Dr. Kara Fitzgerald

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Sandy Hook, CT
Dr. Kara Fitzgerald

Actively engaged in award-winning clinical research on epigenetics & longevity. IFM Faculty & renowned international speaker.

Director of New Frontiers Functional Medicine & Nutrition Clinic. Subscribe to get latest content at www.drkarafitzgerald.com

03/15/2026

Most chronic diseases don’t begin when symptoms appear.

They begin earlier.

Alzheimer’s disease, for example, shows measurable biological changes more than 20 years before cognitive decline becomes visible.

This reflects a core principle of longevity science: Aging is driven by gradual shifts in cellular function, including mitochondrial health, inflammation balance, metabolic regulation, and epigenetic signaling.

These systems respond continuously to your internal and external environment.

Longevity is not determined in a moment.

It’s shaped over time.

Source: Bateman et al., New England Journal of Medicine, 2012 DOI: 10.1056/NEJMoa1202753

03/14/2026

Many clinicians are familiar with mitochondrial dysfunction. Fewer routinely target mitophagy.

Yet mitophagy is one of the most critical longevity pathways in human biology.

Mitophagy is the regulated process by which damaged mitochondria are identified and removed, preserving cellular energy capacity and limiting oxidative stress.

When mitochondrial quality control functions efficiently, cells maintain metabolic flexibility, ATP production, and resilience under stress.

With aging, mitophagy becomes less efficient.

Damaged mitochondria accumulate. Energy output declines. Biological aging accelerates.

This decline is linked to sarcopenia, cognitive changes, metabolic dysfunction, and reduced cellular resilience.

Clinically, mitophagy can be supported through:
• Structured exercise, particularly zone 2 and resistance training
• Time-restricted eating and metabolic flexibility
• Polyphenol-rich dietary patterns
• Targeted nutrients that support mitochondrial quality control pathways
• Sleep optimization and circadian alignment

Supporting mitochondrial quality, not just quantity, is central to preserving long-term healthspan.

Learn more about how mitochondrial pathways influence aging at the link in bio.

03/13/2026

Wow. This is concerning.

A single exposure to the fungicide vinclozolin didn’t just affect one generation of rats.
It altered gene expression for at least 20 generations.

Researchers found that ancestral exposure led to:
• Increased kidney disease
• Higher rates of s***m death
• More birth complications
• Greater maternal and offspring mortality

These weren’t DNA mutations. They were epigenetic changes, chemical modifications to DNA that influence how genes are expressed.

This is the power (and the risk) of epigenetics.

Environmental inputs don’t just impact the individual. They can shape biological outcomes across generations.
It’s a profound reminder that chemical exposures matter, sometimes in ways we are only beginning to understand.

The good news? Epigenetic marks are dynamic. They respond to environment, nutrition, stress, and lifestyle.

Our biology is not fixed. But it is responsive.

PMID 29147574

03/12/2026

🐬 The next breakthrough in healthy aging started with dolphins.

Researchers studying aging Navy dolphins found that the healthiest animals had the highest levels of C15:0 (pentadecanoic acid), now emerging as the first essential fatty acid identified in over 90 years.

Lower levels were linked to insulin resistance, fatty liver, inflammation, and cardiometabolic decline. Higher levels were associated with stronger cell membranes, improved mitochondrial function, and healthier aging biomarkers.
In this blog post, we explore the science behind C15:0 and introduce fatty15, a purified C15:0 supplement designed to support cellular resilience and longevity.

If you’re interested in next-generation geroprotection and foundational nutrient science, this is a fascinating deep dive.

🔗 Comment C15 and we’ll DM you the link to the blog, or head to https://www.drkarafitzgerald.com/2026/03/02/c15-healthy-aging-nutrient/ for the full blog.

Sponsored content. These statements have not been evaluated by the FDA.

03/11/2026

Every cell is constantly making a decision: Renew or accumulate damage.

That decision is governed by energy sensing and mitochondrial quality control.

When cellular energy systems are intact, repair pathways activate.

Damaged components are cleared.
Resilience is preserved.

When mitochondrial function declines, renewal slows.
Dysfunction accumulates.
Biological aging accelerates.

Longevity is not just about producing more energy.

It’s about maintaining the systems that renew it.

Want to stay current on the latest in FxMed? Comment NEWSLETTER and get the link to be added to our email list.

03/10/2026

The USDA released new dietary guidelines.

But do they actually reflect what we know about metabolic health?

On the latest episode of the New Frontiers in Functional Medicine, I sit down with Robert Lustig MD to unpack what the guidelines get right and where they fall short.

We talk about:
• Why sugar and ultra-processed foods still aren’t addressed with enough clarity
• Where nuance around fats and protein is missing
• Why dietary advice alone rarely moves the needle on obesity, diabetes, or cardiometabolic disease
• And how policy, food environments, and biology all intersect in ways guidelines often ignore

If you’re trying to make sense of nutrition guidance, clinically or personally, this episode offers a clearer, more metabolically informed framework for thinking about food, health, and the systems shaping both.

🎧 Comment FOOD PYRAMID and we’ll DM you the link or head to https://www.drkarafitzgerald.com/2026/03/10/robert-lustig-usda-guidelines/ to listen to the full podcast

03/09/2026

Creatine is having a clinical renaissance, and it goes far beyond muscle.

Emerging research shows creatine supports some of the most fundamental processes in human physiology, including cellular energy production, mitochondrial function, brain health, and metabolic resilience.

