Low-carb diet reduces inflammation and blood saturated fat in metabolic syndrome

[Dodger]

Metabolic syndrome is a condition afflicting one quarter to one third of adult men and women and is an established pre-cursor to diabetes, coronary heart disease, and other serious illnesses. Patients have long been advised to eat a low-fat diet even though carbohydrate restriction has been found to be more effective at reducing specific markers, such as high triglycerides, characteristic of the syndrome. Now, a new study indicates that a diet low in carbohydrates is also more effective than a diet low in fat in reducing saturated fatty acids in the blood and reducing markers of inflammation.

While there have been contradictory and confusing messages directed at health conscious consumers about dietary recommendations, most researchers agree on the need to limit inflammatory agents. In a report published in the on-line version of the journal Lipids, researchers at the University of Connecticut with co-authors from SUNY Downstate Medical Center in Brooklyn, the University of Minnesota, and the University of California show much greater improvement in inflammatory markers in patients with metabolic syndrome on a very low carbohydrate approach compared to a low fat diet.

Lead researcher Jeff S. Volek, PhD, RD, associate professor of kinesiology at the University of Connecticut, describes the study as “adding to the evolving picture of improvement in general health beyond simple weight loss in keeping blood glucose and insulin under control.” The work is part of a larger study (currently under review) showing numerous improvements in blood lipids. The current work concludes that “lowering total and saturated fat only had a small effect on circulating inflammatory markers whereas reducing carbohydrate led to considerably greater reductions in a number of pro-inflammatory cytokines, chemokines, and adhesion molecules. These data implicate dietary carbohydrate rather than fat as a more significant nutritional factor contributing to inflammatory processes.”

Richard Feinman, PhD, professor of biochemistry at SUNY Downstate Medical Center, adds, “The real importance of diets that lower carbohydrate content is that they are grounded in mechanism – carbohydrates stimulate insulin secretion which biases fat metabolism towards storage rather than oxidation. The inflammation results open a new aspect of the problem. From a practical standpoint, continued demonstrations that carbohydrate restriction is more beneficial than low fat could be good news to those wishing to forestall or manage the diseases associated with metabolic syndrome.”

One of the remarkable effects in the data presented that may have contributed to the results is that despite the three-fold greater saturated fat in the diet for the low carb group, saturated fat in the blood turned out to be higher in the low fat group due to the process known as carbohydrate-induced lipogenesis. Dr. Volek points out that “this clearly shows the limitations of the idea that ‘you are what you eat.’ Metabolism plays a big role. You are what your body does with what you eat.”


http://www.eurekalert.org/pub_releases/2007-12/sdmc-ldr120207.php

[mike_d]

The work is part of a larger study (currently under review) showing numerous improvements in blood lipids. The current work concludes that “lowering total and saturated fat only had a small effect on circulating inflammatory markers whereas reducing carbohydrate led to considerably greater reductions in a number of pro-inflammatory cytokines, chemokines, and adhesion molecules. These data implicate dietary carbohydrate rather than fat as a more significant nutritional factor contributing to inflammatory processes.”That should be of major interest when its published, except to the mainstream low-fat nutritionists.

[Zei]

It's yet another good motivator for me to stick with my low carb diet even though it's not making me lose weight like I'd wanted, the knowledge that even if I don't get lighter, I'm being healthier. So this is a great article for me to see.

[mike_d]

Critics will say "that just shows you can find anything on the internet to support your personal belief."

Well its a timely study 2 Dec 2007 and maybe more to follow ... we will see. This, the VAP cholesterol test and Gary's book are chipping away at the very foundation of the gov's sacred diet cow -- the "food pyramid."

[oakdryad]

Well its a timely study 2 Dec 2007 and maybe more to follow ... we will see. This, the VAP cholesterol test and Gary's book are chipping away at the very foundation of the gov's sacred diet cow -- the "food pyramid."

mmmm....cow. source of beef, cheese, cream and butter. I call that pretty sacred (and low carb too!).

:D

The food pyramid? Not so much.

[KJF]

I think this may be the beginning of the end for low fat, with all these studies vindicating carbohydrate restriction. Of course, they'll hang on for a while with whole grains and fiber until more studies factoring in total carbohydrate are done.

[Angeline]

I think the whole inflammation aspect gives me some hope. Because it's a fresh approach and has not been completely fossilized by dogma, like in the case of sat-fat causes CHD and obesity is caused by overeating, there is still some open-mindedness about the subject.

[ttlaitin]

here is the abstract of the mentioned research:


Abnormal distribution of plasma fatty acids and increased inflammation are prominent features of metabolic syndrome. We tested whether these components of metabolic syndrome, like dyslipidemia and glycemia, are responsive to carbohydrate restriction.

Overweight men and women with atherogenic dyslipidemia consumed 2 ad libitum diets for 12 weeks:

very low in carbohydrate (VLCKD)
(1504 kcal:% CHO : fat : protein = 12:59:28)
low in fat (LFD)
(1478 kcal:% CHO : fat : protein = 56:24:20)

In comparison to the LFD, the VLCKD resulted in an increased proportion of serum total n-6 PUFA, mainly attributed to a marked increase in arachidonate (20:4n-6), while its biosynthetic metabolic intermediates were decreased. The n-6/n-3 and arachidonic/eicosapentaenoic acid ratio also increased sharply. Total saturated fatty acids and 16:1n-7 were consistently decreased following the VLCKD.

