Including walnuts in a low-fat/modified-fat diet improves HDL cholesterol-to-total cholesterol ratios in patients with type 2 diabetes
ABSTRACT The aim of this study was to examine the effect of a moderate-fat diet inclusive of walnuts on blood lipid profiles in patients with type 2 diabetes.
This was a parallel randomized controlled trial comparing three dietary advice groups each with 30% energy as fat: low fat, modified low fat, and modified low fat inclusive of 30 g of walnuts per day. Fifty-eight men and women, mean age 59.3 +/- 8.1 years, started the trial. Dietary advice was given at baseline with monthly follow-up and fortnightly phone calls for support. Body weight, percent body fat, blood lipids, HbA1c, total antioxidant capacity, and erythrocyte fatty acid levels were measured at 0, 3, and 6 months. Data were assessed by repeated-measures ANOVA with an intention-to-treat model.
The walnut group achieved a significantly greater increase in HDL cholesterol-to-total cholesterol ratio (P=0.049) and HDL (P=0.046) than the two other treatment groups. A 10% reduction in LDL cholesterol was also achieved in the walnut group, reflecting a significant effect by group (P=0.032) and time (P=0.036). There were no significant differences between groups for changes in body weight, percent body fat, total antioxidant capacity, or HbA1c levels. The higher dietary polyunsaturated fat-to-saturated fat ratio and intakes of omega-3 fatty acids in the walnut group were confirmed by erythrocyte biomarkers of dietary intake.
Structured "whole of diet" advice that included 30 g of walnuts/day delivering substantial amounts of polyunsaturated fatty acid improved the lipid profile of patients with type 2 diabetes.
Full-textDOI: · Available from: Lynda J Ross, Dec 17, 2013
- SourceAvailable from: Pablo Hernández-Alonso
[Show abstract] [Hide abstract]
- "However, these lipid-lowering properties attributed to nuts are more controversial in obese subjects or subjects who are resistant to insulin. In these subjects, whereas some authors have reported significant reductions in LDL-C and increases in HDL-C after nut consumption , others have failed to find significant changes in lipid profile . In particular, consumption of pistachio has been reported to induce a significant reduction in total cholesterol (TC), TC/HDL-C ratio and LDL-C/HDL-C ratio [13e15] and a significant increase in plasma HDL-C   in healthy and hypercholesterolemic subjects. "
ABSTRACT: Nuts have been demonstrated to improve several cardiovascular risk factors and the lipid profile in diabetic and pre-diabetic subjects. However, analysis of conventional serum lipid profiles does not completely explain the atherogenic risk associated with pre-diabetes. We therefore investigated whether chronic consumption of pistachio modifies the lipoprotein subclasses to a healthier profile in pre-diabetic subjects. Randomized cross-over clinical trial in 54 subjects with pre-diabetes. Subjects consumed a pistachio-supplemented diet (PD, 50% carbohydrates, 33% fat, including 57 g/d of pistachios daily) and a control diet (CD, 55% carbohydrates, 30% fat) for 4 months each, separated by a 2-week wash-out. Diets were isocaloric and matched for protein, fiber and saturated fatty acids. Nuclear magnetic resonance (NMR) was performed to determine changes in plasma lipoprotein subclasses. Small low-density lipoprotein particles (sLDL-P) significantly decreased after pistachio consumption compared to the nut-free diet (P = 0.023). The non-high-density lipoprotein particles (non-HDL-P i.e. VLDL-P plus LDL-P) significantly decreased under the PD compared to CD (P = 0.041). The percentage of sHDL-P increased by 2.23% after the PD compared with a reduction of 0.08% after the CD (P = 0.014). Consequently, the overall size of HDL-P significantly decreased in the PD (P = 0.007). Chronic pistachio consumption could modify the lipoprotein particle size and subclass concentrations independently of changes in total plasma lipid profile, which may help to explain the decreased risk of cardiovascular disease and mortality associated with those individuals who frequently consumed nuts. This study is registered at www.clinicaltrials.gov as NCT01441921. Copyright © 2015 Elsevier B.V. All rights reserved.Nutrition Metabolism and Cardiovascular Diseases 02/2015; 25(4). DOI:10.1016/j.numecd.2015.01.013
