Thursday, January 10, 2008

Two-Fold Reduction in Triglycerides! How? Low-Carb!

In a recent study - Metabolic Effects of Weight Loss on a Very-Low-Carbohydrate Diet Compared With an Isocaloric High-Carbohydrate Diet in Abdominally Obese Subjects, published in the Journal of the American College of Cardiology, researchers reported favorable results for obese adults randomly assigned a low-carbohydrate diet for 24-weeks (six months).

As reported in heartWire, "After six months, isocaloric energy-restricted very-low-carbohydrate, high-fat and high-carbohydrate, low-fat diets produced similar weight loss and substantial reductions in a number of cardiovascular disease risk markers," write Jeannie Tay (Flinders University, Adelaide, Australia) and colleagues in the January 1, 2008 issue of the Journal of the American College of Cardiology.

"Neither diet displayed adverse effects, suggesting diverse dietary patterns, including very-low-carbohydrate, high-fat diets, may be tailored to an individual's metabolic profile and dietary preference for weight management."

The investigators note that while the traditional diet reduced LDL-cholesterol levels, the low-carbohydrate, high-fat diet resulted in greater increases in HDL cholesterol and singificantly larger reductions in triacylglycerol levels (a two-fold greater reduction compared to the traditional low-fat diet).

In fact, if we go to the full-text, we find the researchers went so far as to write "consistent with other recent studies, the VLCHF (very-low-carb high-fat) diet produced greater reductions in TAG and increases in HDL-C than the HCLF (high-carbohydrate low-fat) diet. This suggests that the VLCHF diet as a weight loss strategy may confer the greatest clinical benefits in patients who present with hypertriglyceridemia, low HDL levels, abdominal adiposity, and insulin resistance"

Did you catch that - "greatest clinical benefits" - part?

In the paper we learn that subjects were randomly assigned to either of the moderately energy-restricted diet plans for 24 weeks. For those assigned to the very-low-carbohydrate, high-fat diet, 4% of total calories were obtained from carbohydrates, 35% from protein, and 61% from fat, including 20% of total calories from saturated fat. Subjects randomized to the high-carbohydrate, low-fat diet followed a more traditional macronutrient profile, with 46% of calories obtained from carbohydrates and 30% from fat, including <8% from saturated fat.

Now we all know the American Heart Association insists we must keep saturated fat at less than 7% of our calories because intakes higher than that will kill us (eye roll) - yet here we have stunning improvements with saturated fat intake at/above 20% daily for six months! If you haven't read it yet, Dr. Richard Feinman wrote a good article about saturated fat recently.

So, what gives? It seems the subjects in this study significantly reduced their carbohydrate, and that carbohydrate does matter. Also, this study confirms previous data published that found similar improvements in those restricting carbohydrate.

Slowly but surely more data is coming forward that validates carbohydrate restriction for not only weight loss, but health improvements!

6 comments:

  1. How do they come up with this conclusion in their abstract?

    Under isocaloric conditions, VLCHF and HCLF diets result in similar weight loss. Overall, although both diets had similar improvements for a number of metabolic risk markers, an HCLF diet had more favorable effects on the blood lipid profile. This suggests that the potential long-term effects of the VLCHF diet for CVD risk remain a concern and that blood lipid levels should be monitored.

    ???

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  2. Sherrie,

    Probably because most people don't read through the full-text, just skimming through the abstract!

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  3. Is anybody on the web building an online annotated bibliography of all this current research about low-carb?

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  4. I recently had a blood test done and my trig levels were 39. The range was 50-200, so mine were extremely low. The reason, I eat almost 0 bread. The only type of "bread" I eat is soy based and some whole-wheat made from my mom (so have to eat).

    Other than that, its all healthy fats, veggies, and high intense training. Carbs should be based on your energy level. I personally start feeling weak when I get down to the 130's. If you're sitting on your but all day, then you can probably get along with less than 100 grams of carbs.

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  5. Thank you for this article! I, too, would be interested in knowing if there is any annotated bibliography of this low-carb research.

    I have CVD and have just recently (almost 3 months ago) changed my diet to one that is low-carb (against the conventional wisdom of all my doctors) and higher in fat. My most recent lipid profile came back phenomenal, with my tryglycerides being the lowest they've ever been. This has all been a scary experiment for me, so I'm hoping these numbers actually mean something and translate into a slowing down of my atherosclerosis.

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