Farvid, M.S., M. Ding, A. Pan, Q. Sun, S.E. Chiuve, L.M. Steffen, W.C. Willett, F.B. Hu, 2014. Dietary linoleic acid and risk of coronary heart disease: a systematic review and meta-analysis of prospective cohort studies. Circulation. 130(18):1568-1578.
Background: Prior studies on intake of linoleic acid (LA), the predominant n-6 fatty acid, and coronary heart disease (CHD) risk have generated inconsistent results. We performed a systematic review and meta-analysis of prospective cohort studies to summarize the evidence regarding the relation of dietary LA intake and CHD risk. Methods and Results: We searched MEDLINE and EMBASE databases through June, 2013 for prospective cohort studies that reported the association between dietary LA and CHD events. In addition, we utilized unpublished data from cohort studies in a previous pooling project. We pooled the multivariate-adjusted relative risk (RR) comparing the highest with the lowest categories of LA intake using fixed-effect meta-analysis. We identified 13 published and unpublished cohort studies with a total of 310,602 individuals and 12,479 total CHD events including 5,882 CHD deaths. Comparing the highest to the lowest category, dietary LA was associated with a 15% lower risk of CHD events (pooled RR, 0.85; 95% confidence intervals (95% CI): 0.78-0.92; I²=35.5%) and a 21% lower risk of CHD deaths (pooled RR, 0.79; 95% CI, 0.71-0.89; I²=0.0%). A 5% of energy increment in LA intake replacing energy from saturated fat intake was associated with a 9% lower risk of CHD events (RR, 0.91; 95% CI, 0.86-0.96) and a 13% lower risk of CHD deaths (RR, 0.87; 95% CI, 0.82-0.94). Conclusions: In prospective observational studies, dietary LA intake is inversely associated with CHD risk in a dose-response manner. These data provide support for current recommendations to replace saturated fat with polyunsaturated fat for primary prevention of CHD.
Burns-Whitmore, B., E. Haddad, J. Sabaté, S. Rajaram, 2014. Effects of supplementing n-3 fatty acid enriched eggs and walnuts on cardiovascular disease risk markers in healthy free-living lacto-ovo-vegetarians: a randomized, crossover, free-living intervention study. Nutr J. 13(1):29.
Background: Plant and marine n-3 fatty acids (FA) may favorably modify select markers of cardiovascular disease risk. Whether supplementing the habitual diet of lacto-ovo-vegetarians (LOV) with walnuts (containing α-linolenic acid, ALA) and n-3 FA enriched eggs (containing primarily docosahexaenoic acid, DHA and ALA) would have equivalent effects on CVD risk factors is explored in this study. Methods: In this study, 20 healthy free-living LOVs following their habitual diet were randomly assigned in a crossover design to receive one of three supplements: n-3 FA enriched egg (6/week), walnuts (28.4 g, 6/week) or a standard egg, 6/week (control) for 8 weeks each with 4-wk washout between treatments. Erythrocyte membrane fatty acids, serum lipids and inflammatory markers were measured at the end of each treatment. Results: Dietary compliance was observed by an expected increase in erythrocyte membrane ALA following the walnut treatment and in DHA following the n-3 FA enriched egg treatment. Walnut treatment lowered serum triacylglycerol, total cholesterol and Apo B (p < 0.05) compared to the standard egg but not the n-3 FA enriched egg treatment. However, walnut treatment significantly reduced total: HDL cholesterol ratio compared to both egg treatments. There were no differences between treatments for any of the inflammatory markers. Conclusions: For LOV, a direct source of DHA such as n-3 FA enriched eggs seems necessary to increase membrane levels of DHA. However for producing an overall favorable blood lipid profile, daily consumption of a handful of walnuts rich in ALA may be a preferred option for lacto-ovo vegetarians.
Farvid, M.S., Ding, M., Pan, A., Sun, Q., Chiuve, S.E., Steffen, L.M., Willett, W.C., Hu, F.B, 2014. Dietary linoleic acid and risk of coronary heart disease: a systematic review and meta-analysis of prospective cohort studies. Circulation. 130(18):1568-1578.
