HeraSphere #33: Strengthen Your Cancer Defense System

Hi friends,

In the past two years, I can count at least a dozen cancer scares in my immediate circle. Friends who endured double mastectomies. Mothers with surprising diagnoses. Sisters who caught something early. Those who didn't…

I started asking whether something bigger was happening. Was this just the age we're at — the stage of life where these things start showing up — or are cancer rates actually rising in women like us?

The answer is both. Rates are climbing. But more importantly, the story most of us were told that cancer is genetic fate is incomplete. Your daily choices shape your risk more than most women know.

The TL;DR

• Cancer rates in women under 50 are now 82% higher than in men the same age — and genetics don't explain it. A growing body of research points to something more actionable: cancer is deeply connected to the aging process itself.

• As we hit midlife, the cellular systems that detect and destroy rogue cells start losing their edge. The good news is that the same lifestyle choices that slow aging also starve cancer.

• The screenings have changed: mammograms now start at 40, colonoscopies at 45, and your mammogram is different if you have dense breast tissue.

• What you eat, how you move, how well you sleep, and whether you show up for screenings all directly affect your risk. This issue covers the science, the foods that protect you, the ones that increase risk, and what to ask your doctor.

The Cancer Story We've Been Told Is Incomplete

• Most of us grew up thinking cancer was mostly genetic fate — the BRCA conversation, the family tree you either inherited or didn't. The science tells a more complicated, and more actionable, story.

• Dr. Thomas Seyfried, a cancer researcher at Boston College, has spent decades building the case that cancer originates in mitochondrial dysfunction — damage to the cell's energy-producing machinery — rather than in genetic mutation alone. Cancer cells abandon normal energy production and instead ferment glucose (sugar) and glutamine (an amino acid) for fuel, even when oxygen is available. That's a metabolic signature — a pattern of how the body processes energy — not purely a genetic one.

• Most cancer cells can't use ketone bodies — the fuel your body produces when you fast or eat low-carb — the way healthy cells can. What you eat directly shapes the fuel environment tumors either thrive or starve in.

• Genetics aren't irrelevant — they're just not the whole story. The part they don't cover is where you have real leverage.

Cancer Incidence is Rising

• From 2010 to 2019, incidence rates for 14 cancer types increased among adults under 50 in the U.S. Someone born in 1990 now has quadruple the risk of rectal cancer, and more than double the risk of colon cancer, compared to someone born in 1950.

• The cancers rising fastest in women are breast, colorectal, endometrial, kidney, and pancreatic. Together, they account for more than 80% of the increase in early-onset diagnoses. Lung cancer in women under 65 has now surpassed rates in men.

• Women under 50 have an 82% higher cancer incidence than men the same age, up from 51% in 2002.

• Endometrial cancer deserves more attention: cancer of the uterine lining is the only major cancer with a lower survival rate than it had 40 years ago. This one is moving in the wrong direction due to declining metabolic health. Fat tissue produces aromatase, an enzyme that converts androgens into estrogen. More adipose tissue means more circulating estrogen, which drives endometrial cell proliferation. Among all 20 common tumor types, endometrial cancer has the strongest association with obesity — each 5-unit increase in BMI carries roughly a 50% higher risk.

• Declining fertility rates are also a factor. The percentage of women aged 15–44 who have never been pregnant hit an all-time high of 54% in 2024, up from 42% in 1998. Pregnancy and breastfeeding generate sustained progesterone exposure, which biologically counterbalances estrogen and is protective against both breast and endometrial cancer. Fewer pregnancies across a population means less of that hormonal protection, compounding over decades. This is a systemic risk factor that public health messaging has largely ignored, and women deserve to know it exists.

• Some causes are environmental. Some causes we can influence. Better screening catches more. But diet, obesity, and physical inactivity are named explicitly by the American Cancer Society as drivers. Rising alcohol consumption in younger women is flagged specifically as contributing to the breast cancer increase.

Why Midlife Is the Inflection Point

• Cancer results when your body’s process of making new cells and getting rid of old or damaged ones breaks down. A damaged cell that should be eliminated instead starts multiplying out of control. Your immune system is supposed to catch these rogue cells early. When it misses them, or can't keep up, a tumor forms.

