The study found that adherence to a Mediterranean diet, rich in fruits, vegetables, whole grains, legumes, fish, and olive oil, is associated with a reduced risk of death among people diagnosed with cancer. The researchers suggest that the same lifestyle habits known to protect the heart may also help improve survival rates after a cancer diagnosis.
The study was based on data from 779 Italian adults with a history of cancer, who participated in a long-term study in southern Italy, and the participants were followed for an average of 14 years.
At the start of the study, researchers assessed participants' health using the Simple Life 7 (LS7) index, developed by the American Heart Association to measure cardiovascular health. This index combines seven modifiable factors: smoking, physical activity, diet, body mass index, blood pressure, total cholesterol, and blood sugar.
The “Simple Living 7” index assesses diet according to general guidelines for healthy eating, such as eating plenty of fruits and vegetables, choosing fiber-rich foods including fish, and limiting salt and sugary drinks, rather than following a specific diet.
During the follow-up period, 269 participants died, including 141 deaths due to cancer, 67 due to heart disease, and 54 due to other causes, including respiratory diseases, neurodegenerative diseases, and cerebrovascular diseases.
When the researchers replaced the overall dietary measure with an index reflecting the extent to which participants adhered to the Mediterranean diet, the benefits became even more apparent, with those who followed diets similar to the Mediterranean diet being 15 to 20% less likely to die, depending on the cause of death.
The Mediterranean diet has previously been linked to a reduced risk of heart disease and premature death in the general population, and this study suggests that its benefits may extend to people recovering from cancer.
More broadly, the researchers found that overall cardiovascular health, as measured by the LS7 index, is strongly associated with cancer survival. Participants with "ideal" cardiovascular health had a 38% lower risk of death from any cause compared to those with "poor" cardiovascular health, after accounting for age, sex, type of cancer, treatment, pre-existing heart conditions, and socioeconomic factors.
The results also showed a direct correlation: every one-point increase in the LS7 score was associated with a 10% decrease in cancer mortality.
The findings support the idea that cancer and cardiovascular disease share common biological pathways. Researchers analyzed blood markers associated with inflammation, heart rate, and vitamin D levels, and found that these factors explain more than half of the link between a healthy lifestyle and reduced mortality.
The researchers emphasize that these results do not prove a causal relationship, as lifestyle and heart health were assessed at the first study visit, about 8.4 years after the cancer diagnosis, which may mean excluding people with more aggressive diseases.
However, the findings emphasize the importance of diet and other healthy habits in the long-term care of cancer survivors, and support the adoption of integrated prevention and follow-up approaches that link cancer care and cardiovascular health within the growing field of cardiac oncology.
