Frequent nut consumption and risk of coronary heart disease in women: prospective cohort study

A Dietary portfolio: Maximal reduction of low-density lipoprotein cholesterol with diet

Over the past two decades, cholesterol-lowering drugs have proven to be effective and have been found to significantly reduce the risk of coronary heart disease (CHD). However, diet and lifestyle factors are still recognized as the first line of intervention for CHD risk reduction by the National Cholesterol Education Program and the American Heart Association, which now advocate use of viscous fibers and plant sterols, and soy protein and nuts, respectively. In a series of metabolically controlled studies, we have combined these four cholesterol-lowering dietary components in the same diet (ie, a dietary portfolio of cholesterol-lowering foods) in an attempt to maximize low-density lipoprotein cholesterol reduction. We have found that the portfolio diet reduced low-density lipoprotein cholesterol by approximately 30% and produced clinically significant reductions in CHD risk. These reductions were the same as found with a starting dose of a first-generation statin drug.

Fatty acid profile, tocopherol, squalene and phytosterol content of walnuts, almonds, peanuts, hazelnuts and the macadamia nut

Nuts are high in fat but have a fatty acid profile that may be beneficial in relation to risk of coronary heart disease. Nuts also contain other potentially cardioprotective constituents including phytosterols, tocopherols and squalene. In the present study, the total oil content, peroxide value, composition of fatty acids, tocopherols, phytosterols and squalene content were determined in the oil extracted from freshly ground walnuts, almonds, peanuts, hazelnuts and the macadamia nut. The total oil content of the nuts ranged from 37.9 to 59.2%, while the peroxide values ranged from 0.19 to 0.43 meq O2/kg oil. The main monounsaturated fatty acid was oleic acid (C18:1) with substantial levels of palmitoleic acid (C16:1) present in the macadamia nut. The main polyunsaturated fatty acids present were linoleic acid (C18:2) and linolenic acid (C18:3). alpha-Tocopherol was the most prevalent tocopherol except in walnuts. The levels of squalene detected ranged from 9.4 to 186.4 microg/g. beta-Sitosterol was the most abundant sterol, ranging in concentration from 991.2 to 2071.7 microg/g oil. Campesterol and stigmasterol were also present in significant concentrations. Our data indicate that all five nuts are a good source of monounsaturated fatty acid, tocopherols, squalene and phytosterols.

Association of Nut and Seed Intake with Colorectal Cancer Risk in the European Prospective Investigation into Cancer and Nutrition

A link between unsaturated fatty acids or phytonutrients and reduced risk of colorectal cancer has been suggested. However, the effects of higher intake of dietary sources of these nutrients, such as the nuts and seeds food group, are less clear. The objective of this study was to determine the effects of nut and seed intake on colorectal cancer risk within the European Prospective Investigation into Cancer and Nutrition study, a large prospective cohort study involving 10 European countries. Total nut and seed intake was determined from country-specific dietary questionnaires. The data set included 478,040 subjects (141,988 men, 336,052 women) with a total of 855 (327 men, 528 women) colon and 474 (215 men, 259 women) rectal cancer cases. A multivariate Cox proportional hazards model, stratified by center and controlled for fruit intake, dietary fiber, energy, height, weight, sex, age, physical activity, and smoking, was used. The data show no association between higher intake of nuts and seeds and risk of colorectal, colon, and rectal cancers in men and women combined, but a significant inverse association was observed in subgroup analyses for colon cancer in women at the highest (>6.2 g/d) versus the lowest (nonconsumers; hazard ratio, 0.69; 95% confidence interval, 0.50-0.95) category of intake and for the linear effect of log-transformed intake (hazard ratio, 0.89; 95% confidence interval, 0.80-0.98), with no associations in men. It is not evident from this data why there may be a stronger association in women or why it may be limited to the colon, suggesting that much further research is necessary.

Functional foods, herbs and nutraceuticals: towards biochemical mechanisms of healthy aging

Aging is associated with mitochondrial dysfunctions, which trigger membrane leakage, release of reactive species from oxygen and nitrogen and subsequent induction of peroxidative reactions that result in biomolecules' damaging and releasing of metals with amplification of free radicals discharge. Free radicals induce neuronal cell death increasing tissue loss, which could be associated with memory detriment. These pathological events are involved in cardiovascular, neurodegenerative and carcinogenic processes. Dietary bioactive compounds from different functional foods, herbs and nutraceuticals (ginseng, ginkgo, nuts, grains, tomato, soy phytoestrogens, curcumin, melatonin, polyphenols, antioxidant vitamins, carnitine, carnosine, ubiquinone, etc.) can ameliorate or even prevent diseases. Protection from chronic diseases of aging involves antioxidant activities, mitochondrial stabilizing functions, metal chelating activities, inhibition of apoptosis of vital cells, and induction of cancer cell apoptosis. Functional foods and nutraceuticals constitute a great promise to improve health and prevent aging-related chronic diseases.

Lifestyle recommendations to prevent prostate cancer, part II: time to redirect our attention?

