Mediterranean Diet Helps Slow Age-Related Physical Decline, Study Finds

A new study pub­lished in JAMA Network Open sug­gests that cou­pling a reduced-calo­rie Mediterranean diet with exer­cise can reduce body fat while main­tain­ing mus­cle mass, a com­bi­na­tion of par­tic­u­lar impor­tance to older indi­vid­u­als.

“The results obtained demon­strate that com­bin­ing a dietary plan based on the tra­di­tional Mediterranean diet with caloric restric­tion and increased phys­i­cal activ­ity can par­tially reverse age-asso­ci­ated changes in body com­po­si­tion in over­weight older adults,” lead author Jadwiga Konieczna said.

The study was con­ducted by researchers from the Biomedical Research Consortium Network – Physiopathology of Obesity and Nutrition (CIBEROBN), a con­sor­tium of 33 work­ing groups under the Spanish Ministry of Science and Innovation, well-known for its research into the ben­e­fits of the Mediterranean diet, the pre­ven­tion of meta­bolic dis­or­ders, child­hood and youth obe­sity and the rela­tion­ship between obe­sity and can­cer.

Most pre­vi­ous stud­ies on weight loss and improv­ing meta­bolic alter­ations asso­ci­ated with abdom­i­nal obe­sity had focused on eval­u­at­ing their effect on over­all body weight, not on body fat dis­tri­b­u­tion, using direct mea­sure­ments of body com­po­si­tion through imag­ing tech­niques.

Therefore, this study aimed to eval­u­ate the effects of a lifestyle inter­ven­tion focused on weight loss on changes in over­all body com­po­si­tion and indi­vid­ual body regions.

The devel­op­ment of obe­sity-asso­ci­ated chronic dis­eases is intri­cately linked to spe­cific com­po­nents of body com­po­si­tion.

Excessive vis­ceral fat and the age-related loss of mus­cle mass have been iden­ti­fied as key fac­tors asso­ci­ated with a height­ened risk of var­i­ous health issues, includ­ing car­dio­vas­cu­lar dis­ease and type 2 dia­betes.

Muscle loss in the elderly is also asso­ci­ated with ele­vated rates of injury due to the result­ing reduc­tion in skele­tal sup­port and an increased risk of acci­dents such as falls.

Consequently, strate­gies address­ing these spe­cific body com­po­si­tion com­po­nents, extend­ing beyond con­ven­tional weight man­age­ment, are essen­tial for long-term health improve­ment.

The Mediterranean diet, espe­cially when energy-reduced, is gain­ing recog­ni­tion as an effec­tive weight loss and sus­tained main­te­nance approach.

The Prevention with Mediterranean Diet (PREDIMED) trial results sup­port that an energy-reduced Mediterranean diet could be opti­mal for weight loss and car­dio­vas­cu­lar dis­ease pre­ven­tion.

Furthermore, a 2017 review of 18 inter­ven­tion tri­als indi­cated that Mediterranean diet inter­ven­tions, whether energy-reduced or not, sig­nif­i­cantly reduce cen­tral obe­sity mea­sures.

Despite chal­lenges in related tri­als, such as indi­rect mea­sure­ment meth­ods or small sam­ple sizes, the pos­i­tive effects of phys­i­cal exer­cise on vis­ceral fat in over­weight adults and on mus­cle mass in older adults have been estab­lished.

However, the com­bined effects of an energy-restricted Mediterranean diet and phys­i­cal activ­ity on body com­po­si­tion in older indi­vid­u­als have remained unex­plored.

The study aimed to ascer­tain the long-term effects of this lifestyle inter­ven­tion on age-related changes in over­all and regional body com­po­si­tion after the ini­tial three years of the ongo­ing PREDIMED-Plus ran­dom­ized clin­i­cal trial.

PREDIMED-Plus was cho­sen because it allowed the researchers to eval­u­ate the impacts of a mul­ti­fac­to­r­ial inter­ven­tion involv­ing an energy-reduced Mediterranean diet, phys­i­cal activ­ity pro­mo­tion and behav­ioral sup­port for weight loss in mid­dle-aged and older adults with meta­bolic syn­drome and ini­tial over­weight or obe­sity.

The trial, con­ducted across 23 Spanish cen­ters, recruited par­tic­i­pants between October 2013 and December 2016. Eligible par­tic­i­pants were mid­dle-aged and older men (55 to 75 years old) and women (60 to 75 years old) with­out prior car­dio­vas­cu­lar events, pre­sent­ing with over­weight or obe­sity and meta­bolic syn­drome.