BACKGROUND: Prior studies on intake of linoleic acid (LA), the predominant n-6 fatty acid, and coronary heart disease (CHD) risk have generated inconsistent results. We performed a systematic review and meta-analysis of prospective cohort studies to summarize the evidence regarding the relation of dietary LA intake and CHD risk. METHODS AND RESULTS: We searched MEDLINE and EMBASE databases through June, 2013 for prospective cohort studies that reported the association between dietary LA and CHD events. In addition, we utilized unpublished data from cohort studies in a previous pooling project. We pooled the multivariate-adjusted relative risk (RR) comparing the highest with the lowest categories of LA intake using fixed-effect meta-analysis. We identified 13 published and unpublished cohort studies with a total of 310,602 individuals and 12,479 total CHD events including 5,882 CHD deaths. Comparing the highest to the lowest category, dietary LA was associated with a 15% lower risk of CHD events (pooled RR, 0.85; 95% confidence intervals (95% CI): 0.78-0.92; I²=35.5%) and a 21% lower risk of CHD deaths (pooled RR, 0.79; 95% CI, 0.71-0.89; I²=0.0%). A 5% of energy increment in LA intake replacing energy from saturated fat intake was associated with a 9% lower risk of CHD events (RR, 0.91; 95% CI, 0.86-0.96) and a 13% lower risk of CHD deaths (RR, 0.87; 95% CI, 0.82-0.94).CONCLUSIONS: In prospective observational studies, dietary LA intake is inversely associated with CHD risk in a dose-response manner. These data provide support for current recommendations to replace saturated fat with polyunsaturated fat for primary prevention of CHD.
Salas-Salvado´, J., M. Guasch-Ferre´, M. Bullo´, J. Sabate´, 2014. Nuts in the prevention and treatment of metabolic syndrome. Am J Clin Nutr. 100(suppl):399S–407S,
Nuts are rich in many bioactive compounds that can exert beneficial effects on cardiovascular health. We reviewed the evidence relating nut consumption and the metabolic syndrome (MetS) and its components. Nuts reduce the postprandial glycemic response; however, long-term trials of nuts on insulin resistance and glycemic control in diabetic individuals are inconsistent. Epidemiologic studies have shown that nuts may lower the risk of diabetes incidence in women. Few studies have assessed the association between nuts and abdominal obesity, although an inverse association with body mass index and general obesity has been observed. Limited evidence suggests that nuts have a protective effect on blood pressure and endothelial function. Nuts have a cholesterol-lowering effect, but the relation between nuts and hypertriglyceridemia and high-density lipoprotein cholesterol is not well established. A recent pooled analysis of clinical trials showed that nuts are inversely related to triglyceride concentrations only in subjects with hypertriglyceridemia. An inverse association was found between the frequency of nut consumption and the prevalence and the incidence of MetS. Several trials evaluated the effect of nuts on subjects with MetS and found that they may have benefits in some components. Compared with a low-fat diet, a Mediterranean diet enriched with nuts could be beneficial for MetS management. The protective effects on metabolism could be explained by themodulation of inflammation and oxidation. Further trials are needed to clarify the role of nuts in MetS prevention and treatment.
Nishi, S.K., C.W.C. Kendall, R.P. Bazinet, B. Bashyam, C.A. Ireland, L.S.A. Augustin, S. Blanco Mejia, J.L. Sievenpiper, D.J.A. Jenkins, 2014. Nut consumption, serum fatty acid profile and estimated coronary heart disease risk in type 2 diabetes. Nutrition, Metabolism & Cardiovascular Diseases. 24(8):845-852.
