Human study links omega-3 DHA to lessened gum disease; omega-3s from fish and greens alike can halve oral disease bacteria... at least in the test tube
by Craig Weatherby
Hold on to your bicuspids... the near-simultaneous findings of two separate studies may put omega-3s on the dental health map.
According to a new Japanese study, lower intakes of omega-3 DHA from fish fat may promote dental disease as we age.
Meanwhile, a University of Kentucky test tube study showed that all types of food-borne omega-3 fats—EPA and DHA from fish and ALA from flax and leafy greens like spinach—cut the numbers of oral disease bacteria by half or more.
Let’s take a closer look at these two preliminary studies, whose findings must be confirmed in clinical trials.
Japanese study links low omega-3 intake to oral disease
Researchers from Japan’s Niigata University recruited 55 older people (average age 74) and used diet questionnaires to estimate the participants’ intakes of long-chain omega-3s (DHA and EPA) from fish or fish oil (Iwasaki M et al. 2010).
The subjects were given dental exams at the study’s start, and once a year for 5 years. The number of teeth in each person that exhibited progression of periodontal disease were counted as “periodontal disease events.”
After comparing the dental exam records and diet surveys, the researchers detected a statistically significant association between the subjects’ DHA intake and the degree of dental disease they suffered.
As the Japanese team wrote, “People with low DHA intake had an approximately 1.5 times higher incidence rate ratio of periodontal disease progression. The findings suggest there may be an inverse, independent relation of dietary DHA intake to the progression of periodontal disease in older people” (Iwasaki M et al. 2010).
The researchers note that this apparent preventive effect was probably related to the anti-inflammatory effects of omega-3 fatty acids: “In periodontal diseases, bacteria trigger inflammatory host responses that cause destruction of the alveolar bone and periodontal connective tissue.”
Omega-3 DHA and EPA give rise to immune-response mediators (eicosanoids) that are less inflammatory than those produced from omega-6 fats.
Because this was Japan, where people eat a lot of fish, the volunteers’ average daily intakes of EPA and DHA—the two major omega-3s found in fish and fish oil—were quite high (947 and 635 milligrams, respectively).
Kentucky lab study finds anti-bacterial potential in omega-3s
New test tube findings suggest that omega-3 fats from fish and plant foods may exert strong anti-bacterial effects against major periodontal pathogens.
The research was conducted by Drs. Brad Huang and Jeff Ebersole of the University of Kentucky College of Dentistry and was sponsored by the U.S. National Institutes of Health.
The researchers say that theirs is the first study to demonstrate that omega-3 fatty acids exert antibacterial activity against oral pathogens (disease bacteria).
Most studies concerning the effects of omega-3s on oral health have focused on these nutrients’ anti-inflammatory influences. Their potential for anti-bacterial activity has been ignored.
But this new study looked at the effects of EPA, DHA, and ALA on a range of oral pathogens.
It also tested the three major omega-3s in each of the two forms in which they most commonly occur in foods and supplements: the triglyceride form and the ethyl ester form.
The results showed that EPA and DHA (from fish fat) and ALA (from flax and leafy greens) can inhibit the growth of oral pathogens—including Streptococcus mutans, Candida albicans, and Porphyromonas ginigivalis—in the test tube.
While EPA and ALA had the strongest antibacterial effects, all three omega-3 compounds cut bacterial activity by at least 50 percent.
This outcome was seen for both forms (triglyceride and ethyl ester) of all three major omega-3 fatty acids.
And, encouragingly, the omega-3s worked at low levels in cells, ranging from one to 10 micrograms per milliliter. (The researchers did not estimate the dietary omega-3 intake levels needed to achieve these cellular levels.)
Drs. Huang and Ebersole said that they planned to conduct the clinical studies needed to confirm that omega-3s work in people’s mouths.
And they said they'd try to translate any clinically confirmed benefits into oral health products… specifically, an omega-3-fortified chewing gum.
- Huang CB, Ebersole JL. A novel bioactivity of omega-3 polyunsaturated fatty acids and their ester derivatives. Molecular Oral Microbiology. Volume 25 Issue 1, Pages 75 – 80 (p 75-80). Published Online Jan 25 2010 DOI: 10.1111/j.2041-1014.2009.00553.x
- Iwasaki M, Yoshihara A, Moynihan P, Watanabe R, Taylor GW, Miyazaki H. Longitudinal relationship between dietary omega-3 fatty acids and periodontal disease. Nutrition. 2010 Jan 22. [Epub ahead of print]