To function at its peak, our brain needs a lot of oxygen – in fact, it uses approximately 20% of ALL our body’s oxygen consumption, pretty hefty for an organ that only takes up 2% (depending on our body weight) of our whole body mass.
Back in January I wrote The Brain is a Calorie Burner explaining how the brain burns 25% of our calories while weighing only around 2% (depending on our body weight) of our body weight.
Now I find out that the brain also sucks up a disproportionate amount of the oxygen we take in, too. Is this an amazing organ, or what?
According to Becoming Smarter, “This is precisely why the brain starts to lose its effectiveness very quickly the moment our oxygen intake goes down – we start to feel sleepy, lazy and un-alert. This is the main reason we feel sleepy after big meals, as our digestive system uses up a larger amount of oxygen to digest the food that we have eaten.”
The website goes on to suggest that by eating a lot of smaller meals each day instead of three bigger ones, you can combat the after-meal letdown. Clearly, there are logistical problems for most people, like the ones who have jobs, to do this.
Supposedly the 7 meal a day plan is one used by body builders to lose weight as there is no excess fat as the energy is used up after each meal.
Presumably our regular readers are too intelligent to smoke which is why John and I haven’t bothered to mention smoking in our 13 months of blogging. If you do smoke, however, you are actually decreasing the amount of oxygen that goes to your brain as it is diluted by the other gases that you inhaled with the smoke. As if you needed another reason not to smoke!
Finally, truly last but not least, exercise increases blood flow and oxygen to the brain. As I wrote in Exercise, Aging and the Brain back in February, modest exercise reversed normal brain shrinkage in older adults and improved their memory function.