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Effects of plant-based diets high in raw or roasted almonds, or roasted almond butter on serum lipoproteins in humans

Spiller, G.A., A. Miller, K. Olivera, J. Reynolds, B. Miller, S.J. Morse, A. Dewell, J.W. Farquhar, 2003. Effects of plant-based diets high in raw or roasted almonds, or roasted almond butter on serum lipoproteins in humans. J Am Coll Nutr,  22(3):195-200.

OBJECTIVE: To compare the lipid-altering effect of roasted salted almonds and roasted almond butter with that of raw almonds, as part of a plant-based diet. METHODS: Thirty-eight free-living, hypercholesterolemic men (n = 12) and women (n = 26) with a mean total serum cholesterol (TC) of 245 + 29 mg/dL (mean + SD) followed a heart-healthy diet including 100g of one of three forms of almonds: roasted salted almonds, roasted almond butter or raw almonds for four weeks. Measurements of serum TC, triglycerides (TG), selected lipoproteins and blood pressure were taken at baseline and after four weeks. RESULTS: All three forms of almonds in the context of a heart-healthy diet significantly lowered low-density lipoprotein-cholesterol (LDL) from baseline to the completion of the study. Both raw and roasted almonds significantly lowered TC, whereas the decrease by almond butter (in a smaller cohort) did not reach statistical significance. High-density lipoprotein-cholesterol (HDL) did not significantly change with raw or roasted almonds but slightly increased with almond butter. At the end of the study, blood pressure did not change significantly from baseline values for any of the groups. CONCLUSION: These results suggest that unblanched almonds-whether raw, dry roasted, or in roasted butter form-can play an effective role in cholesterol-lowering, plant-based diets.

Serum lipid response to the graduated enrichment of a step 1 diet with almonds: a randomized feeding trial

Sabaté, J., E. Haddad, J.S. Tanzman, P. Jambazian, S. Rajaram, 2003.  Serum lipid response to the graduated enrichment of a step 1 diet with almonds: a randomized feeding trial. Am J Clin Nut.77(6):1379-84.

Background: Frequent consumption of nuts may lower the risk of cardiovascular disease by favorably altering serum lipid and lipoprotein concentrations. Objective: We compared the effects of 2 amounts of almond intake with those of a National Cholesterol Education Program Step I diet on serum lipids, lipoproteins, apolipoproteins, and glucose in healthy and mildly hypercholesterolemic adults. Design: In a randomized crossover design, 25 healthy subjects (14 men, 11 women) with a mean (± SD) age of 41 ± 13 y were fed 3 isoenergetic diets for 4 wk each after being fed a 2-wk run-in diet (containing 34% of energy from fat). The experimental diets included a Step I diet, a low-almond diet, and a high-almond diet, in which almonds contributed 0%, 10%, and 20% of total energy, respectively. Results: Inverse relations were observed between the percentage of energy in the diet from almonds and the subject’s total cholesterol (value for trend < 0.001), LDL-cholesterol (< 0.001), and apolipoprotein B (< 0.001) concentrations and the ratios of LDL to HDL cholesterol (< 0.001) and of apolipoprotein B to apolipoprotein A (< 0.001). Compared with the Step I diet, the high-almond diet reduced total cholesterol (0.24 mmol/L or 4.4%; = 0.001), LDL cholesterol (0.26 mmol/L or 7.0%; < 0.001), and apolipoprotein B (6.6 mg/dL or 6.6%; < 0.001); increased HDL cholesterol (0.02 mmol/L or 1.7%; = 0.08); and decreased the ratio of LDL to HDL cholesterol (8.8%; < 0.001). Conclusions: Isoenergetic incorporation of ~68 g of almonds (20% of energy) into an 8368-kJ (2000-kcal) Step I diet markedly improved the serum lipid profile of healthy and mildly hypercholesterolemic adults. Total and LDL-cholesterol concentrations declined with progressively higher intakes of almonds, which suggests a dose-response relation.

 

Plant-based foods and prevention of cardiovascular disease: an overview

Hu, F.B., 2003.  Plant-based foods and prevention of cardiovascular disease: an overview. Am J Clin Nutr. 78:544S-51S.

