This study came through yesterday. The researchers were looking at the effects of a very-low-carbohydrate, high-saturated-fat weight-loss diet (LC) on brachial artery flow-mediated dilatation (FMD). Reduced flow-mediated dilation, as measured in this study, is an early indicator of cardiovascular disease - the vessels are not opening up as the blood flows though - they are not "flexing".
The researchers found that this study showed that a low carb diet does not impair FMD and actually had benficial effects on most other markers of cardiovascular health.
The full abstract is copied below for you to look at.
Now that might be enough to write. However, a few days ago I put up a fairly innocuous post "Low Carb Brief" In the comments to that someone pointed me to a study reported here , the abstract of which is found here
The shock horror headline was that "Low-fat Diets More Likely To Reduce Risk Of Heart Disease Than Low-carb Diets" as those researchers found that their low carb diet diminished FMD. Stephan commented superbly on this research here:
So let me get this straight. What we're looking at is data showing that LC beat or tied LF on every relevant parameter they reported except one, and somehow that means LF diets are healthier than LC? Even though overweight and hypertension are important risk factors for cardiovascular disease? Even though trig/HDL is probably the best predictor of heart disease of any of these measures?
This article wouldn't bother me if it weren't so arrogant. If it had simply reported the facts as an interesting phenomenon, instead of tacking on a politically motivated (and incorrect) interpretation, I would have just found it interesting. But the author is bigger than his britches: "LF diets may confer greater cardiovascular protection than LC diets."
The irony isn't lost on me that the paper is published in the journal Hypertension, shows that LC diets ameliorate hypertension better than LF diets, yet somehow claims LF diets are more protective of cardiovascular disease than LC. Huh?
Unfortunately, this is typical of researchers in the diet-health field and the media that report on it.
Now there is new research that indicates that low carb diets do not affect FMD and have benefits in other areas of cardiovascular health. I wonder how Science Daily will report this one!
Effects of weight loss from a very-low-carbohydrate diet on endothelial function and markers of cardiovascular disease risk in subjects with abdominal obesity
Background: The effects of a very-low-carbohydrate, high-saturated-fat weight-loss diet (LC) on brachial artery flow-mediated dilatation (FMD) and markers of endothelial function are unknown.
Objective: The effect of an LC on markers of endothelial function and cardiovascular disease (CVD) risk was compared with that of an isocaloric high-carbohydrate, low-saturated-fat diet (HC).
Design: FMD and markers of endothelial function (n = 70) and CVD risk were measured before and after 8 wk of weight loss. Ninety-nine subjects aged 50.0 ± 8.3 y with a body mass index (in kg/m2) of 33.7 ± 4.1 completed the study.
Results: Mean (±SD) FMD did not change significantly (P = 0.55) with either diet. Pulse wave velocity improved with both diets (P < 0.01). Endothelial markers, E- and P selectin, intracellular and cellular-adhesion molecule-1, tissue-type plasminogen activator, and plasminogen activator inhibitor-1 decreased (P < 0.001), with no diet effect. Adiponectin did not change significantly. More weight (P = 0.05 for diet x time interaction) and more abdominal fat mass (P = 0.05 for diet x time interaction) were lost with the LC than with the HC. LDL cholesterol decreased more with the HC than with the LC (P < 0.05, time x diet), and C-reactive protein decreased more with the HC than with the LC (P < 0.05 for diet x time interaction). Homocysteine increased more with the LC (P < 0.01 for diet x time interaction). Folate decreased with the LC and increased with the HC (P < 0.05, time; P < 0.001 for diet x time interaction).
Conclusion: A LC does not impair FMD. We observed beneficial effects of both diets on most of the CVD risk factors measured. This trial was registered with the Australian Clinical Trials Registry as ACTR N0 12606000203550.