Research: Hypertension

New study suggests benefits from adding more LOWFAT dairy to your diet

A study published in the May 2005 issue of the American Journal of Clinical Nutrition suggests that increased intake of lowfat dairy foods, as part of a DASH-based eating plan, may lower blood pressure more effectively than a conventional low-fat diet - a significant finding for the estimated 1 in 3 Americans who suffer from high blood pressure. (1,2)

Researchers compared two diets - one based on the DASH eating pattern and the other a typical low-fat diet - combined with increased physical activity. The study found that for comparable weight loss, the DASH-based diet resulted in a greater decrease in blood pressure than did the low-fat diet.

The DASH (Dietary Approaches to Stop Hypertension) eating plan was developed by the National Heart, Lung and Blood Institute (NHLBI) and is comprised of 3 daily servings of lowfat dairy foods and eight to ten daily servings of fruits and vegetables. The government recently highlighted the health benefits of DASH by recommending the eating plan in the new Dietary Guidelines and MyPryamid, and NHLBI has designated May as National Blood Pressure Education Month.

The study participants, consisting of 54 middle-aged men with a body mass index of about 30, were assigned to one of the two diets for 12 weeks and engaged in similar levels of physical activity. Both diet plans included lowfat or fat free dairy foods, fruits and vegetables, but at week 12, the DASH-based group reported a higher intake of dairy foods (approximately 4 daily servings compared to 2½ among the low-fat group). There was no reported difference in fruit and vegetable intake between the two diet groups.

The authors speculate that a combination of factors such as lower sodium and increased potassium, calcium, and magnesium - key nutrients found in dairy - may be responsible for the greater effect of the DASH-based diet on the obesity-related elevated blood pressure. Potassium has long been seen as a key nutrient in lowering blood pressure. Each 8-ounce serving of milk provides about 350-400 mg of potassium, or 11 percent of the Daily Value (DV) per serving. Fluid milk is the number one source of potassium in the American diet and dairy foods provide 18 percent of the potassium in the U.S. food supply.

(1) Nowson C, et al. Blood pressure change with weight loss is affected by diet type in men. American Journal of Clinical Nutrition. 2005; 81: 983-9.
(2) National Heart, Lung and Blood Institute (NHLBI). Facts about high blood pressure. Accessed May 6, 2005.