Study shows that high Mediterranean dietary adherence lowers systemic inflammation in elders

By Pooja Toshniwal PahariaReviewed by Lily Ramsey, LLMMay 7 2024

In a recent study published in Nutrients, researchers investigated the relationship between high Mediterranean dietary pattern (MDP) adherence and decreased low-grade systemic inflammation (LGSI) in Brazil. They also examined which Mediterranean diet components contributed to the relationships.

Study: High Adherence to the Mediterranean Dietary Pattern Is Inversely Associated with Systemic Inflammation in Older but Not in Younger Brazilian Adults. Image Credit: monticello/Shutterstock.com

Background

LGSI is a primary cause of chronic illnesses and metabolic inflammation associated with unhealthy aging. Studies link inadequate food intake, particularly nutritional excess, and metabolic inflammation.

MPD has shown promise in reducing LGSI, with seniors having reduced C-reactive protein (CRP) and interleukin-6 (IL-6) levels.

Recent research has shown that younger individuals adhere less to the MDP. However, there is limited comprehensive scientific evidence among Brazilian populations on the effects of the Mediterranean diet on LGSI.

Further research is required to investigate the features of Mediterranean food consumption and to evaluate the notion that younger individuals have a different adherence profile than older adults.

About the study

In the present cross-sectional study, researchers investigated whether higher MDP adherence decreased systemic inflammation among Brazilian adults and the relationship between different Mediterranean components and inflammation.

The researchers analyzed 2015 ISA-Nutrition data from the Health Survey of São Paulo, including 290 younger individuals (aged 20 to 59 years) and 293 elder individuals (60 years and older).

Between September 2014 and December 2015, they randomly selected individuals residing in permanent private households in São Paulo's metropolitan region, excluding those on enteral or parenteral diets and chronic alcoholics.
The team used the Mediterranean Diet Score (MedDietScore) to examine MDP adherence, acquired from two 24-hour diet recalls (24HDRs).

They obtained blood samples from all participants to calculate LGSI scores [from serum C-reactive protein (CRP), adiponectin, and tumor necrosis factor-alpha (TNF-α)], indicating the inflammatory state. They used the Multiple Source Method (MSM) to calculate habitual food consumption.

The researchers used linear regressions to determine the relationship between the MedDietScore and LGSI, adjusting for age, sex, race, body mass index (BMI), educational attainment, per capita income, and comorbidities. They used the International Physical Activity Questionnaire (IPAQ) to assess physical activity levels.

Results

Most participants were white and male, with a median age of 41–68 years and household earnings higher than the minimum wage. Younger individuals had ten to twelve years of formal education, whereas elderly adults had less.

Most did not satisfy physical activity guidelines and had never smoked. Both groups reported health issues, with 37% younger and 38% older individuals having a normal BMI.

Concerning MDP adherence, the mean varied from 25 to 34 MedDietScore points, indicating poor to high levels of adherence. In the fully adjusted model, high adherence, as opposed to low MDP adherence, was significantly and positively linked with a 9.5% reduction in LGSI scores.

Moderate MDP adherence predominated in the younger (40%) and older (38%) age groups, with mean MedDietScore values representing high MDP adherence, which was comparable among both groups.

Only among elderly individuals was strong abidance by the Mediterranean diet associated with 12% lower LGSI scores. Older individuals who adhered closely to the Mediterranean diet consumed less full-fat-type dairy and meat.

Olive oil and vegetable consumption showed inverse associations with LGSI scores in older adults. Thus, in the older age group, intake of certain Mediterranean foods predicted good MDP adherence and was linked to decreased LGSI.

Younger individuals adhering to the Mediterranean diet ate more non-refined-type cereals, fruits, vegetables, potatoes, olive oil, wine, and fish while eating less poultry.

These similar differences were detected comparing elders with high and low MDP adherence, except wine, which was consumed at the same rate regardless of adherence level and was related to a decreased intake of full-fat-type dairy and meat.

Seniors who consumed olive oil and vegetables and adhered to the Mediterranean diet had lower systemic inflammation. An intake of ≥12 servings of vegetables per week, compared to ≤9 servings, reduced LGSI scores by 13%.

Older adults consuming three or more olive oil servings weekly had 12% lower systemic inflammation levels than those consuming no more than one serving.

Younger individuals consumed more non-refined cereals, vegetables, fruits, fish, and olive oil, but older individuals ate less meat and full-fat dairy.

Consuming olive oil and vegetables rich in short-chain fatty acids, carotenoids, vitamins, and minerals can reduce inflammation by inhibiting the activation of leukocyte adhesion and nuclear factor-kappa B (NF-κB).

Conclusion

Based on the study findings, the Mediterranean diet can effectively control health issues in older individuals, with higher MDP adherence associated with lower LGSI scores.

Among older individuals, a lower intake of full-fat dairy and red meat and higher olive oil and vegetable consumption contributed to lower LGSI scores.

Future studies must include non-cross-sectional designs and more diverse populations to determine causality and increase the generalizability of the study findings.