Augustine Marchie

Dose Response of Almonds on Coronary Heart Disease Risk Factors: Blood Lipids, Oxidized Low-Density Lipoproteins, Lipoprotein(a), Homocysteine, and Pulmonary Nitric Oxide

Background— Although recent studies have indicated that nut consumption may improve levels of blood lipids, nuts are not generally recommended as snacks for hyperlipidemic subjects because of their high fat content. Furthermore, the effective dose is still unknown. Methods and Results— The dose-response effects of whole almonds, taken as snacks, were compared with low-saturated fat (<5% energy) whole-wheat muffins (control) in the therapeutic diets of hyperlipidemic subjects. In a randomized crossover study, 27 hyperlipidemic men and women consumed 3 isoenergetic (mean 423 kcal/d) supplements each for 1 month. Supplements provided 22.2% of energy and consisted of full-dose almonds (73±3 g/d), half-dose almonds plus half-dose muffins, and full-dose muffins. Fasting blood, expired air, blood pressure, and body weight measurements were obtained at weeks 0, 2, and 4. Mean body weights differed <300 g between treatments. The full-dose almonds produced the greatest reduction in levels of blood lipids. Significa...

Type 2 diabetes and the vegetarian diet

Based on what is known of the components of plant-based diets and their effects from cohort studies, there is reason to believe that vegetarian diets would have advantages in the treatment of type 2 diabetes. At present there are few data on vegetarian diets in diabetes that do not in addition have weight loss or exercise components. Nevertheless, the use of whole-grain or traditionally processed cereals and legumes has been associated with improved glycemic control in both diabetic and insulin-resistant individuals. Long-term cohort studies have indicated that whole-grain consumption reduces the risk of both type 2 diabetes and cardiovascular disease. In addition, nuts (eg, almonds), viscous fibers (eg, fibers from oats and barley), soy proteins, and plant sterols, which may be part of the vegetarian diet, reduce serum lipids. In combination, these plant food components may have a very significant impact on cardiovascular disease, one of the major complications of diabetes. Furthermore, substituting soy or other vegetable proteins for animal protein may also decrease renal hyperfiltration, proteinuria, and renal acid load and in the long term reduce the risk of developing renal disease in type 2 diabetes. The vegetarian diet, therefore, contains a portfolio of natural products and food forms of benefit for both the carbohydrate and lipid abnormalities in diabetes. It is anticipated that their combined use in vegetarian diets will produce very significant metabolic advantages for the prevention and treatment of diabetes and its complications.

The effect of combining plant sterols, soy protein, viscous fibers, and almonds in treating hypercholesterolemia.

Reductions in low-density lipoprotein-cholesterol (LDL-C) result from diets containing almonds, or diets that are either low in saturated fat or high in viscous fibers, soy proteins, or plant sterols. We have therefore combined all of these interventions in a single diet (portfolio diet) to determine whether cholesterol reductions could be achieved of similar magnitude to those reported in recent statin trials which reduced cardiovascular events. Twenty-five hyperlipidemic subjects consumed either a portfolio diet (n=13), very low in saturated fat and high in plant sterols (1.2 g/1,000 kcal), soy protein (16.2 g/1,000 kcal), viscous fibers (8.3 g/1,000 kcal), and almonds (16.6 g/1,000 kcal), or a low-saturated fat diet (n=12) based on whole-wheat cereals and low-fat dairy foods. Fasting blood, blood pressure, and body weight were obtained at weeks 0, 2, and 4 of each phase. LDL-C was reduced by 12.1% +/- 2.4% (P<.001) on the low-fat diet and by 35.0% +/- 3.1% (P<.001) on the portfolio diet, which also reduced the ratio of LDL-C to high-density lipoprotein-cholesterol (HDL-C) significantly (30.0% +/- 3.5%; P<.001). The reductions in LDL-C and the LDL:HDL-C ratio were both significantly lower on the portfolio diet than on the control diet (P<.001 and P<.001, respectively). Mean weight loss was similar on test and control diets (1.0 kg and 0.9 kg, respectively). No difference was seen in blood pressure, HDL-C, serum triglycerides, lipoprotein(a) [Lp(a)], or homocysteine concentrations between diets. Combining a number of foods and food components in a single dietary portfolio may lower LDL-C similarly to statins and so increase the potential effectiveness of dietary therapy.

