The National Academy of Science of the USA Analyses the Consequences of Cannabis on Health

The National Academies of Sciences, Engineering, and Medicine was founded more than 150 years ago. It is a private, non-profit organisation whose main objective is to provide reliable and verified information to the public about the state, progress and findings made in different areas of science, engineering and medicine.

One of the issues that are right now on the table, not just for the US government, but for many others, is the so-called "drug war." Cannabis is one of the most commonly consumed drugs around the world, however, the long-term consequences of its use are not yet clear. In 1999, the White House instructed the academy to conduct a systematic review of all scientific studies related to the health risks of cannabis use. Nearly two decades later, this organization has presented its conclusions on the subject. With this report, the National Academies of Sciences, Engineering, and Medicine has shed some light on this issue by providing information on possible health risks in relation to some diseases, as well as highlighting those areas on which further research may be needed.

A valuable document that can help us clarify some doubts and that above all offers scientific and documented information. The committee that has produced this report has selected 100 out of the 10,000 existing studies on this topic and has classified them according to 5 criteria of evidence: conclusive, substantial, moderate, limited and insufficient. Would you like to take a look at this report? Let's go for it!

What therapeutic uses of cannabis can be considered feasible by conclusive evidence?

According to the committee there are three applications of cannabis for therapeutic use that can be considered to have been supported by conclusive evidence. According to this report, cannabis is beneficial for the treatment of:

1. Nausea and vomiting associated with chemotherapy treatments
2. Chronic pain in adults
3. Spasticity due to sclerosis

According to this report, there is moderate evidence that cannabis or cannabinoids are effective in:

• Improving sleep quality in the short-term in individuals with sleep disorders associated with obstructive apnea
• The treatment of chronic pain and multiple sclerosis

Likewise, the committee has also determined that there is limited evidence that cannabis or cannabinoids are effective in:

• Increasing appetite and decreasing weight loss associated with HIV/AIDS
• Alleviating the spasticity symptoms of multiple sclerosis
• Alleviating the symptoms of Tourette's syndrome
• Alleviating the symptoms of anxiety
• Alleviating the symptoms of post-traumatic stress disorder

There is limited evidence of a statistical association between cannabinoids and:

 Obtaining better results by applying a treatment based on cannabis or cannabinoids after a traumatic brain injury or intracranial haemorrhage.

The document states that there is little evidence that cannabis or cannabinoids are ineffective for:

• Alleviating the symptoms associated with dementia.
• Alleviating the intraocular pressure associated with glaucoma.
• Reducing the symptoms of depression in individuals with chronic pain or multiple sclerosis.

The use of cannabis related to cardiometabolic risk

Cannabis use has been linked to an increase in cardiometabolic risk (possibility that a person may have type 2 diabetes or cardiovascular disease), as the interaction of THC with the CB1 receptors in the brain could lead to an increase in blood pressure. In this regard the report specifies that there is no clear evidence linking cannabis use with heart attacks, strokes or diabetes. The report does not rule out the possibility that such risk exists; in this sense, it seems that further research is needed in this field.

Cannabis and the respiratory system

According to this report, consuming marijuana through combustion, i.e. smoking, is associated with chronic cough and the production of phlegm. The committee determines that there is not enough conclusive evidence to determine that cannabis use causes other respiratory problems and /or diseases.

Cannabis and the Immune System

At this point it must be said that there is a large number of studies that claim that cannabis can have many beneficial effects on the immune system. Despite all this multitude of studies, the committee has only focused on studies in which a clinical trial has been conducted in humans. Let us recall that due to the legislative framework that surrounds cannabis, especially in the United States where cannabis is considered at a federal level a Schedule I drug (the same category as heroin), carrying out trials on humans can be enormously complicated.

These are some of the conclusions provided by the study:

• There is not enough data to determine how cannabis therapies affect the immune system.
• There is not enough data to determine how cannabis use affects the immune system.
• There is limited evidence to suggest that exposure to cannabis smoke has anti-inflammatory effects.
• There is insufficient evidence to determine that cannabis use causes adverse effects on the immune system of HIV patients.

Cannabis and Addiction

The eternal debate, is marijuana really addictive? In this sense, the report says that frequent use of cannabis from an early age is associated with the development of addiction to this substance.

Risk of accidents and cannabis

• Cannabis use before driving increases the risk of a car accident.
• In those US states where cannabis is legal, there has been an increase of accidental overdose of cannabis in children.
• There is no clear relationship between cannabis use and mortality or injuries in the workplace.

Cannabis and Mental Illness

The relationship between cannabis use and the development of mental illnesses has been widely discussed and investigated. It is difficult to establish a clear relation on this because when a psychiatric illness appears or is aggravated, there are several factors to take into account, both social and personal. However, the committee states in its report that:

• Cannabis can increase the risk of suffering schizophrenia (at this point it is very important to take into account the genetic predisposition of the individual, since cannabis can act as a trigger in those people who are predisposed to suffer from this disease).
• There is no conclusive evidence to determine that cannabis use increases the likelihood of depression or anxiety.
• Cannabis users who abuse this substance are more likely to have suicidal thoughts.
• Frequent and prolonged use of cannabis may increase the risk of social anxiety disorders.

The relationship between cannabis and psychological problems is very complex and needs a detailed study of each case to analyse what the situation of the individuals is and what causes have influenced in the development of their disease.

At first glance, these conclusions are somewhat contradictory, the truth is that the relationship between cannabis and psychological problems is very complex and needs a detailed study of each case to analyse what the situation of the individuals is and what causes have influenced in the development of their disease.

We have extracted some of the most relevant points that this 400-page study deals with. The committee's findings seem to be that much more research is needed to determine how cannabis affects our health and what potential benefits we get from marijuana. In our opinion, one of the major shortcomings of this report is that it is based only on scientific studies done in humans, whereas there are many studies with cannabinoids that have not been able to pass to the clinical trial phase with people. If you are curious and want to read the full document and get steeped in, you can do so by following this link.