Rewire Your Brain: Think Your Way to a Better Life

particularly problematic, at least for men. Researchers have found 
that for men over sixty, the greater the waist circumference is, the 
smaller the hippocampus is. Since the hippocampus is critical for 
laying down memories, the inference here is that increased body fat 
correlates with decreased memory capacity. 
A twenty - four - year longitudinal study found that people with a 
higher body mass index (BMI) had a higher degree of atrophy of the 
brain. The degree of brain atrophy was 13 to 16 percent for every 
one - point increase in BMI. 
In an extensive study done by Kaiser Permanente, researchers 
examined more than ten thousand people who had been diagnosed 
with dementia to determine the relationship between BMI and 
dementia. They had been followed for twenty - seven years and were 
evaluated for skin - fold thickness and BMI. The results of the study 
indicated that men who had the highest skin - fold category at middle 
age had a 72 percent rate of dementia, whereas women in the same 
category had a 60 percent rate of dementia. 
You can delay or prevent dementia by the following: 
•
Exercising
•
Taking up a hobby, especially something creative like painting, 
ceramics, or gardening
•
Taking a class at the local college or adult education center
•
Increasing your social contacts and involvements, such as by 
joining a club or a social organization
•
Eating a balanced diet
•
Playing games or doing puzzles that are intellectually demand-
ing, such as chess, crossword puzzles, or bridge
•
Volunteering
•
Spending time with young people
•
Traveling
•
Varying your routines
c08.indd 177
c08.indd 177
1/29/10 10:20:11 AM
1/29/10 10:20:11 AM

---

178 Rew i r e
Yo u r
B r a i n
Physical exercise can slow cognitive decline and decrease the risk 
for dementia. For example, a Harvard University study has shown 
that simple walking is associated with signifi cantly better cognitive 
function and the prevention of cognitive decline in older women. 
A University of Virginia study found that walking had the same 
effect in older men. Men who walked the least had almost double 
the risk of dementia, compared to those who walked more than two 
miles per day. 
You can also minimize excessive stress as you age by exercising. 
In addition to being vulnerable to cortisol, the hippocampus can 
decrease in size based on the amount of oxygen it receives. Referred 
to as
anoxia
, a reduction of oxygen accompanies a decrease in the 
health and integrity of the capillaries. This decrease results in less 
oxygen going to the vulnerable hippocampus. Exercise is a great 
stress reliever and it boosts BDNF, especially in the hippocampus. 
The neural networks that were the last to develop are the ones that 
are most vulnerable to aging. Most neuroscientists view the brain as 
aging from the front to the back. Thus, defi cits appear fi rst in the 
frontal lobe as well as in the hippocampus. A typical senior experi-
ences symptoms that refl ect frontal lobe defi cits, including working 
memory (such as forgetting where you put your keys), and hippocam-
pal defi cits (such as forgetting what you did yesterday). The PFC is 
the last area of the brain to mature, so it is the fi rst area to decline. 
Other research shows that age - related defi cits also occur from 
right to left, which means that the right hemisphere begins to lose 
functions before the left. You will recall that the right hemisphere is 
involved in spatial perception and dealing with novelty, whereas the 
left is involved in language and routine behaviors. Some symptoms 
of right - hemisphere defi cits are less visual spatial perception and 
less ability to learn new tasks. This means that you will probably 
forget the directions to the furniture store before you forget the 
name of the store.