Saturday, January 30, 2010

Who pays the piper: Other lipids

About lipids, quote from the discussion in the Bradley and Hunter paper, related to Table 5:



"As expected, the low-fat diet decreased both LDL and HDL cholesterol. Although the low-carbohydrate diet did not decrease LDL cholesterol, it was not associated with a significant decline in HDL cholesterol. Given the established evidence that LDL lowering reduces the risk of coronary heart disease, the lack of a decrease may be of concern. In contrast to the lack of a change in LDL and HDL in response to the low-carbohydrate diet, there was a significant reduction in triglycerides within this group compared with no significant change within the low-fat group. This response has been consistently reported in other studies comparing a low-carbohydrate and low-fat weight reduction diet (12). It has been speculated that this result is due to a combination of a decrease in the VLDL production rate and an increase in triglyceride removal from the blood (31). Previous studies (32,33) indicate that increased triglycerides are an independent risk factor for cardiovascular disease, although it is impossible to predict the overall effect of the lipid changes with the lowcarbohydrate diet. Further examination of the lipid subfraction profile may help elucidate the effects of the dietary regimens on lipid metabolism. Indeed, previous studies have suggested that low-carbohydrate diets increase LDL particle size and decrease small dense LDL particles (34)"

This is a load of mealy mouthed beating around the bush. My translation (couched in terms of the lipid hypothesis, for believers such as Bardley and Hunter):

The low carbohydrate diet did no harm to LDL, this is really good. Low fat diet converted any bouyant LDL around from the pre study diet to sdLDL during the study. This is really bad, it just improved a lab number while actually injuring the participants. The low carbohydrate reduced triglycerides, this is really good. The low fat diet didn't. This is cr@p.

Executive summary: The low carbohydrate beat the low fat diet on lipids, hands down.

Peter

2 comments:

Jim Purdy said...

"This is really bad, it just improved a lab number while actually injuring the participants."

I've had doctors who did exactly that to me, especially with blood pressure pills and diabetes pIlls. They loved the lab numbers, but the meds were killing me.

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Peter said...

It's difficult when you are stuck in the wrong paradigm Jim, don't be too hard on them!

Peter