Every time a new longevity bestseller comes out, I do the same thing.
I flip to the index.
I look for “oral health.” “Periodontal disease.” “Gum disease.” “Oral microbiome.”
Almost never there.
And every time, I close the book and think: How is this possible?
Your mouth sits inside your head. It’s directly connected to your bloodstream. It’s home to over 700 bacterial species — the second most diverse microbiome in your body. And the people shaping the longevity conversation act like it doesn’t exist.
I’ve spent nearly 40 years connecting the dots between what happens in your mouth and what happens in the rest of your body. And I can tell you — the science isn’t subtle. It’s overwhelming. The mainstream just hasn’t caught up yet.
So let me take you on a quick tour — head to toe — of what your mouth is actually connected to. I think you’ll be as stunned as I still am.
Your Brain
The same bacterium that makes your gums bleed — Porphyromonas gingivalis — has been found inside the brains of Alzheimer’s patients. Not just correlated. Physically present. When researchers infected mice with this oral pathogen, it colonized their brains and triggered the production of amyloid-beta — the hallmark plaque of Alzheimer’s disease. (Dominy et al., Science Advances, 2019 — gingipains detected in over 90% of Alzheimer’s brain samples examined.)
Both of my parents had Alzheimer’s. I’ve been tracking this research for decades. It’s personal for me. And it’s one of the reasons I take my own oral health more seriously now than at any point in my career. I also supplement daily with creatine — there’s growing research on its role in supporting brain energy metabolism and neuroprotection. When you’ve watched both your parents lose their minds, you don’t leave anything on the table.
Your Heart
Periodontal pathogens have been found inside arterial plaque — the buildup that causes heart attacks and strokes. In one landmark study, nearly half of all arterial plaque samples from surgery patients tested positive for at least one oral pathogen. (Haraszthy et al., Journal of Periodontology, 2000.) The American Heart Association has formally acknowledged the association between periodontal disease and atherosclerotic cardiovascular disease. (Lockhart et al., 2012.)
When’s the last time your cardiologist asked about your gums?
Your Blood Pressure
This one gets me fired up. Bacteria on the back of your tongue convert dietary nitrate — from leafy greens, beets — into nitric oxide, a critical molecule that keeps your blood vessels dilated and your blood pressure healthy. Antiseptic mouthwash kills these bacteria. In one study, mouthwash reduced oral nitrite production by 90% and raised blood pressure within a single day. (Kapil et al., Free Radical Biology and Medicine, 2013.)
You need the right oral bacteria to be able to produce nitric oxide. And millions of people are killing those exact bacteria every morning and night with antibacterial mouthwash. I take magnesium daily — it supports both healthy blood pressure and the mineral flow that protects your teeth — and I always keep electrolytes on hand because adequate hydration supports saliva production, which is your mouth’s first line of defense. I also worked with nitric oxide researchers to develop these nitric oxide mints. And, of course, if you’ve been reading this newsletter for a while now, you know I’ve swapped mouthwash for this wonderful oil pulling blend.
Your Blood Sugar
Periodontal disease and diabetes fuel each other in a vicious cycle. Each makes the other worse. But treating gum disease has been shown to improve blood sugar control — with HbA1c reductions comparable to adding a second diabetes medication. The International Diabetes Federation and the European Federation of Periodontology now jointly recognize this bidirectional relationship and recommend periodontal care as part of diabetes management. (Sanz et al., J Clin Periodontol, 2018; Madianos & Koromantzos, 2018 — HbA1c reductions of 0.27% to 1.03% across seven meta-analyses of randomized controlled trials.)
If you’re pre-diabetic or managing blood sugar, your dentist might be just as important as your endocrinologist.
Your Breasts
This one surprises almost everyone. A meta-analysis of over 173,000 participants found that women with periodontal disease had a 22% higher risk of developing breast cancer. A separate study of over 73,000 postmenopausal women confirmed a 14% increased risk. (Shao et al., Frontiers in Oncology, 2018; Freudenheim et al., 2016.) Chronic gum inflammation doesn’t stay local. It drives the kind of persistent, low-grade systemic inflammation that fuels cancer progression — which is also why my wife and I take a C15:0 supplement with emerging data on mitochondrial function and reducing systemic inflammation, along with turmeric and zinc as part of a daily protocol to help manage inflammatory load from multiple angles.
