What if up to 90% of all cancer cases—millions each year—never had to happen?
No chemo. No surgeries. No sleepless nights waiting for test results.
It’s not a fantasy. It’s not wishful thinking. It’s what science has quietly confirmed:
“Only 5–10% of all cancer cases can be attributed to genetic defects, whereas the remaining 90–95% have their roots in the environment and lifestyle.”
– PMCID: PMC2515569
In other words?
Prevention isn’t passive; it’s proactive.
And it starts in your home, at your table, in your daily rhythm—often with simple choices that feel too small to matter, until they matter most.
This guide is your no-nonsense, science-backed invitation to take control of what you can. Not through fear, guilt, or gimmicks, but through real habits that heal, nourish, and empower.
Whether you’re focused on protecting your health, lowering your family’s risk, or supporting someone in recovery, this is your starting line. Let’s walk it together.
Step 1: Fill Your Plate with Plants 🌱
Eat mostly plant-based foods.
One of the most powerful habits you can adopt is loading up on vegetables, berries, mushrooms, onions, whole grains, beans, and nuts. These plant foods flood your body with fiber, vitamins, minerals and phytochemicals (natural plant compounds that help protect cells from damage).
Research shows diets rich in plant foods are linked to lower risks of many cancers, like colorectal and breast cancer (American Cancer Society, 2020). In fact, not eating enough fruits and veggies is considered a cancer risk factor. Plants also help with weight control, as they tend to be high in nutrients but low in calories, keeping you full on fewer calories.
An easy rule of thumb is to make at least 2/3 of your plate vegetables, berries, whole grains or beans (American Institute for Cancer Research, n.d.). The remaining 1/3 or less can be lean protein like tofu or tempeh.
By following this New American Plate model, you’ll naturally increase fiber (which helps digestion and feeds healthy gut bacteria) and reduce the proportion of high-calorie foods on your plate.
✨ Pro Tip: Sneak more veggies into daily meals. Add shredded carrots or zucchini to pasta sauce, blend spinach into a smoothie, or blend up extra veggies and berries in a smoothie. Small changes add up to a more plant-powered diet.
Define Ultra-processed foods:
When we say to focus on plants and whole foods, it’s also important to limit “ultra-processed” foods. These are packaged products like chips, cookies, sugary cereals, fast food, and processed meats that are manufactured with additives, high sugar, sodium, and unhealthy fats.
They’re convenient, but offer little nutrition. Ultra-processed foods often make it easy to consume excess calories without feeling full, contributing to weight gain and health issues. Replacing ultra-processed snacks with whole foods (like an apple and almond butter instead of a candy bar) is a smart move for cancer prevention.
✨ Pro Tip: Don’t assume going plant-based means you’re automatically eating healthy. Vegan cookies and fries are still junk food if they’re ultra-processed. Also, be mindful of portion sizes of healthy foods – avocado, olive oil, nuts are good for you, but calorie-dense, so use moderate amounts. The goal is a balanced, predominantly WHOLE FOOD/REAL FOOD plant-focused diet, not perfection.
Step 2: Move More, Sit Less
Exercise has direct benefits related to cancer prevention. Higher activity levels are linked to lower risk of several cancers. For example, active women have about a 12–21% lower risk of breast cancer compared to inactive women, and the most active individuals have about a 19% lower risk of colon cancer than the least active (National Cancer Institute, 2021
Make physical activity a daily habit.
Moving your body every day is a potent cancer-fighting strategy. Regular exercise helps regulate hormones, reduce inflammation, improve immune function, and prevent obesity, all factors that influence cancer risk. You don’t have to be an athlete; any amount of exercise is better than none.
Start by reducing long stretches of sitting. If you have a desk job or screen-heavy lifestyle, take short movement breaks: stand up, stretch, walk around the room at least once an hour. Little bursts of activity throughout the day help counteract the harms of sitting too much (National Cancer Institute, 2021).
The general guideline for substantial health benefits is 150–300 minutes of moderate exercise per week (or 30–60 minutes on most days) or 75–150 minutes of vigorous exercise weekly (U.S. Department of Health and Human Services, 2018).
