Those who are canny will recognize that homocysteine levels can be elevated by taking levodopa, and this may lead to unwanted health side effects. (There are things you can do to mitigate this.)
However, does mean that homocysteine is just bad? Maybe not.
Have a peek the interconnected Methylation cycle and trans-sulfuration pathway:
I didn't realize until I saw this image that homocysteine is involved in one pathway for the formation of cysteine, which is itself a precursor to the a master antioxidant glutathione. Some PWP's try to supplement glutathione either directly or by taking NAC (n-acetyl-cysteine). If homocysteine plays role in methionine metabolism and glutathione synthesis, maybe it is a friend?
Here's the abstract of an article that talks about his two functions that homocysteine plays. pubs.acs.org/doi/10.1021/bi...
And here is a somewhat more accessible discussion on the topic of
"I have watched with interest as the recommended maximum “safe” levels have dropped several times through the past 2 decades as research has progressed. Several months ago, one of the thought leaders in nutritional medicine recommended, at a lecture I attended, that homocysteine should be less than 6 mg/L. I found this intriguing and likely very difficult to attain. Then as I was studying the biochemistry of glutathione for my editorial in February 2014,1 I couldn’t help but notice the homocysteine/methylation cycle, right in the middle of a lot of metabolism. It got me to wondering if, like cholesterol (see my editorial from June 2014),2 perhaps we were inappropriately vilifying a molecule important for health.
"Initially, it looked to me like homocysteine might be an important storage/transfer molecule and the factors that cause its elevation are the actual problem, not the homocysteine itself."
I am currently looking at supplementing with methylfolate (a friendlier version of folic acid) and vitamin B12. These may help the conversion of homocysteine to methionine.
As I was looking to find what a good dose would be, I found this article which talks about vitamin B12 levels and homocysteine levels in patients with early Parkinson's:
Vitamin B12 Supplements May Help Slow Parkinson’s Progression, Study Finds
“Our results suggest that the measurement of B12 levels early in Parkinson’s may be beneficial .... If levels are at the low end of normal, supplementation to get the level into the middle or upper end of the normal range may slow development of symptoms.”
This is somewhat similar to Prof. Frank Church's recommendation in a 2017 blog post:
"You should talk with your Neurologist because it’s straightforward to measure folate, vitamin B6 and B12, and homocysteine levels to see if they are in the normal range if you are taking carbidopa/levodopa. The hidden subplot behind the story is the growing awareness and importance of managing homocysteine levels and also knowing the levels of folate, B6 and B12 to help maintain your neurological health."
Accepted levels of B12 depend on where you live. In Canada the accepted level maxs out at400 which is much lower than many countries. There is sufficient documented and approved research that acknowledges that a person can be B12 deficient with a much higher level. Also increased amounts of B12 on a daily basis is not harmful, but for many people can be really beneficial. I have increased my B12 intake by increments and see how I feel. Mostly I first recognized an increase in clear thinking, my hair was healthier, and my energy improved. After 6 weeks, I went back to the recommended intake by my GP, and noticed the decrease in my overall sense of well being. Hard to describe but once I had recognized the improvements from the higher dosage,it was fairly easy to feel the difference. Subsequently I am now two weeks in on the higher daily intake and already feel better and looking forward (fingers crossed) to continuing improvement.
I am working with my Acupuncturist and her guidance regarding the homocysteine benefits and B12 after she worked on my DNA data, received from the Ancestry organization. I am very lucky to have such an incredibly knowledgeable person leading me through the maze of information..... much of it is way too complicated for my 75 year old PD brain!
As for myself, I haven't started taking B12 yet. There is substantial discussion in online forums about the above cycles and Chronic Fatigue Syndrome. A doctor there (Rich Vank) recommends 2 mg a day of B12 for people with CFS. He also said that it's better to take a sublingual dose (a vitamin that is designed to dissolve under your tongue), because apparently vitamins which you swallow aren't absorbed very well.
I don't know what dosage is recommended for people with Parkinson's. I personally have ordered something that is a mix of two forms of vitamin B12 [Vitamin B12 sublingual (as methylcobalamin & adenosylcobalamin)]. Each has a total of 1 mg, and I will probably start taking one tablet a day.
Sorry I can’t be absolutely specific on the B12 amount.
Currently I am taking 1 B12 Methylcobalamin (1000 mcg) sublingually three times daily, plus 1 full dropper of Adenosyl/Hydroxy B12 liquid sublingually each morning, plus 1 Multi B (Methyl Care from Metagenics) 1000 mcg.
Planning on increasing the Methylcobalamin to 4 daily in another week or so. The printing on the small bottle of liquid B12 is so small I cannot read the contents even with a magnifying glass. The full dropper holds 1 mg, I trust my Acupuncturist!
My GP only wants me to take a Multi B, nothing more!
I tried to send a pic of the B12 containers but can’t do that here.
I would say friend AND foe, depending on anyone's specific case. Like grapefruit juice can be.
Just a note. I requested a blood test for my homocysteine level, per my Acupuncturist. My Neurologist submitted the réquisition thankfully as my GP wasn’t interested.
My Acupuncturist says.....
"Homocysteine level shouldn’t be too high OR too low. Just like cholesterol, not too high or low.
Most credible evidence says around 7. Not too much less or too much more.
For PWP it can build up because L dopa interferes with B6 metabolism."
This is a very good point - it seems that homocysteine has to be in the Goldilocks zone. There is good article on the subject by Dr. Ben Lynch drbenlynch.com/low-homocyst... who states "Most research and, as a result most health practitioners and patients, focus on normal to high homocysteine.
Low homocysteine isn’t even on their radar. Medically speaking, low homocysteine doesn’t really even exist." He also mentions Dr. Joseph Pizzorno, author of the "Homocysteine: friend or foe?"
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