Abstract
Increased attention in dietary research and guidance has been focused on dietary patterns, rather than on single nutrients or food groups, because dietary components are consumed in combination and correlated with one another. However, the collective body of research on the topic has been hampered by the lack of consistency in methods used. We examined the relationships between 4 indices—the Healthy Eating Index-2010 (HEI-2010), the Alternative Healthy Eating Index-2010 (AHEI-2010), the alternate Mediterranean Diet (aMED), and Dietary Approaches to Stop Hypertension (DASH)—and all-cause, cardiovascular disease (CVD), and cancer mortality in the NIH-AARP Diet and Health Study (n = 492,823). Data from a 124-item food-frequency questionnaire were used to calculate scores; adjusted HRs and 95% CIs were estimated. We documented 86,419 deaths, including 23,502 CVD- and 29,415 cancer-specific deaths, during 15 y of follow-up. Higher index scores were associated with a 12–28% decreased risk of all-cause, CVD, and cancer mortality. Specifically, comparing the highest with the lowest quintile scores, adjusted HRs for all-cause mortality for men were as follows: HEI-2010 HR: 0.78 (95% CI: 0.76, 0.80), AHEI-2010 HR: 0.76 (95% CI: 0.74, 0.78), aMED HR: 0.77 (95% CI: 0.75, 0.79), and DASH HR: 0.83 (95% CI: 0.80, 0.85); for women, these were HEI-2010 HR: 0.77 (95% CI: 0.74, 0.80), AHEI-2010 HR: 0.76 (95% CI: 0.74, 0.79), aMED HR: 0.76 (95% CI: 0.73, 0.79), and DASH HR: 0.78 (95% CI: 0.75, 0.81). Similarly, high adherence on each index was protective for CVD and cancer mortality examined separately. These findings indicate that multiple scores reflect core tenets of a healthy diet that may lower the risk of mortality outcomes, including federal guidance as operationalized in the HEI-2010, Harvard’s Healthy Eating Plate as captured in the AHEI-2010, a Mediterranean diet as adapted in an Americanized aMED, and the DASH Eating Plan as included in the DASH score. J. Nutr. 144: 881–889, 2014.
Generated Summary
This research, published in the Journal of Nutrition, investigates the relationship between diet quality and mortality rates among older adults. The study employed a prospective cohort design, analyzing data from the NIH-AARP Diet and Health Study. The primary aim was to examine how adherence to different dietary patterns impacts the risk of all-cause, cardiovascular disease (CVD), and cancer mortality. The study used four indices: the Healthy Eating Index-2010 (HEI-2010), the Alternative Healthy Eating Index-2010 (AHEI-2010), an alternate Mediterranean Diet (aMED), and the Dietary Approaches to Stop Hypertension (DASH) score. Data from a 124-item food-frequency questionnaire were used to calculate the scores, and hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated to assess the associations between diet quality and mortality. The study followed participants for 15 years, documenting deaths and analyzing mortality risks across different quintiles of diet quality for each index. The core methodology involved adjusting for various covariates to isolate the effects of diet and to ensure comparability across different dietary indices and outcomes.
Key Findings & Statistics
- The study documented 86,419 deaths during the 15-year follow-up period.
- These deaths included 23,502 CVD-specific deaths and 29,415 cancer-specific deaths.
- All-Cause Mortality:
- Men:
- HEI-2010 HR: 0.78 (95% CI: 0.76, 0.80)
- AHEI-2010 HR: 0.76 (95% CI: 0.74, 0.78)
- aMED HR: 0.77 (95% CI: 0.75, 0.79)
- DASH HR: 0.83 (95% CI: 0.80, 0.85)
- Women:
- HEI-2010 HR: 0.77 (95% CI: 0.74, 0.80)
- AHEI-2010 HR: 0.76 (95% CI: 0.74, 0.79)
- aMED HR: 0.76 (95% CI: 0.73, 0.79)
- DASH HR: 0.78 (95% CI: 0.75, 0.81)
- Characteristics of Participants:
- Men and women in the highest quintile (quintile 5) of diet quality, across all indices, were more likely to be older, leaner, more physically active, and college graduates.
