The Latest Surprise About Probiotics

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Written by Neal D. Barnard, MD

Probiotics are all over the news, and for good reason. They started out promising to help with tummy troubles, but, in fact, their power goes much further. It turns out they can lower blood pressure.

A new article, published in the journal Hypertension, combined the results of nine smaller studies. To understand what the study showed, let me give you a little background: When a doctor tells you your blood pressure is 120/80, the first number (systolic) is the pressure in your arteries as your heart is beating. The second number (diastolic) is the pressure when your heart is resting between beats.

The new study showed that probiotics can knock about four points off your systolic blood pressure and about two points off your diastolic pressure. At first glance, that doesn’t sound like much. But several things boost that effect:

First, people with higher starting blood pressures got a greater effect. One study of hypertensive patients showed a benefit of about 10 points systolic and 4 points diastolic.

Second, products that included a combination of probiotic strains proved more powerful than products with just one.

Third, it was important to use a probiotic for at least eight weeks. Shorter studies yielded little in the way of results.

Overall, the effect of probiotics on blood pressure is similar to the effect of reducing salt, exercising, or following a vegetarian diet. And if you were to combine these healthy steps, you’ll get a powerful blood-pressure-lowering effect.

How do they work? That is not entirely clear. However, probiotics are known to reduce cholesterol and triglycerides, and reducing the amount of these fatty particles in the bloodstream could reduce blood pressure. The kidneys play an important role in regulating blood pressure and may also be involved.

So is it better to get probiotics in foods or in supplements? When it comes to vitamins and minerals, I usually recommend getting them from foods, rather than from pills. But probiotics are not vitamins; they are living organisms, found only in fermented foods. To make sure you get the right dose, it’s easier to take supplements instead of eating foods with probiotics.

Probiotics are measured in “colony-forming units” or CFUs, which you will see on the label. The daily dose that works in research studies is at least 1 billion CFUs, ideally around 100 billion. Take the supplements just before or with a meal.

Perhaps most importantly, think of probiotics as something you would consider in addition to regular medical evaluation and treatment, not instead of them. High blood pressure is dangerous, so it is essential to have your blood pressure checked regularly. If it is high, follow your doctor’s advice about medication. If probiotics or other steps help you reduce your need for medication—or avoid it completely—so much the better.