de Lorgeril, M., P. Salen, F. Laporte, F. Boucher, J. De Leiri, 2001. Potential use of nuts for the prevention and treatment of coronary heart disease: From natural to functional foods. Nutr Metab Cardiovasc Dis. 11:362-71.
This editorial discusses the research on nuts and coronary heart disease (CHD) and suggests that before using food technology to develop new and artificial foods to help patients follow what they think would be an “optimal diet,” scientists and physicians should first refer to the traditional diets of populations with low CHD rates. Studying the effect of natural or whole foods, such as nuts, should be a priority. According to the authors, natural foods are still the preferred functional foods because they may provide a better nutrient profile than any recomposed food, and the proportions of the various nutrients and non-nutrients are the result of a natural, and biologically compatible, evolution and not of an industrial process.
Zambón, D., J. Sabate´, S. Muñoz, B. Campero, E. Casals, M. Merlos, J.C. Laguna, E. Ros, MD, 2000. Substituting walnuts for monounsaturated fat improves the serum lipid profile of hypercholesterolemic men and women a randomized crossover trial. Ann Intern Med. 132:538-546.
Background: It has been reported that walnuts reduce serum cholesterol levels in normal young men. Objective: To assess the acceptability of walnuts and their effects on serum lipid levels and low-density lipoprotein (LDL) oxidizability in free-living hypercholesterolemic persons. Design: Randomized, crossover feeding trial. Setting: Lipid clinic at a university hospital. Patients: 55 men and women (mean age, 56 years) with polygenic hypercholesterolemia. Intervention: A cholesterol-lowering Mediterranean diet and a diet of similar energy and fat content in which walnuts replaced approximately 35% of the energy obtained from monounsaturated fat. Patients followed each diet for 6 weeks. Measurements: Low-density lipoprotein fatty acids (to assess compliance), serum lipid levels, lipoprotein (a) levels, and LDL resistance to in vitro oxidative stress. Results: 49 persons completed the trial. The walnut diet was well tolerated. Planned and observed diets were closely matched. Compared with the Mediterranean diet, the walnut diet produced mean changes of -4.1% in total cholesterol level, -5.9% in LDL cholesterol level, and -6.2% in lipoprotein(a) level. The mean differences in the changes in serum lipid levels were 20.28 mmol/L (95% CI, 20.43 to 20.12 mmol/L) (-10.8 mg/dL [0-16.8 to -4.8 mg/dL]) (P< 0.001) for total cholesterol level, -0.29 mmol/L (CI, -0.41 to -0.15 mmol/L) (-11.2 mg/dL [-16.3 to -6.1 mg/dL]) (P< 0.001) for LDL cholesterol level, and -0.021 g/L (CI, -0.042 to -0.001 g/L) (P = 0.042) for lipoprotein ( a) level. Lipid changes were similar in men and women except for lipoprotein (a) levels, which decreased only in men. Low-density lipoprotein particles were enriched with polyunsaturated fatty acids from walnuts, but their resistance to oxidation was preserved. Conclusion: Substituting walnuts for part of the monounsaturated fat in a cholesterol-lowering Mediterranean diet further reduced total and LDL cholesterol levels in men and women with hypercholesterolemia.
Zambón, D., J. Sabaté, S. Munoz, B. Campero, E. Casals, M. Merlos, J.C. Laguna, E. Ros, 2000. Substituting walnuts for monounsaturated fat improves the serum lipid profile of hypercholesterolemic men and women. A randomized crossover trial. Ann Intern Med. 132:538-546.
BACKGROUND: It has been reported that walnuts reduce serum cholesterol levels in normal young men. OBJECTIVE: To assess the acceptability of walnuts and their effects on serum lipid levels and low-density lipoprotein (LDL) oxidizability in free-living hypercholesterolemic persons. DESIGN: Randomized, crossover feeding trial. SETTING: Lipid clinic at a university hospital. PATIENTS: 55 men and women (mean age, 56 years) with polygenic hypercholesterolemia. INTERVENTION: A cholesterol-lowering Mediterranean diet and a diet of similar energy and fat content in which walnuts replaced approximately 35% of the energy obtained from monounsaturated fat. Patients followed each diet for 6 weeks. MEASUREMENTS: Low-density lipoprotein fatty acids (to assess compliance), serum lipid levels, lipoprotein (a) levels, and LDL resistance to in vitro oxidative stress. RESULTS: 49 persons completed the trial. The walnut diet was well tolerated. Planned and observed diets were closely matched. Compared with the Mediterranean diet, the walnut diet produced mean changes of -4.1% in total cholesterol level, -5.9% in LDL cholesterol level, and -6.2% in lipoprotein (a) level. The mean differences in the changes in serum lipid levels were -0.28 mmol/L (95% CI, -0.43 to -0.12 mmol/L) (-10.8 mg/dL [-16.8 to -4.8 mg/dL]) (P<0.001) for total cholesterol level, -0.29 mmol/L (CI, -0.41 to -0.15 mmol/L) (-11.2 mg/dL [-16.3 to -6.1 mg/dL]) (P<0.001) for LDL cholesterol level, and -0.021 g/L (CI, -0.042 to -0.001 g/L) (P = 0.042) for lipoprotein(a) level. Lipid changes were similar in men and women except for lipoprotein (a) levels, which decreased only in men. Low-density lipoprotein particles were enriched with polyunsaturated fatty acids from walnuts, but their resistance to oxidation was preserved. CONCLUSION: Substituting walnuts for part of the mono-unsaturated fat in a cholesterol-lowering Mediterranean diet further reduced total and LDL cholesterol levels in men and women with hypercholesterolemia.
