The purpose of this study is to learn more about the effects of walnuts, walnut-oil, almonds and fish oils on blood sugar and insulin levels in polycystic ovary syndrome (PCOS) patients. The hypothesis is that a diet rich in these foods will improve insulin resistance in women with PCOS.

Polycystic ovary syndrome is a common disease that affects 1 out of 16 women. Metabolic and endocrine abnormalities seen in PCOS include insulin resistance, androgen excess and infertility. This study focuses on the insulin resistance aspect because increased insulin resistance leads to premature onset of impaired glucose tolerance or diabetes whereas decreased insulin resistance reduces androgen excess, improves the ovarian function and increases fertility. Although insulin resistance can be treated with insulin-sensitizing drugs, PCOS clinically manifests during adolescence and the long-term safety of the drug-treatment can be a concern. Thus, improving insulin resistance with effective nutritional approaches would be very desirable. Epidemiological studies and animal experiments suggest that replacement of dietary saturated fats with monounsaturated (MUFA) and polyunsaturated (PUFA) fats improves insulin resistance.

Inclusion Criteria:

• Clinical diagnosis of polycystic ovary syndrome
• Body mass index (BMI) 22-52

Exclusion Criteria:

• Habitual dietary intake of less than 30% fat
• Use of oral contraceptives, insulin sensitizers, d-chiro inositol, or any other supplements affecting weight or insulin sensitivity during the preceding two months
• Impaired glucose tolerance
• Diabetes mellitus
• Other system illnesses such as renal, hepatic, gastrointestinal, severe hyperlipidemia and hypertension that require medication
• Smoking, alcohol intake (more than 2 drinks/week)
• The laboratory values used for exclusion of subjects will be fasting glucose > 110 mg/dl, glycosylated hemoglobin (HgBA1) > 6.5%, serum creatinine > 1.5 mg/dl, ALT or AST > 2x the upper limit of normal, cholesterol > 250 mg/dl. The investigators will also exclude subjects with hematocrit < 30%.