Kirkmeyer, S.V, R.D. Mattes, 2000. Effects of food attributes on hunger and food intake. Int J Obesity. 24:1167-75.
OBJECTIVE: To explore the relative importance of a food’s macronutrient composition, energy value, energy density, fiber content, weight, volume, sensory properties and rheology on hunger and food intake. DESIGN: Preloads of peanuts, peanut butter (rheology control), almonds (tree nut), chestnuts (macronutrient control), chocolate (sensory control), rice cakes (volume control), pickles (weight control) and no load (time control) were consumed by subjects in random order at weekly intervals and hunger was assessed over the subsequent 180 min. Free-feeding energy and macronutrient intake were monitored 24 h before and following preload ingestion. SUBJECTS: Twelve male and 12 female healthy, normal weight (12 ±28% body fat), adults (mean (s.d.) age 22±2.5 y) with low dietary restraint. RESULTS: Hunger ratings following consumption of the 2092 kJ (500 kcal) preloads of peanuts, peanut butter, almonds, chestnuts and chocolate were significantly lower than the low energy preloads or no preload condition, but with the exception of peanut butter, did not vary from each other. The rate of hunger recovery was consistent across all preloads so the overall impact of each food on hunger was determined by the initial drop it evoked. Total energy, but not macronutrient, compensation was observed with all preloads. Consequently, the fatty acid profile of the total diet reflected the composition of the preloads. CONCLUSIONS: Energy content may be the primary determinant of a food’s impact on hunger. Because macronutrient compensation is weak, a dietary supplement or substitute may influence the daily dietary nutrient profile.
Lino, M., K. Marcoe, J.M. Dinkins, H. Hiza, R. Anand, 2000. USDA Center for Nutrition Policy and Promotion. The role of nuts in a healthy diet. Insight 23, December.
While not a staple in the American diet, nuts are consumed by many Americans. This Nutrition Insight examines the contribution nuts can make to a diet, consumption of nuts, characteristics of people who eat nuts, and the association of nut consumption with diet quality.
Sze-Tao, K.W.C., S.K. Sathe, 2000. Functional properties and in vitro digestibility of almond (Prunus dulcis L.) protein isolate. Food Chem. 69:153-60.
Almond protein isolate (API) solutions were less viscous than those of soy protein isolate (SPI). The foaming capacity of API at pH 5.0 and 6.46 was comparable to that of SPI at pH 4.42 and 5.0. At pH 8.2, SPI had better foam capacity and stability compared to that of API. API had better oil absorption capacity than that of SPI [3.56 and 2.93 g/g dry weight basis (dwb), respectively]. Emulsion activity index (EAI) of API was significantly higher than that of SPI. API was easily hydrolyzed by pepsin in vitro.
Acosta, M.R., K.H. Roux, S.S. Teuber, S.K. Sathe, 1999. Production and characterization of rabbit polyclonal antibodies to almond (Prunus amygdalus L) major storage protein. J Agric Food Chem. 47: 4053-9.
Rabbits were immunized with purified almond major protein (AMP), the primary storage protein in almonds. Rabbit anti-AMP polyclonal antibodies (PA) could detect AMP when as little as 1-10 ng/mL were used to coat microtiter plates in a noncompetitive enzyme linked-immunosorbent assay (ELISA). Competitive inhibition ELISA assays detected the AMP down to 300 ng/mL. PA recognized the AMP in protein extracts from all U.S. major marketing cultivars of almonds (Mission, Neplus, Peerless, Carmel, and Nonpareil) with specific reactivity of 52.6-75% as compared to that of the AMP alone. Immunoreactivity of protein extracts prepared from commercial samples of blanched almonds, roasted almonds, and almond paste was respectively reduced by 50.0%, 56.6%, and 68.4% (noncompetitive ELISA) when compared to the immunoreactivity of the AMP. Moist heat (121 degrees C, 15 min) pretreatment of the AMP reduced the PA reactivity by 87% (noncompetitive ELISA). Exposing AMP to pH extremes (12.5 and 1.5-2.5) caused a 53% and 57% reduction in PA reactivity, respectively (noncompetitive ELISA). PA showed some cross-reactivity with the cashew major globulin, and to a lesser extent, the Tepary and Great Northern bean major storage protein (7S or phaseolin). The presence of almonds in a commercial food was detected using PA in a competitive ELISA.
