Published in the American Journal of Clinical Nutrition, the study’s authors said the aim was to compare risk factors of following the guidelines with those associated with a traditional British diet.
Results showed that selecting a diet high in fruits, vegetables and oily fish and low in saturated fats could make a difference. The study said such a diet lowered blood pressure and lipids, which in turn could reduce the risk of heart attacks by a third in healthy middle-aged and older people.
The team used a parallel-designed randomised controlled trial in 165 healthy non-smoking men and women aged 40–70 years. The participants followed a traditional British diet (control group) or an adapted one (dietary guidelines group) over a 12-week period.
The researchers measured the participants’ blood pressure (BP), vascular function, and CVD risk factors.
The key dietary targets for the dietary guidelines (DG) diet were to reduce salt intake, total fat, saturated fatty acids, and non-milk extrinsic sugars. It increased the consumption of oily fish to once a week, fruit and vegetables to five times a day, and whole grains to at least twice a day.
Participants were also advised to choose low-fat dairy products and select lean cuts of meat and to avoid meat products, sugar sweetened beverages, and added salt.
The control diet was a nutritionally balanced traditional British diet without restriction on salt and sugar intake. It was based around white bread, pasta, breakfast cereals and white rice, and potatoes with red meat, meat products, or poultry. The intake of oily fish and whole-grain cereals was limited to less than once a month.
Adherence to the dietary advice was confirmed both with dietary records and by measuring specific biomarkers in the participants' blood and urine.
While the average body weight in the DG group fell by 1.3 kg, that in the control group rose by 0.6 kg after 12 weeks. Waist circumference was also 1.7 cm lower in the dietary group compared to the control group, the study said.
“In the dietary guidelines group compared with control, the daytime systolic BP was 4.2 mm Hg
lower …[and] the total cholesterol: HDL cholesterol ratio was 0.13 lower,” said the researchers.
No significant change was recorded in markers for insulin sensitivity, which predicts the risk of developing type 2 diabetes. “Despite the fall in added sugar intake, total sugar intake was unaffected because the added sugars were replaced by sugar supplied by fruit.
“Selecting a diet consistent with current dietary guidelines compared with a traditional UK dietary pattern would be predicted… to reduce the risk of fatal and nonfatal CVD by 15% and 30%, respectively, in the general population,” the team concluded.
Source: The American Journal of Clinical Nutrition
“How effective are current dietary guidelines for cardiovascular disease prevention in healthy middle-aged and older men and women? A randomized controlled trial”
Authors: D. P. Reidlinger, et al