The inter­ven­tion group received per­son­al­ized face-to-face nutri­tional and behav­ioral pro­grams, incor­po­rat­ing a 30 per­cent energy reduc­tion and encour­age­ment to limit spe­cific food con­sump­tion. Additionally, they were moti­vated to increase aer­o­bic phys­i­cal activ­ity pro­gres­sively.

Trained dieti­tians main­tained reg­u­lar con­tact with par­tic­i­pants dur­ing the first year, pro­vid­ing group and indi­vid­ual ses­sions and tele­phone sup­port. Behavioral and moti­va­tional strate­gies, includ­ing self-mon­i­tor­ing and goal set­ting, were inte­gral.

In con­trast, the con­trol group received gen­eral advice to fol­low the tra­di­tional Mediterranean diet with­out spe­cific weight-loss goals.

Comparative analy­sis between the inter­ven­tion and con­trol groups revealed that par­tic­i­pants in the inter­ven­tion group were more likely to exhibit five per­cent or more improve­ments in all body com­po­nents at one and three years of fol­low-up.

Notably, these improve­ments were more pro­nounced in the first year, with absolute risk reduc­tion per­cent­ages for total fat mass, lean mass and vis­ceral fat mass. For instance, for every 12 per­sons under­go­ing the inten­sive lifestyle inter­ven­tion, one addi­tional indi­vid­ual expe­ri­enced a clin­i­cal improve­ment in vis­ceral fat mass at year three.

No sig­nif­i­cant inter­ac­tions were found between sex and smok­ing habits for the stud­ied out­comes dur­ing the fol­low-up, but age showed sig­nif­i­cant inter­ac­tions.

Younger par­tic­i­pants (less than 65 years old) exhib­ited more sub­stan­tial ben­e­fi­cial changes in body com­po­si­tion at year one, which were not sus­tained at year three.

Conversely, older par­tic­i­pants (65 or older) showed lower mag­ni­tude changes ini­tially but main­tained sta­bil­ity over time. Between-group dif­fer­ences were sig­nif­i­cant only in par­tic­i­pants with­out type 2 dia­betes.

Both inter­ven­tion and con­trol groups expe­ri­enced absolute and rel­a­tive loss of total fat mass. Still, the inter­ven­tion group showed appre­cia­ble decreases, espe­cially in the first year, par­tially regain­ing it by the third year. The inter­ven­tion group exhib­ited greater reduc­tions in fat mass (both grams and per­cent­age of body mass) com­pared to the con­trol group through­out the fol­low-up.

Only par­tic­i­pants in the inter­ven­tion group showed decreased vis­ceral fat mass, while the con­trol group showed no change over time.

This reduc­tion appeared related to total fat mass loss, as the inter­ven­tion did not affect the per­cent­age of vis­ceral fat to total fat mass or the android-to-gynoid fat mass ratio.

Intentional weight loss typ­i­cally involves lean mass loss, akin to aging. Both groups expe­ri­enced sig­nif­i­cant absolute lean mass loss, with the inter­ven­tion group show­ing a greater effect.

However, par­tic­i­pants in the inter­ven­tion group dis­played increases in the per­cent­age of total lean mass rel­a­tive to total body mass and the total lean mass to total fat mass ratio, sug­gest­ing a more favor­able body com­po­si­tion pro­file over the three years.

Dora Romaguera, the study’s prin­ci­pal inves­ti­ga­tor, and Jordi Salas-Salvadó, coor­di­na­tor of the PREDIMED-Plus trial, said that ​“given the meta­bolic rel­e­vance of vis­ceral fat and lean mass, the ben­e­fits of this type of lifestyle inter­ven­tion could ben­e­fit older peo­ple in pre­vent­ing age-related loss of mus­cle mass, espe­cially if they need to reduce their weight.”

Despite the mod­est body com­po­si­tion changes, the researchers deemed them clin­i­cally rel­e­vant, with improve­ments of at least five per­cent in base­line val­ues.

However, they stress that con­tin­ued fol­low-up is essen­tial to ascer­tain whether these mod­er­ate improve­ments can effec­tively pre­vent car­dio­vas­cu­lar events or mor­tal­ity.

• PREDIMED Plus
• Critical Reviews in Food Science and Nutrition