Brunner E J, Thorogood M, Rees K, Hewitt G
University College London, Department of Epidemiology and Public Health, 1-19 Torrington Place, London, UK WC1E 6BT.
Cochrane Database Syst Rev. 2005 Oct 19(4):CD002128. doi: 10.1002/14651858.CD002128.pub2.
Changes in population diet are likely to reduce cardiovascular disease and cancer, but the effect of dietary advice is uncertain.
To assess the effects of providing dietary advice to achieve sustained dietary changes or improved cardiovascular risk profile among healthy adults.
We searched the Cochrane Controlled Trials Register on The Cochrane Library (Issue 2 2000), MEDLINE (January 1966 to December 2000), EMBASE (January 1985 to December 2000), DARE (December 2000), CAB Health (December 1999), dissertation abstracts, and reference lists of articles. We contacted researchers in the field.
Randomised studies with no more than 20% loss to follow-up, lasting at least three months involving healthy adults comparing dietary advice with no advice or less intensive advice. Trials involving children, trials to reduce weight or those involving supplementation were excluded.
Two reviewers independently assessed trial quality and extracted data. Study authors were contacted for additional information.
Twenty-three trials with 29 intervention arms (comparisons) comparing dietary advice with no advice were included in the review. Dietary advice reduced total serum cholesterol by 0.13 mmol/l (95% CI 0.03 to 0.23) and LDL cholesterol by 0.13 mmol/l (95% CI 0.01 to 0.25) after 3-12 months. Mean HDL cholesterol levels were unchanged. Dietary advice reduced blood pressure by 2.10 mmHg systolic (95% CI 1.37 to 2.83) and 1.63 mmHg diastolic (95% CI 0.56 to 2.71) and 24-hour urinary sodium excretion by 44.2 mmol (95% CI 33.6 to 54.7) after 3-36 months. Plasma triglycerides, ss-carotene and red cell folate were each measured in one small study which suggested no significant effect. Self-reported dietary intake may be subject to reporting bias, and there was significant heterogeneity in all the following analyses. Compared to no advice, dietary advice increased fruit and vegetable intake by 1.24 servings/day (95% CI 0.43 to 2.05). Dietary fibre intake increased with advice by 7.22 g/day (95% CI 2.84 to 11.60), while total dietary fat as a percentage of total energy intake fell by 6.18 % (95% CI 4.00 to 8.36) with dietary advice and saturated fat intake fell by 3.28 % (95% CI 1.92 to 4.64).
AUTHORS' CONCLUSIONS: Dietary advice appears to be effective in bringing about modest beneficial changes in diet and cardiovascular risk factors over approximately 9 months but longer term effects are not known.
人群饮食的改变可能会降低心血管疾病和癌症的发病率，但饮食建议的效果尚不确定。
评估提供饮食建议以实现持续的饮食改变或改善健康成年人的心血管风险状况的效果。
我们检索了《Cochrane图书馆》（2000年第2期）中的Cochrane对照试验注册库、MEDLINE（1966年1月至2000年12月）、EMBASE（1985年1月至2000年12月）、DARE（2000年12月）、CAB健康数据库（1999年12月）、学位论文摘要以及文章的参考文献列表。我们还联系了该领域的研究人员。
随机研究，随访失访率不超过20%，持续至少三个月，涉及健康成年人，将饮食建议与无建议或低强度建议进行比较。排除涉及儿童的试验、减重试验或涉及补充剂的试验。
两名评价员独立评估试验质量并提取数据。联系研究作者获取更多信息。
本综述纳入了23项试验，其中29个干预组（比较组）将饮食建议与无建议进行了比较。3至12个月后，饮食建议使总血清胆固醇降低了0.13 mmol/l（95%可信区间0.03至0.23），低密度脂蛋白胆固醇降低了0.13 mmol/l（95%可信区间0.01至0.25）。高密度脂蛋白胆固醇平均水平未改变。3至36个月后，饮食建议使收缩压降低了2.10 mmHg（95%可信区间1.37至2.83），舒张压降低了1.63 mmHg（95%可信区间0.56至2.71），24小时尿钠排泄量降低了44.2 mmol（95%可信区间33.6至54.7）。在一项小型研究中分别测量了血浆甘油三酯、β-胡萝卜素和红细胞叶酸，结果显示无显著影响。自我报告的饮食摄入量可能存在报告偏倚，并且在以下所有分析中均存在显著异质性。与无建议相比，饮食建议使水果和蔬菜摄入量增加了1.24份/天（95%可信区间0.43至2.05）。膳食纤维摄入量因建议而增加了7.22 g/天（95%可信区间2.84至11.60），而饮食建议使总膳食脂肪占总能量摄入的百分比下降了6.18%（95%可信区间4.00至8.36），饱和脂肪摄入量下降了
3.28%（95%可信区间1.92至4.64）。
饮食建议似乎在大约9个月内有效地带来了适度的有益饮食和心血管危险因素变化，但长期效果未知。
