Scientists Say Melatonin Can Prevent Cognitive Decline
Scientists finally found a supplement that
can actually help protect the memory, and it turns out that it was
hiding in plain sight all along. The supplement in question is
melatonin, the very same so many people take every night to improve
their sleep. It turns out that the supplement can protect the brain from
cognitive decline according to researchers from Tokyo Medical and
Dental University (TMDU).
The research regarding melatonin’s
memory-boosting potential was published in the Journal of Pineal
Research in October of 2020. The study in question was led by Atsuhiko
Hattori at TMDU in Japan, and it suggests that melatonin and two of its
metabolites have a profound impact - they help the brain hang onto
memories - which means that it can potentially protect patients from
cognitive decline.
Now, the study was conducted on an animal
model, namely mice, but the researchers are confident that future human
trials will showcase that the same is true for the human brain. The
study was conducted by comparing the formation of long-term memory in
young, middle-aged, and older mice.
The Study Explained
The simplest way to test memory in mice is by letting the rodents
examine unfamiliar objects. Mice have a natural propensity towards
inspecting new objects, and not unlike humans, they are always more
curious about the new thing than they are about familiar objects. The
catch is that, in order for an object to be familiar, it needs to be
remembered. And young mice are exceptionally apt at recognizing familiar
objects: showing an object 3 times a day is usually enough for them to
remember it the next day.
Older mice, on the other hand, often have difficulties remembering
familiar objects, which is considered a sign of cognitive decline. When
given the same task, the waning memory of older mice becomes apparent,
as they spend just as much time examining familiar objects as they do
checking out new items, as if both objects were new to them. This is the
point in the study that the researchers introduced half of all the mice
across all age groups to melatonin and 2 of its metabolites - the
substances that form when melatonin is broken down by the body.
As Hattori explains, “We know that
melatonin is converted into N1-acetyl-N2-formyl-5-methoxykynuramine
(AFMK) and N1-acetyl-5-methoxykynuramine (AMK) in the brain, and we
suspected that they might promote cognition”.
The Results
After just 4 days of observation, the researchers noticed that the
memory of all mice improved dramatically. The melatonin metabolite AMK
was found to be the most effective. The researchers also pointed out
that melatonin and its metabolites were all accumulated in the
hippocampus, a brain region that is responsible for turning everyday
experiences into long-term memories.
The findings in the older mice are the most exciting - only 1 dose of
AMK administered after a lone exposure to new items helped them remember
the objects even 4 days later. As the lead author pointed out, “Its
effect on older mice is particularly encouraging and we are hopeful that
future studies will show similar effects in older people. If this
happens, AMK therapy could eventually be used to reduce the severity of
Mild Cognitive Impairment and its potential conversion to Alzheimer’s
disease.”
If the study will be successfully replicated in humans, this could mean
that an AMK or melatonin supplement can be taken as a preventative
measure against cognitive decline, dementia, and Alzheimer’s. Stick
around for any further news on the topic, we will keep you posted.