Healthier diets linked to longer survival in cancer survivors

Key takeaways:

• Sticking to a healthy diet may reduce the risk of major cardiovascular events in cancer survivors.
• Greater adherence was associated with as much as three additional years of life expectancy compared with lower adherence.

Eating well may help cancer survivors live longer and may also lower the risk of ischemic heart disease, heart failure or stroke, according to data published in JACC: Advances.

Researchers said that following or continuing a high-quality, heart-healthy eating pattern after a cancer diagnosis — including the Mediterranean diet, the Dietary Approaches to Stop Hypertension (DASH) diet or the Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diet — may offer cardiovascular protection and improve overall survival.

The study did not find the same reduced cardiovascular risk for a healthy low-carbohydrate diet when high intake was compared with low intake.

“Population-level evidence demonstrated a significantly elevated CVD risk among cancer survivors, including individuals unexposed to chemotherapy or radiotherapy. Furthermore, cardiovascular mortality is the predominant noncancer cause of death among long-term cancer survivors, rivaling or even surpassing cancer-specific mortality in some cases. Given the adverse impact of CVD on patients’ survival and quality of life among cancer survivors, identifying prognostic factors is an urgent need to pinpoint high-risk subgroups and guide targeted clinical management within cardio-oncology care,” Qing-Yuan Gao, PhD, of the department of cardiology at Sun Yat-sen Memorial Hospital, Sun Yat-sen University in Guangzhou, China, and colleagues wrote. “Using data from the UK Biobank cohort, we aimed to systematically investigate the associations between adherence to eight common healthy diet patterns and CVD among cancer survivors and to examine which dietary pattern was more predictive of CVD and life expectancy. We further investigated whether adiposity indices, inflammation index, glucose and lipid metabolism, and biological aging could mediate the association between healthy dietary patterns and CVD in cancer survivors.”

The analysis included 8,716 cancer survivors from the UK Biobank who had no ischemic heart disease, heart failure or stroke at baseline and completed a web-based 24-hour dietary recall questionnaire. The average age was 59.5 years, and 62% were women.

The most common cancer types were breast cancer (31.4%), prostate cancer (9.8%), colorectal cancer (8.26%), lymphatic and hematopoietic tissue cancer (6.68%) and melanoma skin cancer (5.01%).

Based on the questionnaire responses, the investigators measured adherence to eight dietary patterns: the Mediterranean diet, MIND diet, Alternative Healthy Eating Index (AHEI)-2010 diet, DASH diet, healthful plant-based diet index, reversed energy-adjusted dietary inflammation index, healthy low-carbohydrate diet and healthy low-fat diet.

The main outcome was incident cardiovascular disease, defined as a first diagnosis of ischemic heart disease, heart failure or stroke. Median follow-up was 12.3 years.

Adherence scores were calculated from the average dietary intake across all available 24-hour assessments for each participant and grouped into five quintiles, with the lowest quintile representing the least adherence, according to the study methods.

Compared with participants in the lowest quintile of healthy diet adherence, those in the highest quintile had a lower risk for the primary outcome for the Mediterranean diet (HR = 0.72; 95% CI, 0.58-0.88), MIND diet (HR = 0.74; 95%, 0.61-0.89), AHEI-2010 diet (HR = 0.63; 95% CI, 0.52-0.76), DASH diet (HR = 0.65; 95% CI, 0.53-0.79), healthful plant-based diet index (HR = 0.82; 95% CI, 0.68-0.99), reversed energy-adjusted dietary inflammatory index (HR = 0.67; 95% CI, 0.55-0.8) and healthy low-fat diet (HR = 0.8; 95% CI, 0.67-0.96).

The researchers reported no link between adherence to a healthy low-carbohydrate diet and a lower risk for the primary outcome among cancer survivors.

Participants in the highest quintile of adherence to six of the dietary patterns — Mediterranean, MIND, AHEI-2010, DASH, healthful plant-based diet index and healthy low-fat diet — also had a lower risk for all-cause mortality than those in the lowest quintile.

At age 45 years, cancer survivors in the highest quintile of healthy diet adherence were estimated to have a life expectancy gain of 1.66 to 3.32 years compared with those in the lowest quintile.

For specific cardiovascular outcomes, high adherence to the AHEI-2010 diet or the reversed energy-adjusted dietary inflammatory index was linked with lower risk for ischemic heart disease, heart failure and stroke; high adherence to the MIND or DASH diets was associated with lower risk for ischemic heart disease and heart failure; and high adherence to the Mediterranean or healthy low-fat diets was associated with lower risk for ischemic heart disease.

“The food-based analyses reinforce the clinical plausibility of these associations. The cardiovascular benefits associated with increased consumption of vegetables, whole grains, legumes, seafood and dairy products suggest that these foods may contribute to cardiovascular protection in cancer survivorship although the implications of individual food groups should be interpreted cautiously,” the researchers wrote. “These foods may contribute synergistically to cardiovascular protection through multiple pathways: Omega-3 fatty acids from seafood reduce inflammation and improve endothelial function, dietary fiber from vegetables and whole grains modulates lipid profiles and glucose homeostasis, and dairy products provide bioactive peptides with angiotensin-converting enzyme inhibitor properties.”