Friday, September 21, 2012

High Fat, High Health

Stewart, a professor of medicine and director of Clinical and Research Exercise Physiology at the Johns Hopkins University School of Medicine and its Heart and Vascular Institute, says that his team’s latest analysis is believed to be the first direct comparison of either kind of diet on the effects to vascular health, using the real-life context of 46 people trying to lose weight through diet and moderate exercise. The research was prompted by concerns from people who wanted to include one of the low-carb, high-fat diets such as Atkins, South Beach and Zone as part of their weight-loss program but were wary of the diets’ higher fat content.
In the first study, presented June 3 at the annual meeting of the American College of Sports Medicine in Denver, the Johns Hopkins team studied 23 men and women weighing on average 218 pounds and participating in a six-month weight-loss program that consisted of moderate aerobic exercise and lifting weights, plus a diet made up of no more than 30 percent of calories from carbs, such as pastas, breads and sugary fruits. As much as 40 percent of their diet was made up of fats coming from meat, dairy products and nuts.
After shedding 10 pounds, this low-carb group showed no change in two key measures of vascular health: finger tip tests of how fast the inner vessel lining in the arteries in the lower arm relaxes after blood flow has been constrained and restored in the upper arm (the so-called reactive hyperemia index of endothelial function) and the augmentation index (a pulse-wave analysis of arterial stiffness).

While this is another bit of good news about the safety of high fat diets, the funny part is that there wasn't any of this testing 30 to 40 years ago when the "conventional wisdom" adopted the low fat diet. There was very little scrutiny, sadly.  Would that the establishment had been as disciplined about evaluating the effects of low fat diets - but perhaps the current efforts are the result of "lessons learned" about embracing dietary philosophy without rigorous evaluation.

More from the article:

Low-carb dieters showed no harmful vascular changes but also on average dropped 10 pounds in 45 days, compared to an equal number of study participants randomly assigned to a low-fat diet. The low-fat group, whose diets consisted of no more than 30 percent from fat and 55 percent from carbs, took on average 70 days, nearly a month longer, to lose the same amount of weight.
“Our study should help allay the concerns that many people who need to lose weight have about choosing a low-carb diet instead of a low-fat one, and provide reassurance that both types of diet are effective at weight loss and that a low-carb approach does not seem to pose any immediate risk to vascular health,” Stewart said. “More people should be considering a low-carb diet as a good option,” he added.

1 comment:

  1. I love studies like this. This was an interesting study. I almost always put my clients on low carb diets. It's Funny people want to see results fast and if you can get them down just a little it motivates them to keep going.