Researchers at Seoul National University College of Dentistry in South Korea discovered that people with an advanced form of gum disease-also known as 'periodontitis'-have a higher risk of ischaemic stroke (the type caused by a blood clot) than people with diabetes, and around the same risk as people with high blood pressure. Both high blood pressure and diabetes are well-recognized risk factors of ischaemic stroke.
The research, presented at the 89th International Association for Dental Research (IADR) General Session and Exhibition in San Diego, CA, involved 143 hospitalized, non-fatal, ischaemic-stroke cases and 214 non-stroke controls. It found that people with peridontitis-characterized by inflammation and infection that affects not just the gums, but also the ligaments and bones that support the teeth-were four times more likely to have suffered a stroke, which was double the risk posed by diabetes.
As Dr Nigel Carter, Chief Executive of the British Dental Health Foundation, said: "This research is significant because it helps to quantify the importance of oral health compared to other risk factors.
The findings are startling. The fact that high blood pressure carries a similar risk to gum disease is in itself a significant finding. The other finding, which shows that gum disease nearly doubles the risk of non-fatal strokes compared to diabetes, is totally unexpected" (www.medicalnewstoday.com/releases/221159.php).
This is not the first study to find a significant connection between gum disease and stroke, however. In 2004, researchers from the University of Heidelberg, in Germany, studied more than 600 men and women, half of whom had recently suffered an ischaemic stroke. They found that, among men and younger participants, severe periodontitis increased the risk of stroke more than fourfold.
Gingivitis (gum inflammation), a milder form of gum disease, also raised the risk of ischaemic stroke, but dental cavities did not (Stroke, 2004; 35: 496-501).
Yet another study, carried out by Harvard researchers, followed over 41,000 men for 12 years. They discovered that those with gum disease and fewer teeth (tooth loss is a common conse-quence of gum disease if it's not treated) were significantly more likely to suffer a stroke (Stroke, 2003; 34: 47-52). A handful of other studies have reported similar findings.
Periodontal disease has also been linked to atherosclerosis-hardening and narrowing of the arteries that can lead to stroke and heart attack. In one small Italian study, people with carotid plaques (atherosclerosis) had significantly poorer gum health than those who didn't have the problem-even after taking into consideration the presence of established cardiovascular risk factors (Atherosclerosis, 2010; 213: 263-7).
In addition, a review of the medical literature found an association between gum disease and atherosclerosis, myocardial infarction (heart attack) and cardiovascular disease (Ann Periodontol, 2003; 8: 38-53).
Clearly, there is a connection between the health of our gums and our heart health.
The perio-cardio link
Although some argue that the state of our gums is merely a symptomatic reflection of our overall health, there are several plausible theories as to how gum disease might, in fact, cause heart disease and stroke. One suggests that oral bacteria could affect the heart by entering the bloodstream and attaching to fatty plaques in the coronary arteries, thereby contributing to the formation of blood clots (J Am Dent Assoc, 2002; 133 Suppl: 14S-22S). Clots can obstruct normal blood flow, restricting the delivery of nutrients and oxygen that the heart needs to function properly. This could lead to a heart attack or stroke.
Another hypothesis has to do with inflammation-the body's inbuilt reaction to infection. Researchers suspect that gum disease may not just cause inflammation in the mouth but may, over time, also contribute to systemic inflammation, which is now known to play a crucial role in a wide range of diseases that are not usually classified as inflammatory, such as cardio-vascular disease. Indeed, the inflammation theory may explain why periodontal disease has also been linked to other systemic disorders such as diabetes (Ann Periodontol, 2001; 6: 125-37), rheumatoid arthritis (Arthritis Res Ther, 2010; 12: 218), Alzheimer's (Alzheimers Dement, 2008; 4: 242-50) and chronic kidney disease (Curr Opin Nephrol Hypertens, 2010; 19: 519-26).
In further support of this hypothesis, a recent study has discovered that treating gum disease can have beneficial effects for the rest of the body. Researchers in Italy examined the carotid arteries of 35 people with mild-to-moderate gum disease, but who were otherwise healthy, before and after having the problem treated. One year after treatment, the scientists observed significant reductions in oral bacterial load and markers of inflammation, as well as in the thickening of blood vessel walls associated with atherosclerosis (FASEB J, 2009; 23: 1196-204).
Another possible explanation is that gum disease and heart disease are both the consequences of a poor diet and nutritional deficiencies. This would also explain the link between gum disease and other systemic disorders.
Coenzyme Q10 (CoQ10), for example, is a vitamin-like compound found in practically every cell of the human body-and not having enough of it has been linked to both periodon-titis and heart disease. Studies suggest that up to 96 per cent of people with gum disease may have below-normal levels of CoQ10 (Altern Med Rev, 1996; 1: 11-7).