• Dr. David Sinclair, a Harvard longevity researcher, has spent 30 years studying aging at the cellular level. His information theory of aging holds that as we get older, our cells gradually lose their epigenetic identity — the instruction system that tells each cell what type it is and what job it does. Think of it as a conductor losing control of the orchestra. That cellular identity crisis is what aging actually is — and it's the same process that creates the environment cancer needs to take hold.

• The trigger is DNA damage. Every time a chromosome breaks — from smoking, alcohol, ultraprocessed food, radiation, even frequent flying — the cellular repair systems are pulled away from their normal job of maintaining that identity. They fix the break but don't fully return to where they started. Repeated thousands of times over decades, that cumulative drift becomes aging. And aging is cancer's best friend.

• Your immune system is finding and clearing cancer cells right now. Young immune systems do it efficiently. As we age, that surveillance degrades — cells that would have been caught and destroyed start slipping through. Midlife is when the balance begins to tip.

• Chronically high blood sugar and insulin don't cause cancer, but they keep feeding the environment where it grows. Cancer cells running on that backup system can't use ketones — the fuel your body makes when blood sugar is low. What they can use is glucose.

• So what raises blood sugar and insulin chronically? Ultra-processed food. Refined sugar. A body that barely moves. Every time you spike your blood sugar — with a bag of chips, a sweetened coffee drink, a diet built around packaged food — you're flooding your system with the exact fuel that cancer cells prefer. You're not causing cancer with a single meal. But a pattern of high blood sugar, sustained over years, keeps the metabolic door open. That's the connection researchers are paying attention to.

Foods that Protect: How to Play Offense

• Dr. William Li, author of NYT Bestseller Eat to Beat Disease, frames food as biological instruction. Every meal either supports or undermines the body's five innate defense systems: angiogenesis (the growth of new blood vessels), immune function, the microbiome, DNA repair, and cellular regeneration. All five are relevant to cancer.

• Tumors need blood vessels to grow — they can't expand without recruiting a new blood supply. Berries, green tea, dark chocolate, tomatoes, and cruciferous vegetables activate the body's angiogenesis defense, cutting off that supply before a tumor can scale.

• Polyphenols — the compounds that give plants their deep colors — activate the epigenetic repair systems at the center of Dr. Sinclair's work. Eating the rainbow is a reasonable proxy for polyphenol density. Stressed plants — grown with less water, more sun, or shaded before harvest like Japanese matcha — produce more of these compounds as a survival mechanism. The stress that makes the plant more resilient makes the food more protective for you.

• A diverse gut microbiome — the ecosystem of bacteria living in your digestive tract — regulates immune function, reduces systemic inflammation, and influences how the body processes potential carcinogens. Fermented foods like yogurt, kimchi, kefir, and miso feed microbial diversity in ways that processed food actively undermines.

• Research found that 95% of cancer patients weren't getting the recommended daily servings of vegetables and fruit. Dr. Dawn Mussallem, a double board-certified physician at the Mayo Clinic and a stage 4 cancer survivor herself found that people eating five or more daily servings had a 10% lower risk of dying from cancer, compared to those eating two or fewer. Food as medicine has a measurable effect.

• I've started adding beans and fermented foods to meals, and ordering Asian vegetables like bok choy and napa cabbage through Instacart from H Mart. The variety makes it easier to hit the 5 servings a day.

Foods to Cut: Eliminate Carcinogens as Defense

• Alcohol and processed meat are classified as Group 1 carcinogens by the World Health Organization's cancer research arm — the same category as tobacco. Most people don't know that.

• There is no established safe lower limit for alcohol and cancer risk. Even one drink a day is associated with increased breast cancer risk. Alcohol breaks DNA directly and elevates estrogen levels — which matters specifically for hormone-receptor-positive breast cancers, the type fueled by estrogen. The one-glass-of-red-wine-is-good-for-your-heart message has been substantially walked back by the research community. The polyphenols in red wine are real. The alcohol works against them.

• Processed meat — deli meat, bacon, sausage, hot dogs — earns its Group 1 classification through nitrates and heme iron, both of which generate compounds in the gut that damage DNA. Red meat sits in Group 2A: probably carcinogenic, with the strongest evidence for colorectal cancer. The risk builds through consistent, habitual consumption over years.

