Dr. John Gannage, MD

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Dr. John Gannage, MD

Dr. John Gannage is a Leader in Integrative Medicine to Restore Health and Prevent Disease

MARKHAM INTEGRATIVE MEDICINE is a clinic specializing in Integrative Medicine (integrating conventional and complementary/functional medicine) located in the City of Markham’s heritage district. DR. JOHN GANNAGE, MD is a leading provider of Integrative Medicine, offering health services as a licensed medical doctor to the Greater Toronto Area since 1992.

11/21/2025

Autism care cannot be reduced to a single protocol or trend. At Markham Integrative Medicine, we focus on understanding each child’s unique biology first, then layering interventions thoughtfully from sleep and gut health to metabolic and behavioral supports, and targeted medical care when appropriate.

The result is not just symptom management, it’s measurable, sustainable progress designed to help each child thrive physically, emotionally, and cognitively.

Comment CLARITY to learn how a personalized, evidence-informed approach could make a difference for your child.

11/19/2025

You’ve cut the foods and taken the supplements. You’ve followed every low-histamine list, but your symptoms still run the show.

That’s because food isn’t the enemy, inflammation is.
When your body’s overloaded by stress, toxins, or underlying imbalances then it starts reacting to everything. The solution isn’t more restriction, it’s restoring balance.

If food fear has taken over, it’s time to get to the root of what’s driving your symptoms.

Comment BALANCE to book a consultation and learn how functional medicine can help calm your system from the inside out.

11/18/2025

Symptoms like fatigue, headaches, hives, or digestive issues may look similar, but the biology is very different.

MCAS is overactive mast cells releasing histamine and hundreds of inflammatory mediators. Histamine intolerance happens when your body can’t properly break down histamine. MCAS can cause histamine intolerance, but histamine intolerance does not cause MCAS.

Treating them interchangeably delays results. A functional, integrative approach identifies the root cause, addresses triggers, and creates a plan that actually works specifically for you and you symptoms.

If MCAS or histamine-related symptoms have left you frustrated, it’s time for clarity and precision in care.

Comment SYMPTOMS to book a consultation and uncover what’s driving your symptoms.

11/17/2025

Glutathione is your body’s master antioxidant, essential for detoxification, cellular repair, and defending against oxidative stress. But when your toxic load is high, especially from heavy metals like mercury, lead, and cadmium, your glutathione stores get used up fast.

Once glutathione binds to these toxins, it can’t be recycled. That means less protection for your cells and more inflammation over time.

Supporting your body’s natural production with nutrients like vitamin C, selenium, and zinc and reducing exposure wherever possible. This helps keep your glutathione reserves strong.
If you’re feeling sluggish, inflamed, or slow to recover, it might be time to check your glutathione levels and toxic burden.

Comment GLUTATHIONE to learn how to support your body’s natural detoxification pathways.

11/14/2025

If you’ve tried eliminating high histamine foods and still feel reactive then there’s a reason.

Histamine intolerance isn’t only rooted in what you’re eating. Stress, overwhelm, and nervous system dysregulation can activate mast cells the same way certain foods can…and this is the hidden trigger most people never address.

When your system is stuck in constant “threat detection mode,” histamine release becomes easier to spark even when your diet is “clean.”

If you feel like you react to everything, or flare for reasons that make zero sense, it might not be about adding more food rules. It might be about calming the internal signal telling your cells they’re not safe.

Comment HISTAMINE for support that looks beyond lists…and into the root cause.

11/12/2025

B vitamins aren’t just “energy vitamins.” They’re critical for mitochondrial function, neurologic health, blood cell production, and brain performance.

And while we rarely see the classic old textbook deficiencies anymore… what we are now seeing far more often are functional and compartmental deficiencies. Meaning: your blood test can look “normal”, but your cells, tissues, mitochondria, and brain may not be actually getting what they need.