It works by helping regenerate ATP, the core energy currency every cell depends on. This makes creatine especially relevant for high-demand tissues like muscle, brain, and heart.

New human studies suggest creatine may help support:

• Cognitive function and brain energy
• Muscle strength and healthy aging
• Glucose metabolism and cardiometabolic health
• Resilience during metabolic stress

This is why creatine is increasingly being recognized not just as a sports supplement, but as a foundational bioenergetic nutrient.

In our latest blog, we break down the mechanisms, clinical evidence, and what this means for health and aging.

Comment CREATINE BENEFITS and we’ll DM you the link, or head to https://www.drkarafitzgerald.com/2026/02/19/creatine-benefits-brain-health-aging/ for the full blog

03/08/2026

Fatigue. Muscle loss. Slower recovery.

These aren’t just signs of aging. They’re often signs of mitochondrial decline.

Mitochondria are central to energy production, resilience, and long-term healthspan. And one of the most exciting areas of research right now is mitophagy, the process that clears damaged mitochondria and restores cellular function.

Join me live with Dr. Anurag Singh from Timeline for a deep dive into the clinical science behind Urolithin A, the postbiotic nutrient developed by Timeline® shown in human trials to support mitochondrial quality control.

In this webinar, we’ll cover:
• What Urolithin A is, and why most people can’t produce enough through diet
• Why mitophagy is a critical longevity pathway
• Key findings from human clinical trials
• Which patients may benefit, and practical implementation considerations
If you’re interested in precision longevity strategies rooted in cellular biology, this conversation is for you.

Live attendees can join the Q&A. All registrants receive the replay.

Comment Mitophagy and we’ll DM you the link to the register or head to https://www.drkarafitzgerald.com/2026/02/27/webinar-timeline-urolithin-a-mitochondrial-function/ to reserve your spot!

03/07/2026

Spring Forward, Biology Pushes Back ⏰🧬

This weekend we “spring forward” and lose an hour of sleep.

It may seem minor, but even a one-hour shift in circadian timing can ripple through multiple biological systems.

Research links daylight saving time changes with temporary increases in:
• Sleep disruption
• Inflammation
• Cardiovascular events
• Mood disturbances
• Metabolic dysregulation

From a functional medicine perspective, this isn’t surprising. Our biology runs on circadian rhythms that regulate hormones, immune signaling, metabolism, and mitochondrial function.

When sleep timing shifts abruptly, cortisol patterns, melatonin signaling, and glucose regulation can all be affected.

The good news? A few small strategies can help support the transition:
☀️ Get morning sunlight within an hour of waking
🥗 Eat balanced meals at consistent times
🚶‍♀️ Move your body earlier in the day
📵 Dim lights and reduce screens in the evening
😴 Prioritize sleep for the next several nights

Circadian health is foundational to longevity.

Even small disruptions remind us how tightly our biology is linked to the rhythms of light, sleep, and time.

$A hip fracture is not just an injury. It’s often a turning point in overall health.Only 40–60% of people who experience ...$

03/06/2026

A hip fracture is not just an injury. It’s often a turning point in overall health.

Only 40–60% of people who experience a hip fracture ever regain their previous level of mobility. And within the first year, all-cause mortality rises to approximately 22%.

Bone loss develops silently over years, driven by inflammation, hormonal shifts, immune signaling, and emerging evidence points to the gut microbiome as a key regulator of skeletal health.

Protecting bone health isn’t just about preventing fractures. It’s about preserving independence, resilience, and longevity.

In this episode with sōlaria biō, we explore the deeper biology of bone aging and why intervention must begin earlier.

🎧 Comment SOLARIA BIO or head to https://www.drkarafitzgerald.com/2026/02/24/endophytes-bone-health-bondia/ for the full episode.

03/05/2026

Sleep this way to protect your brain. 🧠💤

Sleep isn’t passive. It’s active neurological maintenance.

During deep sleep, the brain’s glymphatic system clears metabolic waste, including beta-amyloid proteins linked to cognitive decline and Alzheimer’s disease.

Researchers found this clearance process becomes dramatically more efficient during sleep compared to wakefulness.
This is one reason chronic sleep deprivation is associated with accelerated brain aging.

Sleep is not lost time. It’s biological repair.

Prioritizing sleep supports cognitive resilience, metabolic health, and longevity.

Source:
Xie L et al. Sleep drives metabolite clearance from the adult brain. Science. 2013;342(6156):373–377. https://pubmed.ncbi.nlm.nih.gov/24136970/

03/04/2026

This is one of my favorite traditional remedies for immune support, and it’s deeply aligned with functional medicine principles.

Fire Cider is a potent blend of apple cider vinegar, garlic, ginger, turmeric, horseradish, and herbs, ingredients rich in polyphenols and bioactive compounds that support immunity, healthy inflammation response, and cellular resilience.

Many of these compounds act as epigenetic modulators, helping influence gene expression and support healthy aging at the cellular level.

We often recommend taking a small amount daily, especially during times of increased immune stress or seasonal transitions.

It’s simple. Food-based. And deeply supportive of whole-body physiology.

Comment FIRE CIDER and we’ll DM you the link, or head to https://www.drkarafitzgerald.com/recipe/fire-cider/ for the full recipe.

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Sandy Hook, CT

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+12033049502

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http://www.drkarafitzgerald.com/

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