Roundup: Colorectal Cancer is Leading Cause of Cancer Death in Adults Under 50; and More News

Cancer Deaths Under Age 50 Are Falling — Except for Colorectal Cancer, New Report Finds

Cancer deaths among U.S. adults younger than 50 have dropped sharply over the past three decades, according to a new study from the American Cancer Society (ACS). But one major exception stands out: colorectal cancer is now the leading cause of cancer death in this age group.

The new study, published in the Journal of the American Medical Association (JAMA), analyzed U.S. cancer death data from 1990 through 2023. On Wednesday, actor James Van Der Beek, 48, known for his role in "Dawson’s Creek," died after several months of fighting colorectal cancer, his family announced. In November 2024, he shared his diagnosis publicly, emphasizing the need for awareness and proactive health management.

Overall Progress: Fewer Young People Are Dying From Cancer

Researchers found that overall cancer mortality (death rates) for people under 50 declined by 44 percent, falling from 25.5 deaths per 100,000 people in 1990 to 14.2 in 2023. Mortality rates adjust for population size so trends can be compared over time.

This progress reflects declining death rates for four of the five most common cancers affecting younger people: breast cancer, lung cancer, brain cancer, and leukemia. Leukemia is a cancer of the blood and bone marrow. Lung and breast cancer deaths have dropped largely due to reduced smoking, earlier detection, and improved treatments.

Colorectal Cancer Is Moving in the Wrong Direction

Colorectal cancer—cancer of the colon or rectum—is the only major cancer showing rising death rates in people under 50. Since 2005, colorectal cancer mortality in this age group has increased by about 1.1 percent per year. As a result, it climbed from the fifth leading cause of cancer death in the early 1990s to the leading cause in 2023.

One key reason is late diagnosis. About three in four people under 50 with colorectal cancer are diagnosed with advanced disease, meaning the cancer has already spread beyond the colon or rectum. Advanced cancers are more difficult to treat and are linked to lower survival rates.

Experts say this trend makes it clear that colorectal cancer is no longer just an older adult’s disease.

Why Screening and Symptom Awareness Matter Now

Half of all colorectal cancer cases diagnosed before age 50 occur in adults ages 45 to 49, underscoring the importance of starting screening at age 45. Screening tests—such as colonoscopy or stool-based tests—can detect cancer early, when treatment works best, or prevent it altogether by removing precancerous growths called polyps.

Knowing the warning signs is also critical. Symptoms may include persistent changes in bowel habits, blood in the stool, ongoing abdominal pain, unexplained weight loss, or constant fatigue.

From 1990 through 2023, more than 1.2 million Americans died from cancer before age 50. While the overall decline in cancer deaths is encouraging, experts stress that continued access to screening, prevention programs, and timely care is essential to reverse the growing impact of colorectal cancer in younger adults.

Explore colon cancer screening options.

Mediterranean Diet Linked to Lower Stroke Risk in Women, Long-Term Study Finds

A long-running study of more than 100,000 women suggests that following a Mediterranean-style diet may significantly reduce the risk of stroke—including both major types—over the course of adulthood.

The research comes from the California Teachers Study, which tracked female educators for more than 20 years. Researchers wanted to know whether eating patterns similar to those traditionally found in Mediterranean countries—such as Greece and Italy—were linked not just to fewer strokes overall, but to fewer specific kinds of stroke.

What is the Mediterranean diet?

The Mediterranean diet emphasizes:

• Plenty of vegetables, fruits, whole grains, beans, and legumes
• Healthy fats, especially olive oil
• Regular fish consumption
• Limited red meat and dairy
• Moderate alcohol intake, usually wine with meals

Healthy eating has already been linked to better heart health, longer life, and lower risk of diseases such as Alzheimer’s. But evidence on different types of stroke has been limited—especially in women.

