Walnuts and almonds may improve metabolic and endocrine parameters in PCOS. - GreenMedInfo Summary
Differential effects of walnuts vs almonds on improving metabolic and endocrine parameters in PCOS.
Eur J Clin Nutr. 2011 Mar ;65(3):386-93. Epub 2010 Dec 15. PMID: 21157477
Department of Internal Medicine, Division of Endocrinology, Diabetes and Metabolism, The University of California at Davis, Davis, CA, USA.
BACKGROUND/OBJECTIVES: Polycystic ovary syndrome (PCOS) is commonly associated with insulin resistance, dyslipidemia and increased inflammation, which all benefit from dietary intake of monounsaturated and n-3 polyunsaturated fatty acids (MUFA and n-3 PUFA). Our goal was to compare the effects of MUFA-rich almonds vs n-3/n-6 PUFA-rich walnuts on metabolic and endocrine parameters in PCOS. SUBJECTS/METHODS: Thirty-one PCOS patients randomly received either walnuts or almonds containing 31 g of total fat per day for 6 weeks. At the beginning and at the end, anthropometric parameters, fasting lipids, phospholipid-fatty acids, inflammatory markers, androgens, oral glucose tolerance tests (OGTT) and frequently sampled intravenous-GTT were obtained. Results: Weight remained stable. Within group, walnuts increased the n-3/n-6 essential PUFA in the diet and plasma phospholipids. Walnuts decreased low-density lipoprotein-cholesterol by 6% from 3.76± 0.27 to 3.38 ± 0.22 mmol/l (P = 0.05) and apoprotein B by 11% from 0.72 ± 0.04 to 0.64 ± 0.05 g/l (P<0.03). Although almonds also reduced low-density lipoprotein-cholesterol by 10% and apoprotein B by 9%, these were not significant. Walnuts increased insulin response during OGTT by 26% (P<0.02). Both walnuts and almonds increased adiponectin (walnuts from 9.5± 1.6 to 11.3 ± 1.8 μg per 100 ml, P = 0.0241; almonds from 10.1 ± 1.5 to 12.2 ± 1.4 μg/dl, P = 0.0262). Walnuts decreased HgBA1 from 5.7 ± 0.1 to 5.5 ± 0.1% (P = 0.0006) with significant intergroup difference from almonds (P=0.0470). Walnuts increased sex hormone-binding globulin from 38.3± 4.1 to 43.1 ± 4.3 nmol/l (P=0.0038) and almonds reduced free androgen index from 2.6 ± 0.4 to 1.8 ± 0.3 (P = 0.0470). Conclusion: Nut intake exerted beneficial effects on plasma lipids and androgens in PCOS.