In the study, researchers took into account other factors that could affect the likelihood of having gum disease, such as age, income, education and other health and socioeconomic factors.
The study is published in the November issue of the Journal of the American Dietetic Association.
Periodontitis is a chronic inflammation of the gums caused by bacteria that accumulate around the gum line, according to background information in the study. Over time, the gum tissue can recede and separate from teeth, leading to "periodontal pockets," or spaces between the gums and the teeth, and loss of the bone that provides the supporting structure for the teeth.
About 54 percent of men and 46 percent of women over age 30 in the United States experience gingival bleeding, the earliest sign of periodontal disease, according to background information in an accompanying editorial.
In the general population, about 11 percent of adults aged 50 to 64 have moderate or severe periodontitis, rising to 20 percent of those over age 75. In the study, about 8.2 percent of participants had periodontitis.
The usual treatment of periodontitis is good dental hygiene, including manually removing bacteria during dental appointments and applying local antibiotics to kill the bacteria, though there is disagreement among dentists about how well local antibiotics work.
In an accompanying commentary, Elizabeth Krall Kaye, a professor in the department of health policy and health services research at Boston University Henry M. Goldman School of Dental Medicine, said the study supports incorporating fatty fish into one's diet, but not necessarily fish oil supplements.
"The study is interesting in that they studied a large population, and they saw some benefit just from consuming moderate amounts of omega-3 fatty acids," Kaye said.
Other sources of omega-3 fatty acids include sa
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