According to the World Health Organization (WHO), about 5% of adults worldwide suffer from depression. Recently, as the number of depressed patients due to COVID-19 increases and the aging population increases, the number of elderly depressed patients is also rapidly increasing. In particular, depression in the elderly can be considered a phenomenon that occurs with aging, but depression has a great impact on all aspects of life and is closely related to physical health such as dementia, cardiovascular disease, and stroke, so the need for prevention is growing.
■ Consuming soybeans 4-7 times a week helps reduce the risk of developing depression in the elderly
According to a study published last September in the International Journal of Psychiatry, Frontiers in Psychiatry, by a research team from the Zhejiang Center for Disease Control and Prevention in China, the higher soy consumption, the lower the risk of depression in the elderly. .
The research team interviewed 10,901 elderly people in Zhejiang Province, China about food intake frequency, and followed up for 6 years to examine the association between food intake and the incidence of depression. Finally, as a result of analyzing a total of 6,253 men and women with an average age of 68.2 years, the more frequent soybean and soybean food intake, the lower the risk of developing depression.
Those who ate soy foods 4-7 times a week had a 54% lower risk of depression compared to those who ate soy foods once a week. As a result of subgroup analysis, a 50 g increase in soy food intake per week was associated with major depressive disorder. The risk was found to be 8% lower. Accordingly, the research team suggested that regular consumption of soy foods may have a beneficial effect on mental health in the elderly.
■ Intake of 25mg~100mg of isoflavone helps to improve symptoms of postmenopausal depression
According to a study by a research team at Lanzhou University in China published in the International Journal of Clinical Practice in August last year, phytoestrogens, especially isoflavones from soybeans, were found to be effective in treating postmenopausal depression.
The research team collected 2,183 studies to evaluate the effect of phytoestrogens on the treatment of depression in postmenopausal women, and conducted a meta-analysis of 19 studies. A meta-analysis showed that phytoestrogens had a positive effect on postmenopausal depression symptoms compared to placebo in 1,248 postmenopausal women. The effect comparison with placebo was calculated through Standardized Mean Differences (SMD), and a negative number and a larger absolute value mean that it is more effective than placebo.
The effect of phytoestrogens on postmenopausal depression was SMD -0.45. Among phytoestrogens, isoflavones (SDM -0.52) showed greater improvement in postmenopausal depression than lignans (SDM -0.23). Long-term intake of 25 mg to 100 mg of isoflavones per day has been shown to reduce symptoms of postmenopausal depression (SDM -0.45). Accordingly, the research team revealed that isoflavones and lignans could be considered as complementary treatments for postmenopausal depression.
Meanwhile, according to a study published in the SCI-level international academic journal ‘Food & Function’, isoflavones, one of the components of soybeans, reconstitute the intestinal microflora and affect neurotransmitters, alleviating behaviors similar to depression. It is known to do
