When you’re managing cancer, the last thing you want is another health condition complicating your journey. Many survivors don’t realize: diabetes and cancer show up together more often than you’d think. But don’t worry, there’s always a way.
The relationship between these two conditions runs deeper than just coincidence. Knowing how they interact gives you real power to protect your health and feel confident about the choices you’re making every single day.
Whether you’re living with both conditions right now or working to prevent them, you deserve clear answers without the fear and confusion.
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This plan is all about the NED Method 5-Pillar Approach which includes improving your nutrition, exercise, hydration, sleep quality and self care. It can help you reduce cancer risk and give you confidence around your health choices.
The Link Between Diabetes and Cancer
Diabetes happens when your body struggles to manage blood sugar properly. With Type 1 diabetes, your pancreas stops making insulin altogether, so you need insulin injections to survive.
Type 2 diabetes is more common and occurs when your cells become resistant to insulin, causing sugar to build up in your blood instead of entering cells for energy.
Over time, high blood sugar damages blood vessels, nerves, and organs throughout your body.
The connection between diabetes and cancer goes both ways, and that’s what makes it so important to understand. Research shows that having Type 2 diabetes increases your risk of developing cancer by about 10% overall, with some cancers showing much stronger links.
But here’s the twist: cancer and cancer treatments can also trigger diabetes, creating what doctors call secondary diabetes.
In my VIP 1:1 Cancer nutrition & Lifestyle Coaching, I work with clients juggling both conditions, and understanding this bidirectional relationship helps us create strategies that support your whole body, not just one condition at a time.
Through personalized guidance, we also focus on reducing the risk of developing diabetes or helping to resolve pre-diabetes, even while managing cancer.
I have had success with clients whose A1c levels have improved significantly. This is especially important as “Pre-Diabetes with Cancer” is a common scenario we address.
Why Does Diabetes Increase Cancer Risk?
The mechanisms linking diabetes and cancer are complex, but understanding them helps you see why managing your blood sugar matters for cancer prevention. Let me break down the main ways diabetes may increase cancer risk:
Hyperinsulinemia and Insulin Resistance
When you have insulin resistance, your pancreas pumps out extra insulin to try to manage blood sugar. This creates hyperinsulinemia, or high insulin levels in your blood.
Insulin acts like a growth factor in your body, and cancer cells have insulin receptors that can respond to these high levels.
Essentially, excess insulin may help cancer cells grow and multiply faster. This happens years before you’re even diagnosed with diabetes, which means the damage might be occurring long before you realize anything is wrong.
Chronic Inflammation
Diabetes creates a state of chronic low-grade inflammation throughout your body. Think of inflammation as your body’s alarm system stuck in the “on” position.
This constant inflammatory state produces chemicals called cytokines that can promote tumor growth, help cancer cells spread, and even interfere with your immune system’s ability to fight abnormal cells.
Hyperglycemia and DNA Damage
High blood sugar doesn’t just make you feel tired and thirsty. Hyperglycemia damages your DNA and disrupts the repair mechanisms your cells use to fix that damage.
When DNA repair pathways like nucleotide excision repair and homologous recombination get disrupted, mutations can accumulate.
Cancer essentially starts with accumulated DNA mutations that allow cells to grow out of control. Keeping your blood sugar stable helps protect the integrity of your DNA.
Obesity as a Shared Risk Factor
Excess body weight significantly increases risk for both Type 2 diabetes and certain cancers. Fat tissue, especially around your abdomen, produces hormones and inflammatory compounds that promote both insulin resistance and cancer development. Weight is linked to at least 13 different types of cancer.
Oxidative Stress
Both high insulin levels and high blood sugar increase production of reactive oxygen species, or free radicals. These unstable molecules damage cells, proteins, and DNA.
Your body has antioxidant systems to neutralize free radicals, but chronic diabetes overwhelms these protective mechanisms. This oxidative stress creates an environment where cancer cells can develop and thrive more easily.
Specific Cancers Linked to Diabetes
Not all cancers show the same connection to diabetes. As your oncology dietitian, I want you to understand which cancers have stronger associations so you can stay vigilant about screening and prevention:
- Liver cancer shows the strongest link with a 2-3 times higher risk in people with diabetes. The combination of insulin resistance, inflammation, and fatty liver disease creates the perfect storm for liver cancer development.
- Pancreatic cancer has about a 2-fold increased risk. This one is tricky because sometimes pancreatic cancer actually causes diabetes as an early symptom, rather than the other way around.
- Endometrial cancer risk increases by about 78% in women with Type 2 diabetes, largely due to the effects of high insulin and estrogen levels.
- Colorectal cancer shows a 20-30% increased risk. The good news is that this is one of the most preventable cancers through diet and lifestyle changes.
- Breast cancer (particularly postmenopausal) has a modest increase of about 5-20% depending on factors like obesity and how well diabetes is controlled.
- Bladder and kidney cancers also show elevated risks, though the mechanisms are still being studied.
Take Control of Your Health Journey
I want to give you something that’s helped thousands of survivors find clarity and confidence. The Clean Scan Plan breaks down the exact steps you need to take to reduce cancer risk and feel empowered about your health, whether you’re managing diabetes or not.