• Ultraprocessed foods create chronic glucose elevation, systemic inflammation, and mitochondrial stress — exactly the metabolic environment cancer cells are optimized to exploit. DNA damage and inflammation feed the same epigenetic disruption Sinclair describes. The carcinogens and the aging mechanism are the same pipeline.

Move Like Your Life Depends on It

• Dr. Mussallem prescribes exercise for cancer patients as a non-negotiable protocol, and most oncologists don't communicate that clearly enough.

• Muscle mass is metabolically active in ways that directly keep cancer cells in check. It regulates insulin sensitivity, systemic inflammation, and immune function. Let it decline and you're degrading the same systems that protect you against cancer.

• Declining estrogen accelerates muscle loss in perimenopause and menopause — sarcopenia (age-related muscle loss) happens faster in midlife women than most people realize. Strength training addresses that directly. It's a cancer-prevention strategy and a fitness goal.

• Aerobic exercise matters too — specifically the kind that makes you lose your breath. The evidence points to at least five minutes of genuinely hard effort, three times a week, as the threshold where significant health benefits accumulate. A walk is good. A walk that occasionally becomes a jog you can't easily talk through is better.

Sleep Is Cancer Surveillance

• During deep sleep, your immune system runs active surveillance — hunting down abnormal cells before they can establish and multiply. It's one of your body's most important quality control systems, and it only runs properly when you're asleep.

• Natural killer cells are immune cells whose job is to identify and destroy damaged or abnormal cells before they become tumors. Research has shown that even a single night of poor sleep can significantly reduce natural killer cell activity. A chronic pattern of poor sleep leaves that surveillance system consistently understaffed.

• Dr. Dawn Mussallem, calls sleep the most overlooked medicine in oncology. That's a high bar given everything else on this list. The WHO has also classified nighttime shift work — which chronically disrupts sleep — as a probable carcinogen, specifically because of what sleep disruption does to immune function.

The Screenings You Actually Need

• Breast cancer: guidelines shifted in 2024. Women 40–44 now have the option to start annual mammograms; women 45–54 should get them yearly; women 55 and older can shift to every two years or continue annually. Since September 2024, the FDA requires all mammogram reports to disclose breast density. Dense breasts increase cancer risk and reduce mammogram sensitivity. If your report says dense, ask your doctor whether you need supplemental ultrasound or MRI.

• Colorectal cancer: screening now starts at 45 for average-risk adults, down from 50. Colonoscopy remains the gold standard. Fecal DNA tests like Cologuard are a viable starting option — a positive result requires a colonoscopy follow-up. Colorectal cancer is now the leading cause of cancer death in men under 50 and second in women that age. Don't defer this one.

• Cervical cancer: the preferred method is now an HPV test alone, every five years, starting at age 25. A meaningful update from the Pap-every-three-years model many women still follow. Ask for the HPV test specifically if you haven't had one recently.

• If you have family history: a first-degree relative diagnosed under 50, or three or more relatives with breast cancer history, warrants a conversation with a genetic counselor. Earlier or more frequent screening, or breast MRI in addition to mammography, may apply. Ask for this conversation. It won't happen unless you do.

This issue made me more motivated than ever to exercise and get to bed at a consistent time. I've been rethinking what's in my fridge too: more fermented foods, more vegetable variety, less alcohol and processed meat as defaults.

I was reassured that cancer risk isn't random fate. The same lifestyle shifts that protect our hearts, our brains, and our hormones also protect us against cancer. We already know what they are. Here is one more reason to actually do them.

With love and data,
Lilly

P.S. If someone in your life needed to read this — a sister, a close friend, anyone who's been putting off a screening — forward it to her. It could make a real difference.

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Note: While I love diving deep into research and sharing what I've learned about women's health and wellness, I want to be crystal clear: I'm a passionate health advocate and researcher, not a medical professional. Think of me as your well-informed friend who does extensive homework – but not your doctor.

Everything I share in HeraSphere comes from careful research and personal experience, but it's meant to inform and inspire, not to diagnose or treat any medical conditions. Your body is uniquely yours, and what works for one person might not work for another. Always consult your healthcare provider before making significant changes to your diet, exercise routine, or wellness practices, especially if you have underlying health conditions or take medications.

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