New study: The link between heart health and cancer survival

Most health advice circles back to the same message: protect your heart. From blood pressure and cholesterol to diet and exercise, heart health has become shorthand for overall health — and for good reason, since heart disease remains the world’s top killer.

Now, a new study suggests those habits may matter even more than we thought, helping people live longer — even after a cancer diagnosis.

Why Heart Health Matters After Cancer

In a study published in the journal European Heart Journal, researchers analyzed data from 779 Italian adults already living with a cancer diagnosis at the time of enrollment and followed them for 15 years. The study also assessed their health status using the Life’s Simple Seven (LS7), a cardiovascular health score that captures key lifestyle and clinical factors tied to heart disease risk.

Researchers looked at how closely participants adhered to heart-healthy behaviors and examined how this related to overall mortality risk. They found that people who maintained healthier habits had a 38% lower risk of death than participants with unhealthy lifestyles. Each point improvement in their score was associated with a 10% reduction in cancer-related mortality.

“Our study shows that a score based on traditional cardiovascular risk factors, already validated in the general population, can also predict better survival in people with a history of cancer,” Marialaura Bonaccio, first author of the paper, said.

Interestingly, when the diet component of the LS7 score, which is based on general criteria of healthy eating such as fruit and vegetable intake, whole grains, and limits on sugar and sodium, was replaced with a measure of adherence to the Mediterranean diet, the link between healthy behaviors and survival became stronger, including deaths related to cardiovascular disease.

The Mediterranean diet is more reflective of diets of people in Southern European countries, including Italy. The diet, which includes fruits, vegetables, whole grains, legumes, fish, and extra-virgin olive oil, is consistently linked to better heart health, lower inflammation, and longer life expectancy across decades of research.

What’s Life’s Simple Seven?

LS7 is a health index developed by the American Heart Association (AHA), designed to measure cardiovascular health and predict long-term risk of heart disease and mortality. It includes seven components:

Smoking status
Physical activity
Diet quality
Body weight
Blood pressure
Cholesterol levels
Blood glucose

Why Heart-Healthy Habits Target Both

Maria Benedetta Donati, the study’s principal investigator, said the findings support the idea that diseases as different as heart disease and cancer can share underlying biology and pathways of progression. In fact, the two conditions overlap in many modifiable risk factors, with about half of cancer patients already having cardiovascular risk factors at diagnosis.

“This concept is known as the common soil hypothesis — a shared terrain of molecular mechanisms and risk or protective factors from which different clinical conditions may arise,” Donati explained.

Because of this, a solution that targets one also targets the other. Based on the study’s analysis, the link between heart-healthy lifestyles and better survival could be partly explained by three shared biological factors:

Low-grade chronic inflammation: a key driver for the progression of both diseases. Heart-healthy habits may dampen inflammatory processes that worsen outcomes for both diseases
Heart rate: a marker of overall heart and autonomic health. A healthier heart profile reflects better cardiovascular fitness and stress regulation.
Blood vitamin D levels: vitamin D plays a role in immune regulation, cardiovascular function, and inflammation control, making it a plausible biological bridge between cancer and heart disease.

CVD and Cancer: Bidirectional Relationship

CVD often coexists with insulin resistance, abnormal cholesterol levels, and obesity — metabolic conditions that create a biological environment in which cancer can thrive. Take insulin resistance, for example. When insulin levels stay high, insulin acts as a growth signal that helps cancer cells grow, avoid dying off, and become more resistant to treatment.

Obesity adds another layer by driving chronic inflammation, which supports tumor growth and makes it harder for the immune system to recognize and eliminate cancer cells. In short, these conditions leave cancer cells “well fed” and harder to kill.

Having CVD also limits people’s treatment options. They’re less likely to receive standard-of-care chemotherapy — they’re more likely to have reduced doses, early discontinuation, or treatment delays, and are often excluded from more aggressive regimens. Having CVD also increases the risk of treatment complications and functional decline.

Cancer also worsens CVD outcomes.

People newly diagnosed with cancer face a sharply higher risk of cardiovascular disease, with the greatest danger in the first year after diagnosis — a critical window when heart problems are most likely to surface.

This early spike may reflect the detection of pre-existing heart conditions, while some may be driven by aggressive treatments started soon after diagnosis or by the cancer itself. Cancer treatments can also strain the heart. Many chemotherapies are directly toxic to heart muscle, with risk increasing at higher doses, while some targeted therapies interfere with normal cardiac signaling.

And the risk doesn’t end when treatment does. Even long after diagnosis, cancer survivors face a 37% to 51% higher risk of cardiovascular disease than people without a cancer history. They are also about 52% more likely to develop heart failure and 22% likely to have a stroke.

Take Care of Your Heart

People often adopt healthy habits like regular exercise, maintaining a healthy weight, and avoiding smoking to prevent disease — but many who already have serious conditions feel it’s “too late” or find lifestyle changes harder amid symptoms and treatment.

This study suggests otherwise. Even with pre-existing conditions, even cancer, heart-healthy habits can still make a meaningful difference.

So go ahead: tie those shoelaces, choose foods that support your heart, and think of heart care not just as prevention, but as part of living longer and better.