DASH Away All
The Associated Press calls it the “strongest evidence yet” that a government- recommended diet can prevent heart attacks and strokes.
I’ll admit, the size is impressive: More than 88,000 subjects were followed for nearly 25 years and their dietary habits reveal no surprise at all: A diet that puts a strong emphasis on a generous daily intake of fruits, vegetables, and whole grains may lower your risk of coronary heart disease, heart attack, and stroke.
But a little digging among some passing comments buried in this study produces a couple of interesting surprises – as well as a couple of important caveats about following a “government” diet.
“Normotensive” is what we aim for – that’s the word that describes the normal blood pressure range between hypertensive and hypotensive. It’s also the target for those who follow the DASH diet (Dietary Approaches to Stop Hypertension), brought to you by the good folks at the National Heart, Lung, and Blood Institute.
NHLBI is a division of the National Institutes of Health. And the NIH kindly provided a grant to Harvard researchers to test the long-term effects of the DASH diet on cardiovascular risks.
Of course, you can’t conduct a study in which 88,000 subjects follow different diets for 25 years. So the next best thing is to use information collected from the Nurses’ Health Study, which began following the medical and dietary records of more than 120,000 nurses in 1976. About every four years, most of the members of the original cohort supplied detailed updates on their dietary intake.
When the Harvard team compared these dietary records against cardiovascular events, they found that subjects whose diets most closely matched the key elements of the DASH diet had a 24 percent reduced risk of heart attack and an 18 percent reduced risk of stroke.
In the AP write up of the study, Dr. Nieca Gold berg (medical director of the NYU Women’s Heart Program) noted that many patients would rather just take a pill than change their diets. So she tries to persuade them to make dietary and other changes, hoping they’ll see the wisdom in avoiding a lifetime commitment to medication.
Dr. Goldberg certainly has her work cut out for her. Just imagine: Most of those patients probably watch television, so every day they see happy, healthy, vibrant people gushing about how this drug or that drug took care of this problem or that problem. In the background there’s always some guy murmuring about side effects, but these enthusiastic folks don’t seem to be suffering from night sweats, depression, vomiting, rashes, heartburn, loss of libido, etc.
Gimme the pill, doc!
Filling in the blanks
Here’s a little detail that wasn’t covered in the AP report, or any of the other mainstream media reports I’ve seen about this study: According to the Harvard researchers: “Women with higher DASH scores tended to use multivitamins.”
Funny how THAT didn’t warrant much attention! Subjects with higher DASH scores also had greater amounts of omega-3 fatty acids in their diets, and consumed fewer trans fats.
While those healthy details may seem obvious to HSI members, they probably won’t to most people who visit the web site that offers DASH dietary recommendations (nhlbi.nih.gov/hbp/index.html). There they’ll be told to eat two or fewer servings of fish, lean meats, or skinless poultry each day. That’s not going to supply much omega-3.
Meanwhile, the DASH plan says it’s fine to consume a couple of teaspoons of soft margarine every day – an excellent source of trans fatty acids.
And DASH doesn’t include any recommendations for multivitamins or other dietary supplements.
In other words, women with the highest DASH scores were savvy about their nutritional needs, so they rejected some of the DASH recommendations.
Their reward: reduced heart disease risk.
“Adherence to a DASH-Style Diet and Risk of Coronary Heart Disease and Stroke in Women” Archives of Internal Medicine, Vol. 168, No. 7, 4/14/08, archinte.ama-assn.org
“Diet Reduces Heart Attacks, Strokes” Lindsey Tanner, The Associated Press, 4/14/08, ap.org
“Your Guide to Lowering High Blood Pressure” National Heart, Lung, and Blood Institute, nhlbi.nih.gov/hbp/index.html