In the second part of my look at lipoic acid, we’ll check out the evidence about its abilities to help treat diabetic neuropathy. This just might be one of the best natural supplements for this condition.
About one in five patients with diabetes suffers from diabetic neuropathy — so it is very common. It’s the result of nerve damage by compromised small blood vessels surrounding the nerve. It occurs most frequently in diabetic patients with prolonged high blood sugar levels.
Patients with diabetic neuropathy may experience these symptoms: stabbing pains; burning sensation, especially in the evening; muscle twitching; impaired speech; difficulty swallowing; muscle weakness; dizziness; blurred vision; drooping eyelid; impotence or erectile dysfunction; chronic diarrhea; reduced sensation anywhere in the body; and, most commonly, numbness and tingling sensation in the extremities.
In general, diabetic neuropathy is divided into three categories: sensorimotor; autonomic; and cranial. Sensorimotor neuropathy involves primarily the long nerves, especially in the foot and lower legs, with numbness or a tingling sensation. Autonomic nerves control the functions of the heart, gastrointestinal tract, and urinary system. When affected by diabetes, heart rate, breathing patterns, and gastrointestinal and urinary functions may change.
Here is some evidence as to how lipoic acid could help treat diabetic neuropathy:
1995: A study with 328 patients used 100, 600, or 1,200 milligrams (mg) of lipoic acid. The first dose lowered symptoms by 38%, the second by 64% and the third by 60%. Note: lipoic acid was administered by IV.
1997: A study tested 800 mg of lipoic acid over four months. It found that the treatment improved neuropathy.
1997: Another study tested the same as above and concluded that lipoic acid slightly improved neuropathy.
1999: Both 600 mg and 1,200 mg used over four months improved the flow of nerves.
1999: Over three weeks, patients took 1,800 mg of lipoic acid. The supplement was safe and lowered symptoms by 47%.
2003: 600 mg of lipoic acid through an IV improved pain and other neuropathic symptoms.
2006: A study found that 600, 1,200 and 1,800 mg over five weeks improved stabbing and burning pain. The smaller dose had the best risk-to-benefit ratio.
Overall, three conclusions have been drawn from the past studies. One: short-term treatment for three weeks with 600 mg intravenously reduced many of the neuropathic symptoms. Two: taking lipoic acid orally for four to seven months reduced both peripheral and cardiac neuropathic symptoms. Three: lipoic acid appears to be quite safe.
Lipoic acid supplements are considered safe in doses of up to 1,800 mg a day for six months. The most commonly reported side effects after oral use include allergic reactions, such as skin rashes, hives and itching, and gastrointestinal complaints, such as vomiting, diarrhea, nausea, and abdominal pain.