A mouthful of evidence - relationship between nutrition and periodontal diseases

Nutrition Health Review, Summer, 2003 by Emanuel Cheraskin

Who among us has not heard the time-honored adage, "Those who cannot remember the past are condemned to repeat it?" The saga of scurvy in stomatology is a superlative case.

You will recall the earlier stories concerning sea voyages. The point was made even back then of a trinity of symptomatology, namely inordinate weakness, the hemorragic diathesis, and spongy (and clearly bleeding) gums. So we have long known of the connection between vitamin C state and the oral tissues.

What is the number one twentieth-century chronic problem in Western culture? No question ... 95 percent of the public suffers with dental caries and/or periodontal disease.

There is also another, and very exciting, uniqueness to symptomatology. Disease is the result of the interplay of nine constellation of environmental challenges as it relates to the internal milieu. The oral cavity is one of than few areas where experiments can be performed delineating the relative importance of the environment and host state.

For example, it is possible to clean and polish only half the teeth (e.g., the right or left side). This then allows a comparison of the effect of modifying the local environment versus letting it remain unchanged. On the other hand, you can give a group of subjects vitamin C versus a placebo. (We tried but failed to give half a person ascorbate!) By these experimental designs, one can derive the relative contributions of these four different ecologic possibilities. There is also the converse. Banding half the teeth makes it possible to compare the added irritation (of bands versus no bands) in the light of vitamin C and placebo supplementation. Such experiments have been described in the literature with various nutrients, including ascorbic acid.

The Current Official Dental Opinion

Russell in 1963 summarized the results of the studies conducted under the auspices of the Interdepartmental Committee for Nutrition in National Defense (ICNND). He recorded the dietary and oral health status of selected samples. The evaluation of nutritional deficiencies was based on clinical examinations and on biochemical tests of blood and urine in a small subsample. Serum levels of ascorbic acid were used in the ICNND studies to assess deficiency levels. The ICNND played a big role in the original standards for blood AA concentrations. Russell concluded from these well-publicized epidemiologic data that age and oral hygiene contributed most to the variance in Periodontal Index (PI) scores. Also, he further saw no correlation between ascorbic acid deficiency and increased PI scores (then the most popular measure of periodontal health). In another study, the Ten State Nutrition Survey, only a "weak" correlation was reported between hypoascorbemia and the presence of gum disease.

These observations in the 1960's dominated and continue to color the thinking of dentistry. They even serve today as a basis for the relative unimportance of the ascorbates in oral health and sickness.

On the other hand, there have been, and still are, clinicians who feel, from their limited but presumably cause-and-effect observations, that Vitamin C seems to play a role in oral health. For these reasons, plus the fact that a large governmental study had been completed, it became possible to reexamine the epidemiologic data.

This project investigated the association (again in an epidemiologic way) between the reported levels of dietary ascorbic acid intake and the presence of periodontal disease. A representative segment of the U.S. population provided by the first National Health and Nutrition Examination Survey (NHANES 1), from 1971 to 1974, was reviewed. The NHANES I survey was a comprehensive accounting of health and nutrition in more than 20,000 individuals, aged 1 to 74, in the continental United States. Data were collected from 8,609 dentulous persons (those with teeth), aged 25 to 74 years, who received a dental examination during NHANES I and with whom a 24-hour dietary recall interview was conducted. The purpose of this analysis was to investigate the possible correlation between periodontal disease and reported dietary intake of vitamin C. A corollary aim was to determine whether a more-than-recommended daily intake of ascorbic acid was associated with better periodontal health.

Periodontal disease status (PI) and oral hygiene state (Simplified Oral Hygiene Index, OHI-S), in addition to other oral and dental health assessments, were collected by 10 trained dentists at 65 locations during the four years of the NHANES I survey.

Ascorbic acid intake was calculated from the foods consumed by each individual during the preceding 24 hours. To ensure the greatest possible accuracy, the interviews were conducted by people trained in gathering dietary data. In this report, the term "dietary ascorbic acid" refers to ascorbate reportedly consumed in the 24-hour dietary recall, without considering vitamin supplements.

The conclusions are complex and convoluted. They can be summarized by two large statements splashed in appropriate places in the original report.