In a recent study published in JAMA Network Open, researchers from Spain investigated the effect of a traditional Atlantic diet on health and the environment. They found that while the traditional Atlantic diet significantly lowered the incidence of metabolic syndrome, it did not significantly alter carbon emissions as compared to the control group.
The global shift in diets poses challenges to human and environmental health, necessitating a move towards sustainable, healthy dietary patterns to achieve the United Nations' Sustainable Development Goals (SDGs) on climate change mitigation (SDG 13) and noncommunicable disease reduction (SDG 3). Traditional diets like the Atlantic diet, akin to the Mediterranean diet, offer promise in promoting health and environmental benefits.
As no prior clinical trial has explored this hypothesis, researchers in this study aimed to address this gap by investigating the effects of a traditional Atlantic diet on both human health, specifically metabolic syndrome (MetS), and environmental sustainability in northwest Spain and northern Portugal.
About the study
The present study involves a secondary analysis of the data from the Galicia Atlantic Diet (GALIAT) study, a novel, 6-month-long, community-focused, randomized clinical trial conducted between 2014 and 2015 in A Estrada, Spain. The trial, rooted in the local traditional Atlantic diet, engaged citizens, businesses, researchers, and institutions in a pragmatic, collaborative approach prioritizing primary care settings' practicality. The study included 574 adults of Spanish ethnicity and Caucasian descent living in family units (n = 250) with ≥2 members in the age group 3 to 85 years. The exclusion criteria were a history of lipid-lowering medication, alcoholism, major cardiovascular disease, dementia, pregnancy, and life expectancy ≤ 1 year.
Participant families were randomized 1:1 to the intervention group (n = 126 families, 287 participants) or control group (n = 124 families, 287 participants). The mean age of the participants was 46.8 years, and 59.8% of the participants were female. The dietary intervention emphasized fresh, local, and minimally processed seasonal foods, including fruits, vegetables, beans, whole grains, and olive oil. High amounts of fish and seafood, accompanied by starch-based foods, dry fruits, cheese, milk, and moderate meat and wine intake characterized the Atlantic diet.
Counseling aimed at modifying food habits without restricting energy intake adapting recommendations to individual preferences and nutritional needs. While the intervention group attended nutrition education sessions and cooking classes and received traditional diet food baskets, the control group maintained their usual lifestyle. Dietary intake, physical activity, medication use, and other variables were assessed at baseline and after six months, with masking procedures implemented to minimize biases.
As the primary health outcome, MetS was characterized based on the criteria outlined in the National Cholesterol Education Program Adult Treatment Panel III (ATP III) guidelines. The environmental impact was assessed via the life cycle assessment (LCA) approach, in which the carbon dioxide (CO2) emissions associated with the diet of each participant were measured.
Statistical analysis involved the use of chi-square tests and Student's t-tests, modified Poisson regressions for rate ratios (RRs), cumulative logit regression models, mixed-effects linear models, and intraclass correlation coefficient (ICC).
Results and discussion
In the 6-month follow-up, the intervention group showed a significant reduction in incident MetS cases compared to the control group (RR = 0.32). Although the overall MetS prevalence did not significantly decrease in the entire sample (n=457), the intervention group exhibited reduced risk in central obesity (RR = 0.90) and low high-density lipoprotein cholesterol (RR = 0.79). Waist circumference significantly decreased in the intervention group, while blood pressure changes were not significant. Participants in the intervention group were approximately 42% less likely to exhibit an additional MetS component compared to the control group. Sensitivity analysis confirmed similar results.
The climate impact analysis showed that both the control and intervention groups experienced a reduction in carbon footprint scores with no significant difference. The sensitivity analysis confirmed similar results. Interestingly, family membership accounted for about 45% of the variability in the carbon footprint score, emphasizing its significant role in potentially regulating food-related greenhouse gas emissions.
The study is strengthened by its randomized design, high retention rates, objective measures, and representative sampling from the general population. However, the study is limited by unaccounted potential unknown factors, a complex intervention, diverse carbon footprint measures, a short duration for metabolic changes assessment, and a potentially low sample size, highlighting the need for larger, long-term studies.
In conclusion, the study highlights the significance of a traditional, family-oriented dietary intervention in potentially reducing the incidence of MetS. Further research is required to comprehend and examine the underlying mechanisms and extend the applicability of these findings to diverse populations, considering regional, cultural, and dietary differences.