Moderate activities include brisk walking, biking, or dancing – anything that gets your heart beating faster but still lets you talk. Vigorous activities (running, aerobic classes, etc.) make you breathe hard.
Additionally, include strength training (like lifting weights, yoga, bodyweight exercises) twice a week to keep your muscles and bones strong (HHS, 2018). But remember: any movement counts.
✨ Pro Tip: Make exercise fun and social. If you dread the treadmill, don’t force it. Instead, find activities you enjoy: a dance class, hiking with friends, swimming, or joining a local sports league or walking group. When exercise feels like play, you’ll look forward to it.
Some people find that using a fitness tracker or step counter motivates them – it can be rewarding to see your steps add up. Try setting a step goal (e.g. 8,000 steps a day to start) and gradually increase it. Remember, consistency matters more than intensity.
Myth Killer: “I’m too old (or too out-of-shape) to exercise.” Nope! It’s never too late or too early to benefit from movement. Older adults gain huge benefits in balance, bone health, and mood from regular activity…just choose safe activities for your level.
If you have physical limitations, there are adapted exercises (like chair yoga or water aerobics) that can work for you. Always check with your doctor if you have health concerns. The bottom line: do what you can, and celebrate every step. Your body will thank you!
Step 3: Slash Added Sugar (Not Fruit!)
Cut back on added sugars in your diet.
This single change can make a big difference for your weight, overall health, and indirectly, your cancer risk.
Too much added sugar, the kind found in sugary drinks, desserts, candy, and many processed foods, contributes to weight gain and obesity, which is linked to higher risk of at least 13 types of cancer (such as postmenopausal breast, colorectal, uterine, and kidney cancers) (National Cancer Institute, 2017).
High-sugar diets can also spike blood sugar and insulin levels chronically, which some studies suggest may promote an environment where cancer cells can grow more easily (Mayo Clinic, 2024).
The American Heart Association recommends no more than 6 teaspoons (25 grams) of added sugar per day for women and 9 teaspoons (36 grams) for men (in my professional opinion and nearly 2 decades of research, this is still WAY TOO HIGH!).
Sadly, the average American adult consumes 17 teaspoons of added sugar a day, far above recommended limits (Harvard School of Public Health, 2020; CDC, 2024). Cutting back will help control your waistline and reduce risk of conditions like type 2 diabetes and heart disease as well.
Know your sugars:
Added sugars are any sugars or syrups added to foods or drinks during processing or preparation. Obvious sources are sodas, sweet tea, energy drinks, candies, cakes, cookies, and ice cream.
But sugar hides in many packaged foods under names like high-fructose corn syrup, dextrose, maltose, etc. Ketchup, salad dressings, flavored yogurts, and cereal can be sneaky sugar sources.
Don’t fear fruit!
Eliminating sugary junk food is great, but sometimes people go overboard and avoid healthy berries andfruits because they contain sugar. In reality, whole fruits are consistently linked with positive health outcomes and are an important part of a cancer-protective diet (American Cancer Society, 2020).
Unlike a candy bar, fruit’s sugar is absorbed more slowly (thanks to fiber) and fruit provides vitamins, potassium, and phytochemicals that may help reduce cancer risk. For example, diets high in fruits have been associated with lower risk of digestive cancers (World Cancer Research Fund, 2018).
So enjoy whole fruits daily – they satisfy sweet cravings in a nutritious way. What about fruit juice? Limit it, as it packs the sugar of fruit without the fiber. It’s better to eat the whole fruit and drink water.
✨ Pro Tip: Become a sugar detective. Start reading Nutrition Facts labels and ingredients. You’ll become aware of how much sugar is in your favorite foods.
Ingredients are listed in order by weight…if some form of sugar is in the top three ingredients, that’s a red flag that the product is high in added sugar.
Try swapping out sugary staples for lower-sugar options: for instance, trade sugary breakfast cereal for oatmeal with berries; choose water or unsweetened tea instead of soda (or try naturally flavored water by adding cucumber or lemon slices).