Luscombe, N., M. Noakes, P. Clifton, 1999. Diets high and low in glycemic index versus high monounsaturated fat diets: effects on glucose and lipid metabolism in NIDDM. Eur J Clin Nutr. 53:473-8.
OBJECTIVE: To examine the relative effects of high and low glycemic index (GI) carbohydrates, and monounsaturated fats on blood glucose and lipid metabolism in NIDDM subjects. SUBJECTS: Fourteen male and seven female variably controlled NIDDM subjects recruited by advertisement. SETTING: Free living outpatients. RESEARCH DESIGN: A repeated measures, within-subject design was used such that each subject consumed three diets: (a) a high-GI diet (53% CHO -21% fat, 63 GI units (glucose= 100)); (b) a low-GI diet (51% CHO -23% fat, 43 GI units); and (c) a high-mono high-GI diet (42% CHO -35% fat, 59 GI units) in random order and cross-over fashion for four weeks. Approximately 45% energy was provided as key foods which differed in published GI values and specifically excluded legumes. Dietary fiber intake was > 30 g/d on each diet. At the end of each dietary intervention, we measured fasting plasma lipids, glucose, insulin, total glycated plasma protein, fructosamine, LDL and HDL particle size as well as 24 h urinary excretion of glucose and C-peptide. RESULTS: HDL-cholesterol was higher on the low-GI and high-mono high-GI diets compared to the high-GI diet (P < 0.05 for overall diet effect). There were no other significant differences in metabolic control between diets, even when adjusted for BMI, glucose control or gender. Body weight and saturated fat intake remained stable between dietary interventions. CONCLUSION: High-mono high-GI and high-CHO, low-GI diets are superior to high-CHO, high-GI diets with respect to HDL metabolism but no effect was noted on glucose metabolism in variably controlled NIDDM subjects.
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.
Hu, F.B., M.J. Stampfer, 1999. Nut consumption and risk of coronary heart disease: a review of epidemiologic evidence. Current Atherosclerosis Reports. (1):205-10.
Traditionally nuts have been perceived as an unhealthy food because of their high fat content. However, recent accumulative evidence suggests that frequent consumption of nuts may be protective against coronary heart disease (CHD). So far, five large prospective cohort studies (the Adventist Health Study, the Iowa Women Health Study, the Nurses’ Health Study, the Physicians’ Health Study, and the CARE Study) have examined the relation between nut consumption and the risk of CHD and all have found an inverse association. In addition, several clinical studies have observed beneficial effects of diets high in nuts (including walnuts, peanuts, almonds, and other nuts) on blood lipids. The beneficial effects of nut consumption observed in clinical and epidemiologic studies underscore the importance of distinguishing different types of fat. Most fats in nuts are mono- and polyunsaturated fats that lower low-density lipoprotein cholesterol level. Based on the data from the Nurses’ Health Study, we estimated that substitution of the fat from 1 ounce of nuts for equivalent energy from carbohydrate in an average diet was associated with a 30% reduction in CHD risk and the substitution of nut fat for saturated fat was associated with 45% reduction in risk. Given the strong scientific evidence for the beneficial effects of nuts, it seems justifiable to move nuts to a more prominent place in the United States Department of Agriculture Food Guide Pyramid. Regular nut consumption can be recommended in the context of a healthy and balanced diet.
Spiller, G.A., D.A.J. Jenkins, O. Bosello, J.E. Gates, L.N. Cragen, B. Bruce, 1998. Nuts and plasma lipids: an almond-based diet lowers LDL-C while preserving HDL-C. J Am Coll Nutr. 17(3):285-90.
