Plant and animal protein intake and its association with depression, anxiety, and stress among Iranian women

Abstract

Background Mental disorders are conditions that affect the usual function of the brain, causing a huge burden on societies. The causes are often unclear, but previous research has pointed out, as is the case with many other diseases, that nutrition could have a major role in it. Amino acids, the building blocks of proteins, are the main precursor of neurotransmitters (the chemical messengers in the brain) malfunction of which is heavily associated with a wide range of brain disorders. Methods We assumed different sources of dietary protein could have different impacts on mental well-being. Hence, we decided to collect the nutritional data (with a validated and reliable semi-quantitative food-frequency questionnaire) from a sample of 489 Iranian women and investigate the association between animal and plant protein sources and the risk of depression, anxiety, and stress. Symptoms of these mental disorders were assessed using a validated Depression, Anxiety, and Stress Scales (DASS) questionnaire with 21 items. Results After multivariable adjustment, it was shown that women in the highest tertile of animal protein intake were more likely to show symptoms of depression (OR: 2.63; 95% CI: 1.45, 4.71; P = 0.001), anxiety (OR: 1.83; 95% CI: 1.04, 3.22; P = 0.03), and stress (OR: 3.66; 95% CI: 2.06, 6.50; p < 0.001). While no significant association was seen between plant protein and any of the studied mental disorders. Conclusion Overall, our findings suggest that a diet high in animal protein could predispose individuals to mental illnesses.

Exploring the Interrelationships between Diabetes, Nutrition, Anxiety, and Depression: Implications for Treatment and Prevention Strategies

“…In contrast, it has been shown that a high-fiber diet improves glucose homeostasis, serum lipid profiles, inflammatory chemokines, and depression and anxiety symptoms in patients with T2DM [95]. Evaluating the effects of different sources of protein on the mental well-being of women showed that women who consumed more animal protein had a higher chance of showing symptoms of depression (OR: 2.63; 95% CI: 1.45, 4.71; p = 0.001), stress (OR: 3.66; 95% CI: 2.06, 6.50; p < 0.001), and anxiety (OR: 1.83; 95% CI: 1.04, 3.22; p = 0.03), while no significant association was found between plant protein and these mental disorders [96]. Polyunsaturated fats have also been found to be effective in reducing symptoms of depression and anxiety.…”

Associations between dietary habits and bipolar disorder: a diet-wide mendelian randomization study

“…These potential mechanisms may mediate the relationship between fish intake and BD risk. Other studies, including a Japanese study linking plant protein with reduced depression symptoms and observational research linking high animal protein intake in women with a higher risk of mental illnesses, support these findings (64,65). A meta-analysis that included eight observational studies showed that meat consumption may be associated with a slightly higher risk of depression (66).…”

correlation between diabetes mellitus and depression

“…Studies have indicated that individuals with mental disorders tend to have a diminished intake of vegetables, fruits, whole grains, and fiber in their dietary habits. [42,43]. Consequently, a low-quality diet consumed during episodes of depressive symptoms may increase the risk of developing diabetes.…”