There's also evidence to show that supplementing with CoQ10 has beneficial effects on oral health. In one recent study, presented at the 63rd Meeting of the Vitamin Society of Japan in Hiroshima, 45 patients with mild-to-moderate gum disease were given ubiquinol (150 mg/day), an active form of CoQ10, or a placebo for two months. At the end of the study, the ubiquinol group showed statistically significant improvements in dental plaque adhesion and bleeding gums.
In another double-blind trial, 18 patients with periodontal disease took either 50 mg/day of CoQ10 or a placebo for three weeks. All eight of those taking CoQ10 improved compared with only three of the 10 taking the placebo (Altern Med Rev, 1996; 1: 11-7).
Vitamin C deficiency has also been linked to both gum disease and heart disease (see the special report in WDDTY vol 16 no 11, pages 6-9, on the vitamin C-heart disease connection). One study of Finnish and Russ-ian men found that those with periodontitis were more likely to have low levels of vitamin C in their bloodstream. The researchers pointed out that "vitamin C deficiency is also an independent risk factor for myocardial infarction", and noted the need for more studies to explore the relationships between vitamin C deficiency, gum disease and cardiovascular disease (Clin Diagn Lab Immunol, 2003; 10: 897-902).
Other research suggests that vitamin C might be a useful treatment for gum disease. When people with periodontitis who normally consumed only 20-35 mg/day of vitamin C were given an additional 70 mg/day, their gum health improved in just six weeks (Int J Vitam Nutr Res, 1982; 52: 333-41).
Omega-3 fatty acids may also play a role in the health of our gums. A recent study by Harvard researchers discovered that higher dietary intakes of docosa-hexaenoic acid (DHA) and, to a lesser degree, eicosapentaenoic acid (EPA), were associated with a lower prevalence of periodon-titis in a study involving more than 9000 adults across the US (J Am Diet Assoc, 2010; 110: 1669-75).
Omega-3 fatty acids are well known for their anti-inflam-matory properties and their beneficial role in heart health. Could it be that a deficiency of omega-3 fatty acids in the diet contributes to the connection between gum and heart health?
Putting it together
More studies are needed to help piece together this intriguing puzzle. But what's already clear is that the state of your mouth and your overall health should not be viewed as separate entities, and that a more holistic way of looking at health in general is key.
Although we still don't know whether gum disease can actually cause heart disease and other systemic inflammatory disorders, the latest evidence suggesting that it's one of the biggest risk factors for stroke should be reason enough to make oral health a top priority.
For more information on the link between oral and overall health, see WDDTY vol 19 no 4, pp 6-9.
Factfile A: Signs of gum disease
Periodontal or gum disease begins when the bacteria in dental plaque (the sticky colourless film that constantly forms on your teeth) cause the gums to become inflamed.
The mildest form of gum disease is gingivitis, which usually causes little or no discomfort. Left untreated, however, it can progress to periodontitis, which attacks both the tissues and bone that support the teeth.
Signs of gingivitis
- Swelling and redness in the gums
- Bleeding after brushing or flossing the teeth.
Signs of periodontitis
- Bad breath
- Foul taste in the mouth
- Receding gumline
- Sensitive teeth
- Loose teeth
- Teeth falling out
- Abscesses (painful collections of pus on the gums or under the teeth).
Factfile B: Plant power
We all know that daily brushing and flossing, and regular trips to the dentist, are essential steps towards healthy gums and teeth. But did you know that incorporating certain herbal remedies into your oral hygiene routine can help to prevent or even reverse gum disease?
- Green tea (Camellia sinensis). The catechins in green tea appear to be good for the gums and bad for mouth bacteria (J Indian Soc Periodontol, 2011; 15: 18-22). In a rat model of gum disease, a dentifrice containing green-tea catechins significantly reduced inflammation of the gums (Arch Oral Biol, 2011; 56: 48-53). These results, however, may not apply to us.
- Salvadora persica (the toothbrush tree). Sticks from the root of this tree (known as 'miswaks' or 'chewing sticks') have been used for centuries across North Africa as a natural method of cleaning the teeth and gums. A recent study found that benzyl isothiocyanate, a major component of these roots, is highly effective against the bacteria responsible for gum disease (PLoS ONE, 2011; 6: e23045). Another study concluded that miswak use is at least as effective as normal toothbrushing for reducing plaque and gingivitis (Swed Dent J Suppl, 2004; 167: 2-75). However, if you don't fancy chewing on a stick (available from www.auravita.com), you could try an S. persica-containing toothpaste, such as Sarakan (www.sarakan.co.uk), instead.
- Propolis. This sticky substance, made by bees from plant resins, is showing considerable promise against a raft of dental problems-from plaque and cavities to gum disease and mouth ulcers. In a preliminary study of Brazilian green propolis (BGP), a mouthwash containing 5-per-cent BGP significantly reduced plaque and gum inflammation after 90 days (Evid Based Complement Alternat Med, 2011; 2011: 750249; doi: 10.1155/2011/750249).
WDDTY VOL 22 NO 8