This article provides a foundation for men who want to incorporate lifestyle changes to reduce their risk for prostate cancer and, more importantly, impact all-cause mortality. Table 1 summarizes some of these lifestyle changes that can be recommended to patients in most settings. Minimal time is required to suggest these changes, and a copy of Table 1 can be provided as a reminder to patients. Although these recommendations may seem simple, past studies of men have demonstrated that few (less than 5%) adhere to numerous healthy behaviors simultaneously. It seems to be more common to follow one healthy change in excess than to make multiple changes in moderation. This may be the result of past studies focusing on one lifestyle change to affect disease risk; poor compliance; lack of attention, time, or understanding to this detail; or lack of motivation on the part of the health professional and the patient. Clinical trials of combined moderate lifestyle changes, however, demonstrate that the total effort to make healthy lifestyle changes is more important than one or two behavioral changes in affecting cardiovascular markers, cancer, and all-cause mortality. Recommending a pill is an easy answer, but few supplements for prostate-cancer prevention or total mortality reduction can be recommended, and long-term compliance is a concern with any agent. Additionally, the potential for supplements to increase the risk for prostate cancer or interfere with conventional treatment continues to be a concern, and no dietary supplement has come close to matching the reduction in all-cause mortality observed in clinical trials of lifestyle changes. The time seems ripe to redirect our attention regarding lifestyle changes and prostate cancer risk. What is heart-healthy is prostate-healthy, which makes it more likely that any man concerned about the risk for prostate cancer will make healthy lifestyle changes.

Alpha-linolenic acid and coronary heart disease

AIM

To summarize our present knowledge about vegetable omega-3 fatty acids.

DATA SYNTHESIS

Alpha-linolenic acid (ALA) is one of the two essential fatty acids in humans. Epidemiological studies and dietary trials strongly suggest that this fatty acid is important in relation with the pathogenesis (and prevention) of coronary heart disease. Like other n-3 fatty acids from marine origin, it may prevent cardiac arrhythmias and sudden cardiac death. The optimal dietary intake of alpha-linolenic acid seems to be about 2 g per day or 0.6 to 1% of total energy intake. Obtaining an optimal ratio of the two essential fatty acids, linoleic and alpha-linolenic acids--ie a ratio of less than 4 to 1 in the diet--is a major issue. The main sources of alpha-linolenic acid for the European population should be canola oil (and canola-oil based margarine if available), nuts (English walnut), ground linseeds and green leafy vegetables such as purslane.

CONCLUSIONS

Epidemiological studies and dietary trials in humans suggest that alpha-linolenic acid is a major cardio-protective nutrient.

Dietary patterns and health outcomes

A systematic review of the literature on dietary patterns (multiple dietary components operationalized as a single exposure) in relation to nutrient adequacy, lifestyle and demographic variables, and health outcome was conducted. Most of the published reports on the subject have used one of two methods to determine dietary patterns: (a) diet indexes or scores that assess compliance with prevailing dietary guidance as dietary patterns, and (b) data-driven methods that use factor or cluster analysis to derive dietary patterns. Irrespective of the approach used, patterns characterized by fruit/vegetable/whole grain/fish/poultry consumption generally have been reported to relate to micronutrient intake, and to selected biomarkers of dietary exposure and disease risk in the expected direction. Age, income, and education have been reported to be among positive predictors of the so-called more healthful dietary patterns. An inverse association of healthful dietary patterns with all-cause mortality and cardiovascular disease risk was reported in most studies. However, the magnitude of risk reduction was modest and was attenuated after control for confounders. Few published studies showed an association between risk of most incident cancers and dietary patterns. Both of the currently used approaches for extracting dietary patterns have limitations, are subject to dietary measurement errors, and have not generated new diet and disease hypotheses.

Coronary heart disease: the female heart is vulnerable

During the past decade, an overall theme has emerged, validating the exploration of gender-based differences in coronary heart disease (CHD) as a basis for clinical strategies to improve outcomes for women. Underrepresentation of women in most of CHD and lack of gender-specific reporting in many clinical trials continue to limit the available knowledge and evidence-based medicine needed to devise optimal managements for women with CHD. Control of conventional coronary risk factors provides comparable cardioprotection for men and women. Current evidence fails to show cardiac protection from menopausal hormone therapy. Clinical presentations of coronary heart disease (CHD) and management strategies differ between the sexes. Underutilization of proven beneficial therapies is a contributor to less-favorable outcomes in women. The contemporary increased application of appropriate diagnostic, therapeutic, and interventional managements has favorably altered the prognosis for women, particularly when the data are adjusted for baseline characteristics. Better education of women during office visits, earlier and more aggressive control of coronary risk factors, and a greater index of suspicion regarding chest pain and its appropriate evaluation may help to reverse the trend of late referral and late intervention. Research indicates that behavioral changes on the part of women and reshaping of practice patterns by their health care providers may dramatically reduce the number of women disabled and killed by CHD each year.

Progression of age-related macular degeneration: association with dietary fat, transunsaturated fat, nuts, and fish intake

BACKGROUND

Individuals with early or intermediate stages of age-related macular degeneration (AMD) make up a large, growing segment of the elderly population. Evidence is sparse regarding modifiable factors that may decrease the risk of progression to the advanced forms of AMD.

OBJECTIVE

To advise patients with a high risk for advanced forms of AMD about preventive measures through our evaluation of the relationship between dietary fat intake and the progression of early or intermediate AMD to the advanced stages of the disease associated with visual loss.

DESIGN

A prospective cohort study with an average follow-up time of 4.6 years.

SETTING

A hospital-based clinical retinal practice specializing in macular degeneration. Patients The 261 participants were aged 60 years and older and had some sign of nonexudative AMD and visual acuity of 20/200 or better in at least 1 eye. Main Outcome Measure Progression to advanced AMD, which was defined as having geographic atrophy or neovascular disease.