If you take sugar in coffee or tea, gradually reduce the amount to retrain your taste buds. And beware of “fat-free” or “healthy” marketed foods that compensate by being loaded with sugar. For example, some fat-free yogurts have more sugar than ice cream!
Myth Killer: “Sugar feeds cancer – if you have cancer, you must cut out all sugar.” This is a common myth that oversimplifies a complex issue.
Cancer cells do consume more glucose (a type of sugar) than normal cells, but giving more sugar to cancer cells doesn’t make them grow faster, and cutting out all sugar won’t always starve them. But limiting sugar is essential and swapping all processed sugars for healthy sugar in it’s real food form in berries, vegetables, beans and grains is the best approach for health. (Mayo Clinic, 2024).
All our healthy cells need glucose too – your brain runs on it! Completely eliminating carbs/sugars can lead to fatigue and poor nutrition. The truth is, a high-sugar diet is unhealthy largely because it can lead to obesity and insulin resistance, which are risk factors for cancer (Mayo Clinic, 2024).
Focus on limiting added sugars (for general health and weight control), but you don’t need to avoid natural sugars in whole foods. Balance and moderation are key.
Step 4: Prioritize Sleep
Make sleep a non-negotiable part of your health routine. In our go-go-go culture, sleep is often sacrificed, but getting enough quality sleep is essential for maintaining a strong immune system and healthy hormone balance.
Chronic lack of sleep can disrupt the body’s natural cell-repair processes and lead to higher levels of stress hormones and inflammation – a setting you don’t want when it comes to cancer prevention (Colditz & Empana, 2022).
In fact, sleep deprivation is associated with various health problems (obesity, diabetes, heart disease) that indirectly raise cancer risk (Centers for Disease Control and Prevention, 2016). Aim for the recommended 7–9 hours of sleep per night for adults (CDC, 2016) (teens and kids need even more). Prioritizing sleep is not lazy – it’s smart self-care for your cells!
Unfortunately, many Americans are chronically short on sleep…about 1 in 3 adults doesn’t get at least 7 hours regularly (CDC, 2016). Are you one of them? If so, consider this your gentle nudge to reorganize your routine in favor of sleep.
Consistently good sleep helps your body perform “maintenance”: repairing DNA damage, clearing out toxins in the brain, and enabling the immune system’s natural killer cells to hunt down abnormal cells.
Keep a healthy sleep schedule. Try to go to bed and wake up around the same time each day, even on weekends. A consistent schedule keeps your body’s circadian rhythm (internal clock) in sync.
Disrupting your circadian rhythm – for example, by frequently pulling all-nighters or doing shift work with overnight hours – has been linked to increased cancer risk (Johns Hopkins Medicine, 2023).
The World Health Organization has even classified night shift work as a “probable carcinogen” because of the stress it puts on the body’s hormonal rhythms. If you do work night shifts, be extra diligent about other healthy habits and talk to your doctor about ways to mitigate risk (like ensuring you sleep in a dark, quiet environment during the day to mimic night).
✨ Pro Tip: Trouble sleeping? Set yourself up for better sleep with a few simple changes: use blackout curtains, switch to blue light–blocking bulbs, stop eating 2–3 hours before bed, and turn off electronics at least an hour before sleep. Instead of scrolling, try reading or a short guided meditation to calm your mind and ease into rest.
Step 5. Relax Your Nervous System
Try relaxation techniques. Deep breathing exercises, progressive muscle relaxation, or mindfulness meditation can help quiet a racing mind.
Interestingly, regular meditation and breath-focused practices do far more than calm the mind. They prime your immune system. Meta-analyses show that mindfulness programs boost natural-killer-cell activity, improve antibody response, and down-regulate pro-inflammatory genes (Black & Slavich, 2022). That means your body is better prepared to detect and destroy abnormal cells before they become disease.
A calmer nervous system also translates to deeper, more restorative sleep. Studies in both healthy adults and cancer survivors reveal that even eight weeks of mindful breathing or body-scan practice can increase total sleep time and reduce nighttime awakenings (Irwin & Olmstead, 2018). Better sleep, in turn, supports hormonal balance and cellular repair—two pillars of cancer prevention.
