Better quality diet may lower post-MI mortality risk

Heart attack survivors who eat a better quality diet may decrease their likelihood of dying from any cause and from heart disease, according to a study published in the Oct. 28 issue of JAMA Internal Medicine.

Researchers led by Shanshan Li, MD, MSc, ScD, of the Harvard School of Public Health in Boston, assessed the diets of more than 4,000 men and women who were part of two large cohorts—the Nurses’ Health Study, consisting of more than 121,000 female registered nurses that began in 1976; and the Health Professionals Follow-Up Study, which included 51,529 male health professionals that started in 1986.

The men and women in Li et al’s analysis had no cardiovascular, stroke or cancer history when they enrolled. They also all survived a first MI and had no stroke history when they had their first MI. Participants all completed a food frequency questionnaire (FFQ) before and after their MI.

The American College of Cardiology and the American Heart Association updated their secondary MI prevention guidelines in 2012, the authors wrote, “but continued to use diet recommendations from 2007 that focus on reducing saturated and trans fat intake and do not address unsaturated fats, the quality of carbohydrates, sugar-sweetened beverages, and red and processed meat.” 

The standard low-fat diet, they added, has not lowered cardiovascular risk or improved MI prognosis.

They assessed the quality of diet using FFQs. They measured diet quality using the Alternative Healthy Eating Index 2010 (AHEI2010), a composite score that includes 11 different food components associated with the risk of heart disease, such as vegetables, fruits, nuts, red meats, sugary drinks, alcohol and salt intake. In general, higher AHEI2010 scores are linked to a lower risk of chronic and cardiovascular diseases.

They used all-cause mortality and cardiovascular mortality as outcomes.

During the follow-up period, there were 682 deaths from all causes among women and 451 among men. The average survival time after the first MI was 8.7 years for women and nine years for men.

They found that higher AHEI2010 scores were associated with better outcomes.

“Greater improvement in diet quality from pre- to post-MI was associated with 30 percent lower all-cause mortality and 40 percent lower cardiovascular mortality,” the authors wrote.

Patients who experienced an MI ate less polyunsaturated fat in addition to eating less saturated and trans fats.

Additional studies on dietary factors warrant additional study, the authors argued, and dietary guidelines may also warrant changing. “Dietary recommendations for secondary prevention need to place more emphasis on polyunsaturated fat intake and reduced consumption of sugar-sweetened beverages and fruit juice,” they wrote.