RESULTS

Higher total fat intake increased the risk of progression to the advanced forms of AMD, with a relative risk (RR) of 2.90 (95% confidence interval, 1.15-7.32) for the highest fat-intake quartile relative to the lowest fat-intake quartile, after controlling for other factors (P trend =.01). Animal fat intake was associated with a 2-fold increased risk of progression (RR, 2.29 for the highest quartile compared with the lowest quartile; 95% confidence interval, 0.91-5.72), although the trend for increasing risk with higher animal fat intake was not significant (P=.09). Higher vegetable fat intake had a stronger relationship with increased risk of AMD progression with an RR of 3.82 (95% confidence interval, 1.58-9.28) for the highest quartile compared with the lowest quartile (P trend =.003). Saturated, monounsaturated, polyunsaturated, and transunsaturated fats increased the likelihood of progression (RR, 2.09 and P trend =.08; RR, 2.21 and P trend =.04; RR, 2.28 and P trend =.04; RR, 2.39 and P trend =.008, respectively). Higher fish intake was associated with a lower risk of AMD progression among subjects with lower linoleic acid intake. Processed baked goods, which are higher in some of these fats, increased the rate of AMD progression approximately 2-fold, and nuts were protective.

CONCLUSIONS

Among individuals with the early or intermediate stages of AMD, total and specific types of fat intake, as well as some fat-containing food groups, modified the risk of progression to advanced AMD. Fish intake and nuts reduced risk. Since advanced AMD is associated with visual loss and reduced quality of life, these preventive measures deserve additional research and greater emphasis.

Proposal for a dietary “phytochemical index”

There is ample reason to believe that diets rich in phytochemicals provide protection from vascular diseases and many cancers; direct antioxidant activity as well as modulation of enzyme expression or hormone activity contribute to this effect. Phytochemicals derived from diverse foods presumably can interact additively and (possibly) synergistically; thus, the total dietary load of phytochemicals may have important implications for health. As a means of very roughly quantifying this load, a "phytochemical index" (PI) is proposed, defined as the percent of dietary calories derived from foods rich in phytochemicals. Calories derived from fruits, vegetables (excluding potatoes), legumes, whole grains, nuts, seeds, fruit/vegetable juices, soy products, wine, beer, and cider - and foods compounded therefrom - would be counted in this index. Partial credit could be given for antioxidant-rich extra virgin olive oil. Other added oils, refined sugars, refined grains, potato products, hard liquors, and animal products - regrettably, the chief sources of calories in typical Western diets - would be excluded. Although the PI would provide only a very rough approximation of the quantity or quality of phytochemical nutrition, it nonetheless could aid epidemiologists in exploring the health consequences of diets high in phytochemical-rich plant foods, and could also help clinical nutritionists in their efforts to improve the phytochemical nutrition of their clients.

Almonds vs complex carbohydrates in a weight reduction program

OBJECTIVE

To evaluate the effect of an almond-enriched (high monounsaturated fat, MUFA) or complex carbohydrate-enriched (high carbohydrate) formula-based low-calorie diet (LCD) on anthropometric, body composition and metabolic parameters in a weight reduction program.

DESIGN

A randomized, prospective 24-week trial in a free-living population evaluating two distinct macronutrient interventions on obesity and metabolic syndrome-related parameters during weight reduction.

SUBJECTS

In total, 65 overweight and obese adults (age: 27-79 y, body mass index (BMI): 27-55 kg/m(2)).

INTERVENTION

A formula-based LCD enriched with 84 g/day of almonds (almond-LCD; 39% total fat, 25% MUFA and 32% carbohydrate as percent of dietary energy) or self-selected complex carbohydrates (CHO-LCD; 18% total fat, 5% MUFA and 53% carbohydrate as percent of dietary energy) featuring equivalent calories and protein.

MAIN OUTCOME MEASUREMENTS

Various anthropometric, body composition and metabolic parameters at baseline, during and after 24 weeks of dietary intervention.

RESULTS

LCD supplementation with almonds, in contrast to complex carbohydrates, was associated with greater reductions in weight/BMI (-18 vs -11%), waist circumference (WC) (-14 vs -9%), fat mass (FM) (-30 vs -20%), total body water (-8 vs -1%) and systolic blood pressure (-11 vs 0%), P=0.0001-0.05. A 62% greater reduction in weight/BMI, 50% greater reduction in WC and 56% greater reduction in FM were observed in the almond-LCD as compared to the CHO-LCD intervention. Ketone levels increased only in the almond-LCD group (+260 vs 0%, P<0.02). High-density lipoprotein cholesterol (HDL-C) increased in the CHO-LCD group and decreased in the almond-LCD group (+15 vs -6%, P=0.05). Glucose, insulin, diastolic blood pressure, total cholesterol, triglycerides, low-density lipoprotein cholesterol (LDL-C) and LDL-C to HDL-C ratio decreased significantly to a similar extent in both dietary interventions. Homeostasis model analysis of insulin resistance (HOMA-IR) decreased in both study groups over time (almond-LCD: -66% and CHO-LCD: -35%, P<0.0001). Among subjects with type 2 diabetes, diabetes medication reductions were sustained or further reduced in a greater proportion of almond-LCD as compared to CHO-LCD subjects (96 vs 50%, respectively) [correction].

