in the worm. The most famous type that has been mostly studied is Cordyceps sinensis (Berk.) is found primarily on the Himalaya and Tibet.

Himalayan Cordyceps are from two parts of butterfly worms, Hepialus armoricanus and of mushroom, Cordyceps sinensis. In winter, the worms stay dormant in snow and when spring comes, they ingest spores of specific mushrooms, which will grow inside them in summer. The worms eventually died leaving only mushrooms growing from their dry bodies. As a result, the Cordyceps are known as worm in winter and mushroom in summer.

In China, Cordyceps have been registered as medicine since 1964 for immune stimulation, improving functions of lung, kidney and liver, prevention of cancers, reduce fats, promote health and fighting free radicals. It also improve sexual ability so is also called “Himalayan Viagra”. Health benefits of Cordyceps was demonstrated in the 1993 Chinese national competition where three female runners broke world records of 1500, 3000 and 10000 meter races. They were examined thoroughly for stimulants but test results came out negative. After a while, the trainer Mr. Ma Zunren disclosed to the public that the racers took Cordyceps drink. The United States Olympic Committee has then legalised Cordyceps because of the health benefits and safety profile.

Good Cordyceps are found on the mountains of China, Bhutan and Nepal (Tibet) at 10,000 to 12,000 feet altitude. They are collected in early Spring, washed and sun-dried. The best Cordyceps are those with mushrooms at the same size of the worms, around 3 - 4 centimeters. They are consumed as fresh, boiled or dried and stored in capsules. Due to high demand, they are also cultivated in Shing Hai, and Chang Tow in Tibet, Shezone, Yunnan and Gui Jow. However, natural Cordyceps are still at much better quality.

There have been several studies in animals and humans showing biological and pharmacologic benefits of Cordyceps, as follows.

  • Reducing blood sugar – A study among 20 DM patiens taking 3 grams per day of Cordyceps resulted in 95% control of blood sugar compared with 54% of cases treated with modern medicine (17).
  • Immune stimulation – Cordyceps stimulate white blood cells, particularly Natural Killer (NK) cells, which play key roles in cancer prevention (19).
  • Reconstitute renal functions – It was found that renal functions of 51 chronic renal failure cases who took 3 -5 grams of Cordyceps a day had improved. Furthermore, after one month, complications of renal failure such as blood pressure, proteinuria and anemia reduced. At the same time, an anti-oxidant, superoxide dismutase (SOD) was found to be increased (19).
  • Improve sexual functions – A study among 22 male subjects who regularly took Cordyceps found a 33% increase of sperms with reduction of deformed sperms by 29% (24). Another study among 189 male and female subjects who started to lose sexual functions, taking Cordyceps could improve their libido by 66% (25).
  • Decrease fatigue and increase general body functions – In addition to the impressive results shown by the three Chines racers in 1993 (28), there were several studies in animal models showing reduction of fatigue and improve efficiency in particular among the elderly.
  • With clear health benefits, evidence on complications and toxicity are still trace. There are some reports on dry mouth, nausea, diarrhea. Prescribing Cordyceps for DM patients should be careful as they could further reduce blood sugar. However the major concern is not only on Cordyceps themselves, but on lead poisoning. There have been some reports where lead filaments were inserted to increase weight of Cordyceps in the market.

In summary, cautions of using Cordyceps include:

  1. Among DM patients because Cordyceps could further reduce blood sugar.
  2. Among those on immune-suppressive therapy because Cordyceps stimulate immune responses.

With various pharmacologic effects and more than a century of using, Cordyceps require more scientific research particularly in human. Cordyceps price increased more than 900% in 1998 to 2009 and is still increasing 20% per year on average. Natural forms grow only on the mountains in China, Tibet, Nepal and Bhutan (31).

Cordyceps must be carefully used. Different types of mushrooms and worms have been cultivated. This requires more research. Data among pregnant and lactating women remains in-sufficient.

Information by: RoyalLife Anti-Aging Center และ Bangkok Health Research Center, Bangkok Hospital.

23 Dec 2016