Advances in Nutrition: An International Review Journal article finds greater adherence to the Guidelines is associated with “a lower risk of mortality from all-cause, cardiovascular disease, and cancer.”

Increasingly, nutrition scientists have found that assessing the health effects of overall dietary patterns may have more value than assessing the health effects of individual foods and nutrients.  In other words, the sum of the parts may be more important than any individual part of our overall dietary pattern.

Developed in 1995, The Healthy Eating Index is a measure of how well a particular dietary pattern aligns with the recommendations published in the Dietary Guidelines for Americans.  The Healthy Eating Index is periodically updated as new Dietary Guidelines are issued.  Healthy Eating Index scores range from 0 to 100, based on the degree to which an individual adheres to Dietary Guidelines’ recommendations for 13 dietary components.  For example, a diet rich in fruits, vegetables, whole grains, low-fat dairy, and lean proteins as well as low in saturated fats, added sugars, refined grains, sodium, and alcohol results in a higher Healthy Eating Index score.  According to the USDA Food and Nutrition Service, the average American scores 58 out of 100 on the Healthy Eating Index.

Recently, the authors of The Healthy Eating Index-2015 and All-Cause/Cause-Specific Mortality: A Systematic Review and Dose–Response Meta-Analysis set out to determine the association between the Healthy Eating Index-2015 (i.e., the Healthy Eating Index associated with the 2015 edition of the Dietary Guidelines for Americans) and all-cause, cancer, and cardiovascular disease mortality.  The results of their research were published in Advances in Nutrition, the international review journal of the American Society for Nutrition.  While other scientific reviews have examined the relationship between the Healthy Eating Index and mortality, this review is the first to examine the dose-response relationship.  In other words, the authors sought to determine how the association of the Healthy Eating Index with mortality varied as Index scores went either up or down in one-point increments.

To conduct their research, the authors performed a comprehensive search of the scientific literature for relevant studies published up until September 2023.  Their search led them 20 studies with a total of more than one million participants.

According to the results of this review, “a higher Healthy Eating Index-2015 score was associated with a lower risk of mortality from all-cause, cardiovascular disease, and cancer.”  Interestingly, the authors found a non-linear relationship between the Healthy Eating Index and all-cause mortality, whereas they found a linear relationship between the Healthy Eating Index and cancer and cardiovascular disease mortality.  In all three cases, however, the authors observed that higher adherence to the Healthy Eating Index resulted in a lower risk of mortality.

The authors noted that a diet with a high Healthy Eating Index score “is considered to be a healthy and balanced dietary pattern, providing a myriad of minerals and vitamins from fruits, vegetables, whole grains, dairy or soy alternatives, protein foods, and unsaturated fatty acids.”  The possible biological mechanisms underlying a healthy diet’s role in reducing mortality are not fully clear; however, studies have found that healthy diets may help decrease systemic inflammation and oxidative stress, two factors which play a critical role in the development of chronic diseases.

The authors did note that “further large prospective studies are still needed to provide more comprehensive information on the potential effects of dietary patterns assessed by the Health Eating Index-2015 on the risk of mortality.”