Several preclinical studies suggest CBD can produce beneficial effects against Parkinson’s disease, Alzheimer’s disease and multiple sclerosis. Huntington’s disease and cerebral ischemia were also tested, although significant positive results were not recorded. Further clinical studies are needed to confirm CBD’s benefits when used as a treatment for these disorders.
The results were interesting, although not entirely conclusive. On one hand, those treated with CBD did not experience much change in pain when compared with placebo patients. On the other hand, there were statistically significant differences between the group receiving the 250-milligram dose and the placebo group when measuring the average weekly improvement of their worst pain levels and their WOMAC (Western Ontario and McMaster Universities Arthritis Index) physical function rating. Additionally, men seemed to benefit from CBD more significantly than women in this test.
Preclinical and clinical studies show that CBD has antioxidant and anti-inflammatory properties. Researchers deduce these characteristics can provide significant neuroprotection, or protection against numerous pathological disorders.
8. Protect Against Neurological Disease
Arthritis involves the deterioration of the tissues in and around your joints. There are several types of arthritis, and symptoms include pain, stiffness and loss of motion. Arthritis treatment usually targets pain relief and improved joint function.
Meanwhile, at least one study in mice revealed CBD had effects similar to the antidepressant imipramine. Human trials are needed, though, to confirm whether CBD can induce this same antidepressant reaction in our bodies.
For starters, tests on human cells found that CBD helps reduce the effects of high glucose levels on other cells in the body, which typically precedes the development of diabetes and various complications. Researchers concluded that with further studies, CBD could have significant benefits when used in patients with diabetes, diabetic complications and plaque buildup in artery walls.
Three well-vetted studies provide the basis of support for the FDA’s decision. In these trials, 516 patients with Lennox-Gastaut syndrome or Dravet syndrome received either Epidiolex or a placebo. Epidiolex, when taken along with other prescribed medications, decreased the frequency of participants’ seizures compared to the placebo.
CBD is commonly used to address anxiety, and for patients who suffer through the misery of insomnia, studies suggest that CBD may help with both falling asleep and staying asleep.
CBD is readily obtainable in most parts of the United States, though its exact legal status is in flux. All 50 states have laws legalizing CBD with varying degrees of restriction, and while the federal government still considers CBD in the same class as marijuana, it doesn’t habitually enforce against it. In December 2015, the FDA eased the regulatory requirements to allow researchers to conduct CBD trials. Currently, many people obtain CBD online without a medical cannabis license. The government’s position on CBD is confusing, and depends in part on whether the CBD comes from hemp or marijuana. The legality of CBD is expected to change, as there is currently bipartisan consensus in Congress to make the hemp crop legal which would, for all intents and purposes, make CBD difficult to prohibit.
The evidence for cannabidiol health benefits
Side effects of CBD include nausea, fatigue and irritability. CBD can increase the level in your blood of the blood thinner coumadin, and it can raise levels of certain other medications in your blood by the exact same mechanism that grapefruit juice does. A significant safety concern with CBD is that it is primarily marketed and sold as a supplement, not a medication. Currently, the FDA does not regulate the safety and purity of dietary supplements. So, you cannot know for sure that the product you buy has active ingredients at the dose listed on the label. In addition, the product may contain other (unknown) elements. We also don’t know the most effective therapeutic dose of CBD for any particular medical condition.
CBD has been touted for a wide variety of health issues, but the strongest scientific evidence is for its effectiveness in treating some of the cruelest childhood epilepsy syndromes, such as Dravet syndrome and Lennox-Gastaut syndrome (LGS), which typically don’t respond to antiseizure medications. In numerous studies, CBD was able to reduce the number of seizures, and, in some cases, it was able to stop them altogether. Videos of the effects of CBD on these children and their seizures are readily available on the Internet for viewing, and they are quite striking. Recently the FDA approved the first ever cannabis-derived medicine for these conditions, Epidiolex, which contains CBD.
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All analyses were conducted in SPSS version 24 (IBM Corporation, Armonk, NY). Valid percentages are reported rather than absolute values for descriptive statistics to account for missing data. We only report data on those reporting using CBD themselves equivalent to 90% of the respondents (e.g., not for veterinary use, not those who had not tried it, and those reporting on behalf of other users). An analysis of non-responders can be found in supplementary materials. We conducted logistic regression models to investigate associations between sex (males [reference category] and females), age (recoded to < 34 years old [reference category], between 35 and 54 years old, and 55+) and location (UK [reference category], other). For CBD use patterns, we used separate models to compare those who did and did not report their primary use of CBD for self-perceived anxiety, stress, and sleep whilst controlling for sex, age, and location. We dummy-coded “time of day” as each category versus all others. We report adjusted odds ratios with 95% confidence intervals and p values with a defined cut-off of 0.05.
A cross-sectional study of 2409 cannabidiol users from the USA found that the top three medical conditions reported were chronic pain, arthritis/joint pain, and anxiety, followed by depression and insomnia (Corroon and Phillips 2018). A recent survey carried out by Wheeler et al. of 340 young adults, some of whom were CBD users, found the top reasons to be stress relief, relaxation, and sleep improvement. They found edible CBD products to be the most prevalent (Wheeler et al. 2020). Another study of 400 CBD patients in New Zealand observed an increase in overall quality of life, a decrease in perceived pain, depression, and anxiety symptoms, as well as an increase in appetite and better sleep (Gulbransen et al. 2020).
The survey demonstrated that CBD is used for a wide range of physical and mental health symptoms and improved general health and wellbeing. A majority of the sample surveyed in this study found that CBD helped their symptoms, and they often used doses below 50 mg. Out of the four most common symptoms, three were related to mental health. Self-perceived stress, anxiety, and sleep problems constitute some of society’s biggest health problems, but we lack adequate treatment options. Further research is needed into whether CBD can efficiently and safely help treat these symptoms.
The bioavailability of CBD varies by route of administration (Millar et al. 2019), but is generally low, between 10 and 31% (Millar et al. 2018). Oral routes have the lowest bioavailability due to first-pass metabolism, whilst inhaled routes have the highest bioavailability (Ohlsson et al. 1986). The bioavailability of sublingual CBD is between 13 and 19% (Mechoulam et al. 2002), and greater than the oral route, thus exerting effects at much lower doses, making it more efficient for users. Investigating plasma levels of low-dose sublingual CBD users, and correlating them to the subjective experience, might give important insights into the optimal dose for treating these low-level mental health problems like self-perceived stress, anxiety, and sleep problems.
Given the low quality of CBD available on the market, it may be that these individuals were not taking CBD, or that CBD is not efficacious in sleep, so many individuals report better sleep by virtue of the placebo effect, fuelled by marketing (Haney 2020). Another reason may be that CBD is acting on other aspects of stress and anxiety that indirectly reduce sleep problems. Still, in this survey, participants directly attributed improved sleep to CBD. This points to the need for RCTs, as the effect of expectations (i.e. the result of the placebo effect), particularly with compounds advertised as cure-alls (Haney 2020). Suggesting that the placebo effect may contribute to the purported impact of CBD does not reject the potential medical value of CBD, but it does mean we must be wary of the results of observational studies (Haney 2020).