Applied nutritional investigationEffects of DASH diet on lipid profiles and biomarkers of oxidative stress in overweight and obese women with polycystic ovary syndrome: A randomized clinical trial
Introduction
Polycystic ovary syndrome (PCOS) is the most common endocrinopathy among reproductive-aged women [1], affecting 6% to 18% of female adults [2]. In Iran the estimated prevalence of this condition has been reported to be 7% based on the National Institutes of Health criteria, 15.2% according to the Rotterdam criteria, and 7.9% according to the Androgen Excess Society criteria [3]. Women with PCOS have androgen excess, insulin resistance, and variable amounts of estrogen exposure, all of which can result in increased lipid profiles and biomarkers of oxidative stress [4], [5]. Additionally, increased visceral fat and the reduction of adiponectin levels in PCOS would result in elevated lipid profiles [6], [7]. Decreased expression of peroxisome proliferator-activated receptor in women with PCOS also can result in dyslipidemia and increased biomarkers of oxidative stress [8]. PCOS is associated with infertility [9], increased risk for endometrial, breast, and ovarian cancers [10], and increased incidence of type 2 diabetes mellitus (T2DM) [11].
First-line treatment in the management of PCOS includes weight loss and lifestyle modifications with increased physical activity [12]. It has been reported that in obese women with PCOS, a 5% loss of body weight can improve hyperandrogenic features [13]. Furthermore, the use of oral contraceptive pills and metformin may help induce regular menses [14] and reduce hyperinsulinemia and ovarian androgens production in these women [15]. Recently, it has been suggested that low-carbohydrate, low-glycemic load, and high-protein diets might beneficially influence PCOS more than a conventional low-fat, high-carbohydrate diet [16], [17].Consumption of a low-glycemic diet in combination with medications has resulted in symptom relief in patients with PCOS [18]. However, adherence to a high-protein and low-glycemic diet for 12 wk did not influence lipid profiles among women with PCOS [19].
The Dietary Approaches to Stop Hypertension (DASH) eating plan is a low-glycemic index, low-energy dense diet that has been suggested for lowering blood pressure [20]; however, its beneficial effects also have been reported in T2DM [21], gestational diabetes mellitus (GDM), [22] and metabolic syndrome (MetS) [23]. Although the influence of some dietary components of the DASH diet, such as antioxidants [24], [25], magnesium [26], and dietary fiber, fruit, and vegetables [25], in PCOS has been assessed in previous studies, we are not aware of any studies examining the effects of the DASH diet on metabolic profiles and biomarkers of oxidative stress in patients with PCOS. High contents of dietary fiber, antioxidants, phytoestrogens, and isoflavones along with its low-glycemic index [21], [23] might help PCOS patients to control their increased levels of lipids and oxidative stress. Furthermore, adherence to the DASH diet has been associated with lower body fat [21], which could in turn result in lower testosterone levels [27], a key component in PCOS. The present study was, therefore, performed to investigate the effects of the DASH eating plan on lipid profiles and biomarkers of oxidative stress in overweight and obese women with PCOS.
Section snippets
Participants
This two-arm parallel, randomized controlled clinical trial (RCT) was carried out in Kashan, Iran, from January to May 2012. With the exception of the study dietitian (ZA), who provided the dietary education, all study personnel and participants were blinded to dietary assignment. Overweight or obese (body mass index [BMI] ≥ 25 kg/m2) women ages 18 to 40 y diagnosed with PCOS based on the Rotterdam criteria were recruited in this study. On the basis of sample-size formula suggested for RCTs [19]
Results
Among individuals in the control diet, three women were excluded (one was undergoing in vitro fertilization, one became pregnant, and one was using medications). Three women were also excluded from the DASH diet group (in vitro fertilization, use of medications, and health problems). Finally, 48 participants (24 in each arm) completed the study (Fig. 1).
Mean age of study participants was not statistically different between the two groups. Comparison of weight and BMI both at baseline and end of
Discussion
Adherence to the DASH eating pattern for 8 wk among overweight and obese women with PCOS had beneficial effects on weight, BMI, serum TGs, VLDL-C, insulin, plasma TAC, and total GSH levels compared with the control diet. However, the effects of the DASH eating pattern on serum TC, HDL-C, and LDL-C were not significantly different between the two groups.
To our knowledge, only a few studies have evaluated the beneficial effects of diet therapy on metabolic status in women with PCOS. According to
Conclusion
Consumption of the DASH diet for 8 wk in overweight and obese women with PCOS resulted in a significant decrease in weight, BMI, serum insulin, TGs, and VLDL-C levels as well as a significant increase in plasma TAC and total GSH levels. Given the high prevalence of PCOS and based on the findings of this study, we believe that the DASH diet could be recommended as a suitable diet for these patients to control abnormal metabolic profiles.
Acknowledgment
The authors acknowledge the staff of Naghavi and Shaheed Beheshti Gynecology Clinics (Kashan, Iran) for their assistance in this project.
