"Parkinson's Disease and the Uric Acid Sweet Spot"
Parkinson's disease is the second most common neurodegenerative disorder
after Alzheimer's, characterized by a slowness of movement,
rigidity, tremor, and stooping posture
that all gets worse and worse, and there's also non-movement symptoms,
like cognitive impairment, sleep, smell, and mood disturbances
as the disease spreads to other areas of the brain.
The cause of Parkinson's is perhaps one of the most important questions
posed by the science of aging.
For example, why is the consumption of dairy products
associated with increased risk for Parkinson's?
Maybe because they contribute to our exposure to pesticides
and other neurotoxins like dieldrin,
which continues to be found in the autopsied brains of Parkinson's victims,
even though it was banned decades ago, but it lingers in the environment,
and we continue to be exposed to the pesticide
through contaminated dairy and other animal products.
It's unlikely to be due to milk compounds such as calcium, vitamin D, fat, or proteins
since there's no association with Parkinson's
when they're derived from other sources.
It could be the milk sugar though, lactose, accounting
for the increased risk of death and bone fractures, as well as Parkinson's,
and earlier onset Huntington's disease, but there's a third possibility as well.
Milk lowers uric acid levels, and uric acid may be protective against Huntington's,
and also slow the decline of Parkinson's.
And most importantly may lower the risk of getting Parkinson's in the first place,
thought to be because uric acid is an important antioxidant in the brain,
something we've known for over 30 years now.
This can be shown directly in human nerve cells in a Petri dish.
Add the pesticide rotenone, and oxidative stress shoots up.
Add the pro-oxidant homocysteine, and it goes up even more.
But add some uric acid,
and it completely suppressed the oxidative stress caused by the pesticide.
But drinking milk has a uric acid-lowering effect,
citing this study describing it as a cute effect of milk,
but it turned out to be just a cute typo.
An acute effect of milk on uric acid levels in the blood.
Drink cow's milk, and uric acid levels drop 10% within hours.
Drink soy milk, and they go up 10% within hours.
Now for the painful arthritic disease, gout, which is caused by too much uric acid,
the uric acid lowering effect of dairy is a good thing,
but uric acid is a double-edged sword.
If our uric acid levels are too high, we can get gout,
but if they're too low, it may increase our risk of neurodegenerative diseases,
such as Alzheimer's, Huntington's, Parkinson's, and Multiple Sclerosis.
Here's the 5-year risk of gout in men for various uric acid levels.
If our uric acid is over 10, we have a 30% chance of suffering an attack of gout
within the next 5 years,
whereas at levels under 7, our risk is less than 1%.
So it might make sense to have levels as high as possible without going over 7
to protect the brain without risking our joints.
But having excessive uric acid in the blood
puts more than just our joints in jeopardy.
Yes, having too low levels may increase our risk
of MS, Parkinson's, Alzheimer's, and even cancer,
but having too high levels may increase our risk of gout, kidney, and heart disease.
So having a uric acid level over 7 isn't just associated with an increased risk of gout,
but an increased risk of dying from all causes.
But having a low uric acid level may also
shorten our lifespan by increasing mortality.
High uric acid is associated with increased risk of death
from heart disease, but low uric acid
is associated with increased risk of fatal stroke, for example.
So keeping uric acid at optimum levels, the sweet spot between 5 and 7,
may protect the brain in more ways than one.
If you measure the uric acid levels in those with Parkinson's,
they come in down around here, which can explain why dairy consumption
may increase risk for Parkinson's because milk pushes uric acid levels down.
Dairy may also explain the differences in uric acid levels
between meat-eaters, vegetarians, and vegans.
If you plot men out, vegans are significantly higher than vegetarians,
presumably because they don't drink milk,
with those who eat meat and milk somewhere in between.