The Most Influential Cannabis Research Studies In Over A Century

In this article I will cite several landmark cannabis studies going back to the end of the 19th century. The goal of these studies was either to advance the understanding of the medicinal benefits and properties of cannabis or to debunk deleterious misinformation which demonized the plant. This list includes present day studies which are ongoing.

Indian Hemp Drugs Commission (1894)

The colonial government of India, under British rule, became concerned about the amount of cannabis consumed by local citizens. This was the impetus behind British and Indian medical professionals traveling throughout India to collect information on the medical, social and moral impact of cannabis use.

The result was a research paper of over 3,000 pages in a seven volume report. The majority of the data corroborated two conclusions:

  1. Moderate consumption of cannabis is relatively harmless or beneficial
  2. Prohibiting cannabis use would cause widespread suffering and is unjust

This research would endure for the next 50 years as the most accepted, thorough and scientifically rigorous information available.

The LaGuardia Report 1944

The LaGuardia Report, endorsed by the New York Academy of Medicine, was an investigation commissioned by Fiorello LaGuardia, mayor of New York City. It was a response to the misinformation about the plant perpetrated by Harry J. Anslinger, head of the Federal Bureau of Narcotics and films like Reefer Madness. The Report panel consisted of doctors, psychiatrists, psychologists, chemists, pharmacologists and sociologists who meticulously reviewed all available scientific literature and research on the cannabis plant.

Here is what the report concluded:

  1. Unlike alcohol, cannabis does not alter one’s basic personality
  2. Cannabis does not cause antisocial behavior
  3. Cannabis is not a gateway drug to opioid usage
  4. Long-term use of cannabis does not cause physical, mental or moral degeneration nor permanent harmful effects
  5. Cannabis and its derivatives have valuable therapeutic benefits which warrant future investigation

The Discovery of THC (1964)

It is pretty safe to say that the discovery of THC by Dr. Raphael Mechoulam and his Israeli team in 1964 was one of the most consequential discoveries in modern science. Not only was it a major breakthrough in understanding cannabis and its myriad of medicinal benefits, but it led to the discovery of the endocannabinoid system (ECS) in the late 1980s. We now know that the ECS is responsible for regulating all the body systems. Researchers continue to learn more and more about the importance of this operating system.

The Shafer Commission Report (1972)

President Richard Nixon was no friend of cannabis and was vehemently opposed to its legalization. He thought he would vilify the cannabis plant by setting up the 1972 Shafer Commission. Ironically, he personally chose the team of experts on the Commission whose findings defied Nixon’s position.

After researching cannabis for over two years, the Commission concluded the following:

  1. Recommended the removal of all criminal penalties for cannabis use including distribution of small quantities
  2. Neither the cannabis user nor the plant poses a danger to the safety of the public
  3. Imposing criminal sentences on users is inappropriate. The potential harm by users does not warrant the intrusion of the criminal justice system into private behavior.

The Shafer Commission panel knew full well that their findings completely contradicted the federal government’s position on cannabis legalization. Nevertheless, they hoped that their extensive research would open a discourse on the evidence, leading to cannabis law reforms.

They couldn’t have been more wrong. Nixon attacked the commission, ignored its recommendations and created the Drug Enforcement Agency (DEA) in 1973. This was the beginning of the Drug War against cannabis that continues to this day.

Cannabis Shrinks Tumors (1974)

Paradoxically, the purpose of the first study that demonstrated the anti-tumor properties of cannabis was intended to show that the plant was dangerous and that it harmed the immune system. It was funded by the National Institute on Drug Abuse (NIDA) and the American Cancer Society.

Researchers at the Medical College of Virginia implanted tumors into mice. They started treating them, beginning the day after the tumor implantation, for 10 consecutive days with delta-9 THC, delta-8 THC and CBN. The expectation was that the THC caused the cancer tumors to grow faster. In fact, cannabis retarded the tumor growth. With mice treated for 20 consecutive days with delta-8 and CBN, there was a reduction in tumor size.

