Listen on: Apple Podcasts | Spotify | Amazon Music | Podcast Index | Overcast | YouTube

Cancer is a word none of us want to hear—and yet, about 1 in 3 people in the U.S. will be diagnosed with it during their lifetime. It’s the second leading cause of death, and for many, it’s the most terrifying. But here’s something you may not hear enough: about 40% of cancers are preventable (American Cancer Society).

This isn’t wishful thinking or alternative theory—it’s grounded in real data. According to the National Cancer Institute, nearly five million cancer deaths have been avoided in the U.S. since 1975. Of those, about 80% were thanks to prevention and screening—not treatment.

In this article, I’ll walk you through six practical, science-backed steps that can help you lower your cancer risk. No hype. No supplements to buy. No sponsors whispering in my ear. Just clear, unbiased insights you can trust.

1. Know Which Cancers Are Most Relevant to You

The most common cancers differ by gender. For women, breast, colon, and lung cancers are the top concerns. For men, it’s prostate, colon, and lung. Some, like ovarian and pancreatic cancer, are less common but understandably feared due to their poor prognosis.

While you may hear about skin cancer often, the most common forms are non-melanoma and typically curable with removal. We focus here on the cancers most likely to affect you—and the ones we can meaningfully act upon.

2. Understand Your Risk Factors

Some risk factors are unavoidable. Your age, sex, and family history all play a role. If you’ve had close relatives with breast or colon cancer, for example, it may be worth discussing early screening or genetic testing with your doctor. Still, it’s important to note that only 5–10% of all cancers are strongly linked to inherited genetic mutations (American Cancer Society).

Where you have more agency is in the category of modifiable risk factors—what you can change. And this is where prevention begins to take hold.

3. Reduce the Risk Factors You Can Control

Let’s start with the biggest one: smoking. Despite public awareness, it still accounts for nearly 1 in 5 cancer cases. If you smoke, quitting is the most powerful thing you can do—not just for your lungs but for your overall cancer risk.

Next is excess weight, which contributes to about 8% of cancer cases. And it’s not just obesity that raises risk—even being overweight can increase susceptibility. In particular, visceral fat, the kind that wraps around internal organs, is more predictive of cancer risk than BMI (PubMed, ScienceDirect).

Alcohol, especially in larger amounts, is associated with cancers of the liver, GI tract, and breast. Even moderate intake may carry risk, depending on your overall health picture.

There are also cancer-specific risks worth noting. For example, nearly all cervical cancers are caused by HPV—making the HPV vaccine an incredibly effective form of prevention. The same applies to Hepatitis B, which can increase liver cancer risk. Both vaccines are part of routine pediatric immunization schedules (CDC).

Sun exposure is the primary driver of melanoma, and air pollution has been associated with a small but measurable increase in lung cancer, particularly due to fine particulate matter (ASCO).

4. Prioritize Movement and a Cancer-Preventive Diet

We know exercise helps with heart health and cognitive decline—but it also plays a role in cancer prevention. A large pooled study of over 1.3 million people found that high levels of exercise were linked to a 10–20% lower risk of major cancers like colon, lung, and breast.

Even more compelling? In colon cancer survivors, regular exercise cut the recurrence rate by 30% in a randomized controlled trial (PubMed).

On the nutrition front, a meta-analysis found that people who ate five servings of fruits and vegetables daily had a 35% lower cancer risk compared to those who ate only two. Another study in The Lancet found a 3% drop in colon cancer risk for every additional 15 grams of fiber consumed daily. That’s roughly a cup of lentils or two cups of beans.

5. Get Screened—Early Detection Saves Lives

Early signs of cancer often go unnoticed or get dismissed. If you notice a lump, unusual bleeding, or persistent symptoms—even if they go away—get checked out.

When it comes to screenings, follow the evidence. Colonoscopies are now recommended starting at age 45. Women should receive regular mammograms and PAP smears, while those with a smoking history may benefit from lung CT scans. If you have a strong family history of pancreatic or ovarian cancer, specialized screening like MRI or transvaginal ultrasound may be appropriate.

I get asked about “total-body MRIs” and “liquid biopsies.” While promising in theory, the current evidence doesn’t support their use for general screening. These tests often detect things that aren’t dangerous—or miss what matters most. Until larger studies prove they improve outcomes, I don’t recommend them for most people.

6. Don’t Waste Time (or Money) on Unproven Supplements

Despite the marketing, most supplements don’t prevent cancer. Large randomized trials have found no benefit for omega-3s, beta carotene, vitamin D, vitamin C, or even aspirin when it comes to cancer prevention (VITAL study, Meta-analysis on Vitamin C, JNCI on aspirin).

I wish these shortcuts worked. But the science says otherwise. And as someone with no sponsors, products, or financial incentives, my only goal is to share what’s true—even when it’s not flashy.

Final Thoughts: You Have More Control Than You Think

Cancer is frightening, but it’s not completely out of our control. You can’t eliminate your risk, but you can lower it. By avoiding tobacco, managing your weight, eating more whole foods, getting regular exercise, and staying on top of screenings, you can tip the odds in your favor.

And if cancer does strike—know that you’re not alone. My own wife, Gail, faced a metastatic uterine cancer diagnosis with zero risk factors. Sometimes, despite everything, it still happens. If you’re navigating a diagnosis, I encourage you to listen to my episode on how to cope with serious illness.

Until then, I hope you keep moving forward, one practical step at a time.

Here’s to living long and well.