Let’s talk about something that often flies under the radar—insulin resistance. We hear so much about blood sugar, diabetes, and weight loss, but few people realize how deeply connected insulin resistance is to cancer. And here’s the thing: it’s not just a matter of keeping sugar levels in check—it’s about protecting your body from the conditions that allow cancer to thrive.

This isn’t just about numbers on a blood test or a scale. It’s about making small changes to how you eat, move, and care for yourself—changes that can genuinely lower your cancer risk and improve your health for the long haul.

What is Insulin Resistance?

Initiation of Insulin Resistance

The pancreas plays a crucial role in glucose metabolism, releasing insulin and glucagon to ensure blood sugar levels stay balanced. Glucagon raises blood glucose levels, while insulin lowers them.

These two hormones work together to keep blood sugar within a healthy range. However, in the typical American diet—high in refined carbs and simple sugars—glucose floods the bloodstream rapidly, forcing the pancreas to produce excess insulin repeatedly. Over time, tissues become resistant to insulin's effects, leaving blood glucose and insulin levels persistently elevated. This metabolic imbalance can lead to Type 2 diabetes and an increased risk of cancer.

And while obesity and a sedentary lifestyle are major risk factors, thin individuals aren’t immune. Stress, lack of exercise, environmental toxins, and diets high in refined sugars and simple carbs can all contribute to insulin resistance.

**Figure 1 demonstrates how insulin resistance can be so damaging and be a root cause of many diseases, including cancer.**

How Insulin Resistance Fuels Cancer

1. Hyperinsulinemia and Cancer Cell Growth

Insulin, along with insulin-like growth factors (IGF-1 and IGF-2), acts as a powerful signal to promote cell growth. This is helpful when everything is in balance, but in insulin resistance, these growth signals are overactive, promoting cancer cell proliferation and blocking apoptosis—the natural process where damaged cells self-destruct.

High insulin levels also suppress the proteins that regulate IGF activity, resulting in more free IGF-1, which stimulates tumor growth and progression. This is one reason people with Type 2 diabetes who require insulin therapy face higher risks of cancer recurrence. Additionally, metformin, a common diabetes medication, not only improves insulin sensitivity but also inhibits the MTOR pathway, which may offer additional anti-cancer benefits and counteract the negative impact of patient who may need insulin for treatment of their diabetes..

Many cancers are heavily glucose-dependent due to mitochondrial damage. Cancer cells often have more insulin receptors than healthy cells, making them adept at pulling in glucose for fuel. This increased glucose uptake can also shield cancer cells from apoptosis. While reducing sugar intake alone won’t cure cancer, a diet high in refined sugars and simple carbs feeds both cancer and elevated insulin levels. Conversely, an anti-cancer diet low in simple carbs and rich in healthy fats and moderate protein can be a vital part of your treatment plan.

Insulin is not just a hormone; it’s a growth hormone with profound effects on cellular development and survival. Elevated insulin levels drive cell division, amplify growth factor signals, and make cells more sensitive to other growth-promoting agents. IGF-1, in particular, has been linked to a heightened risk of many cancers such as breast, liver, pancreatic, colon and rectal, gynecologic, breast, bladder cancer, and aggressive prostate cancer, to name a few.

2. Chronic Inflammation as a Cancer Driver

Fat cells, especially in the abdominal region, release inflammatory molecules like IL-6 and TNF-α, which fuel cancer development. Chronic inflammation creates an environment where cancer cells can thrive while weakening immune defenses. This is why people with insulin resistance often face higher risks of breast, liver, pancreatic, and colorectal cancers.

The Diabetes-Cancer Connection

Diabetes and cancer often go hand-in-hand. Studies show that nearly 80% of individuals with pancreatic cancer also have diabetes, highlighting the deep connection between these two conditions.

What’s more, research indicates that higher doses of insulin therapy can increase both cancer mortality and the risk of new cancers forming over time.