References (59)
Dyslipidemia in PCOS
Steroids
(2012)Inflammation in polycystic ovary syndrome: underpinning of insulin resistance and ovarian dysfunction
Steroids
(2012)- et al.
Psychological benefits of a high-protein, low-carbohydrate diet in obese women with polycystic ovary syndrome—a pilot study
Appetite
(2007) - et al.
Dietary intakes of fat and antioxidant vitamins are predictors of subclinical inflammation in overweight Swiss children
Am J Clin Nutr
(2006) - et al.
Fruit and vegetable consumption and its relation to markers of inflammation and oxidative stress in adolescents
J Am Diet Assoc
(2009) - et al.
The ferric reducing ability of plasma (FRAP) as a measure of “antioxidant power”: the FRAP assay
Anal Biochem
(1996) - et al.
Effects on blood lipids of a blood pressure-lowering diet: the Dietary Approaches to Stop Hypertension (DASH) Trial
Am J Clin Nutr
(2001) - et al.
Dietary L-arginine supplementation reduces white fat gain and enhances skeletal muscle and brown fat masses in diet-induced obese rats
J Nutr
(2009) - et al.
Inadequate dietary magnesium intake increases atherosclerotic plaque development in rabbits
Nutr Res
(2009) - et al.
A randomized controlled clinical trial investigating the effect of DASH diet on insulin resistance, inflammation, and oxidative stress in gestational diabetes
Nutrition
(2013)
A dietary pattern that lowers oxidative stress increases antibodies to oxidized LDL: results from a randomized controlled feeding study
Atherosclerosis
Dietary antioxidants: do they have a role to play in the ongoing fight against abnormal glucose metabolism?
Nutrition
Dietary total antioxidant capacity is negatively associated with some metabolic syndrome features in healthy young adults
Nutrition
Long versus short course treatment with metformin and clomiphene citrate for ovulation induction in women with PCOS
Cochrane Database Syst Rev
Longitudinal weight gain in women identified With polycystic ovary syndrome: Results of an observational study in young women
Obesity (Silver Spring)
The prevalence of polycystic ovary syndrome in Iranian women based on different diagnostic criteria
Endokrynol Pol
Obesity, adipokines and metabolic syndrome in polycystic ovary syndrome
Front Horm Res
Adiponectin modulates oxidative stress-induced autophagy in cardiomyocytes
PLoS One
Association of the polycystic ovary syndrome with genomic variants related to insulin resistance, type 2 diabetes mellitus, and obesity
J Clin Endocrinol Metab
Polycystic ovary syndrome: a common endocrine disorder and risk factor for vascular disease
Curr Treat Options Cardiovasc Med
Is polycystic ovary syndrome, a state of relative estrogen excess, a real risk factor for estrogen-dependant malignancies?
Gynecol Endocrinol
Long-term reproductive and metabolic consequences of PCOS
Curr Diabetes Rev
The treatment of infertility in polycystic ovary syndrome: a brief update
Aust N Z J Obstet Gynaecol
The role of obesity in the development of polycystic ovary syndrome
Curr Pharm Des
Current approaches to the diagnosis and treatment of polycystic ovarian syndrome in youth
Horm Res
Evidence-based lifestyle and pharmacological management of infertility in women with polycystic ovary syndrome
Womens Health (Lond Engl)
Dietary composition in restoring reproductive and metabolic physiology in overweight women with polycystic ovary syndrome
J Clin Endocrinol Metab
An retrospective audit of patients with polycystic ovary syndrome: the effects of a reduced glycaemic load diet
J Hum Nutr Diet
Beneficial effects of a high-protein, low-glycemic-load hypocaloric diet in overweight and obese women with polycystic ovary syndrome: a randomized controlled intervention study
J Am Coll Nutr
Cited by (91)
An overview on effects of micronutrients and macronutrients interventions in management of polycystic ovary syndrome
2022, Clinical Nutrition ESPENThe effect of low glycemic index diet on the reproductive and clinical profile in women with polycystic ovarian syndrome: A systematic review and meta-analysis
2021, HeliyonCitation Excerpt :Finally, eight articles were included in qualitative and quantitative analyses (Figure 1). The final selected studies included 412 overweight and obese individuals with PCOS (207 cases in the LGD group and 205 patients in comparators) with a mean age of 21–32 years (Table 1) [33-40]. Studies varied in length from 3 to 12 months, comparing LGID against high glycemic index diet, low-calorie diet, normal glycemic diet, low-fat diet, therapeutic lifestyle changes, and conventional hypocaloric diet.
The present study was supported by a grant (no. 9213) from the vice-chancellor for research, KUMS, Kashan, Iran. ZA conducted the study, carried out the statistical analyses, drafted the manuscript, and contributed to the interpretation of the findings. MS, ZT, HS, and S-SS contributed to the data collection and assisted in drafting the manuscript. AE contributed to the conception and design, advised on statistical analyses, and assisted in interpretation of the findings. None of the authors had any personal or financial conflict of interest. All authors approved the final version for submission.