Evidence from prospective cohort studies indicates that a high consumption of plant-based foods such as fruit and vegetables, nuts, and whole grains is associated with a significantly lower risk of coronary artery disease and stroke. The protective effects of these foods are probably mediated through multiple beneficial nutrients contained in these foods, including mono- and polyunsaturated fatty acids, n-3 fatty acids, antioxidant vitamins, minerals, phytochemicals, fiber, and plant protein. In dietary practice, healthy plant-based diets do not necessarily have to be low in fat. Instead, these diets should include unsaturated fats as the predominant form of dietary fat (e.g., fats from natural liquid vegetable oils and nuts), whole grains as the main form of carbohydrate, an abundance of fruit and vegetables, and adequate n-3 fatty acids. Such diets, which also have many other health benefits, deserve more emphasis in dietary recommendations to prevent chronic diseases.

Identification and characterisation of the IgE-binding proteins 2S albumin and conglutin γ in almond (Prunus dulcis) seeds.

Poltronieri. P., M.S. Cappello, N. Dohmae, A. Conti, D. Fortunato, E.A. Pastorello, C. Ortolani, G. Zacheo, 2002. Identification and characterisation of the IgE-binding proteins 2S albumin and conglutin γ in almond (Prunus dulcis) seeds. Int Arch Allergy Immunol. 128:97–104.

Background: Almond proteins can cause severe anaphylactic reactions in susceptible individuals. The aim of this study was the identification of IgE-binding proteins in almonds and the characterisation of these proteins by N-terminal sequencing. Methods: Five sera were selected from individuals with a positive reaction to food challenge. Sodium dodecylsulphate-polyacrylamide gel electrophoresis and immunoblotting were performed on almond seed proteins. Purified IgE-binding proteins were tested for immunoblot inhibition with sera preincubated with extracts of hazelnut and walnut. Results: N-terminal sequences of the 12-, 30- and 45-kD proteins were obtained. The 45- and 30-kD proteins shared the same N terminus, with 60% homology to the conglutin γ heavy chain from lupine seed (Lupinus albus) and to basic 7S globulin from soybean (Glycine max). The sequences of the N-terminal 12-kD protein and of an internal peptide obtained by endoproteinase digestion showed good homology to 2S albumin from English walnut (Jug r 1). Immunoblot inhibition experiments were performed and IgE binding to almond 2S albumin and conglutin γ was detected in the presence of cross-reacting walnut or hazelnut antigens. Conclusions: Two IgE-binding almond proteins were N-terminally sequenced and identified as almond 2S albumin and conglutin γ. Localisation and conservation of IgE binding in a 6-kD peptide obtained by endoproteinase digestion of 2S albumin was shown.

A dietary portfolio approach to cholesterol reduction: combined effects of plant sterols, vegetable proteins and viscous fibers in hypercholesterolemia

Jenkins, D.J.A., C.W.C. Kendall, D. Faulkner, E. Vidgen, E.A. Trautwein, T.L. Parker, A. Marchie, G. Koumbridis, K.G. Lapsley, R.G. Josse, L.A. Leiter, P.W. Connelly, 2002. A dietary portfolio approach to cholesterol reduction: combined effects of plant sterols, vegetable proteins and viscous fibers in hypercholesterolemia. Metabolism. 51:1596-1604.

Plant sterols, soy proteins, and viscous fibers are advised for cholesterol reduction but their combined effect has never been tested. We therefore assessed their combined effect on blood lipids in hyperlipidemic subjects who were already consuming a low-saturated fat, low-cholesterol diet before starting the study. The test (combination) diet was 1 month in duration and was very low in saturated fat and high in plant sterols (1 g/1,000 kcal), soy protein (23 g/1,000 kcal), and viscous fibers (9 g/1,000 kcal) obtained from foods available in supermarkets and health food stores. One subject also completed 2 further diet periods: a low-fat control diet and a control diet plus 20 mg/d lovastatin. Fasting blood lipids, blood pressure, and body weight were measured prior to and at weekly intervals during the study. The combination diet was rated as acceptable and very filling. The diet reduced low-density lipoprotein (LDL)-cholesterol by 29.0% +/- 2.7% (P <.001) and the ratio of LDL-cholesterol to high-density lipoprotein (HDL)-cholesterol by 26.5% +/- 3.4% (P <.001). Near maximal reductions were seen by week 2. In the subject who took Mevacor and control diets each for 4 weeks, the reduction in LDL:HDL-cholesterol on Mevacor was similar to the combination diet. We conclude that acceptable diets of foods from supermarkets and health food stores that contain recognized cholesterol-lowering dietary components in combination (a dietary portfolio) may be as effective as the starting dose of older first-line drugs in managing hypercholesterolemia.

