Published on: May 8, 2020
by Women’s Brain Health Initiative:
Use of cannabis by young people up to 25 years of age is discouraged because it can have detrimental effects on their developing brains. But, what is the impact of using cannabis for adults, particularly older adults? This is an important question because more and more older adults are using medical or recreational cannabis.
Older adults can be drawn to using cannabis in an attempt to alleviate various age-related symptoms and diseases that are not adequately controlled with other available treatment options, and now, because of changes in the legality of cannabis in some places such as Canada, it is easier to access cannabis than ever before.
Cannabis is a flowering plant that has been used for thousands of years for its medicinal effects. Its phytochemical contents can vary widely, but the two most commonly-studied components are THC (tetrahydrocannabinol) and CBD (cannabidiol).
THC is responsible for the psychoactive effects, or the “high,” while CBD produces a physical effect without the “high”; in fact, CBD is thought to dampen down or offset the psychoactive effects of THC. Many medical uses of cannabis are CBD-oriented. Labels on legal cannabis describe the amounts of each of these two components.
Research suggests that older adults may benefit from cannabis treatment for a variety of common age-related symptoms, including chronic pain, trouble sleeping, and poor appetite.
Cannabis may also help with some aspects of dementia. However, the research available on cannabis for older populations is very limited at this point in time, and the conclusions are not always consistent. Use of medical cannabis by older adults is on the rise, with prevalence rates estimated to range from 7% to more than one-third, depending on the country.
Late-life cannabis use may (or may not) improve cognition
One recent systematic review conducted by Dr. Emmi Scott and colleagues examined the findings from 26 studies about the neurocognitive effects of medical or recreational cannabis use by older adults, some healthy and some with neurocognitive disorders, including dementia and Parkinson’s disease. They found that with higher doses and heavier lifetime use, generally modest reductions in cognitive performance were detected.
The researchers noted, though, that variation in the cannabis product used, the outcomes measured, and the quality of the research studies limited the conclusions that they could make. And, they emphasized the need for more high-quality research on this subject. These findings were published in October 2019 in Current Addiction Reports.
However, another recent review conducted by Dr. Galit Weinstein and Dr. Sharon Sznitman, and published in May 2020 in Ageing Research Reviews, reached a somewhat different conclusion. These researchers also noted that evidence on late-life cannabis use and cognitive health is limited, and that more research is needed.
But, after reviewing available animal and human studies on the subject, they concluded that cannabis use in old age may not be linked with poorer cognitive function and may, in fact, be associated with improved brain health.
“There is definitely a big gap in the current knowledge about late-life cannabis use and cognitive health, but the limited evidence available on this important topic suggests that the known detrimental effects of early-life cannabis use may not translate to use in older ages,” said Dr. Weinstein, Associate Professor of Neuroepidemiology at the University of Haifa School of Public Health in Israel.
“Cannabis use in older age looks like it might be neuroprotective, although firm conclusions cannot be reached at this point.”
Cannabis may help with some dementia symptoms
While there is currently no research that proves cannabis or cannabis-based products can prevent, stop, slow, or reverse dementia, there is some evidence that suggests cannabis can help with managing some of the symptoms of dementia, including the particularly challenging behavioural and psychological symptoms of dementia (BPSD). This is good news because the current pharmaceutical options for addressing BPSD have limited effectiveness and can have significant side effects that often outweigh their benefits.
Again, there is some inconsistency in the findings to date, though. For example:
These researchers found that overall the evidence about the efficacy of cannabinoids on agitation and aggression in patients with AD was inconclusive, and warned that any usage should be closely monitored to ensure safety because cannabinoid treatment was associated with increased sedation.
“Although the overall quality of the studies we analyzed was low, we concluded that there is preliminary evidence for the efficacy and tolerability of cannabinoids as treatments for the neuropsychiatric symptoms of dementia,” explained Dr. Bahji, a resident in the Department of Psychiatry at Queen’s University School of Medicine in Canada. “More research is needed to determine the real-world effectiveness, but cannabinoids show promise as a potential treatment for NPS.” These findings were published in December 2019 in The Canadian Journal of Psychiatry.
Why are the findings inconsistent?
