Dairy does a body’s blood-pressure good—as long as the dairy is low-fat. That’s the conclusion of a new analysis of data on almost 30,000 participants in the observational Women’s Health Study, which found that an increased intake of low-fat dairy products reduced women’s risk of developing hypertension. Women with the greatest average low-fat dairy consumption were 11% less likely to develop high blood pressure than those consuming the least.
“Our study findings offer additional support to the [2005 Dietary Guidelines for Americans] from the perspective of hypertension prevention and emphasis on the importance of low-fat dairy products,” wrote lead author Lu Wang, MD, PhD, of Brigham and Women’s Hospital in Boston and colleagues.
The latest federal dietary guidelines recommend three servings of low-fat dairy daily for adults. The one-fifth of women in the study getting the most low-fat dairy averaged 2.71 servings daily; those in the lowest-intake group averaged only 0.13.
No significant change in hypertension risk was linked to consumption of high-fat dairy products. Although risk reductions were linked to both dietary calcium (13%) and dietary vitamin D (5%), no similar protective effect was found from calcium or vitamin D in supplement form.
The study, published in the American Heart Association journal Hypertension, followed 28,886 women with an average age of 54. Dietary intakes were assessed using a semi-quantitative food-frequency questionnaire. Over a 10-year follow-up, 8,710 women developed hypertension, defined as having systolic blood pressure greater than 140 mmHg or diastolic greater than 90 mmHg, a history of physician- diagnosed hypertension, or use of anti-hypertensive medications.
“It remains unclear why benefits are observed for low-fat dairy products but not for high-fat dairy products,” commented Dr. Wang and colleagues, noting that a similar phenomenon has been observed for type-2 diabetes and coronary heart disease. “It is postulated that saturated fats in high-fat dairy products may mitigate the beneficial effects of other components of dairy products, including calcium.”
Dairy products account for nearly 80% of the total calcium intake in the average American diet, so it’s important to get enough and to consume low- or non-fat sources.
“Because hypertension remains a highly prevalent disease in the United States,” the researchers said, “even a modest reduction in hypertension risk on an individual level will substantially lower the disease burden in the population.”
Got Milk? Or Yogurt or Cottage Cheese or...
The latest US dietary guidelines recommend that all adults get three servings of low- or non-fat dairy products daily. One serving is equivalent to one cup (8 fluid ounces) of milk. But you don’t always have to drink your dairy or pour it on cereal. You can also count as one serving of dairy:
- 1 regular container of yogurt (8 ounces)
- 2 snack-size yogurts (4 ounces each)
- 2 cups cottage cheese
- 1 cup pudding made with milk
- 1 cup frozen yogurt
- 1 1/2 cups ice cream
Remember to choose low- or non-fat dairy products, whatever form you consume. Besides adding calories and saturated fat, high-fat milk seems to cancel out the benefits of dairy against hypertension, type 2 diabetes and heart disease.
If you usually drink whole milk, switch gradually to fat-free milk. Try reduced-fat (2%), then low-fat (1%), and finally fat-free (skim).
(tuftshealthletter.com)
