Eat more fruit and vegetables to lower frailty risk

By Dr. Sanchari Sinha Dutta, Ph.D.Sep 19 2024

New research shows that eating whole fruits and vibrant vegetables, especially red and orange varieties, significantly reduces frailty risk in adults, helping people maintain strength and vitality as they age.

Study: The Relationship Between Fruit and Vegetable Intake and Frailty: Data from NHANES 2007-2018. Image Credit: drdigitaldesign / Shutterstock

A study published in the journal Heliyon reveals that consuming fruits and vegetables is associated with a reduced risk of frailty.

Background

Frailty is a clinical state of increased vulnerability to stress. The condition is characterized by reduced physical strength, fatigue, diminished mobility, and a decline in overall quality of life. Multiple aspects are associated with frailty, including muscle strength, cognitive function, and immune system function.

The intensity of frailty is measured using a frailty score, which is calculated using multidimensional indicators, including gait stability, grip strength, cognitive function, and physical activity level.

Diet plays an important role in maintaining physical and mental health. Healthy foods, including fruits and vegetables, have been found to reduce the risk of infectious and non-communicable diseases, such as diabetes, obesity, cardiovascular diseases, and neurological and psychological diseases.

Fruits and vegetables are rich sources of vitamins, minerals, antioxidants, and other vital nutrients required for normal physiological functions. Research shows that adequate intake can slow down the progression of frailty and improve various health outcomes, such as quality of life.

In this study, scientists have explored whether fruit and vegetable intake can reduce the risk of frailty in adults in the United States.

Study design

The study utilized epidemiological data of 13,935 adult participants in the National Health and Nutrition Examination Survey (NHANES) between 2007 and 2018. NHANES is a nationally representative cross-sectional study conducted regularly since 1960 to assess the health and nutritional status of children and adults in the United States.

Participants’ average intake of fruits and vegetables over two days was determined using two separate 24-hour dietary recall questionnaires. A frailty index model was utilized to assess participants' frailty levels. The model included 49 items across seven main categories: cognition, dependency, depression, comorbidities, hospital and nursing, anthropometrics, and laboratory results.

Appropriate statistical analyses were conducted to determine the association between fruit and vegetable intake and risk of frailty in different demographic subgroups, including gender, income levels, BMI, and race/ethnicity. The analysis employed Restricted Cubic Splines (RCS) to identify nonlinear relationships between intake and frailty risk.

Important observations

The study population included 13,935 participants. Of them, 2,224 were classified as frail, and 11,711 were classified as non-frail. These two groups showed significant differences in sociodemographic characteristics, including gender, race, marital status, education level, and body mass index (BMI).

The analysis, controlling for potential confounding factors (age, gender, education level, physical activity level, financial status, smoking and alcohol intake status, and BMI), revealed that fruits and vegetables in any form can significantly reduce the risk of frailty.

The study found that the protective effect of fruit and vegetable intake varied across different demographic groups. For example, females and underweight participants experienced a stronger association between high fruit/vegetable intake and reduced frailty compared to other subgroups.

Regarding whole or granular fruits, excluding oranges, melons, and berries, both medium or high-intake groups exhibited significantly lower risk of frailty than the low-intake group.

The subgroup analysis, considering all fruit and vegetable intake categories (total fruit intake, whole fruit intake, juice intake, other fruit intake, red-orange vegetable intake, and total vegetable intake), revealed significant associations between fruit and vegetable intake and frailty risk across different genders, incomes, alcohol intake, education levels, and racial groups.

Further analysis using RCS demonstrated that the relationship between intake and frailty was nonlinear, with a reduction in frailty risk observed up to a certain intake threshold, beyond which the risk began to increase. This pattern was particularly evident for overall fruit intake, except for red and orange vegetables, which continued to lower frailty risk as intake increased.

Study significance

The study finds that adequate intake of fruits and vegetables can significantly reduce the risk of frailty. Notably, the study highlights that intake of starchy vegetables may increase frailty risk.

 In addition, BMI was found to modify the relationship between fruit and vegetable intake and frailty, with underweight individuals showing a more pronounced benefit from higher intake levels compared to individuals with normal or higher BMI. The current study, however, finds that increasing vegetable and fruit intake significantly reduces the incidence of frailty in all participants, irrespective of their BMI levels. This association is more pronounced among underweight participants.

Among different fruit intake categories, the study finds that whole fruit intake has a better frailty risk reduction effect than fruit juice intake. Similarly, a significant risk reduction has been observed with increasing intake of red and orange vegetables, including carrots, red peppers, and sweet peppers.

Overall, the study provides a scientific basis for developing effective nutritional strategies for frailty prevention and management. These strategies should take into account individual demographic characteristics, such as gender and BMI, to maximize the protective effects of fruit and vegetable intake. They should also emphasize consuming whole fruits over fruit juices and red and orange vegetables over starchy vegetables.

As mentioned by the scientists, the current study findings highlight the need for in-depth future investigations into the dietary links with frailty. More clinical studies are needed to validate these findings and understand the mechanisms by which fruits and vegetables may reduce the risk of frailty.