As people gain weight, their blood pressure tends to go up. Fortunately, as they lose weight, their blood pressure tends to go down -- but only so far, says Dr. Karol Watson, co-director of preventive cardiology and director of the hypertension clinic at UCLA. "If your body weight is normal, getting below doesn't help," she says.
Even modest weight loss (say, 5% to 10% of your current heft) is effective at lowering blood pressure for those who have high blood pressure or prehypertension. But the way you lose the weight may matter.
A 2006 review of 17 studies reported that people who lost modest amounts of weight through diet alone, or diet plus the "fat-blocker" orlistat (Xenical, Alli), did experience blood pressure drops. But those who used the appetite suppressant sibutramine (Meridia) did not -- in fact, in some cases, the blood pressure of people taking sibutramine went up.
And in a yearlong study reported Jan. 25 of 146 obese and overweight people, those who lost weight on a low-carbohydrate diet had a greater reduction in blood pressure than those who lost the same amount of weight through a low-fat diet combined with prescription-strength orlistat. That was the case even though both groups shed about the same number of pounds -- about 10%, on average, of their starting weight. Doctors were able to reduce or discontinue blood pressure medication for 47% of the low-carb group -- but for only 21% of the low-fat-and-orlistat group.
Though the association between weight and blood pressure is well established, it isn't well understood. Many believe it's related to food. "If you're overweight, you're usually not eating the healthiest diet," says Dr. Mitra Nadim, director of the Hypertension Center at USC.
But a 2002 study suggests it may be related to decreases in amounts of angiotensin-converting enzyme, or ACE, which plays an important role in blood pressure regulation.
Levels of ACE went down an average of 18% in the study, which tracked 16 obese adults as they shed 5% to 10% of their body weight over five weeks.Copyright © 2015, Los Angeles Times