People with Parkinson's disease (PwP) are at increased risk for getting Peripheral Neuropathy (PN). PN can have many causes.
Multiple causes other than PD such as diabetes, insulin resistance or certain chemotherapy agents can also cause PN. The main consideration is that the nerves are being damaged and this often manifests as pain, burning, tingling or numbness in the feet and or hands that can be overwhelming in terms of pain and downright dangerous in terms of numbness because you lose the nerve sensory input that helps you maintain your balance thus exposing you to the danger of falling.
apdaparkinson.org/article/p....
Here is a relevant quote from the article :
' Peripheral neuropathy is a condition in which there is damage to the peripheral nervous system, the system of nerve fibers that innervates the organs and limbs.
Peripheral neuropathy may cause weakness, imbalance with walking, numbness, pain or paresthesias (abnormal sensation such as tingling or burning), usually in the feet (but sometimes in the hands as well).
There is a higher rate of peripheral neuropathy among people with PD as compared to those without PD, although the nature of this relationship is unclear.
Levodopa treatment may contribute to lower Vitamin B12 levels which may contribute to peripheral neuropathy. '
Vitamin B12
In PD, in particular, it is thought that one potential reason for PN is that Levodopa therapy may contribute to lower vitamin B12 levels and this may result in elevated homocysteine levels and this among other health negatives is thought to be a risk factor for PN. Vitamin B12 is considered as one of the treatments for PN based on available studies. PwP are also noted for having lower B12 levels so it seems like supplementing with a more bioavailable form of B12 is a good starting point.
mountsinai.org/about/newsro....
Here is a relevant quote from the article :
' Vitamin B12 deficiency in humans is known to contribute to a variety of neurological conditions and low vitamin B12 levels have been described in patients with idiopathic PD. A recent study showed that low levels of vitamin B12 predict worse motor symptoms for patients early on in PD progression. '
Vitamin B1 As Benfotiamine
Vitamin B1 is also known to be beneficial for fighting PN, in the form of Benfotiamine at 600 mg per day in two divided doses of 300 mg with meals.
sciencedirect.com/topics/ne....
Here is a relevant quote from the overview :
' Studies have shown that benfotiamine improves neuropathy scores significantly,301,302 increases nerve conduction velocity,303-305 and reduces HbA1c and pain.30 '
Vitamin B6 As P5P
Next in line is Vitamin B6 for PN, but B6 can be a double edged sword when it comes to PN because while the right level of B6 can help fight PN, too much B6 can promote PN as can too little and the damage that too much B6 can cause is considered irreversible in some people. So it is important to work with your doctor to make sure your B6 level is optimal.
tga.gov.au/news/safety-aler....
A relevant quote :
' A known side effect of vitamin B6 is peripheral neuropathy, which has symptoms of tingling, burning or numbness, usually in the hands or feet. It usually occurs at high doses or following long-term use of products containing vitamin B6. Peripheral neuropathy is not associated with normal dietary intakes of vitamin B6.
So the bottom line for PwP with PN is to make sure your B1/Benfotiamine, B6/P5P and B12 levels are optimal.
R-Alpha Lipoic Acid
The next supplement worthy of consideration for PN is R-Alpha lipoic Acid (R-ALA). R-ALA has shown benefit in people with PN at a dose of 600 to 1200 mg /day. The following review gives some detail on ALA relative to PN :
mountsinai.org/health-libra....
Here is a relevant quote from the article :
' Several studies suggest alpha-lipoic acid helps lower blood sugar levels. Its ability to kill free radicals may help people with diabetic peripheral neuropathy, who have pain, burning, itching, tingling, and numbness in arms and legs from nerve damage. Researchers believe Alpha-lipoic acid helps improve insulin sensitivity. '
I think the last sentence from the above quote is especially of importance to PwP, because insulin resistance (IR) is considered a risk factor for PD and IR also causes more damage in PwP, including increased disease progression.
In the following review they discuss the significant negative effects that IR can have in PwP :
ncbi.nlm.nih.gov/pmc/articl...
Here is an important quote from the review :
' Insulin resistance, one of the major hallmark for etiology of T2D, has a detrimental influence on PD, negatively affecting PD phenotype, accelerating its progression and worsening cognitive impairment. '
Melatonin
Another supplement worthy of consideration for PN is Melatonin because it is well noted for protecting the nerves, improving insulin resistance, increasing insulin sensitivity, reducing damaging oxidative stress and reducing multiple inflammatory mediators and cytokines. Here is a study that suggests that melatonin is helpful in nerve repair :
sciencedirect.com/science/a...
Here is a relevant quote from the study :
' The findings of the current study showed that melatonin was involved in repair of peripheral nerves thus further analyses were performed to explore the mechanism underlying the role of melatonin in repair of peripheral nerves. Analysis showed Parkin expression increased in PNI and TBHP-treated RSC96 cells (Fig. 1). Moreover, TBHP increased mitochondrial ROS production, mitochondrial damage, apoptosis, and inhibited autophagy flux in RSC96 cells (Fig. 2). '
Berberine
The sixth supplement I would like to add to the list is Berberine which is now thought to regenerate nerves as outlined here :
spandidos-publications.com/...
Here is a relevant quote :
' Notably, experimental data implied that berberine may promote nerve regeneration through IGFR-mediated JNK-AKT signal pathway, which may be a potential therapeutic agent for nerve injuries therapy and need to be studied for clinical investigations. '
Supplements
1. Vitamin B1 As Benfotiamine
2. Vitamin B6 as P5P
3. Vitamin B12
4. R-Alpha Lipoic Acid
5. Melatonin
6. Berberine
Conclusion
So the above 6 supplements have shown benefit for fighting PN and while there are plenty of others, these are six very common ones that are readily available, inexpensive while having good safety profiles. The B1, B6 and B12 combo have been a mainstay against PN for many years, but doctors seem to generally not mention them to their patients. ALA /R-ALA is a more recent addition, but it has many anecdotal reports of benefit against PN. Melatonin would be the second newest of the bunch, but when you consider its multiple known methods of action against PN, the question would be, why did it take so long to get recognition in nerve repair? Berberine would be the newest addition, but like melatonin it is noted for nerve regeneration which is very important in terms of reversing PN. It is worth noting that all of the above have shown benefit in fighting PN, but it is also worth mentioning that all of the above have shown varying degrees of benefit in PD or PD models.
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