Consumption of junk food worsens mental health
Poor diet quality appears to impair mental health, according to a new study.
“This provides additional evidence that public policy and clinical practice should more explicitly aim to improve diet quality among those with mental illness. Dietary interventions for those with mental illness should especially be targeted at young adults,” said researchers.
Of 245,891 surveyed adults, representing an annual estimated population of 27.7 million, 13.2 percent (n=27,979; 54.6 percent female) showed evidence of moderate psychological distress (MPD) and 3.7 percent (n=8,575; 58.5 percent female) had serious psychological distress (SPD). The group with no or low psychological distress (NLPD) had a more even distribution of sexes (n=209,337; 50.2 percent female). [Int J Food Sci Nutr 2019;doi:10.1080/09637486.2019.1570085]
Analysis of the mean consumption levels for 13 types of food showed that, in general, servings of healthy food progressively decreased with increasing psychological distress. For instance, fruit intake was significantly higher in the NLPD group compared with both the MPD and SPD participants (7.92 vs 7.09 and 6.70, respectively; p<0.001 for both).
Moreover, MPD adults ate significantly more fruit servings than their SPD counterparts (p<0.05).
The same was true for vegetable intake. Those with NLPD ate significantly more weekly servings of vegetables than participants in the MPD and SPD groups (6.73 vs 5.86 and 5.41, respectively; p<0.001 for both). MPD vegetable consumption was likewise higher than that in the SPD group (p<0.01).
In addition, those with NLPD drank more water than those with MPD (5.76 vs 5.52; p<0.01).
On the other hand, an unhealthy diet seemed to be a trademark of increasing psychological distress. Soda intake, for example, was significantly elevated in those with SPD and MPD relative to NLPD (12.28 and 9.84 vs 6.23, respectively; p<0.001). The difference in consumption between SPD and MPD was also significant (p<0.01).
Similar trends were obtained for intake of fast food (1.19 and 1.12 vs 0.89; p<0.001 for both) and French fries (1.93 and 1.87 vs 1.47; p<0.001 for both), which were both higher in the SPD and MPD groups. Those with higher psychological distress also consumed greater monthly volumes of fruit drinks (10.13 and 8.69 vs 5.67; p<0.001 for both).
Multivariable ordinal logistic regression analyses further confirmed these findings. Compared with the reference NLPD group, MPD and SPD participants were much less likely to consume vegetables (adjusted odds ratio [aOR], 0.81; p<0.001 and aOR, 0.68; p<0.001, respectively), fruits (aOR, 0.79; p<0.001 and aOR, 0.65; p<0.001, respectively) and water (aOR, 0.82; p<0.001 and aOR, 0.77; p<0.01, respectively).
The inverse was true for intake of unhealthy foods, which was more likely in those with greater psychological distress: soda (MPD: aOR, 1.23; p<0.001; SPD: aOR, 1.26; p<0.001), French fries (aOR, 1.24; p<0.001 and aOR, 1.30; p<0.001, respectively), fast food (aOR, 1.27; p<0.001 and aOR, 1.30; p<0.05, respectively), cake (aOR, 1.16; p<0.001 and aOR, 1.20; p<0.01, respectively) and ice cream (aOR, 1.09; p<0.05 and aOR, 1.15; p<0.05, respectively).
“Shaping policy and practices, which include access to dietary consults and nutrition education as inclusionary to mental illness treatment and prevention, may yield greater improvement of both mental and physical health,” said researchers.
“Furthermore, due to the confounding of poverty on mental illness and dietary patterns, public assistance programmes … may have the greatest impact when nutrient-rich dietary patterns are supported,” they added.