Meditation is a proven antidote to chronic stress, a state linked to higher levels of inflammation and faster tumor progression (National Cancer Institute, 2020). Breathwork lowers cortisol and sympathetic “fight-or-flight” activity while raising heart-rate variability, a marker of resilience (Brown & Gerbarg, 2017).
Clinical trials in breast, prostate, and colorectal cancer survivors show that mindfulness programs cut fatigue, anxiety, and inflammatory markers, helping patients feel stronger during treatment and beyond (Zhang et al., 2023).
Bottom line: Just a few minutes of focused breathing each day can reinforce your immune defenses, improve sleep quality, melt stress, and create an internal environment far less hospitable to cancer.
Head over to my YouTube channel, Meditation with Nathan, a space I dedicated to heart-centered, science-aligned meditation for wellness and healing.
🎧Or Start With This: 5-Minute Powerful Breathwork
I designed this calming session to quiet mental chatter and bring your body into a deeply relaxed, healing state.
Step 6: Cut the Carcinogens (Tobacco, Alcohol, Processed Meats)
Some of the most impactful cancer prevention steps involve avoiding known carcinogens – substances that cause cancer. You’ve probably heard these before, but they are worth reinforcing because they account for a huge portion of cancer cases and deaths, yet are totally preventable.
The big three lifestyle-related carcinogens to watch are tobacco, alcohol, and processed/red meats.
Quit Tobacco (or never start).
This is by far the most important thing you can do to reduce cancer risk. Tobacco (cigarettes, cigars, chewing tobacco) is responsible for approximately 30% of all U.S. cancer deaths (Centers for Disease Control and Prevention, 2016) – not only lung cancer, but at least 12 different cancers including mouth, throat, esophagus, pancreas, bladder, kidney, cervix, and even certain leukemias.
There are 70+ carcinogenic chemicals in cigarette smoke that damage DNA (CDC, 2016). The message is simple: do not smoke or use tobacco in any form. If you currently smoke, seeking help to quit is one of the best investments in your health you can make.
Within minutes of your last cigarette, your body starts to heal; within a year, your excess risk for heart disease drops by half, and over 10+ years, your cancer risk declines significantly.
Quitting isn’t easy, as nicotine is highly addictive, but millions have done it, including me. Use all the tools at your disposal – nicotine replacement (patches, gum), prescription medications, counseling, support groups, helplines..
Limit Alcohol
You might be surprised to know that alcohol is a bona fide carcinogen. Drinking alcohol raises the risk of at least 7 cancers, including female breast, colorectal, liver, esophageal, mouth, throat, and voice box cancers (American Cancer Society, 2021).
And it doesn’t require heavy drinking – even a few drinks a week can slightly increase breast cancer risk in women, for example.
In total, alcohol use accounts for about 5% of cancer cases and 4% of cancer deaths in the U.S. (American Cancer Society, 2021). How does alcohol cause cancer? It can damage DNA and proteins, generate harmful oxidants, and in the case of alcoholic drinks combined with tobacco (say, smoking and drinking together), it makes it easier for other toxins to enter cells.
If you choose to drink, experts advise a limit of no more than 1 drink per day for women or 2 drinks per day for men (and even at that level, some risk remains). One drink equals 5 oz of wine, or 12 oz beer, or 1.5 oz of liquor. Keep in mind many restaurant pours or cocktails contain multiple “drinks” in one glass.
Remove Processed and Red Meat.
Diets high in processed meats and red meats are linked to certain cancers, particularly colorectal (colon & rectum) cancer. “Processed meats” include things like bacon, ham, sausage, hot dogs, pepperoni, and deli meats – basically, meat that’s been preserved by smoking, curing, salting, or added preservatives.
These processes can create carcinogenic compounds (like nitrosamines). The World Health Organization has classified processed meat as a Group 1 carcinogen, meaning there’s strong evidence it causes cancer in humans.
Eating just 50 grams of processed meat per day (about 2 slices of bacon) is associated with a ~18% increase in colorectal cancer risk (World Health Organization, 2015).
