Brain Power Repair for
Alzheimer's
So what happens in the brain
of an Alzheimer’s patient? On a physical level, it appears that nerves in the Alzheimer’s
brain die, severing important links between two sections of the brain (the
forebrain and hippocampus) responsible for thinking and memory. These nerves
become encrusted with protein deposits which turn them into dysfunctional
tangled masses of abnormal fibers. These “neurofibrillary tangles” occur most
often in the hippocampus, the brain’s memory center.
Brain autopsies of
Alzheimer’s patients also show strange plaques and lesions, which are clots of
dead cellular material. Innumerable brain cells wither and die in the
Alzheimer’s brain as their dendrites (the multiple branching connections
between nerve cells) disappear. There also can be up to a 90% decline in the
levels of an important brain chemical called acetylcholine, considered to be the
prime molecular carrier of memory.
Scientists have a somewhat
better idea as to what causes Alzheimer’s than they do about its treatment. For
one, there might be a genetic factor. It appears that individuals with two
particular genes (called ApoE-4) are eight times more likely to develop
Alzheimer’s than those who don’t have them.
For another, there is a
heart factor. A newly identified high-risk population group is people who have
some degree of pre-existing vascular disease. A lack of oxygen to the brain is
strongly linked with the typical Alzheimer’s symptoms. Brain autopsies of
people with Alzheimer’s have shown they tend to have had a much higher
incidence of strokes, says Dr. Khalsa.
Another consideration is
this: does the patient really have Alzheimer’s? Several other clinical and
treatable conditions can mimic the primary symptoms of Alzheimer’s and must be
ruled out before the diagnosis is valid, Dr. Khalsa explains.
For example, it’s estimated
that 20% of suspected Alzheimer’s patients actually are suffering the effects
of multiple minor strokes; another 20% are reaping the negative results of
“lifestyle errors” (substandard nutrition, excessive alcohol intake,
recreational drug use), and another 10% have clinical depression. Symptoms of
cognitive impairment can also be produced by chronic food allergies, exposure
to environmental chemicals (lead, arsenic, aluminum), and mercury toxicity
(from dental amalgams).
Of the suspected causes of
Alzheimer’s and its precursor, age-associated memory impairment, one factor is
gaining ever stronger emphasis: “a lifetime of chronic, unrelenting stress,”
says Dr. Khalsa. Stress is blamed for so many medical conditions, it sounds
almost trivial to link it with Alzheimer’s, but there is a demonstrable
hormonal basis.
This stress excess releases
inordinate amounts of cortisol, a hormone produced by the adrenal glands. Cortisol is naturally released by the adrenal
glands in response to stress. In moderate amounts, it’s not harmful. But the
brain’s chronic exposure to toxic levels of cortisol, due to daily stress,
injures, even kills, brain cells “by the billions,” says Dr. Khalsa. “I believe
that cortisol toxicity is one of the primary causes
of Alzheimer’s.”
Clinical studies show that
cortisol damages the nerve cells of the hippocampus and blocks their ability to
absorb blood sugar (glucose), the brain’s sole
nutrient. Brain scans of Alzheimer’s patients show that their temporal lobe
(site of the hippocampus) and frontal lobe both have a decreased capacity to
absorb glucose. Cortisol blocks the delivery of glucose to the mitochondria,
the “energy factories” of all cells.
Cortisol also impedes the
smooth functioning of the brain’s messenger chemicals called neurotransmitters.
Information that is supposed to jump from one nerve cell to the next doesn’t,
and you start forgetting names, faces, and contexts. These chemical
abnormalities lead to the brain being flooded with calcium and free radicals
(toxic substances that damage cells) and the free radicals further damage the
mitochondria.
Eventually, nerve cells
swell, then shrink, then often die, especially in the hippocampus and amygdala
(part of the temporal lobe). “Because these are the primary ‘sorting and
shipping’ areas for memories, memory is particularly damaged by cortisol during
the aging process,” Dr. Khalsa says.
The net result is a serious
decline in one’s ability to lay down new memory, to effectively remember
things, and to remain emotionally calm and even. A recent Canadian study showed
that those patients with the highest level of cortisol elevation after a
four-year period had a marked deficit in memory function, such as remembering
previously learned information, Dr. Khalsa reports. Put differently, “increases
in these patients’ cortisol levels accurately predicted decreases in
memory and cognitive function,” he says.