Almonds and almond oil have similar effects on plasma lipids and LDL oxidation in healthy men and women

Hyson, D., B.O. Schneeman, P.A. Davis, 2002. Almonds and almond oil have similar effects on plasma lipids and LDL oxidation in healthy men and women. J Nutr. 132(4):703-7.

ABSTRACT Epidemiologic and clinical studies have shown that nut consumption is associated with favorable plasma lipid profiles and reduced cardiovascular risk. These effects may result from their high monounsaturated fat (MUFA) content but nuts contain constituents other than fatty acids that might be cardioprotective. We conducted a study to compare the effects of whole-almond vs. almond oil consumption on plasma lipids and LDL oxidation in healthy men and women. Using a randomized crossover trial design, 22 normolipemic men and women replaced half of their habitual fat (~14% of ~29% energy) with either whole almonds (WA) or almond oil (AO) for 6-wk periods. Compliance was ascertained by monitoring dietary intake via biweekly 5-d food records, return of empty almond product packages and weekly meetings with a registered dietitian. Fat replacement with either WA and AO resulted in a 54% increase in percentage of energy as MUFA with declines in both saturated fat and cholesterol intake and no significant changes in total energy, total or polyunsaturated fat intake. The effects of WA and AO on plasma lipids did not differ compared with baseline; plasma triglyceride, total and LDL  cholesterol significantly decreased, 14, 4 and 6% respectively, whereas HDL cholesterol increased 6%. Neither treatment affected in vitro LDL oxidizability. We conclude that WA and AO do not differ in their beneficial effects on the plasma lipid variables measured and that this suggests that the favorable effect of almonds is mediated by components in the oil fraction of these nuts.

Variation in the flavonol glycoside composition of almond seedcoats as determined by MALDI-TOF Mass Spectrometry

Frison-Norrie, S.L., P. Sporns, 2002. Variation in the flavonol glycoside composition of almond seedcoats as determined by MALDI-TOF Mass Spectrometry. J Agric Food Chem. 50:6818-22.

Seedcoats of 16 almond varieties were screened for flavonol glycosides by using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Flavonol glycosides were extracted by a simple methanolic extraction followed by a quick cleanup procedure with a Sep-Pak C18 cartridge. Each of the 16 seedcoat samples exhibited a unique composition. Four flavonol glycosides, isorhamnetin rutinoside, isorhamnetin glucoside, kaempferol rutinoside, and kaempferol glucoside, were detected and quantified with use of rutin as an internal standard. Individual peak ratios were very consistent across triplicate analyses of all samples; the average standard deviation was 9%. In all almond varieties, isorhamnetin rutinoside was the most abundant flavonol glycoside, and the total content ranged from 75 to 250 μg/

Identification and quantification of flavonol glycosides in almond seedcoats using MALDI-TOF MS.

Frison-Norrie, S.L., P. Sporns, 2002. Identification and quantification of flavonol glycosides in almond seedcoats using MALDI-TOF MS. J Agri Food Chem. 50:2782-7.

Interest in the molecular composition of almonds is growing, due to their popularity in a wide variety of food formulations. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a powerful new technique that can be used to rapidly identify and quantify possible bioactive compounds in these popular tree nuts. Four flavonol glycosides were identified in almond seedcoats for the first time:  isorhamnetin rutinoside, isorhamnetin glucoside, kaempferol rutinoside, and kaempferol glucoside. A MALDI-TOF MS methodology was developed using rutin (quercetin-3-rutinoside) as an internal standard to quantitatively determine each of the four flavonol glycosides. Results of MALDI-TOF MS analysis were verified by high performance liquid chromatography.