Sadly, not only did the NIDA stop all funding for this research, but the agency suppressed the research results. It was not until March 2000 when a cannabis researcher in Spain replicated the original 1974 study model. Dr. Manuel Guzman, professor of biochemistry at the University of Madrid, reported that cannabinoids not only reduced the cancerous tumors but they left the surrounding tissue undamaged.

Cannabis Treats Nausea Caused by Chemotherapy (1975)

Harvard Medical School Associate Professor Dr. Lester Grinspoon first started researching cannabis back in the 1960s. He quickly realized that the federal government had been leading a misinformation campaign against cannabis, denigrating the plant and its therapeutic properties.

He was able to observe firsthand the powerful antiemetic properties of cannabis when his 15 year old son, Danny, was diagnosed with leukemia. The chemotherapy made Danny vomit and lose his appetite. The first time he took a few puffs of cannabis before his chemotherapy treatment, he asked his parents if they could stop for a submarine sandwich on their way home. They were delighted and astonished!

Dr. Grinspoon became an advocate of cannabis use and was responsible for convincing the head of the oncology department at Boston Children’s Hospital to set up a 1975 study. Published in the New England Journal of Medicine, it was the first study which demonstrated the effectiveness of THC in controlling nausea and vomiting due to chemotherapy.

Cannabis Helps AIDS Patients Without Serious Side Effects (1997)

Inspired by the success of Brownie Mary’s use of cannabis with the AIDS community, Dr. Donald Abrams, now the head of oncology at San Francisco General Hospital, vowed to prove the effectiveness of the plant for those suffering with AIDS-related nausea.

After a prolonged battle with the federal government, he was finally able to secure funding of close to $1 million from NIDA in 1997 to conduct clinical trials with those with HIV. A number of his studies demonstrated the following about cannabis use:

  1. It did not damage the immune system
  2. It did not increase HIV viral load
  3. It did not cause a harmful interaction with protease inhibitors
  4. It successfully increased appetite leading to an increase in caloric intake and weight gain

Cannabis Doesn’t Cause Lung Cancer (2006)

Dr. Donald Tashkin, a renowned pulmonologist at the University of California, Los Angeles, has studied the effects of cannabis on the lungs for over forty years. Some of his early research data on the effect of cannabis on lung health indicated that the tar found in the plant may contain cancer-causing chemicals as potentially harmful as tobacco.

To find out if cannabis caused lung cancer, Dr. Tashkin led the largest case-control study ever undertaken, funded by the NIDA in 2006. The hypothesis of the study posited that there would be a cause and effect association between cannabis and lung cancer which would be even stronger with heavier usage. The results were completely unexpected. In fact, there was absolutely no indication that cannabis use caused lung cancer. Even more surprising was the possibility that cannabis use may provide some protection for lung health.

Cannabis Reduces Opioid Overdoses (2014)

There are two schools of thought regarding the opioid epidemic:

  1. Cannabis use is a gateway drug to opioid use
  2. Cannabis provides a much safer alternative to opioid use for pain relief and may aid in avoiding or recovering from addiction

In a 2011 study, led by oncologist Dr. Donald Abrams, the results showed that cannabis use increases the efficacy of opioid drugs. This means that smaller doses of opioids may provide the same level of pain relief with fewer side effects and less likelihood of addiction.

In 2014, Marcus Bachhuber, assistant professor of medicine at the Montefiore Medical Center in New York City, published a comprehensive research study collected from data collected in 1999-2010. It showed that in legal cannabis states, there was an average reduction in opioid overdose deaths by almost 25%.

Ongoing Studies

  1. Cannabis Use For Veterans with PTSD, lead researcher, Dr. Sue Sisley, Scottsdale Research Institute
  2. CBD Controls Seizures in Both Children and Adults

Sources:, The Most Impactful Cannabis Studies of All Time, David Bienenstock, Nov. 5, 2018, Antineoplastic Activity of Cannabinoids, Sept. 1975