OBJECTIVE: To compare lipid-altering effects of an almond-based diet with an olive oil-based diet, against a cheese and butter-based control diet. METHODS: Forty-five free-living hyperlipidemic men (n = 12) and women (n = 33) with a mean plasma total cholesterol (TC) of 251 +/- 30 mg/dL followed one of three diets; almond-based, olive oil-based, or dairy-based for 4 weeks. Total fat in each diet was matched, and the study-provided sources of fat comprised the major portion of fat intake. RESULTS: Reductions in TC and low-density lipoprotein-cholesterol (LDL-C) between the three groups were significantly different from the almond group (both p < 0.001). Within group analysis revealed that the almond-based diet induced significant reductions in TC (p < 0.05), LDL-C (p < 0.001), and the TC:HDL ratio (p < 0.001), while HDL-C levels were preserved. TC and HDL-C in the control diet were significantly increased from baseline (both p < 0.05), while the olive oil-based diet resulted in no significant changes over the study period. Weight did not change significantly. CONCLUSION: Results suggest that the more favorable lipid-altering effects induced by the almond group may be due to interactive or additive effects of the numerous bioactive constituents found in almonds.
Hu, F.B., M.J. Stampfer, J.E. Manson, E.B. Rimm, G.A. Colditz, B.A. Rosner, F.E. Speizer, C.H. Hennekens, W.C. Willett, 1998. Frequent nut consumption and risk of coronary heart disease in women: prospective cohort study. British Med J. 317:1341-5.
OBJECTIVE: To examine the relation between nut consumption and risk of coronary heart disease in a cohort of women from the Nurses’ Health Study. DESIGN: Prospective cohort study. SETTING: Nurses’ Health Study. SUBJECTS: 86 016 women from 34 to 59 years of age without previously diagnosed coronary heart disease, stroke, or cancer at baseline in 1980. MAIN OUTCOME MEASURES: Major coronary heart disease including non-fatal myocardial infarction and fatal coronary heart disease. RESULTS: 1255 major coronary disease events (861 cases of non-fatal myocardial infarction and 394 cases of fatal coronary heart disease) occurred during 14 years of follow up. After adjusting for age, smoking, and other known risk factors for coronary heart disease, women who ate more than five units of nuts (one unit equivalent to 1 oz of nuts) a week (frequent consumption) had a significantly lower risk of total coronary heart disease (relative risk 0.65, 95% confidence interval 0.47 to 0.89, P for trend=0.0009) than women who never ate nuts or who ate less than one unit a month (rare consumption). The magnitude of risk reduction was similar for both fatal coronary heart disease (0.61, 0.35 to 1.05, P for trend=0.007) and non-fatal myocardial infarction (0.68, 0.47 to 1.00, P for trend=0.04). Further adjustment for intakes of dietary fats, fiber, vegetables, and fruits did not alter these results. The inverse association persisted in subgroups stratified by levels of smoking, use of alcohol, use of multivitamin and vitamin E supplements, body mass index, exercise, and intake of vegetables or fruits. CONCLUSIONS: Frequent nut consumption was associated with a reduced risk of both fatal coronary heart disease and non-fatal myocardial infarction. These data, and those from other epidemiological and clinical studies, support a role for nuts in reducing the risk of coronary heart disease.
Sabaté J., D.G. Hook. Almonds, walnuts, and serum lipids. In: Spiller, G.A. Handbook of Lipids in Human Nutrition. New York, NY: CRC Press, Inc.; 1996.
This chapter reviews human studies that look at the effects of whole almonds and walnuts on blood lipid levels. Although each of the studies differ in methodology, the overriding consensus is that almonds, walnuts, and possibly other nuts with a similar nutrient composition, have a cholesterol lowering effect. The protective effect of nuts on coronary heart disease may be due to their fatty acid composition (mostly unsaturated fats) and other components in nuts.
