More fruit and veggies, less stress

Background

Chronic stress is a risk factor for several illnesses, especially mental health issues such as anxiety and depression.^[1] Mounting evidence suggests that diets rich in fruits and vegetables may protect against stress.^[2] However, stress is a complex, multifaceted phenomenon, and no studies had investigated how fruits and vegetables affected different aspects of stress or optimum intake.

The study

This cross-sectional study of 8,640 Australian adults (ages 33–53) examined whether fruit and vegetable intake is linked to different domains of stress. For this purpose, the researchers used the perceived stress questionnaire,^[3] which measures four different aspects of stress:

• Worries: anxiety and frustration about the future

• Tension: exhaustion and lack of relaxation

• Demands: pressure, overload, and lack of time

• Lack of joy: lack of energy and enthusiasm

The researchers adjusted the results for confounding factors such as age, BMI, cardiovascular disease, diabetes, education, energy intake, physical activity levels, relationship status, sex, and smoking.

The results

A higher intake of fruits and vegetables was associated with lower levels of perceived stress in all four domains. After adjusting for confounding factors, a higher intake was still linked to lower levels of stress related to worries, tension, and lack of joy — but not stress related to demands.

The researchers also found that eating at least 400 grams of fruits and vegetables daily was associated with the greatest reduction in stress levels (16–36%).

Note

The data analyzed in this study were collected in 1999–2000, which may limit the extent to which they can be applied to the present. However, because fruit and vegetable intake has only marginally changed in Australia since 2000, the findings still seem relevant today.

Further, it is surprising that the stress related to demands was not affected. The researchers argue that this may be due to the stress domain of demands being an external stressor rather than a stress reaction.