Diabetic neuropathy occurs when prolonged elevation of blood sugar levels damages nerve fibers causing problems with sensation and nerve function. There are several types of diabetic neuropathy, categorized by which nerves are affected. Diabetic neuropathy occurs in both type 1 and type 2 diabetes, and about 40–70% of diabetics will develop the condition (Topiwala 2012; Boulton 2012; Edwards 2008; Yagihashi 2007; Callaghan 2012a; National Diabetes Information Clearinghouse 2009; Feldman 2012a).
Fortunately, research shows that lifestyle modification along with natural interventions, such as lipoic acid and B vitamins, can modulate the complex pathways that underlie the development and progression of diabetic neuropathy.
Causes and Risk Factors (Feldman 2012b; Edwards 2008; Booya 2005; Forrest 1997; Dyck 1999; Wiggin 2009; Nie 2012)
Diabetic neuropathy is caused by a combination of the direct effects of high blood sugar on nerve cells as well as damage to the small blood vessels that provide blood to the nerves.
Risk Factors include:
- Long-term poor blood sugar control (primary risk factor)
- Cardiovascular disease
- Male gender
- Elevated triglycerides
- High body mass index
- Smoking and excess alcohol consumption
Diagnosis and Treatment (Feldman 2012c; Feldman 2013; National Diabetes Information Clearinghouse 2009; Morales-Vidal 2012; American Diabetes Association 2012; England 2005; Edwards 2008; Feldman 1994; Callaghan 2012a; Topiwala 2012; Ziegler 2009)
- Presence of characteristic symptoms including lower extremity numbness, pain, sensitivity, dryness, muscle weakness/wasting, difficulty walking, and loss of temperature sensation
- Physical exam
- Fasting blood glucose, hemoglobin A1C, CBC/Chemistry panel, others
- Nerve conduction studies or electromyograms on the foot
- Judicious tight blood sugar control is paramount in controlling progression of diabetic neuropathy.
- For painful peripheral neuropathy, pregabalin and/or duloxetine may be prescribed.
- Wound care in limbs affected by peripheral neuropathy is important.
Novel and Emerging Therapies (Sino Stem Cells 2013; GSCN 2013; Kim 2012; Waterman 2012; Toth 2012; Bestard 2011; Yuan 2009; Francisco 2012)
- Stem cells. Research suggests stem cell transplantation can protect and restore pancreatic cells, improve blood flow to damaged nerves, and may reduce inflammation and thus relieve diabetic neuropathy pain.
- Nabilone. Two studies found nabilone, a synthetic cannabinoid, relieves pain and improves sleep in patients with diabetic neuropathy.
- Botulinum toxin. Studies suggest injection of botulinum toxin, a neurotoxin secreted by the bacterium Clostridium botulinum, to sites of painful diabetic neuropathy may significantly reduce pain and improve sleep quality.
Dietary and Lifestyle Considerations include:
- Diet. Eating a healthy, balanced diet rich in fibrous plant foods and healthy fats can help keep blood glucose levels under control and may reduce risk of diabetes and its complications (Gannon 2004; Rizkalla 2004; Smith 2006).
- Exercise. One study found that aerobic exercise, in the form of walking on a treadmill for four hours per week, slowed the progression of diabetic neuropathy (Balducci 2006).
Targeted Natural Interventions
- Lipoic acid. In clinical trials, doses of 600 – 1,800 mg/day of lipoic acid have led to symptom improvement in people with diabetic neuropathy (McIlduff 2011).
- Acetyl L-carnitine and L-carnitine. One study found that two grams of L-carnitine daily for 10 months improved nerve conduction velocity, which is impaired in diabetic neuropathy. Other studies have found that acetyl-L-carnitine reduced pain, improved vibration sensation in the legs, and increased nerve regeneration in patients with diabetic neuropathy (Bansal 2006; Sima 2005; Adriaensen 2005; Evans 2008; De Grandis 2002).
- Omega-3 fatty acids. Two studies on animal models found that supplementation with omega-3 fatty acids improved signs of diabetic neuropathy (Gerbi 1999; Coste 2003).
- Curcumin. Curcumin may modulate pain associated with diabetic neuropathy (Sharma 2006; Lakshmanan 2011).
- Vitamin D. One study on 51 patients with diabetic neuropathy found vitamin D supplementation reduced reported pain levels by 50%. In a case report of a patient with severe pain, vitamin D supplementation provided substantial relief from pain due to diabetic neuropathy (Lee 2008; Bell 2012).