Exploring the effect of vitamin C on sleep deprivation induced memory impairment.
Mhaidat NM, Alzoubi KH, Khabour OF, Tashtoush NH, Banihani SA, Abdul-razzak KK
|Study Model||Animal - Rat|
See how vitamin C, a potent antioxidant, can help you prevent memory loss caused by chronic lack of sleep.
In this video we are discussing a scientific research publication by Nizar M. Mhaidat et al. from Jordan University of Science and Technology, Jordan.
The full article can be accessed here: http://www.ncbi.nlm.nih.gov/pubmed/25724146
Hi everyone, this is Dr Bart Baranowski from Red Planet Nutrition. Today we are going to talk about three things: memory loss, sleep loss, and vitamin C. So, let’s go.
I think we would all agree, sleep is very important. If we go without sleep for too long, you know how you feel, you know what happens to your body. There are two stages of sleep: non-REM and Rapid Eye Movement, so REM here.
REM is very important, because this is when new memories get consolidated into long term memory in your brain, so what we know already is that as you learn more, the amount of your deep sleep increases and as you’re sleep-deprived, for whatever reason: work, studying, staying late every night, the amount of your deep sleep decreases.
The study (01:15)
In this study Nizar and the team looked at how vitamin C can help with the memory loss caused by chronic sleep deprivation.
Materials and Methods (01:29)
Let’s talk about Materials and Methods. Sleep deprivation was induced by placing test animals in a water tank. With platforms, on which these animals could relax and stay. They were, however, too small for them to fall asleep without using their muscles.
As we fall asleep our muscles relax. So what happened to these animals is that as they were falling asleep they would relax and they would have to fall asleep, fall into the water, because they couldn’t keep their muscles active. So they would awake, climb the platform again, and this cycle would repeat for 8 hours a day.
These animals, rats, are nocturnal. That means they would usually sleep during the day. In this case it wasn’t possible. OK, after six weeks of this experiment a test would be performed. This is how we understand whether they actually, whether their memory was impaired or not. So in this situation, it’s a maze, it’s a water maze. You have multiple arms filled with water and a swimming space in the middle.
So, the goal of the experiment is very simple. You are supposed to get to the goal arm with the platform on which the animal can rest. So you put a rat in any of these other arms and you give them one minute to reach the goal arm. If they succeed they have 15 seconds rest, when they can recognise the situation. There are some visual cues on walls, so that next time when experiment is repeated they can actually understand how to get to the goal arm very quickly.
Test groups (03:25)
We had 7 groups, 7 test groups in this experiment. Control group where animals could sleep and do whatever they wanted. A sleep-deprived group, where these animals were forced to be awake, because of the water platform treatment during the day. A wide platform treatment, where the platforms were big enough for them to fall asleep. That means they could sleep and that also means that we understand whether stress caused by the environment had an impact on the results.
Two other groups received vitamin C treatment without the sleep, without the sleep deprivation. That means again they get vitamin C, but they could sleep. And the most interesting groups for us are of course the sleep-deprived animals, which were treated with vitamin C. Right here, two doses, 150 mg or 500 mg per kilogram of body weight.
What did we learn from this study. When the experiment was performed the animal was given 12 chances to understand the experiment, to understand how to find the platform. In each single situation, in each single group, their performance improved over time. So the more they tried to find the goal arm, the better they became. So they actually, the numbers of errors they performed to swim to the right place improved. They got better at the task.
And I think the most important result in this study is right here. Once these 12 trials were completed scientists, so Nizar and the team tried to understand how both short- and long-term memory would be affected by this treatment. So what happened was, 30 minutes after these trials the animals were tested, then 5 hours after the treatment animals were tested again for long-term memory data.
So in this situation it’s very important that you understand that all the sleep-depirved animals had a statistically signifcant number of erros compared to any other group. What it means is that vitamin C, vitamin C treated animals performed as well as a control group, which could sleep as much as they wished to.
What that means is, even though they were sleep-deprived for over 6 weeks thanks to the vitamin C treatment they performed as well as the control group. All the other animals which were sleep deprived and didn’t get the treatment, they made way more mistakes in this situation. So that’s very, very exciting data showing how sleep deprivation-induced memory impairment can be prevented simply by supplementing with vitamin C, this very potent antioxidant.
Scientists wouldn’t be scientists if they didn’t try to understand what is the mechanism responsible for this situation. So the team, Nizar and the team looked at a number of molecules, namely glutathione, superoxide dismutase, and catalase. They all are important and play role in our oxidative stress regulation system in hippocampus.
So, as you can see here oxidized glutathione known as GSSG, the levels of this oxidized glutathione are way higher in the sleep-deprived group compared to other groups. Again, I will highlight here, that means that vitamin C treated animals performed again, had the same levels as glutathione, oxidised glutathione as control groups.
Of course, these are very simplified graphs. For full data set please follow the link below in the description and read the full article. The situation was the opposite for a cathalase and SOD, so superoxide dismutase. Again, this is important, it’s not important whether these levels go up or down in this situation, but how they look compared to the control group.
In this situation the sleep deprived group had way lower levels of both SOD and catalase, in the sleep deprived groups. And of course we need to highlight here that vitamin C treated animals performed as well as the control group. So no statistically significant difference between these groups.
It’s time for the discussion, it’s time for the take home message. And what it actually meands for us. First of all, vitamin C is a potent antioxidant, which in this situation prevented memory impairment caused by chronic sleep deprivation in these animals.
The second point is that this situation showed us that sleep loss, sleep deprivation was much more important than stress caused by the fact that these animals were in a stressful situation, like platforms above water level, because when these platforms were slightly wider and they could fall asleep, they didn’t have any memory problems unlike the sleep-deprived group with narrower platforms, where they were falling into the water.
And the third point to remember here is that antoxidant can reduce the oxidative stress in our brain, caused by reactive oxygen species. So that’s important in a number of situations and it has been shown in a number of cases, that once these levels of oxidative stress are elevated, this occurs in Alzheimer’s, ageing and in other diseases. And it seems to occur also in case of sleep deprivation.
So, when you supplement your diet, or you have a good diet full of antioxidants, full of vitamin C, you help yourself preventing memory loss caused by lack of sleep. What does it really mean? It means that if you study all night, for a long time, if you work all night, for a long time, or if you think you sleep well, but actually you don’t because you don’t get this phase of long sleep. Your memory will be much worse and you should consider getting a good vitamin C supplement to counteract this effect and get you back to the normal level.