CONCLUSION

Our findings suggest that an almond-enriched LCD improves a preponderance of the abnormalities associated with the metabolic syndrome. Both dietary interventions were effective in decreasing body weight beyond the weight loss observed during long-term pharmacological interventions; however, the almond-LCD group experienced a sustained and greater weight reduction for the duration of the 24-week intervention. Almond supplementation of a formula-based LCD is a novel alternative to self-selected complex carbohydrates and has a potential role in reducing the public health implications of obesity.

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.

The contribution of vegetarian diets to health and disease: a paradigm shift?

Advances in nutrition research during the past few decades have changed scientists' understanding of the contribution of vegetarian diets to human health and disease. Diets largely based on plant foods, such as well-balanced vegetarian diets, could best prevent nutrient deficiencies as well as diet-related chronic diseases. However, restrictive or unbalanced vegetarian diets may lead to nutritional deficiencies, particularly in situations of high metabolic demand. If some vegetarian diets are healthier than diets largely based on animal products, this constitutes an important departure from previous views on dietary recommendations to prevent disease conditions. Based on different paradigms, 3 models are presented depicting the population health risks and benefits of vegetarian and meat-based diets. This series of models encapsulates the evolution of scientific understanding on the overall effects of these dietary patterns on human health. Recent scientific advances seem to have resulted in a paradigm shift: diets largely based on plant foods, such as well-balanced vegetarian diets, are viewed more as improving health than as causing disease, in contrast with meat-based diets.

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

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 (eg, 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.

Nut consumption and body weight

Frequent nut consumption is associated with lower rates of coronary artery disease (CAD). Also, nut-rich diets improve the serum lipid profile of participants in dietary intervention trials. However, nuts are fatty foods, and in theory their regular consumption may lead to body weight gain. Because obesity is a major public health problem and a risk factor for CAD, clinicians and policy makers ponder several questions. Will hypercholesterolemic patients advised to consume nuts gain weight? Is recommending increased nut consumption to the general population for CAD prevention sound public health advice? Epidemiologic studies indicate an inverse association between frequency of nut consumption and body mass index. In well-controlled nut-feeding trials, no changes in body weight were observed. Some studies on free-living subjects in which no constraints on body weight are imposed show a nonsignificant tendency to lower weight while subjects are on the nut diets. In another line of evidence, preliminary data indicate that subjects on nut-rich diets excrete more fat in stools. Further research is needed to study the effects of nut consumption on energy balance and body weight. In the meantime, the available cumulative data do not indicate that free-living people on self-selected diets including nuts frequently have a higher body mass index or a tendency to gain weight.

Lessons from dietary studies in Adventists and questions for the future

Comparisons of diets and disease rates between Adventists and non-Adventists, and prospective cohort studies among Adventists, have contributed greatly to our general understanding of nutrition and health. The most fundamental conclusion drawn from the Adventist Health Studies has been that maintaining a lean body weight throughout life is central for optimal health. Other contributions have included the value of nut consumption for prevention of coronary artery disease, and the roles of red meat and dairy products in the etiologies of cardiovascular disease and cancer. Although much progress has been made, many issues remain unresolved. In particular, rates of breast and prostate cancers remain high among Adventist populations despite an overall healthy lifestyle and long life expectancy. There is even some suggestion that risk of breast cancer may increase with duration of being a vegetarian. One topic that may be uniquely studied among an Adventist population is the effect of soy phytoestrogens in disease prevention. Although soy consumption has been hypothesized to contribute to the low rates of breast cancer in Asian populations, several intervention studies using high doses of soy estrogens have shown changes in breast nipple fluid that would predict higher rates of breast cancer. Also, high dairy product consumption has been associated with risk of prostate and ovarian cancers in some but not all studies. The unusually wide range of milk consumption in Adventists will be particularly informative with regard to these relations. Resolution of these issues is needed to provide optimal guidance regarding healthy diets, and the newly funded Adventist Health Study will contribute importantly in this effort.

The role of omega-3 fatty acids in the secondary prevention of cardiovascular disease

It has long been recognized from epidemiological studies that Greenland Eskimos have substantially reduced rates of acute myocardial infarction (MI) compared with Western controls. From these epidemiological observations, the benefits of fatty fish consumption have been explored in cell culture and animal studies, as well as randomized controlled trials investigating the cardioprotective effects of omega-3 fatty acids. Dietary omega-3 fatty acids seem to stabilize the myocardium electrically, resulting in reduced susceptibility to ventricular arrhythmias, thereby reducing the risk of sudden death. These fatty acids also have potent anti-inflammatory effects, and may also be antithrombotic and anti-atherogenic. Furthermore, the recent GISSI-Prevention study of 11 324 patients showed a marked decrease in risk of sudden cardiac death as well as a reduction in all-cause mortality in the group taking a highly purified form of omega-3 fatty acids, despite the use of other secondary prevention drugs, including beta-blockers and lipid-lowering therapy. The use of omega-3 fatty acids should be considered as part of a comprehensive secondary prevention strategy post-myocardial infarction.

Biochemical pharmacology of functional foods and prevention of chronic diseases of aging

The major mechanisms and consequences of free radicals in foods and biological systems that result in the occurrence of chronic diseases of aging (atherosclerosis, cataract, cancers, diabetes, neurological diseases, immune-inflammatory disorders) are described. The main antioxidant defense mechanisms from foods and cells and tissues are also reported. Many nutraceutical substances, with their respective beneficial actions (antioxidant, detoxifying, apoptotic actions) and effects, and most common food sources are also described. There are many options of foods to prevent cancer and chronic diseases, to improve life's quality in maturity.

