Healthy plant-based diets reduce mortality risk for Spain's seniors

Healthy plant-based diets reduce mortality risk for Spain's seniors

Despite the increasing global popularity of healthy pro-vegetarian diets (PVG), including the Mediterranean diet and its derivative DASH (Dietary Approaches to Stop Hypertension), long-term evidence supporting the benefits of these dietary habits is lacking, particularly in older populations. In a study recently published in the journalNutrition, health and aging,Researchers examined the 12-year effects of three predefined PVG diets on both general and specific causes (cardiovascular disease). [CVD] or cancer) mortality.

The study cohort included 597 Spanish adults over 65 years of age. Data collection was primarily questionnaire-based, with diet adherence being the variable of greatest interest in this study. Study results showed that participants who moderately adhered to a healthy PVG diet had a lower risk of mortality (general and cardiovascular diseases), while those with higher adherence to an unhealthy PVG diet had a higher risk of these diseases.

Why is the public interested in healthy eating?

Despite clinical advances that significantly extend human life expectancy, the past few decades have seen an unprecedented increase in chronic diseases, particularly related to cardiovascular diseases (CVDs), cancer, and mental health. A growing body of research attributes these observations to “health behaviors”—actions or habits that directly impact a person's long-term health and clinical well-being. Sleep disorders, poor health choices (smoking and excessive alcohol consumption), exercise, and diet adherence are considered to be the most important factors affecting the long-term health of today's aging global population.

The ongoing coronavirus disease 2019 (COVID-19) pandemic has only worsened the situation as new work schedules, social distancing measures and work from home (WFH) policies have led to greater sleep and mental health disruptions. The increasing adherence to a sedentary lifestyle is potentially leading to a current and future increase in the prevalence of chronic diseases and all-cause mortality.

Unfortunately, despite extensive research examining the current benefits of pro-vegetarian diets (PVGs), the gold standard for healthy eating, long-term data supporting these benefits are lacking. This disadvantage is particularly relevant for older adults, the primary focus group for chronic diseases.

About the study

The present study aims to elucidate the effects of three predetermined PVG dietary regimens (general, healthy and unhealthy) on long-term all-cause mortality of elderly citizens in the Mediterranean region. In addition, efforts are being made to elucidate the contributions of these dietary habits to certain chronic causes of death, including cardiovascular disease and cancer. The study cohort was derived from the European Eye Study (EUREYE), a long-term study of age-related macular degeneration conducted in Spain.

The study population included 597 people (54.3% female) over 65 years old from the Spanish province of Alicante. Data collection was predominantly questionnaire-based and included demographic, medical and lifestyle details. In addition, health, weight and height examinations were carried out regularly.

Adherence to the main variable of interest (dietary adherence) was measured using a Food Frequency Questionnaire (FFQ) validated in Spain, which included 131 foods and their standard (recommended) portion sizes. The nutritional interventions used here consisted ofa priorigPVG patterns (general; developed by Martínez-González) and the hPVG and uPVG patterns (“healthy” and “unhealthy,” respectively; developed by Satija et al.).

“…Dietary patterns were created using information from 18 food groups, including vegetables, fruits, legumes, whole grains, refined grains, boiled potatoes, chips or chips, nuts, olive oil, tea and coffee, fruit juices, sugar-sweetened drinks, sweets and desserts, meat and meat products, animal fats, eggs, fish and seafood, and dairy products.”

The follow-up period of the study was 12 years. During this period, information on participants' mortality was obtained from the Valencia Region Death Register or from the National Death Index of the Spanish Statistical Office. Cause of death was recorded according to the 10th version of the International Classification of Diseases (ICD-10) and classified as either cardiovascular disease, cancer, or all-cause death (cardiovascular disease + cancer + any other cause).

Study results and conclusions

Analyzes of adherence to dietary patterns revealed that hPVG was primarily adhered to by younger participants and those with a history of diabetes or hypercholesterolemia. In contrast, the uPVG diet was predominantly followed by male participants and those with smoking and alcohol habits.

“After 12 years of follow-up, participants with the lowest adherence (T1) demonstrated a 41% (HR: 0.59; 95% CI: 0.43-0.82) and 53% (HR: 0.47; 95% CI: 0.28-0.78) lower risk of an hPVG dietary pattern compared to those with moderate adherence (T2). All-cause mortality or cardiovascular mortality in the adjusted model.”

The study highlights that the healthy PVG (hPVG) dietary pattern was associated with a lower risk of cardiovascular disease and all-cause mortality. Instead, the unhealthy PVG (uPVG) diet was found to be associated with a higher risk of these diseases. This suggests that eating fresh fruits and vegetables, legumes, nuts and olive oil can provide lasting benefits in today's aging world. Unfortunately, this study fails to elucidate the mechanisms by which these foods provide protection, which is a requirement of future prospective studies.

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