Dental floss might really be mental floss--because a new study finds that gum disease can actually increase your risk for Alzheimer's disease.

And that means bleeding gums and painful scaling sessions with the dentist might actually be the least of your worries if you're suffering from periodontal problems.

New York University researchers looked at 20 years of data on 152 participants in Denmark's Glistered Aging Study. These subjects were followed for 20 years, starting when they were 50 and ending when they were 70, and they underwent cognitive tests at the beginning and end.

They also had their periodontal inflammation levels measured, and, as it turned out, those who suffered from that inflammation at the age of 70 were nine times more likely to score on the lower end of the cognitive tests than those with no inflammation--putting them at risk for Alzheimer's, according to the study presented at an International Association for Dental Research meeting in Barcelona, Spain.

A lower dementia risk should be good enough... but of course, that's not the only reason to make sure you have good oral hygiene.

Repeated studies have found a strong link between healthy teeth and gums and overall cardiovascular health. One study last year found that heart attack victims had higher levels of bacteria in their mouths.

A study earlier this year also found that people who brush their teeth the least had a 70 percent increased risk of problems such as heart attack and stroke compared to those who brush at least twice a day.

But brushing isn't the only way you can keep the taint off your teeth. Another recent study found that omega-3 fatty acids can help lower your risk for gum disease, so make sure you eat more fish--or at least take a good fish oil supplement.

And of course, skip the sugar--there's no place for it in a healthy diet anyway, and sugar is the fastest way to dental decay. It's like soaking your teeth in cola.

If a lower risk for heart problems and Alzheimer's disease isn't enough, think about this: Clean teeth and healthy gums will also mean that your visits to the dentist will be shorter... and a lot more pleasant.