[69s] Methylation, Methionine, Homocysteine levels, and Aging
(see Fantastic Voyage Chapter 13
by Ray Kurzweil and Terry Grossman).
The methylation process deteriorates with aging, and between 10% and 44% of the population
suffers from abnormal methylation
because of genetic polymorphisms
characteristic of different racial and ethnic groups.
This can modify DNA synthesis, neural tube development in embryos, activation and inactivation
of genes, gene silencing, and detoxification, possibly leading to cervical cancer, colon cancer,
coronary heart disease, strokes, Alzheimers, ect.
It is tested for by measuring the blood level of
the toxic metabolite homocysteine,
which forms from consuming the amino acid methionine normally found in red meat or poultry,
and which is detoxified by methylation.
Methylation is the addition of the CH3-group to a molecule.
If the body has a genetic defect in managing methylation,
homocysteine builds up to toxic levels
greater than the ideal < 7.5 μmol/L, so one treats the problem with nutritional supplementation
and tests the homocysteine level
at regular intervals.
(I note that reducing methionine to 1/5 the usual dose in mice
markedly increases their life span by > 30%
[FASEB Journal Vol 8, 1302-1307, 1994],
and that red meat containing methionine boosts
colon cancer by a factor of 3 over white meat.
However, the 20%-of-normal-methionine mice are stunted specimens, and methionine is required for methylation:
without it, no methylation takes place.
[Thanks to Ben Best for writing in with this observation.])
Methylation also plays an important role in the
detoxification of heavy metals
such as mercury, lead, antimony, and arsenic, so that as methylation deteriorates with age,
we become more susceptible to heavy metal poisoning from the mercury in Albacore tuna, for instance.
Methylation is also crucial in the
detoxification of pesticides
and estrogen,
which has been linked to several types of cancer.
In the brain, decreased methylation results in a decrease in
the synthesis of acetylcholine,
which requires methylation.
The lower acetylcholine levels result in memory loss and Alzheimer's disease,
but can be treated with acetylcholine-boosting supplements such as
Ashwagandha and
Huperzine-A.
Methylation is also required in the synthesis of melatonin and serotonin,
the calming neurotransmitters derived from the amino acid tryptophan,
and also for the synthesis of the stimulating neurotransmitters adrenaline, noradreneline,
and dopamine prepared from the amino acids phenylanaline and tyrosine.
So defective methylation can modify excitement or calmness in aging patients, producing mood disorders
such as depression and paranoia in addition to increased risk for Alzheimer's disease.
Elevated homocysteine levels are found in a high percentage of psychiatric patients,
and in Alzheimers victims.
In cardiovascular disease, heart attack, and stroke,
elevation of homocysteine levels
can be toxic to the lining of the arteries, damaging and cracking the inner walls,
which are then filled with LDL cholesterol particles, giving rise to atherosclerosis.
Homocysteine increases inflammation levels and boosts
plaque formation,
increasing the chance that the plaque will rupture, causing a heart attack or stroke.
Tested
homocysteine levels are lowered by supplementation with vitamins
B6 (contained in beer),
B12
(less well absorbed from the gastrointestinal tract in aging specimens), and
folic acid,
( folates ) and by reducing consumption of red meat and poultry,
which contain the methionine fueling toxic homocysteine synthesis.
One substitutes fish, vegetables, and fruits for methionine-bearing red meat and poultry.
Vitamin B12 may be injected.
Low B12 levels are the primary reason
homocysteine levels rise with age.
Furthermore, much-higher-than-RDA-dose levels of homocysteine-lowering nutrients
such as vitamin B12, vitamin B6,
vitamin B2,
folic acid, zinc, magnesium, and
trimethylglycine (TMG or betaine)
are typically needed.
Very soon after recommending fish instead of meat here to avoid methionine and consequent high homocysteine levels,
I received a phone call offering life insurance delivered in a thick oriental or Japanese accent.
Now we recommend a combination of Japanese and Mediterranean diets taken in Zen master style with green tea.
See Google:
Links/Methylation and Aging,
Links/Homocysteine levels and Aging,
Links/Methionine and Aging.
Google Books:,
Books/Methylation and Aging,
Books/Methionine and Aging,
Books/Homocysteine and Aging.
Life Extension Search:
Methylation and Aging,
Methionine and Aging,
Hom