Direct comparison of dietary portfolio vs statin on C-reactive protein.

Background:3-Hydroxy-3-methyl-glutaryl-coenzyme A (HMG-CoA) reductase inhibitors (statins) markedly reduce serum cholesterol and have anti-inflammatory effects. The effect of cholesterol-lowering diets on inflammatory biomarkers is less well known.Objective:To compare the efficacy of a dietary combination (portfolio) of cholesterol-lowering foods vs a statin in reducing C-reactive protein (CRP) as a biomarker of inflammation linked to increased cardiovascular disease risk.Methods:In all, 34 hyperlipidemic subjects completed three 1-month treatments as outpatients in random order: a very low-saturated fat diet (control); the same diet with 20 mg lovastatin (statin); and a diet high in plant sterols (1.0 g/1000 kcal), soy protein (21.4 g/1000 kcal), viscous fibers (9.8 g/1000 kcal), and almonds (14 g/1000 kcal) (portfolio). Fasting blood samples were obtained at weeks 0, 2, and 4.Results:Using the complete data, no treatment reduced serum CRP. However, when subjects with CRP levels above the 75th percentile for previously reported studies (>3.5 mg/l) were excluded, CRP was reduced similarly on both statin, −16.3±6.7% (n=23, P=0.013) and dietary portfolio, −23.8±6.9% (n=25, P=0.001) but not the control, 15.3±13.6% (n=28, P=0.907). The percentage CRP change from baseline on the portfolio treatment (n=25) was greater than the control (n=28, P=0.004) but similar to statin treatment (n=23, P=0.349). Both statin and portfolio treatments were similar in reducing CRP and numerically more effective than control but only the change in portfolio was significant after the Bonferroni adjustment.Conclusions:A combination of cholesterol-lowering foods reduced C-reactive protein to a similar extent as the starting dose of a first-generation statin.

Combined effects of a dietary portfolio of plant sterols, vegetable protein, viscous fibre and almonds on LDL particle size.

Studies conducted in the last 20 years have led to the identification of small dense LDL as an important risk factor for CVD. Consumption of plant sterols, soyabean proteins, viscous fibre and nuts are known to modulate the risk of CVD favourably through their cholesterol (Chol)-lowering properties, both independently and more recently in combination. Nevertheless, their combined impact on the LDL particle size phenotype has never been tested. In the present study, we assessed the effect of incorporating concurrently plant sterols (1 g/4.2 MJ), soyabean protein (23 g/4.2 MJ), viscous fibre (9 g/4.2 MJ) and almonds (15 g/4.2 MJ) into a diet very low in saturated fat in twelve patients with mildly elevated plasma LDL-Chol levels. Fasting blood lipids were obtained at the start of the study and at 2-week intervals during the 4-week study. The diet-induced reduction in plasma LDL-Chol of 30.0 (se 3.0) % (P<0.0001) was attributed to concurrent reductions in the serum Chol concentrations of large (>26.0 nm-30 (se 8) %, P<0.001), medium (25.5-26.0 nm-29 (se 3) %, P<0.001) and small (<25.5 nm-21 (sd 6) %, P<0.01) LDL particles, with near maximal reductions seen by week 2. These results indicate that foods and dietary components advocated for their potential to reduce the risk of CVD are effective in reducing serum concentrations of all LDL fractions including small dense LDL, thus potentially further contributing to an overall lower risk of CVD.