However, medications like metformin, which improve insulin sensitivity, have shown protective effects by reducing the risk of several cancers, including colorectal and liver cancers. This underscores how metabolic health plays a critical role in cancer prevention and treatment outcomes.

Insulin and oxidation stress — **Figure 2. This figure shows how insulin resistance can lead to inflammation and oxidation stress.**

How to Reverse Insulin Resistance and Improve Health

Reversing insulin resistance is possible and extremely important. Diet and exercise are the best ways to reverse insulin resistance. Along with diet exercise, a variety of herbs and nutrients can help curb or reverse insulin resistance. Some of those are listed below. Remember, this information is for educational purposes only, and you should always talk with your provider before embarking on any therapy, including diet, exercise, or supplements.

Eat to Balance Blood Sugar

Instead of cutting out carbs completely, try choosing low-glycemic root vegetables. Avoid refined sugars and processed carbs like white bread and pastries, which spike blood sugar. Be sure to check with your care team regarding carb consumption!

Adding protein or healthy fats to meals helps stabilize blood sugar levels. Increasing fiber intake can improve glucose metabolism, slowing the absorption of sugar and preventing spikes. Soluble fiber in foods like flaxseed also feeds beneficial gut bacteria, which play a role in insulin sensitivity.

Vitamin D deficiency is linked to poorer insulin sensitivity and increased inflammation—it’s a modern-day pandemic. Ensuring adequate levels can help improve metabolic health.

Try this tip: Food order matters! To reduce blood sugar spikes, eat proteins and fats first in your meal, followed by vegetables.

**Figure 3 below further elucidates the cancering impact driven by insulin resistance**.

Exercise and Movement

Exercise is one of the best tools for improving insulin sensitivity. Aerobic activities like walking, swimming, or cycling help your muscles absorb sugar from the bloodstream. Strength training builds muscle, which burns glucose even when you’re not active.

Even a 10-minute walk after meals helps regulate post-meal blood sugar. And if you sit for long periods, try to stand up and move every 30 minutes to keep your metabolism active.

Manage Stress and Embrace Mind-Body Practices

Chronic stress sends your cortisol levels soaring, worsening insulin resistance. Simple practices like deep breathing, meditation, and positive visualization can lower cortisol, improving blood sugar control and reducing hemoglobin A1C. Even short sessions of yoga, Qi-gong, or relaxation exercises can make a noticeable difference over time.

For best results, try incorporating one of these mind-body practices into your routine daily or a few times a week. Not only can they improve insulin resistance, but they also foster a sense of relaxation and emotional well-being that supports overall health.

Get Quality Sleep

Lack of sleep disrupts glucose metabolism and worsens insulin resistance. Aim for 7-9 hours of quality sleep each night to help regulate hunger hormones and blood sugar. Improving sleep quality can be as simple as setting a consistent bedtime, reducing screen time before bed, and creating a calming bedtime routine.

Helpful Supplements

In addition to diet and exercise, intermittent fasting, and several nutrients, herbs, and supplements can enhance insulin sensitivity and reduce inflammation:

B Vitamins (B1, B3, B6, B9, B12): These vitamins regulate blood sugar and prevent homocysteine buildup, which worsens insulin resistance.

Vitamin D: It plays a role in regulating insulin sensitivity, especially after meals. Replacing low levels is crucial for reducing inflammation and improving insulin response.

Chromium: Found in foods like apples and spinach, chromium improves insulin signaling and reduces sugar cravings.

CoQ10: This antioxidant lowers insulin levels and boosts energy production at the cellular level.

Omega-3 Fatty Acids & CLA: Found in fish and flaxseed, these healthy fats reduce inflammation and improve glucose control.

Green Tea: Rich in polyphenols, green tea improves insulin sensitivity and reduces inflammation.

Flax Lignans: Present in flax seeds and oil, they reduce IGF levels and inhibit tumor growth signals

Gymnema: This herb supports pancreatic insulin production.