Morgan, W.A., B.J. Clayshulte, 2000. Pecans lower low-density lipoprotein cholesterol in people with normal lipid levels. J Am Diet Assoc. 100(3):312-8.
OBJECTIVE: To compare serum lipid profiles and dietary intakes of people with normal lipid levels who consumed pecans and those who did not consume nuts. DESIGN: Eight-week, randomized, controlled study of pecan treatment group vs control group. SUBJECT: Nineteen people with normal lipid levels completed the study; 10 had been randomly assigned to the pecan treatment group (7 women, 3 men, mean age = 45 +/- 10 years) and 9 to the control group (8 women, 1 man, mean age = 37 +/- 12 years). INTERVENTION: The pecan treatment group consumed 68 g pecans per day for 8 weeks plus self-selected diets. The pecans contributed 459 kcal and 44 g fat daily. The control group avoided nuts and consumed self-selected diets. MAIN OUTCOME MEASURES: Total serum cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and total triglyceride levels were measured at the time of entrance to the study (baseline), week 4, and week 8. Computer analyses were done on five 3-day food records. STATISTICAL ANALYSIS: Comparisons were made using analysis of variance or paired t test. RESULTS: LDL-C was lowered in the pecan treatment group from 2.61 +/- 0.49 mmol/L at baseline to 2.35 +/- 0.49 at week 4 (P < .05) and to 2.46 +/- 0.59 at week 8 (P < .05). At week 8, total cholesterol and HDL-C in the pecan treatment group were significantly lower (P < .05) than in the control group (total cholesterol: 4.22 +/- 0.83 vs 5.02 +/- 0.54 mmol/L; HDL-C: 1.37 +/- 0.23 vs 1.47 +/- 0.34 mmol/L). Dietary fat, monounsaturated fat, polyunsaturated fat, insoluble fiber, magnesium, and energy were significantly higher in the pecan treatment group than in the control group. Body mass indexes and body weights were unchanged in both groups. APPLICATIONS: Pecans can be included in a healthful diet when energy intake and potential weight gain are addressed.
Colquhoun, D.M., 2000. Food for prevention of coronary heart disease: Beyond the low fat, low cholesterol diet. Asia Pacific J Clin Nutr. 9(suppl):S86-90.
The single major cause of death throughout the world is coronary heart disease. Prevalence is stable or decreasing in North America, Australasia and most of Europe, while rapidly increasing in eastern Europe, Asia and Africa. Atherosclerosis is the underlying pathology. This is one of the classic lifestyle diseases on the background of genetic susceptibility. Diet plays a key role in the initiation and progression of coronary heart disease. A low total fat diet is almost universally recommended throughout the world. However, the most successful secondary prevention diet trials have used modification of fat, rather than decrease in total fat per se. Successful diet trials suggest that diet modification is as effective as accepted drug therapy to prevent recurrent coronary events, and importantly is very cost effective. Marine lipid supplementation has been demonstrated beyond reasonable doubt to decrease total mortality and in particular sudden death in patients who have survived their first myocardial infarction. Large-scale diet intervention trials are indicated to improve the scientific basis for dietary recommendations to prevent initial and recurrent coronary heart disease.
Lavedrine, F., D. Zmirou, A. Ravel, F. Balducci, J. Alary, 1999. Blood cholesterol and walnut consumption: a cross-sectional survey in France. Prev Med. 28(4):333-9.
BACKGROUND: The preventive role of polyunsaturated fatty acids in cardiovascular disease has been recognized. We conducted a cross-sectional study to assess the association between walnut consumption (oil and kernel) as a source of polyunsaturated fatty acids and blood lipid levels. METHODS: Seven hundred ninety-three persons, males and females, ages 18-65 years, living in a walnut production area (Dauphiný, France) attended health screening visits organized by the Agriculture Social Security. Past diet (1-year recall, including walnut and animal fat consumption) and cardiovascular risk factors were ascertained using food frequency questionnaires. For each participant a blood sample was taken to measure HDL, LDL, and total cholesterol; apo A1; and apo B. RESULTS: A high level of HDL cholesterol and apo A1 was associated with a high amount of walnut consumption (oil and kernel) in the regular diet, with a positive trend with increasing degree of walnut consumption. This association did not appear to be confounded by dietary animal fat and alcohol as measured in this study. Other blood lipids did not show significant associations with walnut consumption. CONCLUSION: The positive effect of walnut consumption on blood HDL cholesterol and apo A1 is of special interest since these lipid parameters have been shown to be negatively correlated with cardiovascular morbidity.
