Mediterranean diet vs. Ultra-processed foods: Impact on frailty in older adults

By Dr. Priyom Bose, Ph.D.Reviewed by Benedette Cuffari, M.Sc.Sep 6 2024

Higher adherence to the Mediterranean diet and reduced intake of ultra-processed foods may lower the risk of frailty and cardiometabolic diseases in older adults.

Study: Mediterranean Diet and Ultra-Processed Food Intake in Older Australian Adults—Associations with Frailty and Cardiometabolic Conditions. Image Credit: Olena Yakobchuk / Shutterstock.com

A recent Nutrients study develops dietary indices of ultra-processed food (UPF) and Mediterranean Diet Score (MDS) and evaluates whether these scores were associated with frailty and cardiometabolic disease in older adults.

What is the optimal diet for older individuals?

Rising life expectancy rates, combined with reduced fertility, have significantly increased the number of older adults worldwide. This phenomenon is referred to as the aging of the population, which has significantly elevated the economic burden.

Two modelling studies based on American and Australian data predicted a continual increase in health expenditure due to aging-related issues. An increased incidence of multimorbidity and non-communicable diseases in older populations is prevalent in high-, middle-, and low-income countries, which reduces quality of life and increases health expenditure.

The incidence of many age-related morbidities, which are non-communicable, is often associated with modified dietary and lifestyle patterns. To date, few studies have evaluated how diet affects the health status of the elderly.

One study revealed that low vegetable and fiber intake deteriorated total disability in people over 70 years of age. Several studies have also identified different barriers that prevent healthy eating in older adults.

The Mediterranean Diet (MedDiet) has been shown to reduce cognitive impairment, all-cause mortality, depression, and cardiovascular diseases, in addition to improving healthy aging. The MedDiet is mostly a plant-based diet with moderate amounts of fish, meat, and seafood intake.

Although several scoring systems have been developed to assess the extent of adherence to MedDiet, these studies primarily included younger populations without considering older individuals.

A higher intake of energy-dense UPFs, which are generally low in nutrient content, increases the risk of being overweight, obesity, and all-cause mortality. However, additional studies are needed to assess the impact of UPF intake in the older population.

Interestingly, one previous study hypothesized that the hyper-palatability, convenience, and extended shelf-life of UPFs could be beneficial for older adults who are energy deficient, experience reduced appetite, and are at a higher risk of frailty and malnutrition.

About the study

The current study developed MedDiet and UPF scoring tools to assess the dietary habits of community-dwelling older Australian adults who participated in the ASPirin in Reducing Events in the Elderly (ASPREE)/ASPREE Longitudinal Study of Older Persons (ALSOP) trials. The association between MedDiet and UPF scores, as well as the prevalence of cardiometabolic diseases and frailty, was evaluated.

A total of 16,703 Australian participants 70 years of age and older were recruited for the current study. Individuals who were diagnosed with dementia at baseline, lacked functional independence, or had a history of cerebrovascular or cardiovascular disease were excluded from the analysis.

At baseline and follow-up, medical and social histories were obtained, along with lifestyle data and anthropometric measurements. Both the UPF and MedDiet scores were independently generated using the 54-item food-frequency questionnaire (FFQ).

Different morbidities, such as dyslipidemia based on cholesterol and triglyceride levels, type 2 diabetes mellitus (T2DM) based on blood glucose levels, hypertension, and chronic kidney disease (CKD) based on estimated glomerular filtration rate (eGFR) levels in the urine, were evaluated based on dietary patterns. The frailty index was calculated, following which the study participants were classified as non-frail, pre-frail, or frail.

Study findings

The median age of the participants was 76.9 years, 54.4% of whom were female and 45.6% male. As compared to male participants, females were more likely to be older and home alone, as well as less likely to be current drinkers and have completed 13 or more years of education.

Females also exhibited higher body mass index (BMI) values than men with elevated rates of central adiposity and dyslipidemia, as well as a reduced incidence of type 2 diabetes. Importantly, a greater number of pre-frail and frail females were present in the study cohort than males.

Vegetable, non-meat non-seafood protein, and dairy consumption contributed to the overall ASPREE-MDS. Females exhibited marginally higher vegetable, dairy, and seafood scores than men. A higher ASPREE-MDS represented greater adherence to MedDiet.

The ASPREE-UPF score revealed that males are higher consumers of bread, savory snacks, processed meats, and sweetened/processed beverages. A very weak positive relationship between ASPREE-MDS and ASPREE-UPF was observed, thus indicating that enhanced MedDiet adherence does correlate with a significant reduction of UPF consumption.

Higher adherence to the MedDiet, which was sex-dependent, reduced the risk of developing CKD, hypertension, pre-frailty, and frailty. Comparatively, UPF consumption, which was relatively common in older people, was associated with an increased risk of frailty but a lower risk of hypertension.

Conclusions

A very weak relationship between MedDiet adherence and UPF intake was observed in relatively healthy community-dwelling older adults. Nevertheless, higher adherence to the MedDiet and reduced intake of UPF improved frailty, hypertension, and CKD. In the future, more research is needed to identify the causal relationship between UPF and frailty.