How Naturopathic Integrative Oncology Works With Chemotherapy

By Dr. Lena Suhaila, ND, FABNO

There's a moment in almost every initial oncology consult when supplements come up. The cabinet should be cleared. The fasting protocol a friend mentioned should be set aside. The naturopathic doctor someone recommended sounds, in the way it gets framed, like something to pursue at your own peril.

I want to spend some time with that framing, because the version most patients walk out with isn't accurate, and the version that is accurate is more interesting, and more clinically specific, than what gets said in a fifteen-minute consult.

The chemotherapy your oncology team has prescribed isn't acting on a tumor in isolation. It's acting on a body. Specifically, on yours. The terrain of that body, its insulin and glucose signaling, its inflammatory burden, its gut microbiome, its nervous system tone, its nutrient reserves and methylation capacity, isn't background to treatment. It's the substrate the treatment is working through. The same protocol given to two patients with the same molecular subtype produces measurably different outcomes, and a meaningful portion of that difference is biology that conventional oncology isn't structured to assess or modify.

That's what naturopathic integrative oncology, done well, addresses. Not by competing with your treatment. By changing the conditions under which it's delivered.

What Chemotherapy Is Actually Doing, and Why the Body Matters

Cytotoxic chemotherapy works by exploiting one of the few reliable differences between cancer cells and most healthy cells, which is their reliance on rapid replication. The drugs disrupt DNA synthesis, mitotic spindle formation, or cell division, and the tissues that turn over fastest are hit hardest. That's the principle. It's why side effects cluster around bone marrow, gut lining, hair follicles, and mucous membranes.

What gets less time in oncology visits is that the metabolic state of the body shapes both how a tumor responds to that pressure and how the rest of the body recovers between cycles. The PET scan your team uses to find your tumor works because cancer cells take up glucose at rates dramatically higher than surrounding tissue. The imaging itself is built on the Warburg effect, the way many cancer cells preferentially metabolize glucose through glycolysis even in the presence of oxygen (Vander Heiden, Cantley, & Thompson, 2009). And yet most patients are still told that what they eat doesn't matter.

It matters. Pavlova and Thompson's review in Cell Metabolism described in detail how cancer cells reprogram their use of glucose, glutamine, and other substrates in ways that depend on a permissive metabolic environment in the host (Pavlova & Thompson, 2016). The terrain you bring to chemotherapy shapes how vulnerable the cancer is and how protected the rest of you can be.

Insulin, IGF-1, and the Substrate Underneath the Treatment

Insulin and insulin-like growth factor 1 aren't background hormones during cancer treatment. They're central to it. Pollak's foundational review in Nature Reviews Cancer laid out how chronically elevated insulin and IGF-1 signaling activates the PI3K/Akt/mTOR pathway, which is among the most common pathways exploited by cancer cells for proliferation and survival (Pollak, 2012). A patient who walks into chemotherapy with elevated fasting insulin is walking in with a metabolic environment that's actively supporting the very biology her treatment is trying to interrupt.

This is part of why I order labs your oncology team didn't. Fasting insulin. Hemoglobin A1C. Continuous glucose data when it's clinically appropriate. Inflammation markers like hs-CRP and ferritin. The metabolic picture that doesn't appear on a standard oncology workup but that shapes how every cycle of treatment lands. The piece on what the ketogenic diet does in your body, and why it matters for cancer, goes deeper into the metabolic biology if you want to understand it more thoroughly.

When the metabolic terrain shifts, the chemotherapy isn't getting weaker. The environment around the tumor is getting less hospitable to it.

The Microbiome and How Your Body Will Respond to Treatment

If you've been on antibiotics off and on for years, on a proton pump inhibitor since some long-ago endoscopy, on a diet that's been ultraprocessed since college, your gut microbiome has been shaped by all of that. Most patients have never had it mapped. Most oncology intakes don't ask.