Can food variety add years to your life?

The traditional food habits of Greeks and Japanese differ widely, yet both populations have the longest life expectancies in the world. Food variety is one feature common to both food cultures. By eating a wide variety of foods, numerous chemicals that give rise to the diverse range of colours, tastes, textures and smells of different foods are consumed. Many of these naturally occurring chemicals are likely to play a role in health. Within the broad scope of foods available, foods for thought include fish, legumes and nuts. These foods are also likely to protect older adults against some of the diseases more prevalent with ageing such as coronary heart disease and cancer.

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

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 (P value for trend < 0.001), LDL-cholesterol (P < 0.001), and apolipoprotein B (P < 0.001) concentrations and the ratios of LDL to HDL cholesterol (P < 0.001) and of apolipoprotein B to apolipoprotein A (P < 0.001). Compared with the Step I diet, the high-almond diet reduced total cholesterol (0.24 mmol/L or 4.4%; P = 0.001), LDL cholesterol (0.26 mmol/L or 7.0%; P < 0.001), and apolipoprotein B (6.6 mg/dL or 6.6%; P < 0.001); increased HDL cholesterol (0.02 mmol/L or 1.7%; P = 0.08); and decreased the ratio of LDL to HDL cholesterol (8.8%; P < 0.001).

CONCLUSIONS

Isoenergetic incorporation of approximately 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.

Do Nuts Have a Place in a Healthful Diet?

A wealth of nutrition information has been published during the past decade on the healthful nature of nuts. As nut consumption increases, cardiovascular disease risk decreases. This cardioprotective effect of nut consumption is beyond what would be predicted from the fatty acid profile alone. Nuts are a rich source of many other nutrients and bioactive compounds, similar to other whole-plant foods, such as fruits and vegetables. Additional studies during the next decade will delineate additional healthful nutrients of these foods.

Peanut consumption improves indices of cardiovascular disease risk in healthy adults

BACKGROUND

Diets containing nuts reduce cardiovascular disease (CVD) risk factors. This has primarily been attributed to their fatty acid composition, but other constituents may also contribute. Peanuts, the most widely consumed "nut" (actually a legume), are a rich source of monounsaturated fatty acids (MUFA), magnesium and folate, but their effects on CVD risk factors are poorly characterized.

OBJECTIVE

This study determined the effects of chronic peanut consumption on diet composition as well as serum lipids, magnesium and homocysteine concentrations in free-living subjects under different conditions of peanut intake.

DESIGN

Fifteen normolipidemic adults participated in a 30-week cross-over intervention. Subjects were provided 500 (+136) kcal as peanuts during an eight-week free feeding (FF) diet. The same amount of peanuts was added during a three-week addition (ADD) diet or replaced an equal amount of other fats in the diet during an eight-week substitution (SUB) diet.

RESULTS

Energy intake from fat was increased through greater intake of MUFA and polyunsaturated fatty acids, while saturated fatty acid intake remained relatively stable under all conditions. Triacylglycerol (TAG) was reduced by 24% during ADD (p < 0.05), by 17% during SUB (p < 0.05) and by 14% during four-weeks of FF, but then rebounded to baseline by week 8. Dietary fiber, magnesium, folate, alpha tocopherol, copper and arginine increased during all treatments (p < 0.05). Serum magnesium increased in 13 of 15 subjects during FF (p < 0.05). No changes were found in total plasma homocysteine concentration.

CONCLUSIONS

Regular peanut consumption lowers serum TAG, augments consumption of nutrients associated with reduced CVD risk and increases serum magnesium concentration.

The degree of unsaturation of dietary fatty acids and the development of atherosclerosis (review)

Atherosclerosis is the principal contributor to the pathogenesis of myocardial and cerebral infarction, gangrene and loss of function in the extremities. It results from an excessive inflammatory-fibroproliferative response to various forms of insult to the endothelium and smooth muscle of the artery wall. Atherosclerotic lesions develop fundamentally in three stages: dysfunction of the vascular endothelium, fatty streak formation and fibrous cap formation. Each stage is regulated by the action of vasoactive molecules, growth factors and cytokines. This multifactorial etiology can be modulated through the diet. The degree of unsaturation of dietary fatty acids affects lipoprotein composition as well as the expression of adhesion molecules and other pro-inflammatory factors, and the thrombogenicity associated with atherosclerosis development. Thus, the preventive effects of a monounsaturated-fatty acid-rich diet on atherosclerosis may be explained by the enhancement of high-density lipoprotein-cholesterol levels and the impairment of low-density lipoprotein-cholesterol levels, the low-density lipoprotein susceptibility to oxidation, cellular oxidative stress, thrombogenicity and atheroma plaque formation. On the other hand, the increase of high-density lipoprotein cholesterol levels and the reduction of thrombogenicity, atheroma plaque formation and vascular smooth muscle cell proliferation may account for the beneficial effects of polyunsaturated fatty acid on the prevention of atherosclerosis. Thus, the advantages of the Mediterranean diet rich in olive oil and fish on atherosclerosis may be due to the modulation of the cellular oxidative stress/antioxidant status, the modification of lipoproteins and the down-regulation of inflammatory mediators.

Diet quality and major chronic disease risk in men and women: moving toward improved dietary guidance

BACKGROUND

Adherence to the Dietary Guidelines for Americans, measured with the US Department of Agriculture Healthy Eating Index (HEI), was associated with only a small reduction in major chronic disease risk. Research suggests that greater reductions in risk are possible with more specific guidance.

