LCHF Diets

Low carb high fat diets are very much in vogue at the moment and they are without doubt effective for weight loss, blood sugar control and epilepsy treatment. Evidence on how they effect long term CVD risk however is a bit thin on the ground. There was one accidental study referenced on Nutritionfacts.org and copied below. The slight worry however is that the author of the study was prosecuted for medicare billing fraud and failing to carry out research he was paid for by a soy product company. This does not mean what he highlighted below is worthless but then again on its own it would have not been conclusive anyway

There has only been one study ever done measuring actual blood flow to the heart muscles of people eating low-carb diets. Dr. Richard Fleming, an accomplished nuclear cardiologist, enrolled 26 people into a comprehensive study of the effects of diet on cardiac function using the latest in nuclear imaging technology–so-called SPECT scans, enabling him to actually directly measure the blood flow within the coronary arteries.

He then put them all on a healthy vegetarian diet, and a year later the scans were repeated. By that time, however, ten of the patients had jumped ship onto the low carb bandwagon. At first I bet he was disappointed, but surely soon realized he had an unparalleled research opportunity dropped into his lap. Here he had extensive imaging of ten people before and after following a low carb diet and 16 following a high carb diet. What would their hearts look like at the end of the year? We can talk about risk factors all we want, but compared to the veg group, did the coronary heart disease of the patients following the Atkins-like diets improve, worsen, or stay the same?

Those sticking to the vegetarian diet showed a reversal of their heart disease as expected. Their partially clogged arteries literally got cleaned out. They had 20% less atherosclerotic plaque in their arteries at the end of the year than at the beginning. What happened to those who abandoned the treatment diet, and switched over to the low-carb diet? Their condition significantly worsened. 40% to 50% more artery clogging at the end of the year.“.

This study seems to be the best I can come up with so far

http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0055030

It suggests a significant increase in overall mortality for LCHF and no significant increased risk for death from CVD or incidence of CVD. Interestingly though the risk ratios for CVD are a tad over 1.0 which would possibly add weight to the argument that setting out in life on LCHF is not particularly going to kill you from CVD, it is either neutral or at worse so marginally negative that something else is going to get you first. However perhaps in the battle to reverse heart disease (if you accept that this can be achieved) you need some protocol that can improve on neutral.

FOOTNOTE – The following from the Harvard school of public health offers more encouragement for LCHF but with a proviso from where the fat comes from

Low carbohydrate diets and heart disease

Research shows that a moderately low-carbohydrate diet can help the heart, as long as protein and fat selections come from healthy sources.

A 20-year prospective study of 82,802 women looked at the relationship between lower carbohydrate diets and heart disease; a subsequent study looked at lower carbohydrate diets and risk of diabetes. Women who ate low-carbohydrate diets that were high in vegetable sources of fat or protein had a 30 percent lower risk of heart disease (4) and about a 20 percent lower risk of type 2 diabetes, (34) compared to women who ate high-carbohydrate, low-fat diets. But women who ate low-carbohydrate diets that were high in animal fats or proteins did not see any such benefits. (4,34)
More evidence of the heart benefits from a lower-carbohydrate approach comes from a randomized trial known as the Optimal Macronutrient Intake Trial for Heart Health (OmniHeart). (35) A healthy diet that replaced some carbohydrate with protein or fat did a better job of lowering blood pressure and “bad” LDL cholesterol than a healthy, higher-carbohydrate diet.
Similarly, the small “EcoAtkins” weight loss trial compared a low-fat, high-carbohydrate vegetarian diet to a low-carbohydrate vegan diet that was high in vegetable protein and fat. While weight loss was similar on the two diets, study subjects who followed the low-carbohydrate “EcoAtkins” diet saw improvements in blood lipids and blood pressure. (36)

References

1. Mozaffarian D, Hao T, Rimm EB, Willett WC, Hu FB. Changes in diet and lifestyle and long-term weight gain in women and men. N Engl J Med. 2011;364:2392-404.

4. Halton TL, Willett WC, Liu S, et al. Low-carbohydrate-diet score and the risk of coronary heart disease in women. N Engl J Med. 2006;355:1991-2002.

31. Foster GD, Wyatt HR, Hill JO, et al. A randomized trial of a low-carbohydrate diet for obesity. N Engl J Med. 2003;348:2082-90.

32. Samaha FF, Iqbal N, Seshadri P, et al. A low-carbohydrate as compared with a low-fat diet in severe obesity. N Engl J Med. 2003;348:2074-81.

33. Sacks FM, Bray GA, Carey VJ, et al. Comparison of weight-loss diets with different compositions of fat, protein, and carbohydrates. N Engl J Med. 2009;360:859-73.

34. Halton TL, Liu S, Manson JE, Hu FB. Low-carbohydrate-diet score and risk of type 2 diabetes in women. Am J Clin Nutr. 2008;87:339-46.

35. Appel LJ, Sacks FM, Carey VJ, et al. Effects of protein, monounsaturated fat, and carbohydrate intake on blood pressure and serum lipids: results of the OmniHeart randomized trial. JAMA. 2005;294:2455-64.

36. Jenkins DJ, Wong JM, Kendall CW, et al. The effect of a plant-based low-carbohydrate (“Eco-Atkins”) diet on body weight and blood lipid concentrations in hyperlipidemic subjects. Arch Intern Med. 2009;169:1046-54.

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