Helmink and colleagues' synthesis in Nature Medicine documented a decade of research showing that microbial composition influences how patients respond to chemotherapy, immunotherapy, and the inflammatory toxicity that accompanies both (Helmink, Khan, Hermann, Gopalakrishnan, & Wargo, 2019). Specific bacterial taxa metabolize chemotherapy drugs directly. Microbial metabolites, particularly short-chain fatty acids like butyrate, modulate the immune surveillance that has to remain functional during treatment. Disrupted gut microbiomes are correlated with worse outcomes across a growing number of cancers and treatment modalities.

This isn't the kind of finding you want to hear about for the first time after the protocol is finished. It's the kind of information that should shape how you go in. The full piece on the gut microbiome and chemotherapy walks through the specifics.

Fasting Biology and Differential Stress Resistance

One of the most clinically interesting bodies of metabolic research in oncology is the work on differential stress resistance, much of it built from Valter Longo's lab at USC. The principle is that short periods of caloric and protein restriction shift normal cells into a protected, low-replication state while leaving cancer cells, which can't downregulate their replication, more exposed to chemotherapy (Lee et al., 2012).

Clinical translation has been advancing. A 2024 randomized trial of a fasting-mimicking diet during neoadjuvant chemotherapy in breast cancer patients found significantly lower rates of grade III vomiting and neutropenia in the FMD group compared to controls (Bahrami et al., 2024). Earlier phase 2 data from the Netherlands suggested improved radiologic response in patients adherent to multiple cycles (de Groot et al., 2020).

These are protocols that have to be supervised by someone who knows your treatment regimen, your body composition, your nutritional status, and the specific drug interactions involved. They aren't appropriate for every patient, and what's safe for a younger, well-nourished patient on AC-T isn't appropriate for an older patient with cachexia. The deeper post on fasting during cancer treatment lays out the biology in detail.

The Nervous System Is Part of Treatment Biology

This is where the science most clearly outpaces clinical practice. Cole, Sood, and colleagues' landmark review in Nature Reviews Cancer described how sympathetic nervous system activity, specifically the catecholamines released during chronic stress, directly modulates the tumor microenvironment, with measurable effects on angiogenesis, immune cell trafficking, inflammation, and tumor cell behavior across multiple cancer types (Cole, Nagaraja, Lutgendorf, Green, & Sood, 2015).

The chronic stress you've been carrying. The unprocessed grief. The trauma the body has been compensating for. The sympathetic activation you live in because your life hasn't allowed you to rest. These aren't psychological side notes. They're biologically interacting with the tumor environment and with how your body tolerates and recovers from each cycle of chemotherapy.

The work I do here isn't stress management in the casual sense. It's nervous system regulation, informed by polyvagal theory, Internal Family Systems, and Compassionate Inquiry. The parts of a person that have been holding something for decades, often something the body has been compensating for in ways that show up as elevated cortisol, gut dysbiosis, persistent inflammation, and the sympathetic dominance we now know affects tumor biology, the compensation has a cost. The work, when it's done well, lowers that cost. The fuller exploration of this is in what conventional oncology gets wrong about healing.

What I Take Out of the Cabinet, and Why

A responsible naturopathic oncologist is as careful about what she removes from the protocol as what she adds. Patients arrive with cabinets of high-dose oral antioxidants they've been told to take. With certain chemotherapy regimens, particularly those that work in part through oxidative mechanisms, concurrent high-dose antioxidants can theoretically blunt efficacy. The picture is regimen-specific and more nuanced than the original concern suggested, but caution is warranted, and you deserve a clinician who knows the difference between an anthracycline cycle and a platinum agent, between a taxane and a topoisomerase inhibitor, and adjusts recommendations accordingly.

Green tea extract, St. John's wort, grapefruit, certain mushroom preparations, and several herbs commonly recommended online have known or suspected interactions with the cytochrome P450 enzymes that metabolize chemotherapy drugs. A patient who's been told her supplements don't matter is being underestimated. They matter enormously, which is exactly why an integrative oncologist trained in pharmacokinetics belongs on the team rather than as a parallel project run in secret.

What goes in is matched to your pathology, your treatment, your labs, and your individual biology. What comes out is matched to the same.

