The study, published this month in the Journal of Pediatrics , compared the change in blood pressure that occurred when adolescents with a clinical diagnosis of prehypertension or hypertension were put on either the DASH diet or the routine hospital-based nutrition care (RC).
The researchers found reductions in blood pressure were greater for those who followed the DASH diet, and that 50 per cent of them, compared to 36 per cent of the RC group, achieved blood pressure normalisation by post-treatment.
They wrote: "This study provides preliminary evidence for the acceptability and short-term efficacy of… behavioural nutrition intervention emphasising the DASH diet relative to RC to improve diet quality and lower BP in adolescents with hypertension and prehypertension.
"These novel data support the need for a larger study with longer follow-up to evaluate the clinical efficacy of this approach and important mediators of dietary adherence among adolescents over the long term."
High blood pressure (hypertension),defined as having a systolic and diastolic blood pressure (BP) greater than 140 and 90 mmHg, is a major risk factor for cardiovascular disease (CVD) - a disease that causes almost 50 per cent of deaths in Europe, and reported to cost the EU economy an estimated €169bn ($202bn) per year.
According to the study's authors, the prevalence of primary hypertension among youth is on the rise in line with the growing problem of obesity.
The study Fifty-seven adolescents diagnosed with prehypertension or hypertension (systolic BP or diastolic BP) were randomly assigned to a DASH or RC diet.
The DASH diet in this study was slightly modified from the original adult version to more closely meet the nutritional needs of adolescents.
Participants were encouraged to eat eight servings of fruit and vegetables per day, three servings of low fat dairy foods and two servings per day or less of DASH 'unfriendly foods'.
Meanwhile, those following the RC diet were told to reduce dietary sodium and controlling weight by limiting high fat foods, reducing portion sizes and eating the nutrient-dense forms of food.
Results DASH participants ate more fruits, potassium and magnesium and less total fat from baseline to post-treatment.
Reductions in systolic BP scores were significantly greater for DASH participants, with a relative change in SBP of -7.9 per cent compared to -1.5 per cent in the RC group.
By post-treatment, 50 per cent of the DASH group achieved a normal blood pressure level, compared with 36 per cent in the RC group.
By the three-month follow-up, 61 per cent of DASH adolescents had normal blood pressure while 44 per cent did so in the RC condition.
This supports the health benefits that can arise from dairy consumption, in a time when some dairy has been receiving a bad press.
Only last month, dairy industry players called for a reassessment of how their products are perceived under the UK's nutrient profiling system, ahead of a government debate on extending advertising restrictions based on the scheme.
Commenting on the study, Dr Judith Bryans, director of the Dairy Council, said: "We are encouraged by the results of this study as it supports the inclusion of low-fat dairy in the diet and the positive role it plays in promoting healthy blood pressure in adolescents."
Source Journal of Pediatrics April 2008 (Vol. 152, Issue 4, Pages 494-501) "The Efficacy of a Clinic-Based Behavioral Nutrition Intervention Emphasizing a DASH-Type Diet for Adolescents with Elevated Blood Pressure" Authors: Sarah Couch, Brian Saelens, Linda Levin, Kate Dart, Grace Falciglia and Stephen Daniels