Your mouth harbors more than 700 species of bacteria, including those that cause periodontal disease (PD). Also known as gum disease, this chronic oral infection affects the majority of Americans over age 30, many of whom are undiagnosed. Not only can PD lead to tooth loss if untreated, but new studies have also linked it to increased risk for Alzheimer’s disease (AD), a memory-robbing disorder that affects one in ten Americans ages 65 and older and one in three of those ages 85 and up.

Periodontal bacteria have also been linked to increased risk for other forms of dementia. These findings suggest that taking excellent care of your teeth and gums — and seeing your dental provider regularly — may be one of the best ways to keep your memory sharp. Here’s a look at the latest discoveries, plus expert BaleDoneen tips to help you safeguard your oral-systemic health. 

What Is the Oral-Systemic Connection?

A landmark 1954 study was the first to show that oral bacteria, such as those that cause PD, frequently enter the bloodstream and quickly spread throughout the body. Among the ways this can happen are through periodontal cleaning, tooth extractions, tooth brushing and even chewing food.

The spread of these germs throughout the body can result in chronic inflammation, a fiery process linked to many dangerous disorders, including heart disease, type 2 diabetes, rheumatoid arthritis, pregnancy complications and even some forms of cancer. A landmark, peer-reviewed BaleDoneen study was the first to identify periodontal bacteria as a contributing cause of cardiovascular disease (CVD), the leading killer of American men and women.

Earlier research, including a scientific statement by the American Heart Association, has shown a strong, independent association between PD and CVD (which is also called heart disease). Indeed, a 2016 analysis of studies involving more than 7,000 people found that those with periodontitis were 2.5 times more likely to suffer heart attacks than those with healthy gums! 

What’s the Link Between Gum Disease and Memory Loss?

In July 2020, a study of more than 6,000 Americans reported that those with signs of gum disease and oral infections developed Alzheimer’s disease at a higher rate than those with good oral health. Conducted by the National Institute of Aging, the study tracked participants for up to 26 years.

All participants received a dental exam at the start of the study. They also received blood tests to check for antibodies against a gang of 19 bacterial species known to cause gum disease. The researchers looked for a correlation between antibody levels and risk for being diagnosed with AD, dying from it, or developing any form of dementia. Of the 19 bacterial villains studied, Porphyromonas gingivalis is the most common culprit in PD.

The researchers reported that among people ages 65 and older, those with antibodies against P. gingivalis were at the greatest risk of being diagnosed with AD or dying from it. The team also reported that P. gingivalis can gang up with other high-risk oral bacteria, such as Campylobacter rectus, Prevotella melaninogenica, Fusobacterium nucleatum and Streptococcus intermedius, to further magnify those risks.

How Can Oral Bacteria Harm Memory?

Recently, researchers from the University of California San Francisco uncovered a link between periodontal bacteria and the development of AD. They discovered that a toxin secreted by P. gingivalis destroys brain neurons and may contribute to the development of beta-amyloid plaques. Many scientists believe that accumulation of this sticky compound in the brain is the primary cause of AD, with the buildup initially disrupting communication between neurons and ultimately killing them.

According to this theory, known as “the amyloid hypothesis,” the development of the amyloid plaques that are the hallmark of AD activates immune cells, leading to inflammation that eventually destroys brain cells. Inflammation (the body’s immune system response to bacterial invaders) and oxidative stress have also been linked to the buildup of brain deposits of beta-amyloid.

Commenting on the research, Richard Kao, DDS, PhD, president of the American Academy of Periodontology, says, “These recent findings present strong evidence on how periodontal disease can impact the pathogenesis of Alzheimer’s disease and should highlight how crucial it is to manage periodontal disease, especially in older adults or individuals who have increased risk for dementia.”

The findings add to earlier research linking PD and poor oral health to increased risk for dementia. In a 2016 study, people with severe gum disease were 70% more likely to develop Alzheimer’s disease, while another 2016 study found that in people who already had the memory-robbing disorder, cognitive decline progressed six times faster in those with PD.

Do Oral Bacteria Pose Other Serious Health Threats?

A landmark BaleDoneen study was the first to identify certain periodontal bacteria as a contributing cause of cardiovascular disease, the leading killer of Americans. Published in the peer-reviewed journal Postgraduate Medical Journal, the study reported that harmful cardiovascular effects of gum disease are due to a few high-risk bacteria: Aggregatibacter actinomycetemcomitans, P. gingivalis, Tannerella forsythia, Treponema denticola or Fusobacterium nucleatum.

Other studies have linked gum disease to increased risk for a wide range of dangerous disorders diseases, including type 2 diabetes, rheumatoid arthritis, pregnancy complications and even certain types of cancer.

What’s the Best Way to Get Checked for Gum Disease?

To find out if you have PD, ask your dental provider to do a painless exam using a mirror and periodontal probe to check for signs of oral infection. It’s also important to find out if you have high-risk oral bacteria.

Instead of only evaluating the severity of a patient’s symptoms — such as how deep the pockets of infection are, how much the gums bleed, or how loose the teeth are — the BaleDoneen Method recommends using available tests from companies that measure oral pathogens through DNA analysis, including OralDNA, OraVital and Hain Diagnostics.

Treatments for PD include nonsurgical periodontal therapy, a daily program of oral care to follow at home, prescription mouthwashes, dental trays with antibacterial gel (PerioProtect), and in some cases, a short course of antibiotics. Regardless of which treatment is prescribed, the BaleDoneen Method recommends repeating the DNA testing to make sure the treatment was successful. 

What Kind of Home Care Helps Keep Your Mouth Healthy?

A recent study of more than 5,600 older adults found that one of the simplest – and most effective – keys to a long life and lower risk for chronic diseases is combining regular dental checkups with excellent self-care, including daily brushing and flossing.

If you smoke, here’s even more motivation to snuff out the habit: It’s a leading risk for developing gum disease. We also advise these measures to optimize your oral health:

  • Brush and floss twice a day. Although you may have seen headlines claiming there’s not much science to support flossing, in a nine-year study of 5,611 older adults, people who never flossed had a 30 percent higher death rate than those who flossed daily!
  • Go to bed with a clean mouth. The study found that never brushing at night raised mortality risk by 25 percent, vs. nightly brushing. Since your mouth produces less saliva to wash your teeth and gums when you’re sleeping, it’s particularly crucial to floss and brush thoroughly before bed. We recommend brushing with a sonic toothbrush for best results.
  • Get a dental cleaning every 3 months, or as advised by your dental provider. The study also found that people who hadn’t gone to a dentist in the previous year had a 50 percent higher mortality rate than those who went two or more times annually, leading the researchers to conclude that good oral health promotes longevity by helping people avoid lethal systemic diseases sparked by infections and chronic inflammation, such as CVD and possibly, Alzheimer’s disease.