The human brain is mostly water if I remember correctly, with lots and lots of nervous tissue. That sounds funny doesn't it......tissue that could be nervous...ah science humor. There is fatty tissue, too, as well as specialized cells that keep the organ functioning.
There are many reasons that are thought to contribute to brain shrinkage .....normal aging first and foremost.....chronic back pain is thought to bring about brain size reduction, as well as alcohol, Internet addiction, lack of sunlight, sleeplessness, and people not getting enough vitamin B 12.....that might be people who have a vegetable heavy diet and don't get this vitamin in their food or with supplementation.
Is this a trick question?