Background and aims: Nut consumption has been associated with decreased risk of coronary heart disease (CHD) and type 2 diabetes which has been largely attributed to their healthy fatty acid profile, yet this has not been ascertained. Therefore, we investigated the effect of nut consumption on serum fatty acid concentrations and how these relate to changes in markers of glycemic control and calculated CHD risk score in type 2 diabetes. Methods and results: 117 subjects with type 2 diabetes consumed one of three iso-energetic (mean 475 kcal/d) supplements for 12 weeks: 1. full-dose nuts (50e100 g/d); 2. half-dose nuts with half-dose muffins; and 3. full-dose muffins. In this secondary analysis, fatty acid concentrations in the phospholipid, triacylglycerol, free fatty acid, and cholesteryl ester fractions from fasting blood samples obtained at baseline and week 12 were analyzed using thin layer and gas chromatography. Full-dose nut supplementation significantly increased serum oleic acid (OA) and MUFAs compared to the control in the phospholipid fraction (OA: P = 0.036; MUFAs: P = 0.024). Inverse associations were found with changes in CHD risk versus changes in OA and MUFAs in the triacylglycerol (r = -0.256, P = 0.011; r = -0.228, P = 0.024, respectively) and phospholipid (r = -0.278, P = 0.006; r = -0.260, P = 0.010, respectively) fractions. In the cholesteryl ester fraction, change in MUFAs was inversely associated with markers of glycemic control (HbA1c: r = -0.250, P = 0.013; fasting blood glucose: r = -0.395, P < 0.0001). Conclusion: Nut consumption increased OA and MUFA content of the serum phospholipid fraction, which was inversely associated with CHD risk factors and 10-year CHD risk
Sauder, K.A., C.E. McCrea, J.S. Ulbrecht, P.M. Kris‐Etherton, S.G. West, 2014. Pistachio nut consumption modifies systemic hemodynamics, increases heart rate variability, and reduces ambulatory blood pressure in well‐controlled type 2 diabetes: a randomized trial. J. Am. Heart Assoc. doi: 10.1161/JAHA.114.000873
Background Managing cardiovascular risk factors is important for reducing vascular complications in type 2 diabetes, even in individuals who have achieved glycemic control. Nut consumption is associated with reduced cardiovascular risk; however, there is mixed evidence about the effect of nuts on blood pressure (BP), and limited research on the underlying hemodynamics. This study assessed the effect of pistachio consumption on BP, systemic hemodynamics, and heart rate variability in adults with well‐controlled type 2 diabetes. Methods and Results We enrolled 30 adults (40 to 74 years) with type 2 diabetes in a randomized, crossover, controlled feeding study. After a 2‐week run‐in period, participants consumed a low‐fat control diet (27% fat) containing low‐fat/high‐carbohydrate snacks and a moderate‐fat diet (33% fat) containing pistachios (20% of total energy) for 4 weeks each, separated by a 2‐week washout. Following each diet period, we assessed BP, systemic hemodynamics, and heart rate variability at rest and during acute mental stress, and, in a subset of participants (n=21), 24‐hour ambulatory BP. BP at rest and during stress did not differ between treatments. The pistachio diet significantly reduced total peripheral resistance (−3.7±2.9%,P=0.004), increased cardiac output (3.1±2.3%, P=0.002), and improved some measures of heart rate variability (all P<0.05). Systolic ambulatory BP was significantly reduced by 3.5±2.2 mm Hg (P=0.046) following the pistachio diet, with the greatest reduction observed during sleep (−5.7±2.6 mm Hg, P=0.052). Conclusions A moderate‐fat diet containing pistachios modestly improves some cardiovascular risk factors in adults with well‐controlled type 2 diabetes.
Abazarfard Z., M. Salehi, S. Keshavarzi, 2013. The effect of almonds on anthropometric measurements and lipid profile in overweight and obese females in a weight reduction program: A randomized controlled clinical trial. J Res Med Sci. 19:457-64.
Background: Due to the wholesome benefits of nuts increased consumption of them has been recommended. However, because of nut’s high energy density, the role of them in the treatment of overweight and obesity is vague. This current clinical trial study aims to investigate the effects of a balanced hypo-caloric almond-enriched diet (AED) (almond group) in comparison to a balanced Hypo-caloric nut-free diet (NFD) (nut-free group) on body weight and cardiovascular disease risk factors in women with body mass index (BMI) >25 for 3-month. Materials and Methods: A total of 108 overweight and obese women were assigned in our 3-month randomized controlled trial. The subjects were randomly divided into two groups regarding a balanced hypo-caloric diet with or without almond. The planned reduced calorie diets for both groups were identical except for the almond group who consumed 50 g of almonds daily. Anthropometric and laboratory measurements of the participants who completed the study were made prior to and at the end of the study. Results: A total of 100 subjects completed the study. Weight, BMI, waist circumference, waist to hip circumference ratio, total cholesterol, and triglyceride, total: High density lipoprotein-cholesterol (HDL-C), fasting blood sugar and diastolic blood pressure decreased significantly in the almond group compared to the nut-free group (P > 0.001). Greater reduction in low density lipoprotein-cholesterol (P > 0.002) and systolic blood pressure (P > 0.001) and greater increase in HDL-C (P = 0.001) were found in the nut-free group. Conclusion: The balanced hypo-caloric AED in comparison to the balanced hypo-caloric NFD led to a greater weight-loss and overall better improvements in studied cardiovascular disease risk factors.