When you combine this with processed food, milling, soil depletion, fertilizers/pesticides, and dysbiosis impacting the microbiome (which is a major producer of B vitamins itself)… it becomes clear why so many patients are suboptimal today.

This is one of the key reasons I emphasize nutrient density, organic produce where possible, and restoring the gut ecosystem because B vitamins literally fuel energy transfer at the cellular level.

Comment B VITAMINS and I’ll send you details on how to book a consultation.

11/11/2025

Most people think mast cell activation is random… but it’s not.

There are patterns. There are drivers. And there are root causes that go deeper than genetics.

New research shows that environment, stress exposure, toxins, trauma, and nutrient status can actually change how mast cells express genes, which explains why symptoms escalate or multiply over time.

The good news: epigenetic changes are reversible. Which means there are science-based strategies to calm, retrain, and stabilize mast cell function.

Inside the new blog, I break down what this means for diagnostics, treatment planning, and long-term healing.

Comment MAST CELLS to read the full blog and learn how to begin rewiring mast cell behavior at the root.

11/10/2025

Sleep isn’t passive. It’s active, regenerative, restorative medicine.

During deep sleep the nervous system resets, cortisol lowers, insulin sensitivity improves, the immune system calibrates, and your brain literally clears metabolic waste.

So if you’ve been trying to “push through” exhaustion, your body isn’t asking you to push harder. It’s asking you to repair it.

Instead of reaching for another supplement bandaid… we look at the WHY: stress dysregulation, hormones, blood sugar swings, screen exposure, gut imbalance, inflammatory load.

Because when sleep improves everything improves, so tonight, give your body permission to restore, not fight.

Comment SLEEP so we can start rebuilding from the foundation.

11/07/2025

Late nights and World Series baseball stress called for a little extra support, so I went for a Myers Cocktail.

This IV blend delivers key vitamins and minerals straight into the bloodstream for faster absorption and better recovery. It’s especially effective for adrenal support and calming histamine, helping your body reset when stress and fatigue start to catch up.

Sometimes your body just needs a boost especially when rest isn’t on the schedule.

Want to learn how IV therapy can support your energy, mood, and recovery?

Comment MYERS to learn more and book your own infusion.

11/05/2025

If you’re struggling with symptoms like fatigue, headaches, congestion, skin issues, or anxiety that seem to come and go then histamine could be part of the problem.

Histamine isn’t just about allergies. It plays a role in digestion, immune response, and even brain function. But when your body can’t break it down properly, it builds up and causes inflammation.

Here are 10 foods that often make things worse: Smoked salmon, aged cheese, avocados, spinach, tomatoes, walnuts, kombucha, red wine, sauerkraut, and dark chocolate.

If these are part of your daily routine and you’re dealing with unexplained symptoms, it might be time to dig deeper.

Comment HISTAMINE to book a consultation on how to identify triggers and reduce histamine overload naturally.

11/04/2025

Every child deserves care that recognizes their individuality.

At Markham Integrative Medicine, we focus on identifying the underlying biological factors that influence autism symptoms from gut health and nutrient imbalances to inflammation and mitochondrial function.

Our goal isn’t to “treat” autism, it’s to support your child’s health, resilience, and potential through evidence-based, personalized care.

Comment AUTISM CARE to learn more about our integrative approach and how we support families navigating the autism journey.

11/03/2025

“BPA-free” doesn’t always mean safe. Many plastics that swapped out BPA are now made with other bisphenols like BPS, chemicals that can still disrupt hormones, impact metabolism, and influence reproductive health.

If you’re drinking from plastic bottles or takeout cups daily, those small exposures can add up. Choosing stainless steel, glass, or ceramic makes a real difference for both your health and the planet.

Comment BPA to book a consultation with Dr. Yu and learn how to reduce your toxic load safely and effectively.

Address

300 Main Street Markham N
Markham, ON
L3P1Y8

Website

http://www.integrative-medicine.ca/

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