- Men in quintile 5 were also more likely to be married and to have never smoked.
- For HEI-2010, AHEI-2010, and aMED, men and women in quintile 5 had higher intakes of alcohol.
- For DASH, men and women in quintile 5 had lower intakes of alcohol.
- For aMED and DASH, men and women in quintile 5 had higher energy intakes; this was also found in AHEI-2010 for women.
- Correlations:
- For men, the correlations among the total scores for all pairs of indices ranged from 0.53 (for HEI-2010 and aMED) to 0.69 (for HEI-2010 and DASH).
- For women, the correlations ranged from 0.49 (for HEI-2010 and aMED) to 0.62 (for HEI-2010 and DASH).
- All correlations were statistically significant (P < 0.0001).
- Impact of Diet Quality on Mortality (Table 2):
- In men, across all indices (HEI-2010, AHEI-2010, aMED, and DASH), the range of index points varied.
- Mortality rates, CVD, and Cancer cases also varied, with the highest quintile generally showing fewer cases compared to the lowest.
- The same trends were observed in women.
- All-Cause Mortality (Table 4):
- HEI-2010: HR for Quintile 5 (74.1-96.1) = 0.78 (0.76, 0.80).
- AHEI-2010: HR for Quintile 5 (60.5-92.1) = 0.76 (0.74, 0.78).
- aMED: HR for Quintile 5 (6-9) = 0.77 (0.75, 0.79).
- DASH: HR for Quintile 5 (28-37) = 0.83 (0.80, 0.85).
- CVD Mortality (Table 4):
- HEI-2010: HR for Quintile 5 (74.1-96.1) = 0.85 (0.80, 0.89).
- AHEI-2010: HR for Quintile 5 (60.5-92.1) = 0.74 (0.70, 0.78).
- aMED: HR for Quintile 5 (6-9) = 0.80 (0.76, 0.84).
- DASH: HR for Quintile 5 (28-37) = 0.86 (0.81, 0.91).
- Cancer Mortality (Table 4):
- HEI-2010: HR for Quintile 5 (74.1-96.1) = 0.76 (0.72, 0.80).
- AHEI-2010: HR for Quintile 5 (60.5-92.1) = 0.82 (0.78, 0.86).
- aMED: HR for Quintile 5 (6-9) = 0.80 (0.77, 0.84).
- DASH: HR for Quintile 5 (28-37) = 0.80 (0.76, 0.84).
- Impact of Diet Quality on Mortality (Table 5 – Women):
- In Women, across all indices (HEI-2010, AHEI-2010, aMED, and DASH), the range of index points varied.
- Mortality rates, CVD, and Cancer cases also varied, with the highest quintile generally showing fewer cases compared to the lowest.
- All-Cause Mortality (Table 5):
- HEI-2010: HR for Quintile 5 (76.4-96.2) = 0.77 (0.74, 0.80).
- AHEI-2010: HR for Quintile 5 (60.7-90.7) = 0.76 (0.74, 0.79).
- aMED: HR for Quintile 5 (6-9) = 0.76 (0.73, 0.79).
- DASH: HR for Quintile 5 (28-37) = 0.78 (0.75, 0.81).
- CVD Mortality (Table 5):
- HEI-2010: HR for Quintile 5 (76.4-96.2) = 0.79 (0.73, 0.85).
- AHEI-2010: HR for Quintile 5 (60.7-90.7) = 0.72 (0.67, 0.78).
- aMED: HR for Quintile 5 (6-9) = 0.78 (0.72, 0.84).
- DASH: HR for Quintile 5 (28-37) = 0.78 (0.72, 0.83).
- Cancer Mortality (Table 5):
- HEI-2010: HR for Quintile 5 (76.4-96.2) = 0.82 (0.77, 0.87).
- AHEI-2010: HR for Quintile 5 (60.7-90.7) = 0.88 (0.83, 0.94).
- aMED: HR for Quintile 5 (6-9) = 0.79 (0.74, 0.85).