Understanding stroke types

There are two main kinds of stroke:

• Ischemic stroke (about 80–85 percent of strokes): caused by a blocked blood vessel in the brain
• Hemorrhagic stroke: caused by bleeding in the brain

Women have a higher lifetime risk of stroke than men, especially after menopause, making prevention strategies particularly important.

How the study worked

Researchers analyzed data from 105,614 women, with an average starting age of 52. Participants reported their usual diet at the start of the study in the mid-1990s. Each woman received a Mediterranean Diet score from 0 to 9, with higher scores reflecting closer adherence.

Over an average follow-up of 20.5 years, researchers identified strokes using hospital records and death certificates.

Key findings

During the study period, 4,083 strokes occurred:

• 3,358 ischemic strokes
• 725 hemorrhagic strokes

Compared with women who had the lowest Mediterranean Diet scores (0–2), those with the highest scores (6–9) had:

• 18 percent lower risk of any stroke
• 16 percent lower risk of ischemic stroke
• 25 percent lower risk of hemorrhagic stroke

These benefits remained even after accounting for factors like age, smoking, body weight, physical activity, blood pressure, diabetes, cholesterol, and menopause-related hormone use.

Why This Matters

Some experts previously questioned whether a low–saturated fat diet, like the Mediterranean diet, might protect against hemorrhagic stroke. This large study suggests it does—and that the benefits extend to both major stroke types.

Importantly, the findings support diet as a powerful, long-term tool for stroke prevention, especially for women as they age.

Eating a Mediterranean-style diet—rich in plant foods, healthy fats, and fish, and low in red meat—may meaningfully reduce a woman’s risk of stroke over time. While no single food guarantees protection, this study adds strong evidence that everyday dietary choices can have lasting effects on brain and heart health.

How Much of Your Life Span is Due to Genetics? New Study Says: About Half

People often ask whether living a long life is mostly lifestyle, luck or genetics. A new study published in the journal Science comes to this conclusion: after accounting for “outside” causes of death, the genetic contribution to human life span is about 50 percent.

First, A Key Idea: Not All Deaths Reflect “Aging”

The researchers separate mortality (death risk) into two categories:

• Extrinsic mortality: deaths caused by forces outside the body—accidents, infections, environmental hazards, and other events that can kill regardless of your underlying biology.
• Intrinsic mortality: deaths tied more to what’s happening inside the body—aging-related decline, chronic diseases, genetic vulnerabilities, and internal wear-and-tear.

Why does that matter? Because many previous longevity studies used people born in the late 1800s and early 1900s—a time when extrinsic deaths were far more common. If someone dies young from an accident or infection, their death tells you little about the genes that influence aging. That “noise” can hide the genetic signal.

Why Older Studies May Have Underestimated Genetics

Previous estimates often suggested life span is only 6 percent to 25 percent heritable (meaning explained by genetic differences). This study argues those numbers are artificially low because they mix intrinsic and extrinsic deaths together.

To fix that, the authors used:

• Twin studies (identical twins share essentially all genes; fraternal twins share about half on average).
• Mathematical models of mortality to estimate how much early and midlife death risk was driven by extrinsic factors in those historical cohorts.
• A validation dataset from Sweden that included twins raised apart, which helps reduce concerns that twins live similarly only because they share the same household environment.

When they “remove” the effect of extrinsic mortality in the analysis (in other words, focus on the part of life span more connected to aging biology), the estimated heritability rises and levels off around ~50–55 percent.

What Does ‘50% Heritable’ Actually Mean?

This is important: heritability does not mean your life span is 50 percent predetermined. It means that in a given population, in a given environment, about half of the variation in life span is linked to genetic differences. Change the environment (health care, smoking rates, safety, pollution, nutrition), and heritability can change too.

The Biggest Takeaways from the Study

• Genes matter more than many recent headlines suggest, especially when studying aging itself rather than accidents or infections.
• Lifestyle still matters a lot, because roughly half of life span differences are not explained by additive genetics.
• The study strengthens the case for researching “longevity genes” to better understand aging—and eventually prevent or delay age-related disease.