Magnesium: Essential for insulin receptor sensitivity—low levels can worsen insulin resistance. It’s a known global deficiency—most people don’t get enough.

Cinnamon: A powerful spice that enhances insulin receptor sensitivity and helps prevent glucose spikes.

Alpha-Lipoic Acid (ALA): A potent antioxidant that enhances glucose uptake in cells and reduces oxidative stress linked to insulin resistance.

Zinc: Plays a role in insulin production and receptor function, improving glucose control.

Probiotics: Improve gut health and insulin sensitivity.

Curcumin and Resveratrol: Reduce inflammation and oxidative stress.

Other Herbs: Berberine, ginger, and ginseng have also been shown to improve insulin sensitivity.

Myo-inositol, also known as Inositol, may also be considered to reduce insulin resistance.

Incorporating these nutrients into your diet or as part of a supplement plan under the guidance of your healthcare provider can make a meaningful difference in managing insulin resistance.

If you’re currently undergoing cancer treatment, managing insulin resistance becomes even more important. Some treatments, like chemotherapy and steroids, can raise blood sugar levels, making recovery more complicated. Monitoring your glucose levels and discussing insulin management with your care team can make a big difference in your healing journey.

Probiotic supplementation has also shown promise in improving insulin sensitivity and glycemic control. Studies suggest that certain probiotics can positively impact blood sugar levels, making them a helpful addition for managing Type 2 diabetes and insulin resistance. This could serve as an effective complementary therapy, especially for patients with T2DM.

At CIOFM, we focus on targeted nutrition, lifestyle interventions, and supplements to restore metabolic balance and support healing. Personalized anti-cancer diets and carefully selected exercise plans are part of our holistic approach to reducing insulin resistance and lowering the risk of cancer recurrence.

One of the reasons that we assess all patients' single nucleotide polymorphisms is because these subtle genetic changes can also affect insulin resistance. This helps us guide them with specific recommendations based on their Nutrigenomics findings, offering truly personalized recommendations.

Small Steps, Big Impact

The connection between insulin resistance and cancer shows us how deeply our metabolic health influences long-term outcomes. While insulin resistance can feel overwhelming, it’s reassuring to know that simple lifestyle changes—like eating well, moving regularly, and managing weight—can have a profound impact on your health.

If you’re concerned about insulin resistance or managing both cancer and diabetes, take the first step today by consulting with your healthcare team. Together, you can create a plan that supports your body’s healing journey and sets you on the path toward better health.

Remember, every small change counts, and your health is worth the effort.

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This article is for educational purposes only and is not intended to diagnose, treat, or mitigate disease. It may include non-FDA-approved treatments or alternate indications. Please consult your healthcare professional for formal recommendations in your particular case. Always consult with your doctor before starting any supplements.

References:

Hamed-Hamed, D., González-Muñoz, A., & Pruimboom, L. (2023). Physical Activity, Insulin Resistance and Cancer: A Systematic Review. Cancers, 16(3), 656.

Langlais, C. S., Graff, R. E., Van Blarigan, E. L., et al. (2022). Post diagnostic Inflammatory, Hyperinsulinemic, and Insulin-Resistant Diets and Lifestyles and the Risk of Prostate Cancer Progression and Mortality. Cancer Epidemiology, Biomarkers & Prevention, 31(9), 1760–1768.

MD Anderson Cancer Center. (2021). Sugar, Insulin Resistance, and Cancer: What’s the Link?

MD Anderson Cancer Center. Diabetes and Cancer: What You Should Know. (2017).

Ndeke, J. M., Li, X., & Zhang, H. (2023). Molecular mechanisms and potential therapeutic strategies for combating insulin resistance in cancer. Frontiers in Endocrinology, 14, Article 10324246. https://doi.org/10.3389/fendo.2023.10324246

Szablewski, L. (2024). Insulin Resistance: The Increased Risk of Cancers. Current Oncology, 31(2), 998–1027.

How Insulin Resistance Impacts the Cancering Process