Archive

Research Area: Cardiovascular Health

A randomized, controlled trial on the effects of almonds on lipoprotein response to a higher carbohydrate, lower fat diet in men and women with abdominal adiposity.

Williams, P.T., N. Bergeron, S. Chiu, R.M. Krauss, 2019. A randomized, controlled trial on the effects of almonds on lipoprotein response to a higher carbohydrate, lower fat diet in men and women with abdominal adiposity. Lipids in Health and Disease. 18: 83. doi: https://lipidworld.biomedcentral.com/track/pdf/10.1186/s12944-019-1025-4.

Background: Almonds have been shown to lower LDL cholesterol but there is limited information regarding their effects on the dyslipidemia characterized by increased levels of very low-density lipoproteins (VLDL) and small, dense low-density lipoprotein (LDL) particles that is associated with abdominal adiposity and high carbohydrate intake. The objective of the present study was to test whether substitution of almonds for other foods attenuates carbohydrate-induced increases in small, dense LDL in individuals with increased abdominal adiposity. Methods: This was a randomized cross-over study of three 3wk diets, separated by 2wk washouts: a higher carbohydrate (CHO) reference diet (CHOhigh), a higher-CHO diet with isocaloric substitution of 20% kcal (E) from almonds (CHOhigh + almonds), and a lower-CHO reference diet (CHOlow) in 9 men and 15 women who were overweight or obese. The two CHOhigh diets contained 50% carbohydrate, 15% protein, 35% fat (6% saturated, 21% monounsaturated, 8% polyunsaturated), while the CHOlow diet contained 25% carbohydrate, 28% protein, 47% fat (8% saturated, 28% monounsaturated, 8% polyunsaturated). Lipoprotein subfraction concentrations were measured by ion mobility. Results: Relative to the CHOlow diet: 1) the CHOhigh +almonds diet significantly increased small, dense LDLIIIa (mean difference ± SE: 28.6±10.4nmol/L, P=0.008), and reduced LDL-peak diameter (−1.7±0.6Å, P=0.008); 2) the CHOhigh diet significantly increased medium-sized LDLIIb (24.8±11.4nmol/L, P=0.04) and large VLDL (3.7±1.8 nmol/L, P=0.05). Relative to CHOlow, the effects of CHOhigh on LDLIIIa (17.7±10.6nmol/L) and LDL-peak diameter (−1.1±0.6Å) were consistent with those of CHOhigh + almonds, and the effects of CHOhigh +almonds on LDLIIb (21.0± 11.2nmol/L) and large VLDL (2.8±1.8nmol/L) were consistent with those of CHOhigh, but did not achieve statistical significance (P>0.05). None of the variables examined showed a significant difference between the CHOhigh + almonds and CHOhigh diets (P>0.05). Conclusion: Our analyses provided no evidence that deriving 20% E from almonds significantly modifies increases in levels of small, dense LDL or other plasma lipoprotein changes induced by a higher carbohydrate low saturated fat diet in individuals with increased abdominal adiposity.

Effects of almond consumption on metabolic and liver function in overweight and obese adults with elevated fasting blood glucose: A randomized controlled trial.

Bowen, J., N.D. Luscombe-Marsh, W. Stonehouse, C. Tran, G.B. Rogers, N. Johnson, C.H. Thompson, G.D. Brinkworth, 2019. Effects of almond consumption on metabolic and liver function in overweight and obese adults with elevated fasting blood glucose: A randomized controlled trial. Clin. Nutr. ESPEN 30:10-18.

Background: Almonds are a rich source of bioactive components. This study examined the effects of daily almond consumption on glycaemic regulation, liver fat concentration and function, adiposity, systemic inflammation and cardiometabolic health. Methods: 76 adults with elevated risk of type 2 diabetes (T2D) or T2D (age: 60.7 ± 7.7 years, body mass index: 33.8 ± 5.6 kg/m2) were randomly assigned to daily consumption of either 2 servings of almonds (AS:56 g/day) or an isocaloric, higher carbohydrate biscuit snack (BS) for 8 weeks. Glycosylated haemoglobin (HbA1c), glycaemic variability (GV), liver fat, serum aminotransferases, body weight and composition, markers of cardio-metabolic risk and systemic inflammation were assessed at baseline and week 8. Results: No group differential effects were observed on HbA1c, GV, body weight and composition, liver fat and aminotransferases, cardio-metabolic health and inflammatory markers (all P > 0.05). For serum TC/HDL-C ratio a significant gender × treatment × time interaction occurred (P < 0.01), such that in women TC/HDL-C ratio was significantly reduced after AS compared to BS (-0.36 [0.26] mmol/L [n = 14] vs. -0.14 [0.32] mmol/L [n = 17]; P = 0.05), but not in men (P = 0.52). Conclusions: Compared to BS, AS consumed between meals did not substantially alter glycaemic regulation, liver fat or function, adiposity, and metabolic health and inflammatory markers. Serum TC/HDL-C ratio improved in women, but not in men with AS; but as this sub-analysis was not defined a priori the results should be interpreted with caution. Further research should examine the longer-term health effects of regular almond consumption and differential gender responses.

