Nishi, S.K., E. Viguiliouk, S. Blanco Mejia, C.W.C. Kendall, R.P. Bazinet, A.J. Hanley, E.M. Comelli, J. Salas Salvado, D.J.A. Jenkins, J.L. Sievenpiper, 2021. Are fatty nuts a weighty concern? A systematic review and meta-analysis and dose–response meta-regression of prospective cohorts and randomized controlled trials. Obes Rev. doi: 10.1111/obr.13330.
Nuts are recommended for cardiovascular health, yet concerns remain that nuts may contribute to weight gain due to their high energy density. A systematic review and meta-analysis of prospective cohorts and randomized controlled trials (RCTs) was conducted to update the evidence, provide a dose-response analysis, and assess differences in nut type, comparator and more in subgroup analyses. MEDLINE, EMBASE, and Cochrane were searched, along with manual searches. Data from eligible studies were pooled using meta-analysis methods. Interstudy heterogeneity was assessed (Cochran Q statistic) and quantified (I2 statistic). Certainty of the evidence was assessed by Grading of Recommendations Assessment, Development, and Evaluation (GRADE). Six prospective cohort studies (7 unique cohorts, n = 569,910) and 86 RCTs (114 comparisons, n = 5873) met eligibility criteria. Nuts were associated with lower incidence of overweight/obesity (RR 0.93 [95% CI 0.88 to 0.98] P < 0.001, “moderate” certainty of evidence) in prospective cohorts. RCTs presented no adverse effect of nuts on body weight (MD 0.09 kg, [95% CI -0.09 to 0.27 kg] P < 0.001, “high” certainty of evidence). Meta-regression showed that higher nut intake was associated with reductions in body weight and body fat. Current evidence demonstrates the concern that nut consumption contributes to increased adiposity appears unwarranted.
Wang, J., S. Wang, S.M. Henning, T. Qin, Y. Pan, J. Yang, J. Huang, C.-H. Tseng, D. Heber, Z. Li, 2021. Mixed tree nut snacks compared to refined carbohydrate snacks resulted in weight loss and increased satiety during both weight loss and weight maintenance: A 24-week randomized controlled trial. Nutrients. 13(5), 1512; doi.org/10.3390/nu13051512
Mixed tree nuts (MTNs) are an excellent source of protein and healthy fat contributing to satiety. However, their relatively high caloric content might not be beneficial in a weight loss diet. The present study was designed to test whether including MTNs in a weight loss and maintenance program interferes with weight management compared to a refined carbohydrate pretzel snack (PS). We performed a randomized, controlled, two-arm study in 95 overweight individuals consuming 1.5 oz of MTNs or PS daily as part of a hypocaloric weight loss diet (−500 kcal) over 12 weeks followed by an isocaloric weight maintenance program for 12 weeks. Participants in both groups experienced significant weight loss (12 weeks: −1.6 and −1.9 and 24 weeks: −1.5 and −1.4 kg) compared to baseline in the MTN and PS groups, respectively. However, there was no difference in weight loss and other outcome parameters between the MTN and PS groups. The MTN group showed a significant increase in satiety at 24 weeks. Both groups had a decrease in diastolic blood pressure at 12 weeks. Participants in the MTN group showed significant decreases in heart rate at 4, 12, and 24 weeks. Plasma oleic acid was significantly increased at 12 and 24 weeks in the MTN group but only at 12 weeks in the PS group. Plasma MCP-1 was decreased significantly in the MTN group at 4 weeks. In summary, participants in both groups lost weight, but only the MTN intervention increased satiety at 24 weeks, enhanced retention, decreased heart rate, and increased serum oleic acid at 24 weeks.
Nishi, S. K., C.W.C. Kendall, R.P. Bazinet, A.J. Hanley, E.M. Comelli, D.J.A. Jenkins, J.L. Sievenpiper, 2021. Almond bioaccessibility in a randomized crossover trial: is a calorie a calorie? Mayo Clin. Proc. 96(9):2386–2397. https://doi.org/10.1016/j.mayocp.2021.01.026
Objective: To investigate the energy and macronutrient bioaccessibility of almonds in individuals with hyperlipidemia. Methods: In a previously reported randomized crossover trial, men and postmenopausal women with hyperlipidemia incorporated 3 isoenergetic supplements into a National Cholesterol Education Program Step 2 diet for 1 month each between September 20, 2000, and June 27, 2001. Supplements provided consisted of full-dose almonds (73±5 g/d), half-dose almonds (38±3 g/d) plus half-dose muffins, and full-dose muffins (control). Energy and macronutrients, including individual fatty acids, were measured in the dietary supplements and fecal samples using gas chromatography and Association of Official Analytical Chemists methods. Serum was measured for lipids and fatty acids. Bioaccessibility of energy and macronutrients from almond consumption was assessed from dietary intake (7-day food records) and fecal output. Results: Almond-related energy bioaccessibility was 78.5%±3.1%, with an average energy loss of 21.2%±3.1% (40.6 kcal/d in the full-dose almond phase). Bioaccessibility of energy and fat from the diet as a whole was significantly less with almond consumption (in both half- and full-dose phases) compared with the control. Bioaccessibility of fat was significantly different between treatment phases (P<.001) and on average lower by 5.1% and 6.3% in the half- and full-dose almond phases, respectively, compared with the control phase. Energy bioaccessibility was significantly different between the treatment phases (P=.02), decreasing by approximately 2% with the inclusion of the full dose of almonds compared with the control. Conclusion: Energy content of almonds may not be as bioaccessible in individuals with hyperlipidemia as predicted by Atwater factors, as suggested by the increased fat excretion with almond intake compared with the control.
Park, S.K., C.-M. Oh, J.G. Kang, H.S. Seok, J.Y. Jung, 2021. The association between left ventricular hypertrophy and consumption of nuts, including peanuts, pine nuts, and almonds. Nutr Metab Cardiovasc Dis. 31(1):76-84.
Background and aims: Studies have reported that nut consumption is potentially beneficial in preventing cardiovascular disease. However, data are insufficient regarding the association between nut consumption and left ventricular hypertrophy (LVH). Methods and results: In the Kangbuk Samsung Health Study, the participants were 34,617 men and 12,257 women who completed a food-frequency questionnaire for nut consumption and received echocardiography. Nut consumption was evaluated only for peanuts, pine nuts, and almonds defining 15g as one serving/servings dose. Multivariable adjusted odds ratio (OR) and 95% confidence interval (CI) for LVH were evaluated according to the consumption frequency of one serving dose of nut. The frequency of nut consumption was categorized into five groups (<1/month, 1/month-1/week, 1-2/week, 2-4/week, and ≥4/week). The subgroup analysis was conducted by dividing the participants into the following two groups: the nonhypertensive/nondiabetic group and hypertensive or diabetic group. In women, nut consumption ≥2/week had the lower multivariable adjusted OR and 95% CI for LVH (2-4/week: 0.46 [0.26-0.81] and ≥4/week: 0.48 [0.25-0.92]) when compared with nut consumption <1/month. This association was identically observed in the subgroup analysis for women without hypertension and diabetes mellitus (DM) and women with hypertension or DM. However, men did not show the significant association. Conclusion: In women, nut consumption ≥2/week was associated with the decreased probability of LVH. Further research studies should investigate whether the beneficial effect of nut consumption on LV structure results in better cardiovascular prognosis.