Red meat (beef, pork, lamb) is classified as Group 2A “probably carcinogenic” – the evidence isn’t as ironclad as for processed meat, but high consumption is linked to higher risk of colon, and possibly pancreatic and prostate cancer.
The American Institute for Cancer Research recommends eating no more than 12–18 ounces of cooked red meat per week (that’s roughly 3–4 small servings) and saving processed meats for rare occasions, if at all.
Instead, emphasize proteins like beans, lentils, tempeh, chickpeas, and tofu. For example, swap deli ham in your sandwich for tempeh and chickpea hummus.
Other carcinogens to avoid:
Tobacco, alcohol, and processed meat are big ones, but they’re not the only culprits. People believe the sun causes cancer, but I do not believe that’s true. From all of the research I’ve done, I believe it’s the chemicals on your skin from the lotions, sunscreens, shampoos, soaps, and so forth, once interacting with the UV light from the sun, which causes things like skin cancer.
Just look at the tribes who have lived their lives spending many hours in the sun every day, and almost never getting skin cancer, and even people with dark skin in the West aren’t getting massive amounts of skin cancer? Why? What’s the difference?
The only difference is that today our modern society loads their skin with all kinds of chemicals found in their skincare products, and then exposes them to the UV radiation. In fact, sunshine is essential for Vitamin D, which is one of the most important vitamins for enhancing your immune system to fight cancer.
So how to be in the sun safely? Of course getting sunburned on a regular basis is not ideal, so spending 30 minutes to an hour a day in the sun is a great start, and with time, your skin will grow darker and you can spend even more time in the sun.
Ditch the sunscreen and toxic chemicals in your skincare products! If you feel your skin starting to burn, just put a thin long sleeve shirt and a hat on, and you’re good to go. That’s been my natural sunscreen for years, and it always works.
Common mistakes to avoid:
Don’t switch from cigarettes to other tobacco, thinking it’s safer – chewing tobacco, snuff, cigars, and hookah all carry cancer risks (like oral and throat cancers).
E-cigarettes (“vaping”) are still being studied, but they contain many chemicals; they might be useful as a quitting aid for some adult smokers if it leads to eventually quitting all nicotine, but vaping is not harmless and is not recommended for non-smokers or youth.
Step 7: Get Regular Screenings 🩺
Stay on top of cancer screening tests – they can save your life. Screening means checking for cancer (or precancerous changes) before you have any symptoms. It’s about finding cancer early, when it’s easiest to treat, or even catching abnormal cells so early that they can be removed before they turn into cancer.
Thanks to screening, certain cancers have dramatically decreased. So which screenings should you get? It depends on your age, sex, and risk factors. Here are general guidelines for average-risk adults (those without special risk factors like strong family history). Always discuss with your functional medicine doctor what’s right for you, but broadly:
Colorectal Cancer:
Start regular screening by age 45 (recently lowered from 50 because of rising colon cancer in younger adults). Options include colonoscopy every 10 years, or less invasive tests like FIT/stool tests every year (with colonoscopy if something is positive).
Colonoscopy is the most thorough – the doctor uses a camera to look at your colon and can remove any polyps on the spot. It’s done under sedation, so you won’t feel anything.
If your colonoscopy is completely normal, you’re good for 10 years. If polyps are found, you might need it more often. Stool-based tests check for hidden blood or cancer DNA in your poop – they’re easy to do at home, but abnormal results must be followed by colonoscopy.
Breast Cancer:
Women of average risk should avoid mammograms (breast X-rays) as they are known to cause and and spread cancer. Instead, opt for safer testing like thermography or perfeQTion imaging from my colleague, Dr. Jenn Simmons.
All Forms of Cancer:
There are two highly regarded tests that can give you profound insight to see if you have cancer growing out of control in your body, the first test is called the Cancer Profile Test, and the second test is the Greek Test, or the RGCC test.
You can simply consult any Functional Medicine Doctor from CancerDoctor.com to see if they can order these tests for you today.
There are two highly regarded tests that can give you profound insight to see if you have cancer growing out of control in your body, the first test is called the Cancer Profile Test, and the second test is the Greek Test, or the RGCC test.