Managing Both Diabetes and Cancer Together
Juggling diabetes and cancer treatment feels overwhelming, but you don’t have to figure it out alone. Here’s what works based on years of helping clients navigate both conditions successfully:
Monitor Blood Sugar Levels Closely
Your blood sugar will likely fluctuate more during cancer treatment. Some chemotherapy drugs raise blood sugar, steroids almost always do, and treatment side effects like nausea can cause dangerous drops.
Check your blood sugar more frequently than usual, especially before and after treatments. Keep detailed logs so your diabetes team can spot patterns and adjust medications proactively rather than reactively.
Nutrition Strategies for Both Conditions
This is where things get really practical. You need to eat enough to maintain strength during cancer treatment, but you also need to manage carbohydrate intake for blood sugar control. As your oncology dietitian, here’s my approach with clients:
- Focus on protein at every meal to maintain muscle mass and help stabilize blood sugar. Aim for palm-sized portions of fish, poultry, eggs, or plant-based proteins.
- Choose fiber-rich carbohydrates like vegetables, berries, and whole grains that provide nutrients without causing blood sugar spikes.
- Include healthy fats from sources like avocados, nuts, seeds, and olive oil to support energy and hormone production without affecting blood sugar.
- Eat smaller, more frequent meals if you’re dealing with nausea or reduced appetite. This helps maintain stable blood sugar and ensures adequate nutrition.
- Stay hydrated because dehydration affects both blood sugar control and recovery from cancer treatments.
One of my survivors shared, “Every meal used to feel like a test, now it feels simple and safe.” That’s exactly what I want for you.
How Cancer Treatment Affects Blood Sugar
Understanding how different treatments impact blood sugar helps you prepare and respond appropriately. Here’s what to expect:
Steroid-Induced Hyperglycemia
Steroids like dexamethasone are commonly used to prevent nausea and reduce inflammation during chemotherapy. They work beautifully for those purposes, but they also increase insulin resistance dramatically. Your blood sugar can double or triple within hours of taking steroids.
The effect typically peaks 4-8 hours after taking the medication and may require temporarily increasing diabetes medications or starting insulin. Most people return to baseline blood sugar levels once steroids are stopped, but some develop permanent diabetes, especially if they had pre-diabetes before treatment.
Chemotherapy and Blood Sugar Changes
Different chemotherapy drugs affect blood sugar in different ways. Some drugs directly increase blood sugar, while treatment side effects like nausea and vomiting can cause dangerous lows if you’re taking diabetes medications but unable to eat.
Appetite changes are common, making it challenging to maintain consistent carbohydrate intake for blood sugar stability.
This is exactly why individualized support through VIP 1:1 Cancer nutrition & Lifestyle Coaching makes such a huge difference because we adjust your nutrition plan in real-time based on how you’re feeling and what your blood sugar is doing.
Reducing Your Risk: Prevention Strategies
Whether you’re working to prevent diabetes, prevent cancer, or prevent recurrence, these evidence-based strategies make a real difference. As your oncology dietitian, I’ve watched these work for countless clients:
Weight Management and Healthy BMI
Maintaining a healthy weight is one of the most powerful tools for reducing risk of both diabetes and cancer. Even losing 7-10% of body weight improves insulin sensitivity, reduces inflammation, and lowers cancer risk markers.
Physical Activity (5-7 Days Per Week)
Regular exercise lowers insulin resistance, helps control weight, reduces inflammation, and directly lowers risk for multiple cancers. Aim for at least 150 minutes of moderate activity weekly, plus strength training twice weekly.
This doesn’t mean you need to become a gym rat. Walking, swimming, dancing, or gardening all count as long as you’re moving consistently. My survivors often tell me they feel stronger and more energetic when they prioritize movement.
Blood Sugar Control
Keeping your blood sugar well-controlled isn’t just about feeling better day-to-day. Good glycemic control reduces the cancer-promoting effects of hyperinsulinemia, hyperglycemia, and inflammation. Aim for an A1C below 7% if possible, though your personal target should be discussed with your diabetes specialist based on your specific situation.
What This Means for Cancer Survivors
If you’re in survivorship, managing diabetes becomes part of your long-term prevention plan. Research shows that cancer survivors with well-controlled diabetes have better outcomes and lower recurrence risk compared to those with poorly controlled diabetes.
This isn’t about adding more stress to your life. It’s about recognizing that the same healthy habits that reduce recurrence risk also support better diabetes management. They work together, not against each other.
Ready to Feel More Confident About Your Scans?
Healing doesn’t stop when treatment ends. The Clean Scan Plan helps you build lasting habits around food, hydration, movement, sleep, and stress that reduce recurrence risk and restore peace of mind.
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References
- https://pmc.ncbi.nlm.nih.gov/articles/PMC8873103/
- https://www.mdanderson.org/publications/focused-on-health/Diabetes-and-cancer.h26Z1591413.html
- https://pmc.ncbi.nlm.nih.gov/articles/PMC2890380/
- https://www.nature.com/articles/s41598-020-73668-y
- https://diatribe.org/understanding-diabetes/reducing-your-risk-cancer-type-2-diabetes
- https://www.cancer.gov/about-cancer/causes-prevention/risk/obesity/obesity-fact-sheet
- https://www.mdanderson.org/cancerwise/diabetes-as-a-side-effect-of-cancer-treatment–8-things-to-know.h00-159464001.html