Your Gut
Every longevity expert tells you to optimize your gut. But almost none of them mention where your gut microbiome begins: your mouth. You swallow about 1.5 liters of saliva daily. When your oral microbiome is out of balance, pathogenic bacteria colonize the gut. In a landmark study, oral Klebsiella bacteria were shown to drive severe intestinal inflammation when they took hold in a disrupted gut. (Atarashi et al., Science, 2017.)
You can take all the probiotics you want. If your mouth is flooding your gut with pathogenic bacteria with every swallow, you’re fighting a losing battle. For a wonderful book on this topic, check out my favorite one here.
So Why Doesn’t Anyone Talk About This?
Dentistry has been siloed from medicine for over 150 years. Insurance treats your mouth like it’s not part of your body. Medical schools barely cover oral health. Dental schools barely cover systemic health. We simply aren’t trained to see the mouth as a systemic organ.
They talk about the four pillars of chronic disease: heart disease, cancer, neurodegenerative disease, metabolic disease. Periodontal disease is linked to every single one. But it never makes the list, somehow.
This is one of the reasons I’m writing a book right now with Penguin Random House — to bring this science to the mainstream in a way that’s never been done. I want to put the mouth back in the body, once and for all. If you’d be interested in being part of the book launch team when the time comes, hit reply and let me know. I’d love to have you along for the ride.
What To Do Starting Today
Find a dentist who connects the dots.
Not every dentist is trained in oral-systemic health, airway science, or the microbiome. My Functional Dentist Directory can help you find one near you.
Get an airway evaluation.
This isn’t optional, and it’s not just for people who snore. Here’s what most people don’t realize: how you breathe shapes everything — your sleep quality, your blood pressure, your facial development, your inflammatory load, even your risk for cognitive decline. Children who mouth-breathe develop narrower jaws, crowded teeth, and a lifetime of compromised sleep. Adults with undiagnosed sleep-disordered breathing are silently driving up their cardiovascular risk every single night. And the vast majority of them have never been screened. Your dentist may actually be the first provider to catch it — they see your airway, your tongue posture, your jaw structure at every visit.
Find an airway-focused dentist here. This is one of the highest-impact things you can do for your long-term health, at any age.
Stop nuking your oral microbiome.
Ditch antiseptic mouthwash — Listerine, alcohol-based rinses, chlorhexidine, even “natural” mouthwashes with essential oils that disrupt your bacterial balance. Try an oil pulling blend and tongue scraper or simply nothing at all. Your mouth bacteria are doing more for you than you realize.
Treat bleeding gums as a systemic red flag.
Bleeding when you floss isn’t normal. It’s an open wound connected to your bloodstream, your brain, and your heart. Do what you need to do to make flossing a habit, and see your dentist 2-4 times a year for checkups and cleanings.
Rebuild your enamel, don’t just clean it.
I nearly my whole career looking for a toothpaste that was actually formulated with the oral microbiome in mind — no essential oils, no harsh detergents, nothing that would disrupt the bacterial balance we’ve been talking about this entire newsletter. I couldn’t find one. So I made one.
The Fifth Pillar
Heart disease. Cancer. Neurodegeneration. Metabolic disease. After four decades of practice, I believe there’s a fifth pillar — and it’s been hiding in your mouth.
Oral disease is the most common chronic disease on the planet. It’s linked to all four of the others. And it’s the one you can do something about today, at home, without a prescription.
I’m not here to live forever. But if I’m around, I want to make it good. And I want the same for you. Thank you for being a reader and for your interest in this topic.
To your health,
Mark
Citations and Further Reading
– Dominy et al., Science Advances (2019) — P. gingivalis gingipains in Alzheimer’s brains
– Haraszthy et al., Journal of Periodontology (2000) — Periodontal pathogens in 44% of atheromatous plaques
– Lockhart et al., Circulation (2012) — AHA statement on PD and atherosclerotic CVD
– Kapil et al., Free Radical Biology and Medicine (2013) — Mouthwash reduces nitrite 90%, raises BP
– Sanz et al., J Clin Periodontol (2018) — EFP/IDF consensus on diabetes-periodontitis bidirectional relationship
– Madianos & Koromantzos, J Clin Periodontol (2018) — HbA1c reductions 0.27%–1.03%
– Shao et al., Frontiers in Oncology (2018) — PD increases breast cancer risk 1.22-fold (173,162 participants)
– Freudenheim et al. (2016) — 73,000+ postmenopausal women, 14% increased breast cancer risk
– Atarashi et al., Science (2017) — Oral Klebsiella colonizes gut, drives TH1 inflammation