Sabaté, J., 1999. Nut consumption, vegetarian diets, ischemic heart disease risk, and all-cause mortality: evidence from epidemiologic studies. Am J Clin Nutr. 70(suppl):500S.
Perhaps one of the most unexpected and novel findings in nutritional epidemiology in the past 5 y has been that nut consumption seems to protect against ischemic heart disease (IHD). Frequency and quantity of nut consumption have been documented to be higher in vegetarian than in nonvegetarian populations. Nuts also constitute an important part of other plant-based diets, such as Mediterranean and Asian diets. In a large, prospective epidemiologic study of Seventh day Adventists in California, we found that frequency of nut consumption had a substantial and highly significant inverse association with risk of myocardial infarction and death from IHD. The Iowa Women’s Health Study also documented an association between nut consumption and decreased risk of IHD. The protective effect of nuts on IHD has been found in men and women and in the elderly. Importantly, nuts have similar associations in both vegetarians and nonvegetarians. The protective effect of nut consumption on IHD is not offset by increased mortality from other causes. Moreover, frequency of nut consumption has been found to be inversely related to all-cause mortality in several population groups such as whites, blacks, and the elderly. Thus, nut consumption may not only offer protection against IHD, but also increase longevity.
Edwards, K., I. Kwaw, J. Matud, I. Kurtz, 1999. Effect of pistachio nuts on serum lipid levels in patients with moderate hypercholesterolemia. J Am Coll Nutr. 18(3):229-32.
BACKGROUND: Elevated serum cholesterol levels play an important role in the development of coronary artery disease. Previous studies have suggested that nut consumption benefits lipid profile. Pistachio nuts are widely available, inexpensive and frequently consumed by the general population. OBJECTIVE: To determine whether substituting 20% of the daily caloric intake in the form of pistachio nuts will improve the lipid profiles of humans with primary, moderate hypercholesterolemia. DESIGN: Controlled, randomized crossover design. SETTING: Outpatient dietary modification, counseling and blood analysis. PATIENTS: Ten patients with moderate hypercholesterolemia. INTERVENTION: Three weeks of dietary modification with 20% caloric intake from pistachio nuts. MEASUREMENTS: Body weight, blood pressure, total cholesterol, LDL, HDL, and triglycerides were monitored. Lipid profiles were analyzed prior to, during and after dietary modification. RESULTS: After three weeks, there was a decrease in total cholesterol (p<0.04), an increase in HDL (p<0.09), a decrease in the total cholesterol/HDL ratio (p<0.01) and a decrease in the LDL/HDL ratio (p<0.02). Triglycerides and LDL levels decreased, but not significantly. Body weight and blood pressure remained constant throughout the study. CONCLUSIONS: Results suggest that eating pistachio nuts instead of other dietary fat calories can improve lipid profiles, thereby decreasing coronary risk. Further studies will be required to confirm these results and to determine the mechanism of this effect.
Durak, I., I. Koksal, M. Kacmaz, S. Buyukkocak, B.M. Cimen, H.S. Ozturk, 1999. Hazelnut supplementation enhances plasma antioxidant potential and lowers plasma cholesterol levels. [Letter to the Editor]. Clin Chim Acta. 284(1):113-5.
In this study, 30 healthy medical students added 1 gram of hazelnuts per kilogram of body weight per day to their normal daily diet for 30 days. Total cholesterol was lowered by 6%, LDL by 19%, while HDL increased 7% and triglycerides 25% compared to baseline values. Plasma antioxidant potential (AOP) also increased by 20
Kris-Etherton, P.M., S. Yu-Poth, J. Sabaté, H.E. Ratcliffe, G. Zhao, T.D. Etherton, 1999. Nuts and their bioactive constituents: effects on serum lipids and other factors that affect disease risk. Am J Clin Nutr.70 (suppl.):504S-11S.
Because nuts have favorable fatty acid and nutrient profiles, there is growing interest in evaluating their role in a heart-healthy diet. Nuts are low in saturated fatty acids and high in monounsaturated and polyunsaturated fatty acids. In addition, emerging evidence indicates that there are other bioactive molecules in nuts that elicit cardioprotective effects. These include plant protein, dietary fiber, micronutrients such as copper and magnesium, plant sterols, and phytochemicals. Few feeding studies have been conducted that have incorporated different nuts into the test diets to determine the effects on plasma lipids and lipoproteins. The total- and lipoprotein-cholesterol responses to these diets are summarized in this article. In addition, the actual cholesterol response was compared with the predicted response derived from the most current predictive equations for blood cholesterol. Results from this comparison showed that when subjects consumed test diets including nuts, there was a ~25% greater cholesterol-lowering response than that predicted by the equations. These results suggest that there are non-fatty acid constituents in nuts that have additional cholesterol-lowering effects. Further studies are needed to identify these constituents and establish their relative cholesterol lowering potency.