OBJECTIVE

We evaluated whether 2 alternate measures of diet quality, the Alternate Healthy Eating Index (AHEI) and the Recommended Food Score (RFS), would predict chronic disease risk reduction more effectively than did the HEI.

DESIGN

A total of 38 615 men from the Health Professional's Follow-up Study and 67 271 women from the Nurses' Health Study completed dietary questionnaires. Major chronic disease was defined as the initial occurrence of cardiovascular disease (CVD), cancer, or nontraumatic death during 8-12 y of follow-up.

RESULTS

High AHEI scores were associated with significant reductions in risk of major chronic disease in men [multivariate relative risk (RR): 0.80; 95% CI: 0.71, 0.91] and in women (RR: 0.89; 95% CI: 0.82, 0.96) when comparing the highest and lowest quintiles. Reductions in risk were particularly strong for CVD in men (RR: 0.61; 95% CI: 0.49, 0.75) and in women (RR: 0.72; 95% CI: 0.60, 0.86). In men but not in women, the RFS predicted risk of major chronic disease (RR: 0.93; 95% CI: 0.83, 1.04) and CVD (RR: 0.77; 95% CI: 0.64, 0.93).

CONCLUSIONS

The AHEI predicted chronic disease risk better than did the RFS (or the HEI, in our previous research) primarily because of a strong inverse association with CVD. Dietary guidelines can be improved by providing more specific and comprehensive advice.

Functional foods: benefits, concerns and challenges-a position paper from the american council on science and health

Functional foods can be considered to be those whole, fortified, enriched or enhanced foods that provide health benefits beyond the provision of essential nutrients (e.g., vitamins and minerals), when they are consumed at efficacious levels as part of a varied diet on a regular basis. Linking the consumption of functional foods or food ingredients with health claims should be based on sound scientific evidence, with the "gold standard" being replicated, randomized, placebo-controlled, intervention trials in human subjects. However, not all foods on the market today that are claimed to be functional foods are supported by enough solid data to merit such claims. This review categorizes a variety of functional foods according to the type of evidence supporting their functionality, the strength of that evidence and the recommended intakes. Functional foods represent one of the most intensively investigated and widely promoted areas in the food and nutrition sciences today. However, it must be emphasized that these foods and ingredients are not magic bullets or panaceas for poor health habits. Diet is only one aspect of a comprehensive approach to good health.

Therapeutic lifestyle change and Adult Treatment Panel III: evidence then and now

The Third Report of the National Cholesterol Education Program's Adult Treatment Panel (ATP III) has an extensive section on nonpharmacologic therapy for those with abnormal blood lipids. ATP III focused on the high-saturated fat atherogenic diet, obesity, and sedentary lifestyle and recommended a program of therapeutic lifestyle change (TLC). This review discusses several issues, including 1) why ATP III changed from the Step I and Step II diets to TLC; 2) the benefits of keeping trans fatty acid intake low and the addition of viscous fiber and plant stanol/sterol esters to reduce low-density lipoprotein cholesterol beyond that seen with the Step II diet; 3) the de-emphasis on total fat and a sharper focus on the kinds of fat ingested in the new guidelines; 4) the endorsement of regular physical activity and weight loss as important first steps in reversing the unwanted metabolic effects of the metabolic syndrome; and 5) the emphasis of health-promoting aspects of the diet that include, among other things, fish and omega-3 fatty acids. At all stages of TLC, ATP III encourages the referral to registered dietitians or other qualified nutritionists for medical nutrition therapy. TLC and the ATP III guidelines should provide guidance to practitioners who wish to get low-density lipoprotein cholesterol to goal (whether or not drugs are used), prevent or treat the metabolic syndrome, and improve the overall health of the patient.

Dose response of almonds on coronary heart disease risk factors: blood lipids, oxidized low-density lipoproteins, lipoprotein(a), homocysteine, and pulmonary nitric oxide: a randomized, controlled, crossover trial

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. Significant reductions from baseline were seen on both half- and full-dose almonds for LDL cholesterol (4.4+/-1.7%, P=0.018, and 9.4+/-1.9%, P<0.001, respectively) and LDL:HDL cholesterol (7.8+/-2.2%, P=0.001, and 12.0+/-2.1%, P<0.001, respectively) and on full-dose almonds alone for lipoprotein(a) (7.8+/-3.5%, P=0.034) and oxidized LDL concentrations (14.0+/-3.8%, P<0.001), with no significant reductions on the control diet. No difference was seen in pulmonary nitric oxide between treatments.

CONCLUSIONS

Almonds used as snacks in the diets of hyperlipidemic subjects significantly reduce coronary heart disease risk factors, probably in part because of the nonfat (protein and fiber) and monounsaturated fatty acid components of the nut.

Understanding the Mediterranean diet. Could this be the new "gold standard" for heart disease prevention?

The traditional Mediterranean diet as outlined in this article is an ideal eating pattern for prevention of cardiovascular disease. The essence of this diet is the use of natural, whole foods and the avoidance of highly processed ones. We believe that current understanding and scientific evidence are adequate to recommend this diet widely as a practical, effective, and enjoyable strategy--the new "gold standard"--in heart disease prevention.

Effects of chronic peanut consumption on energy balance and hedonics

OBJECTIVE

To investigate the effects of chronic peanut consumption on energy balance and hedonics.

