It is New Year’s day today, and instead of nursing a hangover as I have in so many New Year days of past, I have been up and about for ages, just taken my daughter to the movies, gone out for lunch, and now I’m writing this blog.
A memory about NYE came back to me yesterday: about 10 years ago (give or take) I missed midnight on NYE because I was passed out. Naked. In the bath of a person’s house that I didn’t really know that well. I guess I had been trying to take a bath (either that or I just want to get naked when I’m blackout drunk?). And because the toilet was located in said bathroom, many people (apparently) saw me lying naked in the bath, one of whom was kind enough to tell my (now) husband, who picked me up and put me in one of the beds at whatever house I was at. I then woke up at around 1am with no idea where I was, and no-one around to tell me because they’d gone to watch the fireworks. That was scary, confusing, and took me a long time to recover from. Yeah, a sober NYE is certainly preferable!
*Warning Sciencey bit*
That aside, one topic I thought would be particularly well suited to a post on New Year’s day is that of neurogenesis – the process by which (two very specific parts of) the brain produces new brain cells. It is something I have touched on in previous blog posts, but have never really explored in detail before.
The discovery of neurogenesis a couple of decades ago was, at the time, contrary to the long-held belief that the number of brain cells we have is fixed for life. Since then, there has been an explosion of research into what the purpose/consequence of these new neurons is, how to increase neurogenesis, and what processes decrease neurogenesis. It is a fascinating field. I should also mention that it is a somewhat controversial field – some research groups have cast doubt on whether neurogenesis even occurs in humans, whereas others strongly suggest that it does. My personal view is that it more likely occurs than doesn’t, but can be difficult to detect in certain studies for particular reasons. I could be wrong of course. It has happened once before (but let us never talk of that dark time). In any case, neurogenesis is certainly robust in other mammalian species, with a lot of what we know about it coming from rodent studies.
*End Sciencey bit*
Alcohol and Neurogenesis
There’s so much I could say about neurogenesis, but to stay on topic for today I will stick to two aspects of it: how it is affected by alcohol, and what that might mean for the individual with alcohol use disorder in recovery (i.e. me).
*Warning Sciencey bit*
New neurons arise from neural stem cells, a kind of embryonic cell that, under the right circumstances, can become a neuron. Fetal alcohol syndrome occurs when alcohol consumed by a pregnant woman affects the neural stem cells in the developing foetus. Likewise, in adults, consumption of alcohol interferes with this process via multiple mechanisms. In the adult human, it is difficult to say what exactly the consequences of this is, but certainly neurogenesis has been shown to be critical for learning, memory, regulation of mood, and decision-making. All of these things are also, of course, affected in alcohol use disorder. This does not necessarily mean that alcohol’s effect on neurogenesis alone is what underlies impairments in learning, memory, mood, and so on in AUD, but it likely plays a role.
*End Sciencey bit*
New Year’s Neurogenesis
But I’m not here to bring you gloomy news on this New Year’s day. This is a day about new beginnings. No doubt, some people will be making resolutions today; perhaps to give up alcohol for a month, a year, or for life, and other people will be resolving to eat more healthily or do more exercise. Well the great news for your brain is that ALL of these things are likely to lead to an increase in neurogenesis. Aerobic exercise, in particular, sports (pun intended) a wealth of evidence across a number of species (including humans) that it enhances the birth of new neurons in our brains. This is often cited as the reason why exercise improves mood, as well as learning and memory. Interestingly, neurogenesis has also been linked to forgetting. Although this seems contradictory to its role in learning and memory at first, forgetting is in fact a crucial function of the brain, allowing for the constant turnover and categorising of information; prioritising what it is we need to remember, and letting go of what we don’t. Moreover, my suspicion is that the role of new neurons in our brains in forgetting is what also helps to elevate mood, by encouraging forgetting of negative events and emotions, thus decreasing rumination over these events (which is heavily linked to depression) and allowing us to move on.
2019 and Beyond
So I hope that this information can provide a little extra motivation for those of you aiming to drink less, quit drinking, start eating healthily, and/or do more exercise. As for myself, I have already quit drinking and I already do a lot of exercise, but I certainly could do with eating a little more healthily. However, I have talked about the fact that I have had an eating disorder in the past, and have a tendency to become a little obsessive if I try to eat healthily. Therefore, my new year’s resolution this year is simply to try and be more mindful about what I eat, thinking about the taste and texture of each bite, and being guided by my hunger rather than just eating out of habit. Not sure if I’ll succeed, but if I don’t I won’t beat myself up. After all, each day is a new day, not just New Year’s day :).