Long-term effects of a plant-based dietary portfolio of cholesterol-lowering foods on blood pressure

Objective:To determine the effect on blood pressure of dietary advice to consume a combination of plant-based cholesterol-lowering foods (dietary portfolio).Methods:For 1 year, 66 hyperlipidemic subjects were prescribed diets high in plant sterols (1.0 g/1000 kcal), soy protein (22.5 g/1000 kcal), viscous fibers (10 g/1000 kcal) and almonds (22.5 g/1000 kcal). There was no control group. Seven-day diet record, blood pressure and body weight were monitored initially monthly and later at 2-monthly intervals throughout the study.Results:Fifty subjects completed the 1-year study. When the last observation was carried forward for non-completers (n=9) or those who changed their blood pressure medications (n=7), a small mean reduction was seen in body weight 0.7±0.3 kg (P=0.036). The corresponding reductions from baseline in systolic and diastolic blood pressure at 1 year (n=66 subjects) were −4.2±1.3 mm Hg (P=0.002) and −2.3±0.7 mm Hg (P=0.001), respectively. Blood pressure reductions occurred within the first 2 weeks, with stable blood pressures 6 weeks before and 4 weeks after starting the diet. Diastolic blood pressure reduction was significantly related to weight change (r=0.30, n=50, P=0.036). Only compliance with almond intake advice related to blood pressure reduction (systolic: r=−0.34, n=50, P=0.017; diastolic: r=−0.29, n=50, P=0.041).Conclusions:A dietary portfolio of plant-based cholesterol-lowering foods reduced blood pressure significantly, related to almond intake. The dietary portfolio approach of combining a range of cholesterol-lowering plant foods may benefit cardiovascular disease risk both by reducing serum lipids and also blood pressure.

The effect on the blood lipid profile of soy foods combined with a prebiotic: a randomized controlled trial

The value of soy protein as part of the cholesterol-lowering diet has been questioned by recent studies. The apparent lack of effect may relate to the absence of dietary factors that increase colonic fermentation and potentiate the cholesterol-lowering effect of soy. Therefore, unabsorbable carbohydrates (prebiotics) were added to the diet with the aim of increasing colonic fermentation and so potentially increasing the hypocholesterolemic effect of soy. Twenty-three hyperlipidemic adults (11 male, 12 female; 58 +/- 7 years old; low-density lipoprotein cholesterol [LDL-C], 4.18 +/- 0.58 mmol/L) completed three 4-week diet intervention phases-a low-fat dairy diet and 10 g/d prebiotic (oligofructose-enriched inulin, a fermentable carbohydrate), a soy food-containing diet (30 g/d soy protein, 61 mg/d isoflavones from soy foods) and 10 g/d placebo (maltodextrin), and a soy food-containing diet with 10 g/d prebiotic--in a randomized controlled crossover study. Intake of soy plus prebiotic resulted in greater reductions in LDL-C (-0.18 +/- 0.07 mmol/L, P = .042) and in ratio of LDL-C to high-density lipoprotein cholesterol (-0.28 +/- 0.11, P = .041) compared with prebiotic. In addition, high-density lipoprotein cholesterol was significantly increased on soy plus prebiotic compared with prebiotic (0.06 +/- 0.02 mmol/L, P = .029). Differences in bifidobacteria, total anaerobes, aerobes, and breath hydrogen did not reach significance. Soy foods in conjunction with a prebiotic resulted in significant improvements in the lipid profile, not seen when either prebiotic or soy alone was taken. Coingestion of a prebiotic may potentiate the effectiveness of soy foods as part of the dietary strategy to lower serum cholesterol.

Effect of almonds on insulin secretion and insulin resistance in nondiabetic hyperlipidemic subjects: a randomized controlled crossover trial

Nuts appear to have a marked effect in cohort studies in reducing the risk of coronary heart disease (CHD), but their demonstrated ability to lower cholesterol can only explain a proportion of the reduction in risk. Our aim was to assess whether improvement in carbohydrate metabolism provides a further explanation for the effect of nuts in reducing CHD. The effects of whole almonds, taken as snacks, were compared with the effects of low saturated fat (<5% energy) whole-wheat muffins (control) in the therapeutic diets of hyperlipidemic subjects. In a randomized crossover study, 27 hyperlipidemic men and women consumed 3 isoenergetic (mean, 423 kcal/d) supplements each for 1 month. Supplements provided 22.2% of energy and consisted of full-dose almonds (73 +/- 3 g/d), half-dose almonds plus half-dose muffins, and full-dose muffins. Subjects were assessed at weeks 0, 2, and 4 and fasting blood samples were obtained. Twenty-four-hour urinary output was collected at the end of week 4 on each treatment. Mean body weights differed by less than 300 g between treatments. No differences were seen in baseline or treatment values for fasting glucose, insulin, C-peptide, or insulin resistance as measured by homeostasis model assessment of insulin resistance. However, 24-hour urinary C-peptide output as a marker of 24-hour insulin secretion was significantly reduced on the half-and full-dose almonds by comparison to the control after adjustment for urinary creatinine output (P = .002 and P = .004, respectively). We conclude that reductions in 24-hour insulin secretion appear to be a further metabolic advantage of nuts that in the longer term may help to explain the association of nut consumption with reduced CHD risk.

