Integrative Oncology: Functional Medicine Meets Cancer Care

The Metabolic Theory — A Different Lens on Cancer

For nearly a century, we have treated cancer primarily as a genetic disease — mutations accumulate, cells go rogue, we poison or cut them out. But there is an older thread, stretching back to Otto Warburg’s 1924 observation that cancer cells ferment glucose even in the presence of oxygen — the famous Warburg effect. This metabolic anomaly was largely ignored as the genetic paradigm dominated.

Then Thomas Seyfried, in his 2012 book Cancer as a Metabolic Disease, picked up the thread Warburg left behind. His argument is straightforward and backed by decades of mitochondrial research: cancer is fundamentally a disease of damaged mitochondria. When mitochondria lose the ability to perform oxidative phosphorylation properly, the cell compensates by upregulating fermentation — both glucose and glutamine fermentation. The genetic mutations we observe are downstream consequences, not primary causes.

Think of it this way. If your house floods, you see water damage everywhere — warped floors, peeling paint, mold. The genetic theory says each of those damages is a separate problem. The metabolic theory says: find where the pipe burst.

This does not mean genetics are irrelevant. It means the terrain matters as much as — perhaps more than — the tumor.

The IFM Terrain Approach

The Institute for Functional Medicine (IFM) frames chronic disease through a systems biology lens, and cancer is no exception. Rather than focusing solely on the tumor, integrative oncology asks: what is the biological terrain that allowed this tumor to grow?

This terrain-versus-tumor framework identifies modifiable cancer hallmarks — the conditions in the body that promote tumor initiation, growth, and metastasis:

• Chronic inflammation (NF-kB activation, elevated hs-CRP, IL-6)
• Insulin resistance and hyperinsulinemia (IGF-1 as growth factor)
• Immune evasion (impaired NK cell surveillance)
• Oxidative stress (mitochondrial dysfunction, glutathione depletion)
• Hormonal imbalance (estrogen dominance, elevated cortisol)
• Toxin burden (carcinogens, endocrine disruptors)
• Microbiome dysbiosis (estrobolome, immune training)
• Chronic stress and circadian disruption

Each of these is modifiable. Each offers a therapeutic lever that complements — never replaces — standard oncologic treatment.

Evidence-Based Integrative Interventions

Exercise — The Non-Negotiable

If exercise were a drug, it would be the most prescribed medication in oncology. The American College of Sports Medicine (ACSM) guidelines for cancer survivors recommend 150 minutes of moderate aerobic activity plus twice-weekly resistance training. Friedenreich’s meta-analyses show exercise reduces breast cancer risk by 25-30%, colorectal cancer by 20-25%, and improves outcomes in patients already diagnosed.

Exercise reduces insulin and IGF-1, improves immune surveillance (increased NK cell activity), lowers inflammation, and improves mitochondrial function. During treatment, exercise reduces fatigue more effectively than any drug — the Cramp and Byron-Daniel Cochrane review confirmed this across 56 trials.

Mediterranean Diet

The PREDIMED trial (Toledo 2015) showed a 62% reduction in breast cancer incidence with a Mediterranean diet supplemented with extra virgin olive oil. The mechanisms are multiple: polyphenols, omega-3 fatty acids, fiber supporting the microbiome, and low glycemic load reducing insulin signaling.

Stress Reduction and Sleep

Chronic psychological stress activates the sympathetic nervous system, releasing norepinephrine and epinephrine that directly promote angiogenesis and metastasis (Thaker 2006). Mindfulness-Based Stress Reduction (MBSR) has been shown to improve immune function and quality of life in cancer patients. Sleep disruption compounds the problem — IARC classifies shift work as a probable carcinogen (Group 2A) because circadian disruption suppresses melatonin, which is itself an oncostatic agent.

Key Supplements with Evidence

Vitamin D

Maintain serum 25(OH)D above 40 ng/mL, ideally 50-80 ng/mL. Mohr’s 2014 meta-analysis showed higher vitamin D levels associated with significantly lower incidence and mortality for breast and colorectal cancers. Lappe’s 2007 RCT demonstrated a 60% reduction in all-cancer incidence with calcium plus vitamin D supplementation over 4 years. Dose: 4,000-10,000 IU/day, titrated to blood levels.

Curcumin

The principal polyphenol in turmeric, curcumin inhibits NF-kB, COX-2, and multiple cancer signaling pathways. Clinical trials show benefit as adjunct therapy, particularly in colorectal and pancreatic cancers. Dose: 1,000-2,000 mg/day of bioavailable forms (with piperine or liposomal). Caution with anticoagulants.

Green Tea EGCG

Epigallocatechin-3-gallate (EGCG) inhibits angiogenesis, induces apoptosis, and modulates multiple oncogenic pathways. Population studies consistently show lower cancer rates in heavy green tea consumers. Dose: 3-5 cups green tea daily or 400-800 mg EGCG supplement. Caution: high-dose EGCG may affect liver function in sensitive individuals.

