Diet, Resilience and Quality of Life

Recent interest in Health-Related Quality of Life (HRQoL), defined as the perceived physical and mental health of individuals or groups over time, has led to its frequent assessment alongside medical and psychological outcomes in clinical and public health settings, particularly during the development of new treatments. Despite historical recognition of nutrition's impact on health, the link between nutrition and HRQoL remains underexplored. Our Research Topic, "Nutrition and health-related quality of life: is it an ignored outcome? Volume II," sought to bridge this gap, attracting international submissions from America and Europe, resulting in three accepted studies. The studies investigated various aspects: Han et al. in the U.S. linked dietary magnesium intake and serum vitamin D status to handgrip strength, an HRQoL indicator; de Lourdes Moreno et al. in Spain validated a Spanish version of the Coeliac Disease Questionnaire for better HRQoL assessment in coeliac patients; and Alonso-Cabezas et al., also in Spain, examined dietary adherence in premenopausal women, emphasizing the need for healthy diets for better HRQoL. These studies highlight the importance of nutrition in HRQoL and call for further research to consolidate these findings and address measurement challenges.

As the evidence investigating the links between physical resilience and dietary intake remains lacking, Sotos-Prieto et al. (2021) conducted their study to look at the impact of dietary patterns, in particular, fidelity to the Mediterranean diet, on physical resilience, using data from a population of 1301 participants (60 or more years of age) of the Seniors-ENRICA (The Study on Nutrition and Cardiovascular Risk in Spain). The participants submitted a Mediterranean Diet Adherence Screener and the Alternate Healthy Eating Index 2010 to evaluate their dietary fidelity, while their health was evaluated at baseline and during follow-up via a 52-item health Deficit Accumulation Index (DAI), which involved investigating four domains, namely physical and cognitive function, self-rated health/vitality, mental health, and morbidity. Finally, the physical resilience of participants was inferred as aggregating a lower DAI score than expected values according to age, irrespective of exposure status to acute and chronic stressors. Analysis of the results revealed that Mediterranean Diet fidelity was linked to higher chances of increased and maintained physical resilience, as evident in 610 participants observed over 3.2 years. This was further corroborated by observing how the individuals in the highest group of Mediterranean Diet Adherence Screener scores demonstrated higher odds of physical resilience compared to those in the lowest adherence group. The authors conclude that Mediterranean diet fidelity is linked to higher odds of physical resilience. [NPID: Cohort study, Mediterranean diet, older adults, physical resilience]

Imbalances in the dietary intake of long-chain (LC) n-3 and n-6 polyunsaturated fatty acids (PUFAs) were found to potentially affect emotional regulation and lead to developing mental disorders, including depression. In their earlier works, Yoshikawa et. Al (2015) demonstrated an association between fish consumption, a major source of LC n-3PUFA, and resilience to depression in Japanese company workers, where Yoshikawa et al. define resilience as being able to withstand stress despite hardships. The conventional Japanese diet, consisting of high fish intake, was shown to be associated with low symptoms of depression. However, the Japanese dietary patterns of today have become more westernized. A major difference is seen with westernized diets entailing excessive consumption of linoleic acid (a LC n-6 PUFA) found in vegetable oils used to fry food. This is in addition to processed foods, which are associated with an increased risk of depression. Thus, in this updated work (2016), the authors examined the association between frequency of eating fried foods and resilience to depression in a population of 715 Japanese company workers. The authors used the Center for Epidemiologic Studies Depression scale (CES-D) to evaluate depressive symptoms, and a 14-item Resilience Scale (RS-14) to evaluate resilience. A self-report questionnaire adapted from the Food Frequency Questionnaire was used to measure the frequency of consuming fish and fried food. The results demonstrated significant links between the frequency of eating fried food and total CES-D and RS-14 scores, and between depression and resilience scores. In conclusion, the authors culminate that an increased frequency of eating fried foods was found to be linked to lower resilience to depression. In addition, the authors recommend conducting further interventional studies focused on using nutrition to raise resilience and prevent depressive symptoms. [NPID: Western diet, fried food consumption, depressive symptoms, resilience]

Aubry and team (2019) experiments on a strain of mice highly susceptible to chronic social defeat stress (CSDS) to test the efficacy of 1.5% dietary curcumin, a polyphenol compound found in the turmeric plant known to possess anti-inflammatory and antidepressant properties, on promoting resilience. Although a 4.5 fold improvement in stress resilience was seen in the mice with administration during CSDS, 36% of the mice were still susceptible to the effects of the stress (non-responders). Those who demonstrated resilience (responders) were found to release less corticosterone following acute restraint stress and had lower concentrations of peripheral IL-6 compared to non-responders, which could indicate the involvement of the NF-κB pathway in the response. Another promising sign was the preventative effect curcumin had on anxiety-like behaviour in both responders and non-responders in the elevated-plus maze and open field test. The study provides the first preclinical evidence of curcumin in improving resilience in response to CSDS, and also suggests its potential role in preventing anxiety-like symptoms during exposure to chronic social stress. [NPID: resilience, stress, CSDS, curcumin, polyphenols, turmeric, anti-inflammatory, inflammation, depression, corticosterone, anxiety, social stress]

Yin et. al (2019) tackled the association between dietary diversity (DD) and psychological resilience in an elderly Chinese population. With 8571 community-based citizens taking part in this study, the frequency of food groups in their diets were reported, and psychological resilience assessed through a simplified resilience score (SRS). Lower DD resulted in poorer resilience compared to those with good DD, with the association proving significant [ β (95% CI) = -0.94 (-1.07, -0.81) for SRS (p<0.01) and odds ratio (OR) of 1.83]. The interaction effects of age with DD were also statistically significant with p-value less than 0.001 for SRS and low SRS status. When age groups were analysed, it was revealed that the younger subgroup was more likely to score less on SRS if on a poor DD compared to the older subgroup, with 83% and 61% increases in occurrence in separate analyses. The younger subjects consuming diets with higher diversity on average scored higher on SRS than others (compared to this group, risk of scoring low in resilience was higher in those younger with low DD, oldest with good DD, oldest old with poor DD, as ORs were 2.39, 1.28, and 2.03 respectively). Increased consumption of vegetables, fruits and nuts proved to contribute most to the DD. The researchers may have discovered that greater diet diversity is crucial in maintaining/improving resilience in the Chinese elderly and perhaps even more important in the younger elderly. [NPID: resilience, diet diversity, Chinese, China, elderly, vegetables, fruits, FV intake, nuts]