[Show abstract] [Hide abstract]
- "Hence, the inclusion of walnuts in a healthy diet can decrease serum cholesterol concentrations . Fifty-eight subjects were randomized into three treatment arms of different dietary advice: a conventional low-fat control diet, a low-but modified-fat diet higher in eicosapentaenoic and docosahexaenoic acids and PUFAs, and a low-fat plus a diet of walnuts 30 g/d high in a-linolenic acid . The results indicated that body fat did not change during the walnut (30 g/d) intervention period of 6 mo compared with the baseline level (Fig. 5). "
ABSTRACT: Nuts are an integral part of the Mediterranean food patterns, and their incorporation into the regular diets of human beings is believed to provide many health benefits. The recent recognition of nuts as "heart-healthy" foods by the U.S. Food and Drug Administration has given a major boost to the positive image of nuts. Nut consumption has been associated with several health benefits, such as antioxidant, hypocholesterolemic, cardioprotective, anticancer, anti-inflammatory, and antidiabetic benefits, among other functional properties. However, although nuts possess these many health benefits, their consumption has been hampered by a lack of adequate information regarding those benefits. In addition, because nuts are energy-dense foods with high-fat content, there is a misconception among consumers that increased consumption may lead to unwanted gain in body weight with the risk of developing overweight/obesity. Nonetheless, available epidemiologic studies and short-term controlled feeding trials have supported the theory that the inclusion of nuts in the typical diet does not induce weight gain, despite an expected increase in total caloric intake. To address the misperception about nuts and body weight gain, the present review focuses mainly on the relation between nut consumption and body weight gain, in the context of the many health benefits of nuts.Nutrition 11/2012; 28(11-12):1089-97. DOI:10.1016/j.nut.2012.01.004
[Show abstract] [Hide abstract]
- "Shukitt-Hale). to reduced inflammation and lipid peroxidation, internalization of Toll-like receptors (TLR 4) and induction of neurogenesis at cellular and molecular levels. Furthermore, supplementation with 28 g (~1oz) of walnuts/day improved lipid profile in Type 2 diabetic patients as well as patients with higher cardiovascular risk factors     and 60 g (2oz) of whole walnuts for an 8-week duration in young college students resulted in improved inferential verbal reasoning . Along with increased oxidative stress and inflammation, aging is also accompanied by a weakened neuronal housekeeping function known as autophagy, a process to sequester the accumulation of toxic/misfolded polyubiquitinated proteins in brain. "
ABSTRACT: An increase in the aggregation of misfolded/damaged polyubiquitinated proteins has been the hallmark of many age-related neurodegenerative diseases. The accumulation of these potentially toxic proteins in brain increases with age, in part due to increased oxidative and inflammatory stresses. Walnuts, rich in omega fatty acids, have been shown to improve memory, cognition and neuronal effects related to oxidative stress (OS) and inflammation (INF) in animals and human trials. The current study found that feeding 19-month-old rats with a 6% or 9% walnut diet significantly reduced the aggregation of polyubiquitinated proteins and activated autophagy, a neuronal housekeeping function, in the striatum and hippocampus. Walnut-fed animals exhibited up-regulation of autophagy through inhibiting phosphorylation of mTOR, up-regulating ATG7 and Beclin 1, and turnover of MAP1BLC3 proteins. The clearance of polyubiquitinated protein aggregates such as p62/SQSTM1 was more profound in hippocampus, a critical region in the brain involved in memory and cognitive performance, than striatum. The clearance of ubiquitinated aggregates was in tandem with significant reductions in OS/INF, as indicated by the levels of P38-MAP kinase and phosphorylations of nuclear factor kappa B and cyclic AMP response element binding protein. The results demonstrate the effectiveness of a walnut-supplemented diet in activating the autophagy function in brain beyond its traditionally known antioxidant and anti-inflammatory benefits.The Journal of nutritional biochemistry 08/2012; 24. DOI:10.1016/j.jnutbio.2012.06.009