Milk, orange juice: good for
By LOIS BAKER
Milk drinkers and orange-juice lovers may be doing their gums a favor.
Two studies by researchers in the School of Dental Medicine show that people with low levels of Vitamin C in their diets, and those who had too little calcium as young adults, appear to have nearly twice the risk of developing periodontal disease later in life than people with higher dietary levels of either nutrient.
The two studies add a new element to public-health efforts to promote dental health, said Sara Grossi, senior research scientist and director of the UB Periodontal Research Center, where the study was conducted.
"It is no longer enough to tell children and adults to brush their teeth, floss and see their dentist," Grossi noted. "Diet plays a larger role than we anticipated."
Results of the studies were presented June 26 in Nice, France at the annual meeting of the International Association for Dental Research.
Both studies used data from National Health and Nutrition Examination Surveys (NHANES) I and III, carried out in 1971-75 and 1988-94 respectively. NHANES I involved 2,392 persons; 12,412 people were surveyed for NHANES III.
Analysis of dietary calcium for both survey periods showed that women consumed less than the minimum recommended daily intake of 800 milligrams, the amount in four glasses of milk, while the average for men was slightly more than 800 mg.
Comparison of calcium intake with periodontal disease, defined by the amount of gum detachment from underlying bone, showed that in the total study population, men and women who had low levels of the mineral in their diets were half again as likely to develop periodontal disease as those who met or exceeded the recommended dietary allowance for calcium.
When only participants between the ages of 20 and 39 years were analyzed, low calcium intake doubled the risk of periodontal disease.
"This is a new piece of evidence," Grossi said. "We never knew people so young were at risk of gum disease and of losing bone around their teeth. It points out how important it is for children and teens to get enough calcium during those formative years to reach their peak bone mass in the jaw and everywhere else.
"It really is true that calcium builds strong bones and teeth," she noted. "If the underlying bone is not strong to start with, it will not be able to counter noxious agents, such as bacteria and substances in cigarette smoke, which attack bone, teeth and gums."
A similar risk of periodontal disease was found among persons with low dietary intakes of Vitamin C. That study showed that those with the lowest intake were at the highest risk, and the association was particularly strong among smokers.
Grossi said Vitamin C's role in maintaining and repairing healthy connective tissue, along with its antioxidant properties, was likely responsible for the relationship. "Vitamin C in the diet increases the ability of tissue to repair itself and fight invading bacteria and other toxins. We found a very strong association for all age groups, but the results were most pronounced in smokers. They experience more of an insult to the gum tissues, so they need higher levels of vitamin C to help counteract smoke's toxins."
Other researchers involved in the studies were Mieko Nishida, Robert G. Dunford, Alex Ho and Robert Genco, all of the Department of Oral Biology, and Maurizio Trevisan, of the Department of Social and Preventive Medicine.