Researchers find association with cannabis and cataracts

Cannabis consumers who had used the drug 11 to 100 times or more were four to five years younger “when they developed cataracts than subjects who never used cannabis.”

Researchers were not surprised by their recent findings, but argue added study is needed to determine if cannabis smoking, like cigarette smoking, is a risk factor for developing cataracts.

“Like tobacco smoke, cannabis smoke contains thousands of organic and inorganic chemical compounds,” U.S. investigators write in the study, published on Jan. 31 in the Journal Français d’Ophtalmologie.

In the new study, the authors point out that cannabis tar is chemically similar to tobacco smoke tar. That, coupled with the fact that more than 50 known carcinogens have been identified in cannabis tar, means “the association of cannabis with cataracts that we report here is not entirely surprising.”

To get a firmer grasp of the association, if any, researchers at the Icahn School of Medicine at Mount Sinai and at Severn Health Solutions analyzed data from the U.K. Biobank, a large-scale biomedical database and research resource, containing genetic and health information from half a million U.K. participants.

All subjects had cataracts and their tobacco/cannabis habits were known. Those who had ever smoked cannabis were included as part of the study group.

As for current smokers, investigators note cigarette smoking was significantly associated with the odds of developing cataracts while cannabis use was not.

Given the findings, “further studies are warranted.”

Research, published last year in the journal Nature Structural and Molecular Biology, concluded the protein solution present within the eye plays a key factor in the characteristic clouding of the lens felt by those with cataracts.

“When the balance of the proteins in the lens is destroyed, they clump together and the lens becomes cloudy,” explained Johannes Buchner, one of the study’s authors and chair of Biotechnology at the Technical University of Munich.

Cannabis has actually been suggested as a treatment for certain eye conditions, including glaucoma.

The National Center for Biotechnology Information reports that “both marijuana and THC reduce intraocular pressure, a key contributor to glaucoma.” However, “conventional therapies for intraocular pressure outperform cannabinoids, and the next generation of glaucoma drugs is expected to treat the disease more directly or even reverse its progress.”

With regard to cataracts, health care technology company Veriheal notes that while there is “no conclusive evidence that medical cannabis can adequately treat cataracts, it has proven to reduce  inflammation,  which is apparent in the condition.”

According to All About Vision, an eye health and vision correction resource for consumers, study findings to date indicate that being high on cannabis can help with glaucoma for a few hours, but not longer-term.

As for cataracts, “There’s no scientific proof that either marijuana or CBD help with cataracts,” the company reports.