Thursday, January 25, 2007

Study: High-Carb Consumption Leads To Lower HDL, Higher Triglyceride Levels

Dr. Anwar T. Merchant studied how to raise HDL and lower triglycerides

This Reuters Health column about a new study from Canadian researchers on the ethnic differences in cholesterol levels among various people groups reveals an important fact about livin' la vida low-carb that most people eating this way are already abundantly aware of.

Lead researcher Dr. Anwar T. Merchant, assistant professor in the Department of Clinical Epidemiology & Biostatistics at the Hamilton, ON-based McMaster University and a member of the Population Health Research Institute, and his fellow researchers observed the diet and lipid profile of 619 Canadians of Native American, South Asian, Chinese and European descent to determine if the differences in cholesterol and other blood fat levels could possibly be tied to diet.

However, unlike previous studies that had exclusively look at the role of dietary fat, Dr. Merchant and his colleagues decided to see if carbohydrate consumption had something to do with the disparity among the different ethnic groups. South Asian participants eat more carbohydrates and had the lowest levels of HDL cholesterol in their blood. Conversely, the Chinese participants ate the least amount of carbohydrates and they exhibited the highest levels of HDL cholesterol (something this study showed could happen to HDL levels when a low-carb diet is implemented).

Dr. Merchant noticed that when fat was removed from the diet and replaced with an equal number of carbohydrate calories, both the LDL and HDL cholesterol levels drop while triglycerides go way up.

The following is a list from most to least amount of carb consumption:

1. South Asians
2. Europeans
3. Native Americans
4. Chinese

Even when adjustments are made for age, ethnicity, body mass index and alcohol intake, the carbohydrate connection to lower HDL levels was undeniable. The high-carb group saw an average level of 1.08 mmol/L while the low-carb group experienced an HDL level of 1.21 mmol/L.

The researchers found that for each additional 100 grams of carbohydrates consumed daily led to a 0.15 mmol/L drop in HDL cholesterol and a corresponding rise in triglycerides. The primary culprits named in the study for higher carb intake include sugary soft drinks, fruit juices and junk food snacks with extra sugar and carbohydrates.

"Reducing the frequency of intake of sugar-containing soft drinks, juices and snacks may be beneficial," the researchers conclude.

This study was published in the January 2007 issue of the American Journal of Clinical Nutrition.

Despite the fact that low-fat diet activist Dr. Dean Ornish described HDL cholesterol in his interview with me last year as "garbage trucks" to get rid of the junk (fat) that you put in your body, the fact is that higher HDL cholesterol and lower triglycerides is a VERY GOOD thing. It's also an excellent indicator if you are actually livin' la vida low-carb or not because your HDL will be over 50 and your triglycerides will be below 100.

We have seen from previous research that lower HDL levels put at a greater risk for heart disease; thus, we can infer that higher levels of HDL actually PROTECTS against heart disease. Plus, respected nutrition researcher Dr. Jeff Volek from the University of Connecticut has asserted that examining the triglyceride/HDL ratio is a much better marker than total cholesterol and LDL levels for protecting against heart disease.

I don't know about you, but I trust the findings of a researcher like Dr. Volek who has poured his entire life into this subject over a self-righteous and inaccurate 30-second television ad that blares across my screen 20,000 times a night (by the way, have you seen the new Zetia commercial with that fat lady who has a healthy cooking show calling statins "a good option?" I wanna throw up every time I hear her say that! But isn't it quite ironic that she has to take a medicine to lower her cholesterol when she is supposedly making "healthy" recipes? If they were low-carb she wouldn't need the drugs! But I digress!).

Anyone who is confused about why LDL, HDL, and triglyceride levels are important or simply wants to educate themselves further on the role of cholesterol in the body needs to get a copy of independent researcher Anthony Colpo's magnificent book "The Great Cholesterol Con." He recently expanded and updated it with brand new content, so you will be armed with the facts rather than relying on the pharmaceutical companies to give you the information you need. They're in it to make a buck, so you probably should take EVERYTHING you hear from a cholesterol-lowering medication ad with a grain of salt.

