Campuran Konsentrat Buah dan Sayur Meningkatkan Plasma Antioksidan Vitamin dan Folat dan Homosistein Plasma Rendah pada Pria (SHALLY MARLI MAULANA)
A Mixed Fruit and Vegetable Concentrate Increases Plasma Antioxidant
Vitamins and Folate and Lowers Plasma Homocysteine in Men
Samir Samman, Gayathri Sivarajah, June C. Man, Ziaul I. Ahmad, Peter Petocz* and Ian D. Caterson
Human Nutrition Unit, School of Molecular and Microbial Biosciences, University of Sydney NSW 2006 and
*Department of Mathematical Sciences, University of Technology, Sydney NSW 2007, Australia
Introduction
Cardiovascular disease is the largest single cause of death in the United States, the UK and Australia (1–3). It is a multifactorial disease, but a fundamental environmental factor is diet (4). Recent large-scale cohort studies have shown that the risk of coronary heart disease (CHD) is inversely associated with the intake of vegetables in men (5) and a higher intake of fruit and vegetables is associated with lower risk of myocardial infarction in women (6). This inverse association between fruit and vegetable intake and CHD appears to be consistent across different geographical locations and in populations that differ in lifestyle, gender and age (7–9). These observations have led to continued support for the recommendation to increase the consump- tion of fruit and vegetables (10 –12). There remains considerable scientific debate about the contribution of specific dietary constituents to the reduc- tion in CHD risk. It has been suggested that the association of a lower rate of CHD with the intake of fruit and vege- tables is attributed to the displacement of foods that are high in Na, energy density and fat, particularly saturated fat (11,13). In addition, fruit and vegetables are recognized sources of a number of nutrients that may interact to reduce LDL cholesterol (soluble fiber and plant sterols) (14,15), blood pressure (lower Na/K ratio) (16) and homocysteine (folate) (17), and to improve antioxidant status (18) and endothelial function (19).
SUBJECTS AND METHODS
Study design. Subjects participated in a double-blind, randomized, placebo-controlled, crossover trial, consisting of two intervention periods of 6 wk separated by a 3-wk wash-out period. They were randomly assigned to one of two groups to receive first either a mixed fruit and vegetable supplement produced from dehydrated juice concentrates (4 capsules; Juice Plus, Natural Alternatives International, San Marcos, CA) or a placebo. The supplement was provided as two capsules of “fruit blend” in the morning and two capsules of “vegetable blend” in the evening (composition shown in Table 1). The placebo capsules were physically identical to the intervention capsules but contained alfalfa and beetroot to mimic the colors of the vegetable and fruit supplements, respectively. At the beginning of each period, subjects were provided with a known number of capsules and asked to return any that were unused. These were counted to determine apparent compliance. Subjects were asked to maintain their habitual dietary and exercise patterns and to refrain from commencing any form of vitamin or herbal supplementation during the intervention.
Study design. Subjects participated in a double-blind, randomized, placebo-controlled, crossover trial, consisting of two intervention periods of 6 wk separated by a 3-wk wash-out period. They were randomly assigned to one of two groups to receive first either a mixed fruit and vegetable supplement produced from dehydrated juice concentrates (4 capsules; Juice Plus, Natural Alternatives International, San Marcos, CA) or a placebo. The supplement was provided as two capsules of “fruit blend” in the morning and two capsules of “vegetable blend” in the evening (composition shown in Table 1). The placebo capsules were physically identical to the intervention capsules but contained alfalfa and beetroot to mimic the colors of the vegetable and fruit supplements, respectively. At the beginning of each period, subjects were provided with a known number of capsules and asked to return any that were unused. These were counted to determine apparent compliance. Subjects were asked to maintain their habitual dietary and exercise patterns and to refrain from commencing any form of vitamin or herbal supplementation during the intervention.
RESULTS
Thirty-eight men were selected for the study. Six subjects withdrew during the first phase of supplementation: four cited logistic reasons and were unable to meet the study schedule, two withdrew because they had reconsidered their participation. Thirty-two subjects completed the trial and their baseline data are presented in Table 2. Smokers and nonsmokers did not differ in nutrient intakes (Table 2) or any of the biochemical variables. It is noteworthy that the intakes of vitamin C and folate were beyond the recommended dietary intake [40 mg and 200 g, respectively; (34)] due mainly to the consumption of fruit juice and foods fortified with folic acid. The degree of compliance was estimated as the difference between the number of capsules issued and the number of capsules returned. Apparent compliance was 87.4 10.2 and 88.7 10.0% for the placebo and supplementation periods, respectively. There were no differences in compliance of smokers and nonsmokers.
Thirty-eight men were selected for the study. Six subjects withdrew during the first phase of supplementation: four cited logistic reasons and were unable to meet the study schedule, two withdrew because they had reconsidered their participation. Thirty-two subjects completed the trial and their baseline data are presented in Table 2. Smokers and nonsmokers did not differ in nutrient intakes (Table 2) or any of the biochemical variables. It is noteworthy that the intakes of vitamin C and folate were beyond the recommended dietary intake [40 mg and 200 g, respectively; (34)] due mainly to the consumption of fruit juice and foods fortified with folic acid. The degree of compliance was estimated as the difference between the number of capsules issued and the number of capsules returned. Apparent compliance was 87.4 10.2 and 88.7 10.0% for the placebo and supplementation periods, respectively. There were no differences in compliance of smokers and nonsmokers.
In conclusion, supplementation with a mixed fruit and vegetable concentrate increases plasma AA, -carotene and folate, and lowers plasma homocysteine. A large body of evidence suggests that fruit and vegetables lower the risk of heart disease, and the results of the present study suggest that one of the mechanisms, in the absence of dietary displacement, is the reduction in plasma homocysteine.
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