You can simply consult any Functional Medicine Doctor from CancerDoctor.com to see if they can order these tests for you today.
Your Cancer Prevention Daily Checklist ✅ (Print this out and stick it on your fridge!)
| # | Habit / Risk Area | Daily Self-Check (ask yourself) | Sun | Mon | Tue | Wed | Thu | Fri | Sat |
| 1 | Fill Your Plate with Plants | Did I include fruits, veggies, or other plant foods at every meal (≈ 5+ servings total)? | |||||||
| 2 | Move More, Sit Less | Did I log ≥ 30 min of activity (can be 3 × 10 min) and stand/stretch each hour? | |||||||
| 3 | Slash Added Sugar | Did I keep added sugars minimal and choose water/unsweetened drinks? | |||||||
| 4 | Prioritize Sleep | Did I get 7–9 h last night and set up for the same tonight (screens off 1 h before bed)? | |||||||
| 5 | Tobacco‐Free | I didn’t smoke or use tobacco today (or I worked my quit plan). | |||||||
| 6 | Smart Alcohol Limit | ≤ 3 drinks this week? | |||||||
| 7 | Processed / Red Meat | Did I avoid processed meats & reduce all meats? | |||||||
| 8 | Small Steps & Consistency | Did I celebrate at least one win in each category? | |||||||
| 9 | Family Involvement | Did we do something healthy together today? |
Print this checklist and use it daily. Even better, involve your family…everyone can tick off what they achieved each day. It turns staying healthy into a team game.
And if you want to go deep into learning how to beat cancer naturally, sign up for the first 3 modules of my Becoming Cancer-Free Masterclass here, for free, for a limited time.
Wishing you health and happiness,
Nathan Crane
References
Cancer is a Preventable Disease that Requires Major Lifestyle Changes PMCID: PMC2515569
American Cancer Society. (2017). More than 4 in 10 cancers and cancer deaths linked to modifiable risk factors. Retrieved from American Cancer Society website
American Cancer Society. (2020). American Cancer Society guideline for diet and physical activity for cancer prevention. CA: A Cancer Journal for Clinicians, 70(4), 245-271. doi:10.3322/caac.21591
American Cancer Society. (2021). Alcohol use and cancer. Retrieved from American Cancer Society website
Centers for Disease Control and Prevention. (2016a). 1 in 3 adults don’t get enough sleep. CDC Newsroom Press Release. Retrieved from CDC.gov
Centers for Disease Control and Prevention. (2016b). Vital Signs: Disparities in Tobacco-Related Cancer Incidence and Mortality – United States, 2004–2013. MMWR, 65(44), 1212–1218
Centers for Disease Control and Prevention. (2017). Only 1 in 10 adults get enough fruits or vegetables. CDC Newsroom Press Release. Retrieved from CDC.gov
Centers for Disease Control and Prevention. (2024). Get the facts: Added sugars. National Center for Chronic Disease Prevention and Health Promotion. Retrieved from CDC.gov
Johns Hopkins Medicine. (2023). Lack of sleep and cancer: Is there a connection? Retrieved from HopkinsMedicine.org
Larsen, H., Hermans, R. C. J., Kayabal, S., Renders, C. M., & Vrijkotte, T. G. M. (2023). Associations between parental and pre-adolescents’ physical activity and diet quality: The role of parental child care involvement and child’s sex. Eating Behaviors, 51, 101741.
Mayo Clinic. (2024). Cancer causes: Popular myths about the causes of cancer. Retrieved from MayoClinic.org
National Cancer Institute. (2020). Stress and cancer (PDQ®) – Health professional version. Retrieved from cancer.gov
National Cancer Institute. (2021). Physical activity and cancer – NCI fact sheet. Retrieved from cancer.gov
World Health Organization / International Agency for Research on Cancer. (2015). Q&A on the carcinogenicity of the consumption of red meat and processed meat. Retrieved from WHO.int
(Additional references for statistics and guidelines: CDC (2018) Physical Activity Guidelines; USPSTF (2021) screening recommendations; American Academy of Family Physicians (2018) on behavior change techniques, etc., were consulted in the preparation of this guide.)
