Although the neuropathy investigated here was caused by HIV, the pattern in which it develops is the same as that of diabetic neuropathy--feet first, followed by hands after the neuropathy reaches the knee level. More importantly, the mechanism the researchers discovered is fundamental physiology and should apply to all neuropathies.
Here's a detailed discussion of the study from Science Daily. I urge you to read it:
Science Daily: Feet First? Old Mitochondria Might Be Responsible for Neuropathy in the Extremities
WHAT DOES THIS MEAN FOR PEOPLE WITH DIABETES?
If this finding holds up, its value it two-fold. First of all, it suggests that neuropathy may come from damage to the mitochondria that burn energy to supply the nerves, not just, as hitherto believed, the tiny capillaries that supply the nerve tissue.
There are other cross connections between mitochondrial dysfunction and diabetes, though this isn't an area that gets much attention in the health press. This Google Search will show you a sampling of studies that link the two:
GOOGLE Search "Diabetes and Mitochondrial dysfunction"
What's new and interesting about this new study is the discovery that mitochondria are born at one end of the nerve nearest the spine and migrate toward other end, and that, because the feet nerves have the longest journey, their mitochondria take the longest time to make the trip and hence the oldest and the most prone to manifest damage.
The study suggests it takes two to three years for the mitochondria in the feet to migrate to their destination. What we can take from is is the following: If you have developed neuropathy in your feet due to exposing your nerves to high blood sugar levels, once you take steps to stop diabetic neuropathy from happening--by lowering your blood sugar to normal levels--you should expect it to take at least three years for your new and improved mitochondria--the ones that haven't already been damaged--to make the long trip down the nerve cell to your toes.
This is why dietary studies that only last a year are useless for showing the real impact on health that is achieved by a diet that lowers blood sugar to normal levels. But if you know it will take three years after you have brought the damage to a halt to restore your nerves, you should have the patience to stick to it.
The benefits are incalculable. Especially when you remember that nerve damage from high blood sugars doesn't just affect your toes. It affects other long nerves, like the vagus nerve that controls everything from heart beat to your digestive tract.
The best technique for lowering your blood sugar to the level that will avoid nerve damage (keeping blood sugars under 140 mg/dl at almost all times) is described here:
How to Lower Your Blood Sugar
Try it. It works.
You should start seeing some improvements in your neuropathy fairly quickly after normalizing blood sugar, but the findings described above should remind you that it will take quite a while to fully correct previous damage.
As the nerves heal you may experience some pain, tingling, or itching in your extremities as the nerves start working again. This is normal and happens when any damaged nerve starts to heal, especially ones that previously were numb. The pain is a short term effect and should be replaced in a few months by normal function.