Eat a Healthy Diet and Drink Wisely to Postpone Dying If You Survived a Myocardial Infarction?

Abstract

Coronary heart disease (CHD) is largely preventable through ahealthful lifestyle, particularly ahealthydiet.However, CHD is the leading cause of death and disability worldwide. Dietary guidelines to promote good health and reduce major chronicdiseases, includingCHD,arebasedondataabout foods, nutrients, and dietary patterns predictive of chronic disease risk in epidemiologic studies. What is the best dietary pattern to avoid CHD and increase longevity? A systematic review1 of the evidence supporting thecausal linkbetweendietary factorsandCHDranked the Mediterranean diet as the most likely dietary model to provide protection against CHD. In prospective cohort studies,2 increasing adherence to the Mediterranean diet has been consistently beneficial for prevention of major chronic diseases, including fatal and nonfatal CHD, as well as all-cause mortality. The results of a large intervention study about the effects of a Mediterranean diet in the primary prevention of cardiovascular disease in high-risk subjects, the PREDIMED (Prevencion con Dieta Mediterranea) trial, have been published recently.3 In this study, high–unsaturated-fat Mediterraneandiets supplementedwith extra-virgin olive oil or nuts for almost 5 years reduced by 30% the incidence of an aggregate of fatal and nonfatal cardiovascular disease events (CHD and stroke) compared with a control diet consisting of advice to reduce all types of dietary fat. Among components of theprimaryoutcome, incident stroke, butnotCHD,was significantly reduced in the 2 Mediterranean diet arms.3 A secondary prevention trial,4 the LyonDiet Heart Study, showed remarkable reductions inCHDevent rates andcardiovascular mortality in patients who survived a myocardial infarction (MI) and were allocated to a Mediterranean diet enrichedwith α-linolenic acid comparedwith a control diet. No large dietary secondary prevention trial has been conducted since. Thus, despite the growingnumberofMI survivors globally, information on the effects of diet on cardiovascular and overall mortality after MI is limited. In this issue of JAMA Internal Medicine, Li et al5 make a novel and relevant contribution to the field by examining the association of post-MI dietary quality with all-cause and cardiovascularmortality among 4098 participants in theNurses’ Health Study and Health Professionals Follow-up Study who survived an initial MI. Noticeably, average dietary quality, assessedbytheAlternativeHealthyEatingIndex2010(AHEI2010), improved only marginally post-MI among the highly educatedhealthprofessionals in these 2 cohorts.Nevertheless, for participantswhoincreasedtheAHEI2010score, therewasa29% reduction in all-cause mortality and a 40% reduction in cardiovascular mortality in comparison when the extreme quintiles were compared. The AHEI2010 includes 11 components: vegetables, fruits, nuts and legumes, red meat and processed meats, sugar-sweetened beverages, alcohol, polyunsaturated fat, trans fat, omega-3 fat,whole grains, and sodium intake.As discussed by Li et al,5 many of the recommendations regarding these foodsandnutrientsaresimilar to the traditionalMediterranean diet. Both dietary models share a high consumption ofwhole grains, fruits, and vegetables; substantial intake ofprotein fromplant sources (nuts and legumes);moderate intake of polyunsaturated fat; fish as a source of omega-3 fatty acids; and alcohol; and a low consumption of trans fat, meat andmeat products, and sugar-sweetened beverages. Two importantdifferencesbetween individual foods in the AHEI2010 and theMediterranean diet need to be underlined: olive oil andwine. Olive oil is the predominant fat for cooking anddressing salads, and sauteing and stir frying are the cooking techniques characteristic of theMediterranean diet.6 The presumedantiatherogenicproperties of oliveoil havebeenattributed to its high oleic acid content, but in recent years converging evidence indicates that polyphenols, present only in virgin and extra-virgin olive oil, contribute to the benefits of its consumption. The concentrationof phytochemicals in oils is influenced by the oil extraction procedures. Virgin olive oil is obtained from the first pressing of the ripe fruit and has a highcontentofantioxidants (tocopherolsandpolyphenols)and phytosterols. Lower-qualityoliveoils (refinedandcommonoliveoils) lose antioxidant andanti-inflammatory capacities because they are refined by physical-chemical procedures, although their fatty acid composition is close to that of virgin olive oil. Phenolics (mainly hydroxytyrosol and tyrosol) from virgin olive oil have shown strong antioxidant and antiinflammatory activities in experimental and clinical studies. In addition, consumption of phenolic-rich virgin olive oil linearly reduces the total cholesterol–high-density lipoprotein cholesterol ratio andoxidized low-density lipoprotein cholesterol levels.6Extra-virginoliveoil consumptionprovidesmore cardiovascular benefit than common olive oil consumption, as shown in the PREDIMED trial.3 Given that olive oil consumption is marginal in the United States, this key component of the Mediterranean diet is not included in the healthy eating indexes designed outside the Mediterranean basin. Another specific and key component of the Mediterraneandiet iswine, consumedinmoderation,mainlywithmeals. There is ample scientific evidence that regular light-tomoderate consumption of alcohol is associated with a lower risk of fatal and nonfatal CHD and all-cause mortality, as opRelated article page 1808 Diet Quality andMortality AmongMI Survivors Invited Commentary Research