10 Year Anniversary: What I Learned After 200+ Conversations with the Best Minds in FxMed

Fitzgerald and her colleague Romly Hodgers developed this protocol in their clinic before testing it in a randomized controlled trial. The diet emphasizes a high intake of colorful plant foods, quality proteins, and healthy fats, while minimizing processed foods and sugar. The research showed significant epigenetic age reversal, and subsequent analysis revealed the diet provided about 3,000 mg of polyphenols per day—higher than many other interventions studied for epigenetic effects. Fitzgerald emphasizes that the protocol was born from clinical practice, where they saw remarkable turnarounds in patients with diverse conditions. In her book 'Younger You,' she provides guidance on how to adapt the protocol for individuals with specific dietary needs, underscoring the functional medicine principle of personalization.

Fitzgerald contrasts the functional medicine approach with the popular biohacker mentality of jumping on the latest supplement based on animal studies. She gives concrete examples: vitamin D supplementation only reverses bio-age in those who are deficient; time-restricted eating can be detrimental for individuals with high stress or caloric needs. She emphasizes that functional medicine's toolkit—detailed history, advanced lab testing, physical exam—allows identification of each person's unique 'flavor' of imbalance, whether metabolic, allergic, or dysbiotic. Only after correcting these foundations should one consider layering on longevity compounds. This approach not only improves efficacy but also safety.

Fitzgerald highlights emerging science showing that the most longevity-promoting physical activities are those done with other people. She connects this to her own life, where she used to combine cycling with phone calls to friends and family, effectively merging exercise and social connection. She stresses the importance of fostering community and designing a lifestyle that naturally incorporates movement with others, whether through organized sports or simply walking with neighbors.

Fitzgerald shares that after vacationing in Baja California, she noticed her HRV—a key marker of stress resilience and longevity—reached its highest levels ever. This sustained improvement, along with her daughter's thriving social life, convinced her to move there permanently. She now lives car-free, biking everywhere, immersed in a tight-knit community. She uses this as an example of how aligning one's environment with health values can yield profound physiological benefits, and encourages others to seek out or create environments that naturally support well-being.

Dr. Fitzgerald interviewed Paul Turner from Yale, who has brought phage research back to the US. She explains that phages were the precursor to antibiotics, but when antibiotics were developed, phage therapy was halted. However, in Eastern Europe, scientists continued to refine phage therapy, developing sophisticated understanding of indications. Turner's lab is now advancing this science, and some functional medicine practitioners are already using phages clinically. The conversation included anecdotes of 'pond to bedside' where phages isolated from environmental sources saved patients with resistant infections. Fitzgerald encourages listeners to explore this underappreciated field, suggesting it will become a major tool against infection and possibly autoimmune conditions linked to dysbiosis.

Fitzgerald recounts interviewing Moshe Szyf in 2017, where he described the promise of using cell-free fetal DNA from maternal blood to detect epigenetic marks predictive of neurodevelopmental disorders, and then intervening with nutrients like S-adenosylmethionine (SAMe) and vitamin A to reverse those marks. She then fast-forwards to 2024, when she interviewed Janine LaSalle, who has mapped the placental methylome and linked it to the fetal brain. LaSalle is now developing the actual assays to detect these methylation changes, bringing Szyf's vision to fruition. Fitzgerald expresses excitement that once diagnostics are available, functional medicine practitioners could use nutrient-based interventions to correct imbalances before birth, and speculates that similar approaches could eventually address age-related chronic diseases.

Fitzgerald shares that when she and Romly Hodgers first proposed studying a dietary intervention's effect on DNA methylation, they were nervous to even mention it. She would cautiously bring it up at the end of podcasts with scientists like David Sinclair and Walter Longo, and was uniformly met with excitement. Jeff Bland, her mentor, was a steadfast believer from the start, providing encouragement and connections. She notes that their study became the first randomized clinical trial to show that a diet and lifestyle program could reverse epigenetic aging clocks. Now, human data is emerging daily, and the once-controversial idea is mainstream. This shift underscores the power of functional medicine's systems approach.

Fitzgerald describes her long pursuit to interview Charles Serhan, whom she considers Nobel-worthy. She explains that SPMs are produced in the brain, immune system, heart, liver, and circulation, where they attenuate and clean up immune responses. In the modern chronic disease epidemic, SPM production is inadequate, largely due to insufficient omega-3 intake. She emphasizes that functional medicine practitioners should care deeply about this science because it provides a mechanistic basis for why omega-3 supplementation and a diet rich in these fats are so crucial. The conversation with Serhan was one of her all-time favorites, blending deep science with clinical relevance.

Fitzgerald argues that functional medicine is inherently longevity medicine because it addresses the whole person in their environment, optimizing healthspan and potentially lifespan. She warns that layering longevity supplements onto an unbalanced foundation is ineffective or harmful. For example, vitamin D only reverses bio-age in deficient individuals; time-restricted eating can cause malnutrition and stress in some. She stresses the importance of individualizing interventions, citing her own research: the Younger You protocol worked on average, but she believes results would be even better when tailored to the individual's unique imbalances. She also highlights the ripple effect—when one person in a family or community gets healthier, it influences those around them, making functional medicine 'contagious' in a positive way.