NAC Improves Insulin Sensitivity in Women with PCOS

Insulin resistance, the inability to efficiently utilize the hormone insulin, is thought to be a primary cause of polycystic ovary syndrome. Although not every woman with PCOS has an insulin problem, the majority probably do. Therefore, anything that helps to normalize insulin is worth considering.

An interesting study evaluated the effect of N-acetyl-cysteine (NAC) on insulin secretion and peripheral insulin resistance in subjects with polycystic ovary syndrome.

Six lean and 31 obese women, aged 19-33 years, were treated for 5-6 weeks with NAC at a dose of 1.8 g/day orally. A dose of 3 g/day was arbitrarily chosen for massively obese people. Six of 31 obese with PCOS were treated with placebo and served as controls.

Before and after the treatment period, the hormonal and lipid (cholesterol, triglycerides) blood profile and insulin sensitivity were evaluated and an oral glucose tolerance test (OGTT) was performed.

The women who had an exaggerated insulin response to a glucose challenge and who were treated with NAC showed an improvement in insulin function in the peripheral tissues.

This finding is important because women with PCOS frequently have an abnormally high insulin response to sugars and refined starches. The high insulin throws other hormones out of balance and disturbs many body functions.

The NAC treatment also induced a significant fall in testosterone levels and in free androgen index values.

The researchers concluded: "NAC may be a new treatment for the improvement of insulin circulating levels and insulin sensitivity in hyperinsulinemic patients with polycystic ovary syndrome."

We don't recommend that you start using NAC at the 1.8 - 3 gram (that's 1,800 - 3,000 milligrams) dose used in this study. A health professional should assist you with this, especially if you are taking metformin. However, 500 milligrams or so daily should be OK for a start.

Although this is a small study, it suggests that NAC can play a role in improving your insulin sensitivity. Many of you are taking metformin for the same purpose. Improved insulin sensitivity is crucial to reversing PCOS.

Fatty Liver Degeneration from PCOS Helped by NAC

A startling percentage (possibly 55%) of women with PCOS also have a fatty liver degeneration disease called "nonalcoholic fatty liver disease" or NAFLD. NAFLD can develop into a more serious medical condition called "nonalcoholic steatohepatitis" or NASH, which is a form of liver inflammation.

There is no proven medical therapy for the treatment of non-alcoholic steatohepatitis (NASH).

Oxidative stress and insulin resistance are the mechanisms that seem to be mostly involved in the progression of NAFLD and NASH. Oxidant stress occurs when your antioxidant defenses are insufficient to control biochemical processes. The result is tissue damage and all sorts of health problems, including chronic inflammation.

Medical studies have shown that women who have polycystic ovary syndrome also tend to have both oxidative stress and insulin resistance. Insulin resistance is a condition where insulin does not work efficiently in your body.

Because oxidative stress and insulin resistance are so common in PCOS, it's no surprise that the liver is adversely affected, thus increasing the risk of NAFLD and possibly NASH.

Metformin is a drug that is often prescribed to treat insulin resistance. If insulin resistance can be reduced, stress on the liver is also reduced.

A recent study from the University of São Paulo School of Medicine in Brazil has shown that NAC in combination with metformin may be effective in treating NASH.(3)

NAC (1.2 g/day) and metformin (850-1000 mg/day) were given orally for 12 months. A low calorie diet was prescribed for all patients.

At the end of the 12 months, fat deposits in the liver went down, and liver fibrosis was reduced. Other aspects of liver function were unchanged.

The researchers said: "Based on the biochemical and histological evidence in this pilot study, NAC in combination with metformin appears to ameliorate several aspects of NASH, including fibrosis."

Sources:
N-acetyl-cysteine treatment improves insulin sensitivity in women with polycystic ovary syndrome, Fulghesu AM, et al, Fertil Steril 2002 Jun;77(6):1128-35
de Oliveira CP et al, Combination of N-acetylcysteine and metformin improves histological steatosis and fibrosis in patients with non-alcoholic steatohepatitis, Hepatol Res. 2008;38(2):159-65.