Lipid lowering effect of almonds (Prunus Dulcis) in healthy adults.

Tahir, F.N., M. Danyal, S.I.A. Shah, J.A. Qureshi, 2019. Lipid lowering effect of almonds (Prunus Dulcis) in healthy adults. Pakistan Journal of Medical and Health Sciences. 12(4):1356-1358.

Background: Almonds (Prunus dulcis) are low in saturated fats and cholesterol and high in unsaturated fatty acids. Almonds also contain high concentrations of other nutrients like vitamin E, plant sterols, phytochemicals and dietary fibers. Almonds are associated with a reduced risk of cardiovascular disorders (CVD) by having a potentially beneficial impact of on serum lipids due to their nutrient composition. Aim: To investigate the effect of regular almond consumption on the serum lipid profile of normolipidemic adults. Methods: In this non-randomized prospective study, 19 normolipidemic adults (10 males, 9 females) with an age range from 21 to 60 years consumed 50 grams of raw almonds for 30 days. Fasting blood samples were collected from each participant at baseline and on the 31st day for lipid profile analysis. Results: Marked decreases in serum total cholesterol level (p-value= 0.000) and serum low-density lipoprotein (LDL) level (p-value= 0.047) were observed from baseline values following almond treatment for a month. An increase in high density lipoprotein (HDL) level was also seen but it was not statistically significant (p-value=0.081). Conclusion: Regular intake of almonds can help maintain a normal lipid profile in healthy adults and reduce the risk of CVD. Almond consumption should be encouraged in the local healthy population for improved metabolic and cardiovascular health outcomes.

Nut consumption in relation to cardiovascular disease incidence and mortality among patients with diabetes mellitus.

Liu, G., M. Guasch-Ferre, Y. Hu, Y. Li, F.B. Hu, E.B. Rimm, J.E. Manson, K. Rexrode, Q. Sun, 2019. Nut consumption in relation to cardiovascular disease incidence and mortality among patients with diabetes mellitus. Circulation Research. doi.org/10.1161/CIRCRESAHA.118.314316

Rationale: The evidence regarding the potential health benefits of nut consumption among individuals with type 2 diabetes is limited. Objective: To examine intake of total and specific types of nuts, including tree nuts and peanuts, in relation to subsequent risk of cardiovascular disease (CVD), including coronary heart disease (CHD) and stroke, and all-cause and cause-specific mortality among individuals with diabetes. Methods and Results: This prospective analysis included 16,217 men and women with diabetes at baseline or diagnosed during follow-up (Nurses’ Health Study: 1980-2014, Health Professionals Follow-Up Study: 1986-2014). Nut consumption was assessed using a validated food frequency questionnaire and updated every 2-4 years. During 223,682 and 254,923 person-years of follow-up, there were 3,336 incident CVD cases and 5,682 deaths. Higher total nut consumption was associated with a lower risk of CVD incidence and mortality. The multivariate-adjusted hazard ratios (95% confidence intervals) for participants who consumed 5 or more servings of total nuts per week (1 serving=28g), compared with those who consumed less than 1 serving per month, were 0.83 (0.71-0.98; P trend=0.01) for total CVD incidence, 0.80 (0.67-0.96; P trend=0.005) for CHD incidence, 0.66 (0.52-0.84; P trend<0.001) for CVD mortality, and 0.69 (0.61-0.77; P trend<0.001) for all-cause mortality. Total nut consumption was not significantly associated with risk of stroke incidence or cancer mortality. For specific types of nuts, higher tree nut consumption was associated with lower risk of total CVD, CHD incidence, and mortality due to CVD, cancer, and all causes, while peanut consumption was associated with lower all-cause mortality only (all P trend<0.001). In addition, compared with participants who did not change the consumption of total nuts from pre- to post-diabetes diagnosis, participants who increased consumption of total nuts after diabetes diagnosis had an 11% lower risk of CVD, a 15% lower CHD risk, a 25% lower CVD mortality, and a 27% lower all-cause mortality. The associations persisted in subgroup analyses stratified by sex/cohort, body mass index at diabetes diagnosis, smoking status, diabetes duration, nut consumption before diabetes diagnosis, or diet quality. Conclusions: Higher consumption of nuts, especially tree nuts, is associated with lower CVD incidence and mortality among participants with diabetes. These data provide novel evidence that supports the recommendation of incorporating nuts into healthy dietary patterns for the prevention of CVD complications and premature deaths among individuals with diabetes.