Effect on body weight of a free 76 kilojoules (320 calorie) daily supplement of almonds for 6 months.

Fraser, G.E., H.W. Bennett, K.B. Jaceldo, J. Sabaté, 2002.  Effect on body weight of a free 76 kilojoules (320 calorie) daily supplement of almonds for 6 months. J Am Coll Nutr. 21(3): 275-83.

Objective: Regular nut consumption is associated with lower rates of heart attack. However, as nuts are fatty foods, they may in theory lead to weight gain, although preliminary evidence has suggested otherwise. We tested the hypothesis that a free daily supplement (averaging 76 kJ) of almonds for six months, with no dietary advice, would not change body weight. Methods: Eighty-one male and female subjects completed the randomized cross-over study. During two sequential six-month periods, diet, body weight and habitual exercise were evaluated repeatedly in each subject. Almonds were provided only during the second period. The design was balanced for seasonal and other calendar trends. Results: During the almond feeding period, average body weight increased only 0.40 (kg) (~ 0.09). The weight change depended on baseline BMI (= 0.05), and only those initially in the lower BMI tertiles experienced small and mainly unimportant weight gains with the almonds. We estimated that 54% (recalls) or 78% (diaries) of the extra energy from almonds was displaced by reductions in other foods. The ratio unsaturated/saturated dietary fat increased by 40% to 50% when almonds were included in the diet. Conclusion: Incorporating a modest quantity (76 kJ) of almonds in the diet each day for six months did not lead on average to statistically or biologically significant changes in body weight and did increase the consumption of unsaturated fats. Further studies are necessary to evaluate longer term effects, especially in men.

Effect of an Indo-Mediterranean diet on progression of coronary artery disease in high-risk patients (Indo-Mediterranean Diet Heart Study): a randomized single-blind trial.

Singh, R.B., G. Dubnov, M.A. Niaz, S. Ghosh, R. Singh, S.S. Rastogi, O. Manor, D. Pella, E.M. Berry, 2002.  Effect of an Indo-Mediterranean diet on progression of coronary artery disease in high-risk patients (Indo-Mediterranean Diet Heart Study): a randomized single-blind trial. Lancet. 360:1455-61.

BACKGROUND: The rapid emergence of coronary artery disease (CAD) in south Asian people is not explained by conventional risk factors. In view of cardioprotective effects of a Mediterranean style diet rich in alpha-linolenic acid, we assessed the benefits of this diet for patients at high risk of CAD. METHODS: We did a randomized, single-blind trial in 1000 patients with angina pectoris, myocardial infarction, or surrogate risk factors for CAD. 499 patients were allocated to a diet rich in whole grains, fruits, vegetables, walnuts, and almonds. 501 controls consumed a local diet similar to the step I National Cholesterol Education Program (NCEP) prudent diet. FINDINGS: The intervention group consumed more fruits, vegetables, legumes, walnuts, and almonds than did controls (573 g [SD 127] vs 231 g [19] per day p<0.001). The intervention group had an increased intake of whole grains and mustard or soy bean oil. The mean intake of alpha-linolenic acid was two-fold greater in the intervention group (1.8 g [SD 0.4] vs 0.8 g [0.2] per day, p<0.001). Total cardiac end points were significantly fewer in the intervention group than the controls (39 vs 76 events, p<0.001). Sudden cardiac deaths were also reduced (6 vs 16, p=0.015), as were non-fatal myocardial infarctions (21 vs 43, p<0.001). We noted a significant reduction in serum cholesterol concentration and other risk factors in both groups, but especially in the intervention diet group. In the treatment group, patients with pre-existing CAD had significantly greater benefits compared with such patients in the control group. INTERPRETATION: An Indo-Mediterranean diet that is rich in alpha-linolenic acid might be more effective in primary and secondary prevention of CAD than the conventional step I NCEP prudent diet.