Diets and CVD

When I was first diagnosed I had an echograph on my arteries. My doctor was a bit concerned about the amount of plaque but the blood flow was fine. I more or less followed the French dietary suggestions, from various leaflets but took account of GI of carbs. My dietitians advice was directed this way and at the start I was far too afraid to vary my insulin by much so ate fairly prescribed amounts of carbs. At the end of the first year my HbA1c was down in the low fives and another echograph showed much less plaque. I now get scans every 2 years and my diabetologue is far less worried. What I do works for me.
On the other hand,there are lots of people on various diabetes forums who advocate a low carb , sometimes very low carb approach. They frequently decry mainstream science and like to claim that it is carbohydrates alone that are responsible for CVD and the current world obesity problems.
Their gurus are people like Drs Atkins and Bernstein, their hero is the science writer G Taubes .They love to cite certain high profile blogs.I'm sure most people reading have come across them.I have dutifully read much of the required reading, but I haven't been convinced. I feel that extremely low carb diets have not been shown to be either effective or safe in the longterm . ( I certainly don’t buy a high in anything diet either).
At times I have been really worried about the way they promote the diet., their woe (way of eating) as the only way, a diet to be embraced no matter what a person's lifestyle, activity level or medical history .
Recently these people have been able to quote limited studies, which suggest low carb diets as being effective in the short term for losing weight, and for lowering glucose levels in type 2 diabetes . These studies have suggested that LDL cholesterol and triglycerides fall whilst HDL rises.
(funnily enough quite frequently low carbers argue that cholesterol levels don’t matter, but thats another subject)
Its not surprising that this headline caught my attention this morning.
Low-carb diets linked to atherosclerosis and impaired blood vessel growth
It related to a study on arterial plaque and diet using mice model
The press release contained some background anecdote to the study.

"The study’s first author Shi Yin Foo, an HMS instructor in medicine and a clinical cardiologist in the Rosenzweig laboratory at BIDMC, first embarked on this investigation after seeing heart-attack patients who were on these diets – and after observing Rosenzweig himself following a low-carbohydrate regimen.
“Over lunch, I’d ask Tony how he could eat that food and would tell him about the last low-carb patient I’d admitted to the hospital,” said Foo. “Tony would counter by noting that there were no controls for my observations.”
“Finally,” said Rosenzweig, “I asked Shi Yin to do the mouse experiment – so that we could know what happens in the blood vessels and so that I could eat in peace.”
So the researchers from the Beth Israel Deaconess Medical Center devised a study. They used ApoE mice...... apparently normal mice don’t spontaneously develop artherosclerosis but this particular strain has been created in laboratories. When fed a western type diet the mice quickly develop very high levels of VLDL (very low density lipoproteins) and develop arterial plaque resembling human plaque . These mice have been used as a human model in a variety of studies on dietary interventions, pharmaceuticals and investigations into lipid metabolism. They are useful, but as with all animal studies the results may not be directly applicable to humans. (Meir and Leitersdorf 2004)
They fed the mice one of three diets: a normal mouse “chow” diet (65 percent carbohydrate; 15 percent fat; 20 percent protein), ; a “Western diet” (43 percent carbohydrate; 42 percent fat; 15 percent protein; and 0.15 percent cholesterol); or a low-carb/high-protein diet (12 percent carbohydrate; 43 percent fat; 45 percent protein; and 0.15 percent cholesterol). They observedthe mice at 6 and 12 weeks (growth is a lot faster in mice than humans!) Just as in recent human trials the ‘low carb mice’ gained less weight than the ‘Western diet mice’ but greater amount of artherosclerosis. The control group of ‘normal chow mice’ had ‘minimal
evidence of artherosclerosis’. When the markers for CVD such as cholesterol levels were investigated, mice on the low carb diet had similar or lower markers to those on the Western diet. So this didn’t explain things. However one finding was that these low carb diet mice had a 40% reduction in EPC ( endothelial or vascular progenitor cell ). What they don’t yet know is what the roles of these cells actually is.

So what was Professor Rosenzweigs reaction to the study?

“ these results succeeded in getting me off the low-carb diet......... This issue is particularly important given the growing epidemic of obesity and its adverse consequences. For now, it appears that a moderate and balanced diet, coupled with regular exercise, is probably best for most people.” (Prescott 2009(Augus24))

Meir, Karen S., and Eran Leitersdorf. “Atherosclerosis in the Apolipoprotein E–Deficient Mouse.” Arteriosclerosis, Thrombosis, and Vascular Biology, 2004: 1006-1014.
Shi Yin Foo, et al
Vascular effects of a low-carbohydrate high-protein dietPNAS published online before print August 24, 2009
Prescott, Bonnie. “Low-carb diets linked to atherosclerosis and impaired blood vessel growth.” online press release , Beth Israel Deaconess Medical Center, 2009 (August 24). http://www.harvardscience.harvard.edu/medicine-health/articles/low-carb-diets-linked-atherosclerosis-and-impaired-blood-vessel-growth

It will be interesting to read the various responses on diabetes' forums to this research