You can e-mail Dr. Anwar T. Merchant about his fantastic study at

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Blogger Unknown said...

(by the way, have you seen the new Zetia commercial with that fat lady who has a healthy cooking show calling statins "a good option?" I wanna throw up every time I hear her say that! But isn't it quite ironic that she has to take a medicine to lower her cholesterol when she is supposedly making "healthy" recipes? If they were low-carb she wouldn't need the drugs! But I digress!).

Hahaha! You are so right! And she's probably on statins for an elevation that is so small as to not matter!

1/26/2007 1:32 AM  
Blogger Kevin M. said...

Studies demonstrating the dramatic improvements in cholesterol levels are perhaps more important than any others in convincing medical professionals of the profound benefit of low-carb. Low carb is not just another possible solution, it is the only real solution.

1/26/2007 2:32 PM  
Blogger Science4u1959 said...

It is a common misconception that Asians consume more carbs than us Westerners. In reality, they do not. Excessive amounts of (cheap) carbohydrates are consumed by the very poor (rice is cheap) and the very rich (as a result of their in-vogue "Western lifestyle" with fast food and Western food preparation practices).

The "man in the street", however, has a overall natural, low-carb, low-GI diet that would make most Western dietitians shudder. If and when carbs are consumed, it is almost always combined with a high protein and especially high fat intake, with generous intake of low-glycemic veggies as well as sufficient roughage. This results in a overall quite low glycemic load.

I have heard and read many stories from UK and US ex-pats, many of them full-blown diabetics, that they do so much better on the (tasty and healthy) native diets of the respective Asian countries they live and work in. Glycemic control is much better than on the average Western diet and, as a result, quite a few of them do not need medication anymore.

Of course, if one simply assumes the common wisdom that Asians consume mountains of rice, then it's easy to make such simplistic conclusions and statements. It would be wise and beneficial if these researchers would actually visit the countries they are crowing about and live with the common man. Would be an eye-opener for most of them, in my experience.

The important and large-scale China Study -incidentally much abused by many "mainstream" (read: consensus) researchers- tells quite an interesting and different story about dietary patterns and health in Asia.

1/28/2007 12:37 AM  
Blogger Science4u1959 said...

This totally unscientific nonsense from Ornish about his "HDL garbage trucks" is irritating me more and more. He has been repeating that ludicrous statement for years now, and it's absolute nonsense.

He should stop buying his physiology texts at Toys' R' Us: Neither LDL-raising fats nor LDL are "garbage", nor is HDL a "garbage truck". Such analogies are simply a load of overly simplistic and misleading nonsense. The only undesirable fats are man-made trans fats which raise LDL.

LDL is the lipoprotein that transports cholesterol from the liver to the cells. Given that cholesterol is one of the most important substances in our body, essential for healthy nerve and brain function, cell membrane integrity, hormone production, skin vitamin D formation, and so forth LDL performs an absolutely vital function and hardly deserves to be labeled garbage!

As for all his talk about the effect of HDL and LDL cholesterol and CVD risk, it is by now very well known and readily verifiable in the published literature that cholesterol does not cause (or promotes) heart disease. As such, any alleged superior cholesterol-lowering effect of Ornish's diet can in no way be considered any sort of advantage, especially given that low-cholesterol is frequently associated with suicidal and violent behavior and shortened life span! Animal studies showing that cholesterol and saturated fats protect lower mortality from infection, and human studies showing that dietary and drug cholesterol-lowering measures impair cognition and worsen mood, suggest that these observations are more than just novel statistical associations.

Ornish should stop talking about garbage as long as all he proffers are unscientific dietary delusions and, indeed, advice that best can be kept where it belongs: in the garbage bin.

1/28/2007 1:02 AM  
Blogger badbikersally said...

Great blog!
The Zetia commercial reveals how Merck regards its target audience - as ignorant, obese bigmouths who would rather pop a pill than cut back on the pastry (which is not made healthful by stuffing it with peas!). Their obnoxious spokesperson attempts to validate a lifestyle that is good for only one thing - increasing demand for statins.

2/15/2007 6:17 PM  

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