Bao, Y., J. Han, F.B. Hu, E.L. Giovannucci, M.J. Stampfer, W.C. Willett, C.S. Fuchs, 2013. Association of nut consumption with total and cause-specific mortality. N Engl J Med. 369:2001-2011.
Background: Increased nut consumption has been associated with a reduced risk of major chronic diseases, including cardiovascular disease and type 2 diabetes mellitus. However, the association between nut consumption and mortality remains unclear. Methods: We examined the association between nut consumption and subsequent total and cause-specific mortality among 76,464 women in the Nurses’ Health Study (1980–2010) and 42,498 men in the Health Professionals Follow-up Study (1986–2010). Participants with a history of cancer, heart disease, or stroke were excluded. Nut consumption was assessed at baseline and updated every 2 to 4 years. Results: During 3,038,853 person-years of follow-up, 16,200 women and 11,229 men died. Nut consumption was inversely associated with total mortality among both women and men, after adjustment for other known or suspected risk factors. The pooled multivariate hazard ratios for death among participants who ate nuts, as compared with those who did not, were 0.93 (95% confidence interval [CI], 0.90 to 0.96) for the consumption of nuts less than once per week, 0.89 (95% CI, 0.86 to 0.93) for once per week, 0.87 (95% CI, 0.83 to 0.90) for two to four times per week, 0.85 (95% CI, 0.79 to 0.91) for five or six times per week, and 0.80 (95% CI, 0.73 to 0.86) for seven or more times per week (P<0.001 for trend). Significant inverse associations were also observed between nut consumption and deaths due to cancer, heart disease, and respiratory disease. Conclusions: In two large, independent cohorts of nurses and other health professionals, the frequency of nut consumption was inversely associated with total and cause-specific mortality, independently of other predictors of death.
Sabaté, J., M. Wien, 2013. Consumption of nuts in the prevention of cardiovascular disease. Curr Nutr Rep. 2:258–266.
The leading cause of morbidity and mortality in highly developed and low- and middle-income nations is cardiovascular disease (CVD). The establishment of healthy dietary patterns is one of the cornerstones of CVD prevention, and nuts have emerged as favorable components of dietary patterns associated with reducing the CVD epidemic. The etiological connection between nuts for the prevention of CVD is based upon several lines of evidence. First, nuts are nutrient-dense whole foods that contain a distinctive mix of macronutrients, specific micronutrients and non-nutrients that have been associated with cardioprotection. Second, numerous human feeding trials have demonstrated that nut intake improves the serum lipid profile, reduces oxidation and inflammation, and improves vascular reactivity. Third, nut consumption is consistently associated with a reduced risk of CVD in many epidemiological studies. Lastly, a recent large randomized clinical trial conducted in Spain demonstrated that consuming mixed nuts daily lowers CVD risk by 30%.
Rohrmann, S., D. Faeh, 2013. Should we go nuts about nuts? BMC Medicine. 11:165.
Since the beginning of the 1990s, increasing evidence supports beneficial effects of nut consumption on health. A new analysis of the Spanish PREDIMED trial, published in BMC Medicine, has expanded our knowledge. The study showed that individuals eating nuts more than three times per week died less often from cardiovascular disease and cancer than non-consumers. The study also adds an important finding that previous epidemiological studies could not provide: a protective effect on premature mortality was only seen in the intervention group in which nut consumption increased during the 4.8 years of follow-up, not in the intervention group with additional olive oil consumption or in the control group. Nut consumption actually decreased during follow-up in the latter two groups. Questions remain to be answered on the quantity of nuts to be consumed for health benefits, on possible mechanisms of action, and on whether some types of nuts should be favored.
