According to a recent study in the Nutrition Journal, dairy consumption might actually improve high blood pressure. When your doctor tells you that you have a blood pressure of one-twenty over eighty (written 120/80), the first number is called your systolic blood pressure (systolic BP) and the second is called your diastolic blood pressure (diastolic BP).
Systolic BP is the measure of the pressure on your artery walls from the muscular action of your heart. Systolic BP is higher than diastolic BP, which is the measure of the pressure in between heart beats. When both these numbers are too high, a condition known as hypertension results.
Hypertension can put a strain on the heart, leaving it vulnerable to associated diseases. The high pressure is also bad for the arteries and increases their risk of weakening and possibly rupturing. These conditions have frightening results, like aneurysms and some kinds of strokes.
Although dairy is often vilified, the newest research suggests when it comes to blood pressure, it might actually be helpful.
Study Design
There were 76 participants that completed the newest study. All of them had a systolic blood pressure between 135-160 and a diastolic pressure of 110 or less. This means they all had slightly elevated blood pressure.
The subjects were assigned to one of two groups. One group consumed dairy, and the control group consumed dairy substitutes for four weeks. After a second four-week washout period, during which they had a chance to normalize their diets and hypertension levels, the subjects then entered into a final four-week period in the opposite group. The order of dairy and control was randomized.
The participants in the dairy group consumed milk, cheese, and yogurt three times a day. In the control group, they substituted the dairy products for fruit and vegetable juices, salted cashews, and a cookie. The two conditions were the same in calories, and similar in carbs, fat, and salt.
The participants weren’t blinded to the conditions. When a study involves taking a pill or even drinking a liquid, it’s easy to make the subjects think two different study conditions are the same. This is done to minimize the placebo effect. However, when it comes to real foods, you simply can’t do this. It’s practically impossible to hide the difference between cheese and cashews, which were two of the foods included in this particular study. That said, the researchers were blinded to the conditions so as not to bias the results. I think the design is as good as a study like this could be.
Results
On average the dairy did improve average hypertension in men, but not women. The improvement was a modest, but significant -2 points in systolic blood pressure. In other words, on average it seems as though dairy is good for blood pressure, even when compared with other foods that have similar profiles. Dairy may be a good addition to your diet if blood pressure is an issue.
It’s important to note there was a large degree of personal difference in response to dairy. In other words, it’s clear that dairy consumption is linked to improvements blood pressure in some cases, but you might respond differently. If you’ve noticed recent changes in blood pressure, try adjusting your dairy intake to see what kind of responder you are.
References:
1. Jean-Philippe Drouin-Chartier, et. al., “Impact of dairy consumption on essential hypertension: a clinical study,” Nutrition Journal, 13:83, 2014
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