Equol status and blood lipid profile in hyperlipidemia after consumption of diets containing soy foods

BACKGROUND Recent analyses have challenged the effectiveness of soy foods as part of a cardiovascular risk reduction diet. OBJECTIVE The objective of the study was to show whether equol status determines the effectiveness of soy foods to lower LDL cholesterol and to raise HDL cholesterol. DESIGN Eighty-five hypercholesterolemic men and postmenopausal women (42 men, 43 women) participated in 1 of 3 studies that represented a range of soy interventions and that followed the same general protocol at a Canadian university hospital research center. Soy foods were provided for 1 mo at doses of 30-52 g/d for the 3 studies as follows: 1) soy foods with either high-normal (73 mg/d) or low (10 mg/d) isoflavones, 2) soy foods with or without a prebiotic to enhance colonic fermentation (10 g polyfructans/d), or 3) soy foods with a low-carbohydrate diet (26% carbohydrate). Studies 1 and 2 were randomized controlled crossover trials, and study 3 was a parallel study. RESULTS The separation of the group into equol producers (n = 30) and nonproducers (n = 55) showed similar reductions from baseline in LDL cholesterol (-9.3 ± 2.5% and -11.1 ± 1.6%, respectively; P = 0.834), with preservation of HDL cholesterol and apolipoprotein A-I only in equol producers compared with reductions in nonproducers (HDL cholesterol: +0.9 ± 2.7% compared with -4.3 ± 1.1%, P = 0.006; apolipoprotein A-I: -1.0 ± 1.1% compared with -4.7 ± 1.0%; P = 0.011). The amount of urinary equol excreted did not relate to the changes in blood lipids. CONCLUSIONS Soy foods reduced serum LDL cholesterol equally in both equol producers and nonproducers. However, in equol producers, ~35% of our study population, soy consumption had the added cardiovascular benefit of maintaining higher HDL-cholesterol concentrations than those seen in equol nonproducers. This trial was registered at clinicaltrials.gov as NCT00877825 (study 1), NCT00516594 (study 2), and NCT00256516 (study 3).

Effects of a diet high in plant sterols, vegetable proteins, and viscous fibers (dietary portfolio) on circulating sterol levels and red cell fragility in hypercholesterolemic subjects

Plant sterols, soy proteins, viscous fibers, and nuts are advised for cholesterol reduction, but their combined effect on plant sterol absorption has never been tested. We assessed their combined action on serum sterols in hyperlipidemic subjects who were following low-saturated fat diets before starting the study and who returned to these diets post-test. The 1-mon test (combination) diet was high in plant sterols (1 g/1,000 kcal), soy protein (23 g/1,000 kcal), viscous fiber (9 g/1,000 kcal), and almonds (14 g/1000 kcal). Fasting blood was obtained for serum lipids and sterols, and erythrocytes were obtained for fragility prior to and at 2-wk intervals during the study. The combination diet raised serum campesterol concentrations by 50% and β-sitosterol by 27%, although these changes were not significant after Bonferroni correction; near-maximal rises were found by the end of the first week, but no change was found in red cell fragility despite a 29% reduction in the LDL cholesterol level. No significant associations were observed between changes in red cell fragility and blood lipids or sterols. We conclude that plant sterols had a minimal impact on serum sterol concentrations or red cell fragility in hyperlipidemic subjects on diets that greatly reduced their serum lipids.