What This Looks Like in Practice

A first visit is 75 minutes. I review your pathology, your treatment plan, your imaging, your full lab history, and the questions no one else has had time to ask. We discuss what your life was like in the years before the diagnosis. What you were carrying. What had no exit. What you weren't allowed to feel. Where you felt safe.

Then we look at your terrain. I order the labs your oncology team didn't. The metabolic markers. The inflammation panels. The full thyroid and adrenal picture. The gut function workup. Genomic individualization through the Nutrition Genome report, which lets us see how your specific body methylates, detoxifies, handles oxidative stress, and metabolizes specific nutrients. Your protocol isn't generic. It's built from your biology.

The treatment plan from your medical oncologist stays in place. What changes is the condition of the body the protocol is acting on. The chemotherapy is doing its work. Your body is being supported to do its work alongside it. You come out the other side more whole than you would have otherwise, with a foundation that's positioned for what comes after treatment ends.

The Longer Arc

This conversation doesn't end at remission. Most patients are discharged into surveillance, which is to say, into scans and labs and the ongoing measurement of whether the disease has returned. What's missing is any structured attention to the biology that allowed the cancer to develop in the first place, which is, by definition, still there if nothing has changed.

I call the work that follows treatment Vigilant Remission. It's the active cultivation of the terrain so that what comes next isn't just the absence of cancer but the presence of metabolic, immunological, and nervous-system health that makes recurrence biologically less likely. The work that begins during chemotherapy lays the foundation for that longer arc.

If You're Ready

If you're navigating active chemotherapy or preparing for it, and you've sensed there's more to this picture than what your oncology team is structured to give you, you've been right. The biology supports your instinct. The translation of that biology into care is what's missing in most conventional settings, and it's what I do.

If you're ready to bring that level of attention to your own body during treatment, I'd welcome the conversation.

References

1. Bahrami, A., Haghighi, S., Malekzadeh Moghani, M., Khodakarim, N., & Hejazi, E. (2024). Fasting mimicking diet during neo-adjuvant chemotherapy in breast cancer patients: a randomized controlled trial study. Frontiers in Nutrition, 11, 1483707. https://doi.org/10.3389/fnut.2024.1483707

2. Cole, S. W., Nagaraja, A. S., Lutgendorf, S. K., Green, P. A., & Sood, A. K. (2015). Sympathetic nervous system regulation of the tumour microenvironment. Nature Reviews Cancer, 15(9), 563–572. https://doi.org/10.1038/nrc3978

3. de Groot, S., Lugtenberg, R. T., Cohen, D., et al. (2020). Fasting mimicking diet as an adjunct to neoadjuvant chemotherapy for breast cancer in the multicentre randomized phase 2 DIRECT trial. Nature Communications, 11(1), 3083. https://doi.org/10.1038/s41467-020-16138-3

4. Helmink, B. A., Khan, M. A. W., Hermann, A., Gopalakrishnan, V., & Wargo, J. A. (2019). The microbiome, cancer, and cancer therapy. Nature Medicine, 25(3), 377–388. https://doi.org/10.1038/s41591-019-0377-7

5. Lee, C., Raffaghello, L., Brandhorst, S., et al. (2012). Fasting cycles retard growth of tumors and sensitize a range of cancer cell types to chemotherapy. Science Translational Medicine, 4(124), 124ra27. https://doi.org/10.1126/scitranslmed.3003293

6. Pavlova, N. N., & Thompson, C. B. (2016). The emerging hallmarks of cancer metabolism. Cell Metabolism, 23(1), 27–47. https://doi.org/10.1016/j.cmet.2015.12.006

7. Pollak, M. (2012). The insulin and insulin-like growth factor receptor family in neoplasia: An update. Nature Reviews Cancer, 12(3), 159–169. https://doi.org/10.1038/nrc3215

8. Vander Heiden, M. G., Cantley, L. C., & Thompson, C. B. (2009). Understanding the Warburg effect: The metabolic requirements of cell proliferation. Science, 324(5930), 1029–1033. https://doi.org/10.1126/science.1160809