DESIGN

Thirty-week, cross-over, intervention study. Participants were provided 2113+/-494 kJ/day (505+/-118 kcal/day) as peanuts for 8 weeks with no dietary guidance (free feeding-FF), 3 weeks with instructions to add peanuts to their customary diet (addition-ADD) and 8 weeks where peanuts replaced an equal amount of other fats in the diet (substitution-SUB).

SUBJECTS

Fifteen, healthy, normal-weight (BMI of 23.3+/-1.8) adults, aged 33+/-9 y.

MEASUREMENTS

Dietary intake, appetitive indices, energy expenditure, body weight and hedonics.

RESULTS

During FF, peanut consumption elicited a strong compensatory dietary response (ie subjects compensated for 66% of the energy provided by the nuts) and body weight gain (1.0 kg) was significantly lower than predicted (3.6 kg; P<0.01). When customary dietary fat was replaced with the energy from peanuts, energy intake, as well as body weight, were maintained precisely. Participants were unaware that body weight was a research focus. Resting energy expenditure was increased by 11% after regular peanut consumption for 19 weeks (P<0.01). Chronic consumption of peanuts did not lead to a decline in pleasantness or hunger ratings for peanuts nor did it lead to any hedonic shift for selected snack foods with other taste qualities during any of the three treatments.

CONCLUSIONS

Despite being energy dense, peanuts have a high satiety value and chronic ingestion evokes strong dietary compensation and little change in energy balance.

Recent discoveries in inclusive food-based approaches and dietary patterns for reduction in risk for cardiovascular disease

PURPOSE OF REVIEW

To discuss new evidence-based dietary recommendations founded on an inclusive food strategy and to address the challenges that are posed by integrating a growing list of heart healthy foods into the diet without increasing energy intake beyond that required to achieve a healthy body weight.

RECENT FINDINGS

New food-based dietary recommendations issued by the American Heart Association with the objective of reducing risk for cardiovascular disease (CVD) promote an inclusionary approach. The American Heart Association recommends a variety of foods to target four major goals: achieve a healthy overall diet, achieve a healthy weight, promote desirable lipid levels, and promote desirable blood pressure. Specific foods recommended include fruits and vegetables, grain products (including whole grains), fish, lean meat and poultry, fat-free or low-fat dairy products, and legumes. In addition, the new National Cholesterol Education Program Adult Treatment Panel III recommends reductions in saturated fat and cholesterol and therapeutic dietary options for enhancing LDL-cholesterol lowering, with inclusion of plant stanols/sterols (2 g/day) and increased viscous (soluble) fiber (10-25 g/day). In parallel with the evolution of new dietary recommendations is the expanding list of specific foods that have cardioprotective effects. Additional foods on this list are nuts, soy, legumes, alcohol, tea, and garlic.

SUMMARY

It will be challenging to include all foods that reduce CVD risk in the diet and still maintain energy control. Strategies are needed that facilitate developing heart healthy dietary patterns that maximally reduce CVD risk.

Serum lipid profiles in Japanese women and men during consumption of walnuts

OBJECTIVE

To determine the serum cholesterol, apolipoproteins and LDL oxidizability in young Japanese women and men during walnut consumption and to evaluate its active principle.

DESIGN

Experimental study with a randomized design.

SUBJECTS

Twenty healthy women and 20 healthy men.

INTERVENTIONS

Subjects were randomly assigned to consume each of two mixed natural diets for 4 weeks in a cross-over design. Reference and walnut diets were designed and the walnut diet had 12.5% of the energy derived from walnuts (44-58 g/day).

RESULTS

The total cholesterol and serum apolipoprotein B concentrations, and the ratio of LDL cholesterol to HDL cholesterol was significantly lowered in women and men when fed on the walnut diet, than when on the reference diet (P<or=0.05). The LDL cholesterol concentration was significantly lowered in women on the walnut diet (0.22 mmol/l, P=0.0008), whereas this decrease was not significant in men (0.18 mmol/l, P=0.078). The most prominent change in the fatty acid composition of the cholesteryl esters from serum after the walnut diet was an elevation of alpha-linolenic acid in women (76%, P<0.001) and men (107%, P<0.001). This elevation was negatively correlated to the change in LDL cholesterol in women (r=0.496, P=0.019) and men (r=0.326, P=0.138). The LDL oxidizability in women was not influenced by the diets (P=0.19).

CONCLUSIONS

alpha-Linolenic acid in the walnut diet appears to be responsible for the lowering of LDL cholesterol in women.

SPONSORSHIP

Kyushu University (Fukuoka, Japan) and the California Walnut Commission (California, USA).

Cardiovascular disease

The primary care physician is in a position to advise patients on the efficacy of alternative and complementary therapies as they relate to cardiovascular diseases. Anti-oxidant vitamin supplementation has not been shown to be efficacious in decreasing cardiovascular events. N-3 fatty acids appear to be beneficial in secondary prevention of cardiovascular events but their use in primary prevention is not clear. Adoption of vegetable-based diets, including whole grains, can be recommended to decrease cardiovascular events, lower cholesterol and help lower blood pressure. For patients with hypercholesterolemia, cholestin, a red-yeast rice supplement, has been shown to be effective. Garlic supplements may have some mild cholesterol-lowering effect, but this effect is not significant enough to recommend clinically. Herbal therapies with hawthorn and ubiquinone (Q10) are of possible benefit in congestive heart failure. An integrated program of rigorous diet, exercise and stress reduction in motivated patients with cardiovascular disease may have value as an alternative to cardiovascular medications and surgical interventions.

