How to prevent cancer at younger ages

Hi everyone –

The alarming rise of cancer rates in younger populations is occupying a lot of space in my head these days. Today, I talk about why that is, what we can do to prevent it and how to reverse course.

The Wall Street Journal reported last week that in the US, despite an overall decrease in cancer deaths—primarily due to reduced lung cancer rates from lower smoking rates—other cancer types like colorectal, breast, and melanoma are increasingly affecting those under 50. The American Cancer Society notes a particular increase in colorectal cancer in people born after 1950, with 20% of cases now diagnosed under 50, up from 11% in the 1990s.

A report from the British Medical Journal last fall revealed a stark reality: a 79.1% increase in early-onset cancers (diagnosed before age 50) and nearly a 30% rise in related deaths from 1990 to 2019.

My journey into medicine began with my grandmother, who died unnecessarily young from colon cancer. This could have been prevented but she lacked good primary care and didn’t get a screening in time. She also smoked cigarettes and ate the Standard American Diet (also known as the SAD) for many years — two of the top risk factors for cancer. Despite the National Cancer Institute’s assertion that nearly 50% of cancers are preventable, it’s clear that over 20 years after her death, we are heading in the wrong direction.

So, why are more young people getting cancer?

Authorities often claim ignorance, which is a little bit like watching a car crash happen and then throwing up your hands and saying you don’t know how the car got totaled. While certain variables contributing to higher cancer rates in specific groups remain elusive, the overarching risk factors are evident. The car crash keeps happening right in front of us. The American Cancer Society attributes 42% of cancers to factors like diet, toxin exposure (including tobacco), lack of physical activity, and conditions such as diabetes and obesity.

If you look at the trend lines, the percentage of people who are diabetic, have metabolic syndrome (i.e. pre-diabetes) and are sedentary have gone up dramatically for the last 50 years. From my perspective and from what we see at Parsley, this is all preventable, or “adjustable”. The factors increasing cancer rates are everywhere and easy to spot. Most importantly, we can change this trend if we act on the knowledge we already have.

Here are my top 4 preventable cancer risk factors. Nothing is perfect, but I’ll take really good over perfect when it comes to cancer any day if perfect doesn’t exist:

  1. Sugar Consumption, Diabetes, and Metabolic Syndrome: The higher risk of cancer and death from cancer in patients with diabetes and pre-diabetes is well established. Per a paper in Nature from 2020, diabetics have a 10% higher chance of cancer risk across the board and a 14% higher risk of death from cancer.
    In the past 100 years, sugar consumption has more than doubled, with the average person consuming 60lbs of added sugars per year, and much more than that in total sugar. With rising sugar consumption causing insulin resistance, the precursor to diabetes, the incidence of diabetes has increased in parallel. Now, nearly 40% of US adults have prediabetes; that’s almost 100M people!
  2. Ultra Refined Diets (URDs): These are diets lacking fiber, whole plant sources of antioxidants and healthy fats. A 2023 paper in the Lancet showed that for every 10% increase in the consumption of ultraprocessed foods, overall cancer rates and death from cancer increased. Today 73% of our food supply is considered ultraprocessed.
  3. Lack of Exercise: Exercise is associated with lower overall cancer risk, per the American Cancer Society. While the studies make it hard to tease out the impact of exercise alone, controlling for reductions in obesity and blood sugar, the fact remains that too few people avail themselves to regular, vigorous exercise. Per JAMA, the average adult sits around 8 hours per day, starting in their teenage years. Additionally, with the rise in “white collar” work, sedentary jobs have increased 83% since 1950.
  4. Alcohol and Tobacco: Here is where you will find the best established links. Any level of alcohol consumption increases cancer risk, and the data reveals an exponential increase in risk occurring for moderate and high levels of drinking vs those with low alcohol consumption. The same is true of tobacco use: the reduction in tobacco use over the past 50 years is the number one reason lung cancer rates have declined by over 30%.

Other factors that might contribute to cancer, though less understood, include plastics, aspartame, and other food supply toxins; microbiome disruption from antibiotics, medications, and refined foods; and impaired immune systems due to high sugar diets, food allergens, chronic stress, and intestinal permeability. While some factors remain unidentified or unquantified, I strongly advise focusing on controllable elements, specifically numbers 1-4 above.  

Additionally, regular screening is crucial: mammograms at age 40, colonoscopies at 45, PSA tests at 55 (or 40 for men with a family history or who are African American), and pap smears for women starting at age 21. At Parsley, we order and review all these tests for our patients.

For those willing to go the extra mile, consider these options:

  1. Cologuard Non-Invasive Colon Cancer Screening: Given my family history I did this at age 41 and paid out of pocket (the cost was $650) because I was too young to qualify for coverage. I have patients who refuse to do a colonoscopy – even though they are over 45 – and having this as an option that detects 99% of cancers is an amazing backup. That said, I highly recommend colonoscopy.  
  2. Full Body MRI: At $2500+ this is expensive though increasingly available. I’ll discuss the pros and cons in more detail in an upcoming post.  
  3. Galleri Blood-Based Cancer Screening: This is effective for a variety of cancer markers, available through Parsley Health and costs $500+ depending on the array of markers.

I hope you leave this feeling deeply inspired to prevent cancer. What is the first thing you are going to change? Tell me on IG.


What’s New at Parsley: If you’re thinking about resolutions and testing, Parsley can help. Use my code RBMD50BACK on sign up for $50 back after your first medical visit!. Note that this code can’t be combined with other offers.

‘Til next time,