Canudas, S., P. Hernández-Alonso, S. Galié, J. Muralidharan, L. Morell-Azanza, G. Zalba, J. García-Gavilán, A. Martí, J. Salas-Salvadó, M. Bulló, 2019. Pistachio consumption modulates DNA oxidation and genes related to telomere maintenance: a crossover randomized clinical trial. Am J Clin Nutr. 0:1–8.
Background: Telomere attrition may play an important role in the pathogenesis and severity of type 2 diabetes (T2D), increasing the probability of β cell senescence and leading to reduced cell mass and decreased insulin secretion. Nutrition and lifestyle are known factors modulating the aging process and insulin resistance/secretion, determining the risk of T2D. Objectives: The aim of this study was to evaluate the effects of pistachio intake on telomere length and other cellular aging-related parameters of glucose and insulin metabolism. Methods: Forty-nine prediabetic subjects were included in a randomized crossover clinical trial. Subjects consumed a pistachio supplemented diet (PD, 50 E% [energy percentage] carbohydrates and 33 E% fat, including 57 g pistachios/d) and an isocaloric control diet (CD, 55 E% carbohydrates and 30 E% fat) for 4 mo each, separated by a 2-wk washout period. DNA oxidation was evaluated by DNA damage (via 8-hydroxydeoxyguanosine). Leucocyte telomere length and gene expression related to either oxidation, telomere maintenance or glucose, and insulin metabolism were analyzed by multiplexed quantitative reverse transcriptase-polymerase chain reaction after the dietary intervention. Results: Compared with the CD, the PD reduced oxidative damage to DNA (mean: −3.5%; 95% CI: −8.07%, 1.05%; P = 0.009). Gene expression of 2 telomere-related genes (TERT and WRAP53) was significantly upregulated (164% and 53%) after the PD compared with the CD (P = 0.043 and P = 0.001, respectively). Interestingly, changes in TERT expression were negatively correlated to changes in fasting plasma glucose concentrations and in the homeostatic model assessment of insulin resistance. Conclusions: Chronic pistachio consumption reduces oxidative damage to DNA and increases the gene expression of some telomere-associated genes. Lessening oxidative damage to DNA and telomerase expression through diet may represent an intriguing way to promote healthspan in humans, reversing certain deleterious metabolic consequences of prediabetes. This study was registered at clinicaltrials.gov as NCT01441921.
Basiak-Rasała, A., D. Różańska, K. Zatońska, 2019. Food groups in dietary prevention of Type 2 diabetes. Rocz Panstw Zakl Hig 70(4):347-357.
According to the World Health Organization diabetes will be the seventh leading cause of death worldwide in 2030. Majority of diabetic patients suffer from type 2 diabetes (T2DM), which is mostly avoidable. The most important modifiable risk factors of type 2 diabetes are: overweight and obesity, improper diet, sedentary lifestyle and tobacco smoking. Even in prediabetic state, improving diet and physical activity can slow down or even stop progression to diabetes. In the view of health burden of diabetes it is essential to thoroughly investigate the risk factors and develop more specific preventive strategies. Recently published studies focus on food groups rather than individual products to assess the link between nutrition and risk of type 2 diabetes. Identifying food groups of possible beneficial and deleterious effect on the risk of type 2 diabetes could facilitate the dietary counselling. The aim of the overview is to summarize the possible association between consumption of food groups on the risk of type 2 diabetes on the basis of available literature. Observations from studies and meta-analyses indicate on an inverse association between consumption of fresh vegetables and fruit, whole grains, lean dairy, fish, nuts and the risk of type 2 diabetes. Food groups that seemed to increase the risk of type 2 diabetes are: red and processed meat, refined grains, sugar-sweetened beverages. It is important to note, that no individual nutrients, but diverse dietary pattern, composed of every recommended food group in adequate amounts can contribute to healthy lifestyle and T2DM prevention.
Palacios, O.M., K.C. Maki, D. Xiao, M.L. Wilcox, M.R. Dicklin, M. Kramer, R. Trivedi, B. Burton-Freeman, I. Edirisinghe, 2019. Effects of consuming almonds on insulin sensitivity and other cardiometabolic health markers in adults with prediabetes. Journal of the American College of Nutrition. doi:10.1080/07315724.2019.1660929.