- DASH: HR for Quintile 5 (28-37) = 0.82 (0.77, 0.88).
Other Important Findings
- Higher index scores were associated with a 12-28% decreased risk of all-cause, CVD, and cancer mortality.
- High adherence to each index was protective for CVD and cancer mortality when examined separately.
- In the by-components models, different components were independently associated with mortality outcomes.
- There were a few unexpected findings; for example, for all-cause mortality: increased risk was found among both men and women with higher scores on the HEI-2010 refined grain component, for men with higher scores on the AHEI-2010 sugar-sweetened beverages and fruit juice component, and for men on the AHEI-2010 and DASH sodium components.
Limitations Noted in the Document
- The study assessed diet with a food frequency questionnaire (FFQ), which is known to contain measurement error.
- The study only had a single measure of diet at baseline, so changes in intake over time could not be accounted for.
- The NIH-AARP cohort has a limited number of participants in races and ethnic groups other than white and black non-Hispanic, limiting generalizability.
- Optimal dietary patterns may be a marker for other healthy behaviors not fully captured in the study.
Conclusion
The study’s findings underscore the importance of diet quality in reducing mortality risks among older adults. The consistent benefits observed across various dietary indices—HEI-2010, AHEI-2010, aMED, and DASH—highlight the shared core tenets of a healthy diet: emphasis on whole grains, vegetables, fruits, and plant-based proteins. This suggests that the specific choice of dietary pattern may be less critical than the overall adherence to these fundamental principles. The reduced risk of all-cause, CVD, and cancer mortality associated with higher diet quality, as demonstrated in this study, provides valuable insights for both policymakers and individuals seeking to improve their health outcomes. The findings support the need to optimize the U.S. food environment to promote these beneficial dietary components. The study’s results suggest the need for future research to clarify the effects of scoring metrics, as different metrics may yield varying results. The need for further analyses to explore the role of body weight as a mediator in the relationship between diet and mortality is warranted. The research’s strength lies in its comprehensive measures of diet, mortality, and other key variables, as well as the standardization of methods across the different indices. Furthermore, the study’s findings are consistent with the growing body of evidence emphasizing the role of diet in overall health, providing a solid foundation for public health guidelines and future research in this area. The study’s findings are generalizable to an older U.S. population and provide clear evidence that following any of the studied dietary recommendations can significantly lower the risk of mortality.
IFFS Team Summary
- Data collected from the NIH AARP (formerly the American Association of Retired Persons)
- 492 000 people between ages of 50-71, followed avg 15 years
- 86 000 deaths
- 23 000 from cardiovascular disease, 29 000 from cancer
- 86 000 deaths
- 23 000 from cardiovascular disease, 29 000 from cancer
- Analyzed according to 4 healthy eating scores that are plant based
- Healthy Eating Index 2010, Alternative Healthy Eating Index 2010, Alternative Mediterranean diet and Dietary Approaches to Stop Hypertension (DASH) Score
- Healthy Eating Index 2010, Alternative Healthy Eating Index 2010, Alternative Mediterranean diet and Dietary Approaches to Stop Hypertension (DASH) Score
- Regardless of Index, similar benefits were shown for highest quality plant diet scores, first vs 5th quintiles
- 17-24% decrease in all cause mortality
- 15-28% decrease in cardiovascular mortality
- 12-24% decrease in total cancer mortality
- 17-24% decrease in all cause mortality
- 15-28% decrease in cardiovascular mortality
- 12-24% decrease in total cancer mortality
- All of the diet indices show statistically significant benefit for the highest plant based scores in a dose response fashion
- Adjusted for Age, Ethnicity, Education, BMI, Smoking, Exercise, Energy Intake , Marital Status, Diabetes, Menopausal Status, Hormone replacement use
- BMI and diabetes adjustment likely favour animal based foods – so may weaken the results
- BMI and diabetes adjustment likely favour animal based foods – so may weaken the results
- Advantage of quintile studies is to show larger diet difference and reduce the healthy volunteer effect of diet
- Main entry in All Cause Mortality, and Also listed in Cardiovascular disease and Total Cancer Mortality sections