The active ingredient in marijuana can improve the memories of Alzheimer's patients, suggesting preliminary results of a study on mice.
Mice treated with THC, the psychoactive compound found in weed, saw a 20% reduction in the brain plaques associated with Alzheimer's.
These animals also showed behavioral signs that their memories were better than those of mice with Alzheimer's who had not been treated with THC in the preliminary results of a German study presented at the Society for Neuroscience conference this week.
Paradoxically, marijuana actually alters memory and learning in animals (and people) that do not have debilitating memory sickness.
The active ingredient in marijuana, THC, alters memory and learning in healthy brains, but can fight the development of Alzheimer's plaques and protect cognition in diseased brains
Now that marijuana is legal for medical or recreational use in more than half of the US states, the drug is not used only by larger studies.
Historically, it has been seen by some as a healing herb, and for others as a harmful drug.
So far, our scientific study of the effects of marijuana has shown that they are split (but not as extreme) as older and less evidence-based opinions.
Cannabis can really relieve pain, but it is not a cure.
And it can really create feelings of paranoia and anxiety – but they are not permanent.
Now, new research suggests that marijuana could be bad for more memory – but good for the memories of those with the worst dementia.
A new study in mice suggests that THC – the same ingredient that gives users the feeling of "high" and inhibits learning and memory – can reduce the effects of Alzheimer's.
Dr. Yvonne Bouter and her team at the University Medical Center in Goettingen, Germany, began treating a group of mice with THC for six weeks.
Both the group and the study control group were raised to develop Alzheimer's.
And they did – but the disease greatly reduced the brain damage of the THC-treated mice.
Alzheimer's is characterized by disorders of memory and confusion in terms of behavior.
Physiologically, a substance called beta amyloid accumulates on the brains of extraordinary Alzheimer's patients. It is thought that these so-called plaques interfere with the function of brain cells and are considered the classic signal of the disease.
Scientists also noted that Alzheimer's patients lose their brain mass and think that chronic inflammation can contribute to the development of dementia.
With all these measures, the mice that took THC were more fit.
Their brain had 20% less beta amyloid plaques and showed fewer signs of inflammatory damage.
The mice that obtained THC also achieved better results in their memory tests.
The success of these experiments suggests that marijuana may be useful for the treatment of Alzheimer's in humans.
But we have no idea how therapy works.
However, it is not the first study to link THC and Alzheimer's.
A 2014 study suggests that the brain cannabis receptor system – the endocannabinoid system – may play a role in Alzheimer's.
A key substance in the development of Alzheimer's plaque is called A-beta, but it has not always been clear exactly how it damages the memory networks of the brain.
Endocannabinoids draw the attention of the brain to new important information that needs attention. But only some A-beta can dull endocannabinoid receptors.
Endocannabinoids are used by important brain cells of plasticity, so when endocannabinoids are out of use, plasticity is reduced.
After their study in 2014, Stanford researchers did not think that THC or marijuana had many promises for the treatment of Alzheimer's disease.
They said that marijuana "floods" the endocannabinoid system with THC, which means that it does not know what to watch out for, while the small and fast explosions the brain receives from endocannabinoid receptors keep the mind focused on important information.
"The endocannabinoids in the brain are very transient and only act when important inputs enter", said Dr. Daniel Madison, author of the 2014 study, in a statement.
"The exposure to marijuana in minutes or hours is different: more like indiscriminately improving everything, so you lose the filtering effect. It's like listening to five radio stations at the same time. "
It is not clear what dose of THC the German scientists have given to the mice studied, but it could shed light on how marijuana can be manipulated to improve the symptoms of Alzheimer's.