In a recent study published in The Journal of nutrition, health and aging, researchers used the a posteriori dietary approach involving empirically derived dietary patterns to investigate the cardiovascular outcomes of various diets in men over 75. Their study cohort comprised 539 men with major adverse cardiovascular events (MACE) scores available. Statistical analyses of the relationship of participant diet with MACE scores revealed that vegetables-legumes-seafood resulted in significantly improved cardiovascular health and reduced MACE risk when compared to diets consisting of wholegrains-milk-other fruits or discretionary-starchy vegetables-processed meats.
Study: Empirically derived dietary patterns are associated with major adverse cardiovascular events, all-cause mortality, and congestive cardiac failure in older men: The Concord Health and Ageing in Men Project. Image Credit: photolampocka / Shutterstock
Age, cardiovascular disease, and the role of diet
Cardiovascular diseases (CVDs) are an umbrella term for disorders of the heart and blood vessels. They include coronary heart disease (CHD), cerebrovascular disease, and rheumatic heart disease and serve to predict major adverse cardiovascular events (MACE). CVDs are the leading cause of global human mortality, and alarmingly, their prevalence is on the rise. A combination of poor dietary choices and increased sedentary lifestyles have resulted in the number of CVD cases doubling from 271 million in 1990 to over 523 million in 2019, with these conditions estimated to claim more than 17.9 million lives each year.
Extensive research has established the impacts of modifiable lifestyle and health behaviors on CVD and MACE. Sleep, physical activity, and diet have been given special attention due to their dual causal and protective effects on cardiovascular health. Interestingly, recent studies suggest that age may play a role in the physiological response of individuals to health behavioral interventions, particularly diet.
"…there is emerging evidence on the different effects in older adults compared to their younger counterparts, whereby some research showed weaker associations between dietary patterns and CVD risk factors in adults aged 60 years and over."
Dietary patterns refer to the amalgamation of food items, nutrients, and their consumption frequency. Research into dietary patterns is slowly replacing studies on single dietary items due to the former's ability to represent synergistic effects of food invisible to the latter. Evaluations of dietary patterns are of three main types – 1. a posteriori (data-driven), 2. a priori (hypothesis-driven), and 3. hybrid (combinations of the a posteriori and a priori). The a posteriori approach is ideal for best understanding the impacts of diets on cardiovascular health.
"…this approach is independent of existing knowledge, takes into account multiple dimensions, provides valuable insights into the interrelationships between food combinations and the habitual dietary patterns adopted by individuals."
Previous research into the associations between dietary patterns and cardiovascular health presents two main shortcomings – they focus on younger adults, and the outcomes of interest surround CVD, CHD, or mortality, with MACE being largely ignored.
About the study
The present study aims to assess the associations between dietary patterns and MACE metrics in adult Australian men over the age of 75 years. The study sample group was derived from the Concord Health and Ageing in Men Project (CHAMP), a prospective epidemiological cohort investigating aging in men. Of the 1,705 men recruited during the first wave (2005-2007) of the CHAMP study, 794 men continued participation during the third wave (2010-2013), during which time dietary data collection was performed. Of these, 782 possessed both medical and MACE history data and were included in preliminary analyses. Participant follow-up was conducted for a median of 5.3 years.
Individuals with a history of myocardial infarction (MI), congestive cardiac failure (CCF), stroke, or coronary revascularization were excluded from the study, resulting in a final sample cohort of 539 men. Data collection comprised dietitian-administered diet history queries (for dietary intake), MACE data obtained from the New South Wales (NSW) Centre for Health Record Linkage (CHeReL), and 'other measurements.' The 'other measurements' refer to participant anthropometry, lifestyle, socio-demographics, and self-reported health factors. The Physical Activity Scale for the Elderly (PASE) metric was used to assess participants' physical activity levels.
Dietary data was assessed per the Australian Guide to Healthy Eating and comprised 23 food groups. The Kaiser–Meyer–Olkin measure and Bartlett's test were used to derive factor scores and participant dietary pattern conformity, respectively. MACE outcomes were computed using the five-point MACE scale consisting of all-cause mortality, coronary revascularisation, MI, CCF, and ischaemic stroke. A four-point MACE computation was also carried out, wherein all-cause mortality data was excluded from analyses.
Statistical analyses included median tests, Bonferroni corrections, and Cox regressions to elucidate the associations between the five- or four-point MACE with different dietary patterns, with results expressed as hazard ratios (HRs).
Study findings
Factor analysis revealed three broad dietary patterns in included participants, namely 'vegetables-legumes-seafood' (9.13%), 'discretionary-starchy vegetables-processed meats' (7.07%), and 'wholegrains-milk-other fruits' (7.73%).
Analyses of the associations between these dietary patterns and MACE revealed that the 'vegetables-legumes-seafood' dietary pattern resulted in lower HRs for both the five- and four-point MACE. In contrast, both the other dietary patterns were associated with increased MACE HRs, with 'wholegrains-milk-other fruits' predicting the most adverse MACE outcomes.
"…the results of this study showed that empirically derived dietary patterns can provide insight on how the interactions between foods consumed habitually in the population can influence associations. Although the middle tertile of the 'vegetables-legumes-seafood' dietary pattern also had higher intakes of red meat than the bottom tertile, a food group associated with increased risks of CVD mortality, the high consumption of cardioprotective foods such as vegetables may have attenuated the association."
These findings highlight the benefits of the 'vegetables-legumes-seafood' diet, particularly in elderly men above the age of 75, and may form the basis for future research aimed at evaluating the differences between the dietary responses of younger and older individuals.
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