Flax Seeds Have Profound Effect on Hypertension
A recent article in the journal, Meat Science, acknowledged that a sector of the population perceives meat as a food that is detrimental to their health because of studies associating meat consumption with heart disease and cancer. So, meat consumers may look for healthier food alternatives as a means to maintain good health, which represents a good opportunity for the meat industry to develop some new products. The industry felt that natural foods could be added to meat to reach those health-oriented consumers by boosting antioxidants levels, for example. Foods like flax seeds and tomatoes are healthy, associated with reduced risks of cancer and cardiovascular disease. So by making flax-y tomato burgers, they figure they can reduce saturated fat intake and maybe eat less sugar somehow. Wouldn’t it be easier to just cut out the middle-cow and eat flax seeds ourselves?
Flax seeds have been described as a “miraculous defense against some critical maladies.” I’m a fan of flax, but this title seemed a bit over-exuberant; I figured something just got lost in translation, but then I found a prospective, double-blinded, placebo-controlled, randomized trial—you know how hard that is in a nutrition study? For drugs, it’s easy: you have two identical looking pills, one’s active, one’s placebo, and until the end of the study, neither the researcher nor the patient has any idea which is which, hence “double blind.” But people tend to notice what they’re eating. So how did they sneak a quarter cup of ground flax seeds into half of the people’s diets without them knowing? They created all these various flax or placebo containing foods, and even added bran and molasses to match the color and texture, so it was all a big secret until six months later when they broke the code to see who ate which.
Why test it on hypertension? Because having a systolic blood pressure over 115—that’s the top number—may be the single most important determinant for death in the world today. If you take a bunch of older folks, most of them on an array of blood pressure pills, and don’t improve their diet at all, despite the drugs, they may start out on average hypertensive and stay hypertensive six months later. But those who were unknowingly eating ground flaxseeds every day, dropped their systolic blood pressure about ten points, and their diastolic, the lower number, by about seven points. That might not sound like a lot, but a drop like that could cut stroke risk 46 percent and heart disease 29 percent, and that ten point drop in the top number could have a similar effect on strokes and heart attacks. And for those that started out over 140, they got a 15-point drop.
In summary, flaxseed induced one of the most potent antihypertensive effects ever achieved by a dietary intervention. In other words, the magnitude of this decrease in blood pressure demonstrated by dietary flaxseed, is as good or better than other nutritional interventions and comparable to many drugs, which can have serious side effects. And they’re not exaggerating about the comparable to drugs bit. The flax dropped systolic and diastolic up to 15 and 7. Compare that to powerful ACE inhibitors like Vasotec, which may only drop pressures five and two, and calcium channel blockers like Norvasc or Cardizem which drop pressures eight and three. Side effects of these drugs include a large list of serious medical issues (as seen in the video below), compared to the side effect of flax seeds, “its pleasant nutty flavor.”
During the six-month trial there were strokes and heart attacks in both groups. Even if the flax seeds can cut risk in half, though, any avoidable risk is unacceptable. Isn’t high blood pressure just inevitable as we get older? No – the prevalence of hypertension does increase dramatically with age, but not for everyone. People who eat more plant-based diets or keep their salt intake low enough tend not to exhibit any change in blood pressure with advancing age. It’s always better to prevent the disease in the first place.
Michael Greger, M.D.
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