Modified Citrus Pectin

Isaac Eliaz’s research on PectaSol-C (modified citrus pectin) demonstrates inhibition of galectin-3, a molecule that promotes metastasis, angiogenesis, and immune evasion. Dose: 15 grams/day in divided doses.

Medicinal Mushrooms — Turkey Tail (Trametes versicolor)

Paul Stamets championed Turkey Tail’s PSK (polysaccharide-K) and PSP (polysaccharopeptide) — immunomodulatory compounds that enhance NK cell activity, T-cell function, and dendritic cell maturation. PSK has been used in Japan as an approved adjunct to chemotherapy for decades. The Bastyr University trial (Torkelson 2012) demonstrated significant immune enhancement in breast cancer patients taking Turkey Tail after radiation. Dose: 3-6 grams/day of whole mushroom extract or PSK/PSP.

Mistletoe (Viscum album)

Used widely in European integrative oncology, particularly as Iscador, mistletoe extract improves quality of life, reduces chemotherapy side effects, and may enhance immune surveillance. Tröger’s 2009 randomized trial showed significant improvement in quality of life for breast cancer patients. Mistletoe is administered by subcutaneous injection and should be prescribed and monitored by trained practitioners.

The Antioxidant Timing Debate

Few topics generate more heat and less light than antioxidant supplementation during chemotherapy and radiation. The debate has two camps.

Charles Simone and colleagues argue that antioxidants protect normal cells without protecting cancer cells, and their review of 50+ studies suggests antioxidants do not reduce chemotherapy efficacy. Keith Block’s research supports strategic antioxidant use with careful timing.

The opposing view holds that antioxidants could protect cancer cells from the oxidative damage that chemotherapy and radiation rely on for tumor kill.

The practical middle ground most integrative oncologists follow: avoid high-dose single antioxidants (vitamin C >1g, vitamin E >400 IU, NAC) within 24-48 hours before and after chemotherapy or radiation. Multi-target, food-based antioxidants (turmeric, green tea, vegetables) at dietary doses are generally considered safe. Always coordinate with the oncology team.

Fasting Around Chemotherapy

Valter Longo’s research on fasting-mimicking diets (FMD) around chemotherapy is among the most promising developments in integrative oncology. The theory: short-term fasting puts normal cells into a protected, quiescent state (differential stress resistance) while cancer cells, unable to downregulate growth signaling, become more vulnerable to chemotherapy.

De Groot’s 2015 pilot study demonstrated that a fasting-mimicking diet around chemotherapy reduced hematological toxicity and DNA damage in normal cells. Dorff’s 2016 Phase I trial of 24-72 hour water fasting showed fasting was safe and reduced IGF-1 while protecting immune cells (lymphocyte counts recovered faster).

The practical application: a 48-72 hour fast or FMD (approximately 300-500 calories of plant-based, low-protein, low-sugar food) starting 24-48 hours before and continuing 24 hours after chemotherapy infusion. This must be supervised by the medical team, and patients who are underweight, sarcopenic, or malnourished are NOT candidates.

The Integrative Oncology Team

Cancer care is not a solo sport. The ideal integrative oncology team includes:

• Medical oncologist — leads conventional treatment decisions (surgery, chemo, radiation, immunotherapy)
• Naturopathic oncologist — trained in both natural medicine and oncology (FABNO board certification), manages supplements, IV therapies, avoids interactions
• Functional medicine nutritionist — individualized anti-cancer diet, manages weight, addresses nutrient deficiencies
• Psycho-oncologist — addresses the emotional terrain, fear of recurrence, existential distress, caregiver burnout
• Exercise oncologist/physiotherapist — prescribes cancer-specific exercise programs
• Integrative pharmacist — checks herb-drug and supplement-drug interactions

Communication between team members is critical. The naturopathic oncologist should provide the medical oncologist with a complete supplement list before each treatment cycle.

Informed Consent — The Ethical Foundation

This must be stated clearly: integrative oncology never replaces standard cancer treatment. The evidence base for surgery, chemotherapy, radiation, immunotherapy, and targeted therapies is robust and continues to improve. Patients who refuse standard treatment in favor of “alternative” approaches have significantly worse outcomes — this is documented and unambiguous.

Integrative oncology is additive. It optimizes terrain, reduces side effects, improves quality of life, supports immune function, and may enhance treatment efficacy. It works alongside oncology, not against it.

Every intervention should be:

• Evidence-informed (not just anecdotal)
• Discussed with the oncology team
• Documented in the medical record
• Monitored for efficacy and adverse effects
• Discontinued if it interferes with treatment

The metabolic terrain approach gives patients agency in their care — actionable steps in diet, exercise, stress management, sleep, and targeted supplementation that support their body’s ability to fight cancer and recover from treatment. That agency, combined with skilled conventional oncology, represents the best of integrative medicine.

When we stop asking “how do we kill this tumor?” and start also asking “what made this terrain hospitable to cancer?” — we open doors that neither approach could open alone. What terrain element in your own life might be silently shifting the soil?