Nutriceuticals and cardiovascular health in women

This article examines the evidence on use of nutriceuticals for promotion of cardiovascular health in women. Studies elucidating mechanism of action, physiologic effects of antioxidant vitamins, carotenoids, flavonoids, and garlic are presented. Emerging evidence for the impact of homocysteine on cardiovascular risk factors and events and evidence for the impact of different types of fats on cardiovascular markers are reviewed. The effects of a heart-healthy diet are supported in this review of research on nutriceuticals. Primary prevention of cardiovascular disease in women is clearly efficacious, and this article summarizes information to be shared with women about nutriceuticals and diet to better enable decisions they can adopt to promote cardiovascular health.

Antioxidant vitamins in the prevention of cardiovascular disease: a systematic review

Do antioxidant vitamins, in regular food or as food supplements, protect against myocardial infarction and stroke? In this systematic literature review on the effects of antioxidant vitamins in the primary prevention of cardiovascular disorders, studies with ischaemic heart disease, stroke or combined cardiovascular events as end-points have been included. Studies on the effects of antioxidant vitamins on intermediary end-points (such as blood lipids and blood pressure) and as secondary prevention in patients with manifest cardiovascular disease are reviewed in a conventional manner. In observational studies (case-control or cohort design), people with high intake of antioxidant vitamins by regular diet or as food supplements generally have a lower risk of myocardial infarction and stroke than people who are low-consumers of antioxidant vitamins. The associations in observation studies have been shown for carotene, ascorbic acid as well as tocopherol. In randomized controlled trials, however, antioxidant vitamins as food supplements have no beneficial effects in the primary prevention of myocardial infarction and stroke. Serious adverse events have been reported. After an initial enthusiasm for antioxidants in the secondary prevention of cardiovascular disease, recent reports from of several large randomized trials have failed to show any beneficial effects. Thus, the apparent beneficial results of high intake of antioxidant vitamins reported in observational studies have not been confirmed in large randomized trials. The discrepancy between different types of studies is probably explained by the fact that supplement use is a component in a cluster of healthy behaviour. Antioxidant vitamins as food supplements cannot be recommended in the primary or secondary prevention against cardiovascular disease.

The scientific evidence for a beneficial health relationship between walnuts and coronary heart disease

The author and four independent experts evaluated the intent and quality of scientific evidence for a potential beneficial health relationship between the intake of walnuts and the reduction and prevention of coronary heart disease. The report also addresses the supporting evidence for the health benefit of other tree nuts and selected legumes. Compared to most other nuts, which contain monounsaturated fatty acids, walnuts are unique because they are rich in n-6 (linoleate) and n-3 (linolenate) polyunsaturated fatty acids. Walnuts contain multiple health-beneficial components, such as having a low lysine:arginine ratio and high levels of arginine, folate, fiber, tannins, and polyphenols. Though walnuts are energy rich, clinical dietary intervention studies show that walnut consumption does not cause a net gain in body weight when eaten as a replacement food. Five controlled, peer-reviewed, human clinical walnut intervention trials, involving approximately 200 subjects representative of the 51% of the adult population in the United States at risk of coronary heart disease were reviewed. The intervention trials consistently demonstrated walnuts as part of a heart-healthy diet, lower blood cholesterol concentrations. None of these studies were of extended duration that would be essential for evaluation of the sustainability of the observed outcomes. These results were supported by several large prospective observational studies in humans, all demonstrating a dose response-related inverse association of the relative risk of coronary heart disease with the frequent daily consumption of small amounts of nuts, including walnuts.

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

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 (approximately 14% of approximately 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.

Current concepts in optimum nutrition for cardiovascular disease

For the past decade, nutritionists have focused on consensus guidelines (National Cholesterol Education Program) to reduce dietary saturated fatty acids, cholesterol, and excess body weight. However, researchers are looking at other ways that diet may influence the progression of cardiovascular disease, including lipoprotein oxidation, thrombosis progression, cardiac arrhythmia, and medication interaction. Some areas of investigation include the role of various fatty acids and supplements-in the form of vitamins, minerals, herbs, and functional foods-as well as traditional foods and diets from other parts of the world. This review outlines some of the new and relevant nutritional approaches including: specific fatty acids (omega 3, monounsaturated and trans fatty acids), dietary supplements (herbs, antioxidants, vitamins C and E, Coenzyme Q10, B vitamins and homocysteine, L-arginine, Chinese red yeast rice, garlic, soy, flax seed, and dietary fiber), food and drink (tea, nuts, plant-sterol and stanol-ester-containing spreads, alcohol, and grapefruit juice), and the Mediterranean diet. (c) 2000 by CHF, Inc.

Differential effect of walnut oil and safflower oil on the serum cholesterol level and lesion area in the aortic root of apolipoprotein E-deficient mice

Walnut oil (WO) is a good source of alpha-linolenic acid. We compared the effects of WO and high-linoleic safflower oil (HLSO) on the serum lipid level and atherosclerosis development in male and female apolipoprotein (apo) E-deficient mice. The WO diet resulted in a higher level of serum cholesterol than with HLSO. Female mice fed on the WO diet had a greater lesion area in the aortic root than did those on the HLSO diet. There was no diet-dependent difference in the level of cholesterol and its oxidation products in the abdominal and thoracic aorta. These results suggest that the unpleasant effects of the WO diet on apo E-deficient mice may be attributable to alpha-linolenic acid.