Research conducted to date is quite limited, and differences in research design and quality may be contributing to the inconsistent findings.
For starters, “cannabis” is not a single substance; rather, it consists of hundreds of phytochemicals, some of which are cannabinoids and others that are not. The amounts of each phytochemical can vary across strains of the plant, and across batches of strains. Many factors influence the concentration of phytochemicals in a cannabis plant, including nutrition, humidity, temperature, the age of the plant, when it was harvested, and how it was stored.
Additionally, the effects will vary depending on whether the whole cannabis plant is used, or just an individual component or combination of components, and whether those components are naturally derived or synthetically produced.
There are even more variables that affect how an individual responds to cannabis or cannabinoid use, including the dose, how it is consumed, and differences in individual physiology.
More research is needed
While much of the research to date is promising, it is also inconclusive. More research is required in order to flesh out what cannabis “product” – at what dose and frequency – is best for which people, with what symptoms or conditions (if any).
As additional studies are being conducted, researchers should be sure to consider the potentially unique effects on different populations.
For example, older adults may need to take special caution in using cannabis because of other drugs that they already take, differences in how drugs are absorbed, metabolized, and eliminated in old age, or increased cardiovascular risk.
Sex and gender differences should be considered, too. “As with all substances, there is a wide range of sex- and gender-related factors that influence how substances are consumed, and their physical, mental, and social impacts,” said Dr. Lorraine Greaves, clinical professor at the University of British Columbia and senior investigator with the Centre of Excellence for Women’s Health in Canada.
“In particular, females are more affected by cannabis, in lower amounts, than males. Women often ‘telescope’ to dependence much faster than men.”
“Sex-related factors include the biological, physiological, anatomical, and genetic differences that impact how cannabis affects female versus male bodies, while gender-related factors include the effects of gender norms, relations, and identity,” continued Dr. Greaves.
“Men, for example, use cannabis more often and in larger amounts, and are more likely to smoke it. All research on cannabis should take sex and gender into account, analyze data accordingly, and report on it so that more precise recommendations can be made for men and women, but this is an area that needs considerably more attention and growth.”
In the meantime, should you or a loved one try cannabis?
Because of the promising findings to date, people might be tempted to investigate cannabis for dementia or other common symptoms of older age, without waiting for further research.
If you find yourself wanting to explore the potential therapeutic benefits of cannabis for yourself or a loved one, and you live in a place where medical cannabis is legal, it is best that you seek out the advice of a cannabis prescriber and/or a health professional in your area. Do not just purchase and use recreational cannabis, even if it is legal.
A health professional should provide you with a personalized prescription and monitor your response to the treatment.
A research paper published in November 2019 in Journal of Clinical Medicine provides doctors with a suggested treatment protocol for medical cannabis specifically for older adults. The researchers’ recommendations provide an idea of what you might expect if you get a prescription for medical cannabis. They advise that medical cannabis should be considered carefully and individually for each patient after a risk-benefit analysis, and followed by frequent monitoring for efficacy and adverse events.
“It’s important to note that cannabis treatment is not suitable for all patients and should only be used after other evidence-based treatments have failed,” explained Dr. Ran Abuhasira, lead author of the study, and a doctor at Soroka University Medical Center and Ben-Gurion University of the Negev in Israel. “While there are no absolute contraindications for cannabis treatment in the geriatric population, doctors must consider the potential risks of treatment. In particular, we suggest avoiding cannabis treatment if someone has severe cardiovascular disease, an existing psychotic disorder, or a history of addiction. Caution is also needed for patients with gait instability, nervous system impairment, polypharmacy, or reduced drug elimination mechanisms.”
“The preferred method of administration of medical cannabis for older adults is sublingual – oil placed under the tongue. Smoking cannabis should be avoided because of the negative impact on lung and respiratory function,” Dr. Abuhasira continued. “Most importantly, we recommend starting with a low dosage, raising it slowly if necessary, and keeping it as low as possible.”
Synergy might be key
Some researchers have found an “entourage effect” with cannabis, where it seems to work better in certain instances when it is administered as a whole-plant extract, rather than as an isolated phytochemical part(s).
Source: MIND OVER MATTER V10
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