Objective: This study was designed to assess the effects of replacing high-carbohydrate (CHO) foods with raw almonds on insulin sensitivity and cardiometabolic health markers in overweight or obese adults with prediabetes. Method: This randomized crossover study consisted of two 6-week dietary intervention periods, separated by a ≥ 4-week washout. Subjects incorporated 1.5oz of raw almonds twice daily or isocaloric CHO-based foods into their diets, with instructions to maintain body weight. Dietary intakes as well as insulin sensitivity, CHO metabolism indices, lipoprotein lipids and particles, and inflammatory markers were assessed. Results: Thirty-three subjects (17 male, 16 female), mean age 48.3±2.2years and body mass index 30.5±0.7kg/m2, provided evaluable data. Compared to CHO, almonds resulted in significantly (p<0.01) higher intakes of protein, fat (unsaturated fatty acids), fiber, and magnesium and significantly (p<0.001) lower intakes of CHO and sugars. No differences were observed between diet conditions for changes from baseline in the insulin sensitivity index from a short intravenous glucose tolerance test or other indices of glucose homeostasis. No significant differences were observed in biomarkers of cardiovascular risk except that the CHO intervention led to a shift toward a higher concentration of cholesterol in small, dense low-density lipoprotein subfraction 3+4 (LDL3+4) particles (p = 0.024 vs almonds). Conclusions: Intake of 3.0 oz/d raw almonds, vs energy-matched CHO foods, improved the dietary nutrient profile, but did not significantly affect insulin sensitivity and most markers of cardiometabolic health in overweight and obese men and women with prediabetes.
Njike, V.Y., V.C. Costales, P. Petraro, A. Annam, N. Yarandi, D.L. Katz, 2019. The resulting variation in nutrient intake with the inclusion of walnuts in the diets of adults at risk for type 2 diabetes: A randomized, controlled, crossover trial. Am J Health Promot. 33(3):430-438.
Purpose: We previously demonstrated that including walnuts in the diets of adults at risk for type 2 diabetes mellitus (T2DM) led to improved overall diet quality. This report examines the specific changes in their nutrient intake. Design: This was a randomized, controlled, modified Latin square parallel design trial with 2 treatment arms. Participants were randomized to walnut intake with, or without, dietary advice to regulate caloric intake. Within each treatment arm, they were further randomized to one of 2 sequence permutations (walnut-included/walnut-excluded or walnut-excluded/walnut-included diet), with a 3-month washout between treatment phases. Setting: Community hospital in Lower Naugatuck Valley in Connecticut. Participants: Cohort of 112 participants (31 men and 81 women) at risk for T2DM. Intervention: Participants included 56 g (366 kcal) of walnuts in their daily diets for 6 months. Measures: Nutrient intake was assessed using web-based Automated Self-Administered 24-Hour Dietary Assessment. Analysis: Data were analyzed using generalized linear models. Results: Walnut inclusion led to increased intake of total fat, calcium, magnesium, thiamin, total saturated fatty acids, and monounsaturated and polyunsaturated fatty acids (379.0 ± 90.3 g vs -136.5 ± 92.7 g, P < .01; 230.7 ± 114.2 mg vs -95.2 ± 117.4 mg, P = .05; 111.0 ± 33.9 mg vs -32.3 ± 34.9 mg, P < .01; 0.28 ± 0.2 mg vs -0.47 ± 0.2 mg, P = .02; 8.6 ± 3.4 g vs -1.1 ± 3.5 g, P =.05; 6.3 ± 3.9 g vs -6.3 ± 4.0 g, P = .03; and 25.4 ± 4.0 vs -6.6 ± 4.2 g, P < .01, respectively). Vitamin C intake decreased (-65.3 ± 55.3 mg vs 98.9 ± 56.8 mg, P = .04). Protein intake increased from baseline with the inclusion of walnuts (20.0 ± 8.8 g, P < .05). Walnut inclusion led to an increase in total calories consumed when caloric intake is not regulated. Conclusion: Including walnuts in the diets of these adults led to increased dietary intake of some nutrients associated with lower risk of developing T2DM and other cardiometabolic risk factors.