Both diets significantly decreased the concentration of several serum inflammatory markers, but there was an overall greater anti-inflammatory effect associated with the VLCKD, as evidenced by greater decreases in TNF-α, IL-6, IL-8, MCP-1, E-selectin, I-CAM, and PAI-1.

Increased 20:4n-6 and the ratios of 20:4n-6/20:5n-3 and n-6/n-3 are commonly viewed as pro-inflammatory, but unexpectedly were consistently inversely associated with responses in inflammatory proteins.

In summary, a very low carbohydrate diet resulted in profound alterations in fatty acid composition and reduced inflammation compared to a low fat diet.

Comparison of Low Fat and Low Carbohydrate Diets on Circulating Fatty Acid Composition and Markers of Inflammation (http://www.springerlink.com/content/r1x1143pl42737u8/)

[mike_d]

I can't find it now, but I read a study on this forum not long ago saying the exact opposite was true for those on Atkins "once they reach maintenance" ie. more inflammation markers measured and higher LDL. My LDL has indeed gone up but triglycerides and HDL have improved.

Opposing paper:

http://forum.lowcarber.org/showthread.php?t=354318&highlight=cholesterol

Ill have to read this one again, its most likely biased?

[LC FP]

Opposing paper:

http://forum.lowcarber.org/showthre...ght=cholesterol

Ill have to read this one again, its most likely biased?
The "oppposing paper" is a 4 week study, comparing high fat Atkins versus low fat South Beach and Ornish!!. Pretty bizarre study!

But the current study is interesting:
the VLCKD resulted in an increased proportion of serum total n-6 PUFA
So even though the high fat diet worsened the omega-3 to omega-6 ratio, all the other markers of inflammation improved. You wouldn't predict that if you are a believer in the O-3/O-6 ratio hypothesis.

If true, I would think Atkins dieters should all supplement with fish oil to improve the ratio anyway, just to be on the safe side. Or maybe the ratio isn't very important...

[K Walt]

The "oppposing paper" is a 4 week study, comparing high fat Atkins versus low fat South Beach and Ornish!!. Pretty bizarre study!

But the current study is interesting:

So even though the high fat diet worsened the omega-3 to omega-6 ratio, all the other markers of inflammation improved. You wouldn't predict that if you are a believer in the O-3/O-6 ratio hypothesis.

If true, I would think Atkins dieters should all supplement with fish oil to improve the ratio anyway, just to be on the safe side. Or maybe the ratio isn't very important...

As Taubes would say, the O-3/O-6 thing is a nice hypothesis, but no one has demonstrated its effect clinically. Willet of Harvard even ran some loose experiments showing even that with a ton of n-6 from corn oil in the diet, there was no adverse inflammatory effect.

The thought is, a preponderance of n-6 would stimulate the inflammatory side of the prostaglandin cascade. But it does seem odd that the body would produce inflammatory compounds willy nilly just because there's a lot of raw material available. I'm guessing it ain't that simple. It may well be that a distinct shortage of n-3's may starve the anti-inflammatory pathways, but simply making a LOT of n-3 available won't suddently make the pathway run harder.

Anyway, the ratio thing sounds nice, but no one knows if it's real or not.

[mike_d]

So even though the high fat diet worsened the omega-3 to omega-6 ratio, all the other markers of inflammation improved.I eat more fish and green veggies on LC than I ever did when I was eating mostly sandwiches, rice and pasta. A problem with grain fed animals and eggs now is a lower Omega-3 content. I try to shop around that issue when I can. I am not sure what was eaten during the study, but standard high-fat is very high in Omega-6.

[LC FP]

Originally posted by mike_d
I eat more fish and green veggies on LC than I ever did when I was eating mostly sandwiches, rice and pasta. A problem with grain fed animals and eggs now is a lower Omega-3 content

I agree. That's why I'd supplement fish oil. In a 12 week study the O-3/O-6 ratio might not matter much, but it might in a 12 year study.

[Turtle2003]

Overweight men and women with atherogenic dyslipidemia consumed 2 ad libitum diets for 12 weeks:

very low in carbohydrate (VLCKD)
(1504 kcal:% CHO : fat : protein = 12:59:28)
low in fat (LFD)
(1478 kcal:% CHO : fat : protein = 56:24:20)

I've got a question. The article says the subjects were eating ad libitum but the results say they only ate about 1500 calories on each plan which sounds awfully low for people not required to restrict their caloric intake, or am I misinterpreting the meaning of ad libitum, or the results?

[LessLiz]

My LC eating runs 1200 - 1400 cals per day if I don't make an effort to eat more. On LF my eating runs 2400+ cals per day if I don't make an effort to eat less. :D

I think you got ad libitum correct unless I'm also mistaken.

[LC FP]

I think ad lib is used wrong in that paragraph. I think they meant to say that the subjects were on their own to follow the recommended diet.