Tag Archives: Cleave-Yudkin

Dental Problems and Chronic Systemic Disease: A Carbohydrate Connection?

Dentists are considering a return to an old theory that dietary carbohydrates first cause dental diseases, then certain systemic chronic diseases, according to a review in the June 1, 2009, Journal of Dental Research.

We’ve known for years that some dental and systemic diseases are associated with each other, both for individuals and populations. For example, gingivitis and periodontal disease are associated with type 2 diabetes and coronary heart disease. The exact nature of that association is not clear. In the 1990s it seemed that infections – chlamydia, for example – might be the unifying link, but this has not been supported by subsequent research.

The article is written by Dr. Philippe P. Hujoel, who has been active in dental research for decades and is affiliated with the University of Washington (Seattle). He is no bomb-throwing, crazed, radical.

The “old theory” to which I referred is the Cleave-Yudkin idea from the 1960s and ’70s that excessive intake of fermentable carbohydrates, in the absence of good dental care, leads both to certain dental diseases – caries (cavities), periodontal disease, certain oral cancers, and leukoplakia – and to some common systemic chronic non-communicable diseases such as coronary heart disease, type 2 diabetes, some cancers, and dementia. In other words, dietary carbohydrates cause both dental and systemic diseases – not all cases of those diseases, of course, but some.

Dr. Hujoel does not define “fermentable” carbohydrates in the article. My American Heritage Dictionary defines fermentation as:

  1. the anaerobic conversion of sugar to carbon dioxide and alcohol by yeast
  2. any of a group of chemical reactions induced by living or nonliving ferments that split complex organic compunds into relatively simple substances

As reported in David Mendosa’s blog at MyDiabetesCentral.com, Dr. Hujoel said, “Non-fermentable carbohydrates are fibers.” Dr. Hujoel also shared some personal tidbits there.

In the context of excessive carbohydrate intake, the article frequently mentions sugar, refined carbs, and high-glycemic-index carbs. Dental effects of excessive carb intake can appear within weeks or months, whereas the sysemtic effects may take decades.

Hujoel compares and contrasts Ancel Keys’ Diet-Heart/Lipid Hypothesis with the Cleave-Yudkin Carbohydrate Theory. In Dr. Hujoel’s view, the latest research data favor the Carbohydrate Theory as an explanation of many cases of the aforementioned dental and systemic chronic diseases. If correct, the theory has important implications for prevention of dental and systemic diseases: namely, dietary carbohydrate restriction.

Adherents of the paleo diet and low-carb diets will love this article; it supports their choices.

I agree with Dr. Hujoel that we need a long-term prospective trial of serious low-carb eating versus the standard American high-carb diet. Take 20,000 people, randomize them to one of the two diets, follow their dental and systemic health over 15-30 years, then compare the two groups. Problem is, I’m not sure it can be done. It’s hard enough for most people to follow a low-carb diet for four months. And I’m asking for 30 years?!

Dr. Hujoel writes:

Possibly, when it comes to fermentable carbohydrates, teeth would then become to the medical and dental professionals what they have always been for paleoanthropologists: “extremely informative about age, sex, diet, health.”

Dr. Hujoel mentioned a review of six studies that showed a 30% reduction in gingivitis score by following a diet moderately reduced in carbs. He mentions the aphorism: “no carbohydrates, no caries.” Anyone prone to dental caries or ongoing periodontal disease should do further research to see if switching to low-carb eating might improve the situation.

Don’t be surprised if your dentist isn’t very familiar with the concept. Has he ever mentioned it to you?

Steve Parker, M.D.

Reference: Hujoel, P. Dietary carbohydrates and dental-systemic diseases. Journal of Dental Research, 88 (2009): 490-502.

Mendosa, David. Our dental alarm bell. MyDiabetesCentral.com, July 12, 2009.

High-Carbohydrate Eating Promotes Heart Disease in Women

Women double their risk of developing coronary heart disease if they have high consumption of carbohydrates, according to research published in the Archives of Internal Medicine.

Men’s hearts, however, didn’t seem to be affected by carb consumption. I mention this crucial sex difference because many experts believe that replacing saturated fat with carbohydrates is a major cause of heart disease. If true, it seems to apply only to women.

(Another nutrition science trend to keep an eye on is the thought that excessive consumption of omega-6 fats contributes to hardening of the arteries, including coronary heart disease. I’m talking about soy oil, safflower oil, corn oil, among others. No doubt, we’re eating a lot more omega-6 now than at the start of the 20th century.)

We’ve known for a while that high-glycemic-index eating was linked to heart disease in women but not men. Glycemic index is a measure of how much effect a carbohydrate-containing food has on blood glucose levels. High-glycemic-index foods raise blood sugar higher and for longer duration in the bloodstream.

High-glycemic-index foods include potatoes and white bread, for example.

The study at hand included over 47,000 Italians who were interrogated via questionnaire as to their food intake, then onset of coronary heart disease—the cause of heart attacks—was measured over the next eight years.

Among the 32,500 women, 158 new cases of coronary heart disease were found.

Researchers doing this sort of study typically compare the people eating the least carbs with those eating the most. The highest quartile of carb consumers and glycemic load had twice the rate of heart disease compared to the lowest quartile.

The Cleave-Yudkin theory of the mid-20th century proposed that excessive amounts of refined carbohydrates cause heart disease and certain other chronic systemic diseases. Gary Taubes has also written extensively about this. The research results at hand support that theory in women, but not in men.

Practical Applications

Do these research results apply to non-Italian women and men? Probably to some, but not all. More research is needed.

Women with a family history coronary heart disease—or other CHD risk factors—might be well-advised to put a limit on total carbs, high-glycemic-index foods, and glycemic load. I’d stay out of that “highest quartile.” Don’t forget: heart disease is the No. 1 killer of women.

See NutritionData’s Glycemic Index page for information you can apply today.

FYI, the Low-Carb Mediterranean Diet and Ketogenic Mediterranean Diet are also low in glycemic index.

Steve Parker, M.D.

Disclaimer: All matters regarding your health require supervision by a personal physician or other appropriate health professional familiar with your current health status. Always consult your personal physician before making any dietary or exercise changes.

Addendum: Alert reader Nadia Hassan brought to my attention that I had originally written that pasta has a high glycemic index. Citing appropriate references, Nadia convinced me that pasta has a low-to-moderate glycemic index, from around 30 to 60. Its GI also is higher if over-cooked. I corrected my original post.


Sieri, Sabina, et al. Dietary glycemic load and index and risk of coronary heart disease in a large Italian cohort. The EPICOR study. Archives of Internal Medicine, 170 (2010): 640-647.

Barclay, Alan, et al. Glycemic index, glycemic load, and chronic disease risk – a meta-analysis of observational studies [of mostly women]. American Journal of Clinical Nutrition, 87 (2008): 627-637.