Effect of Folate Supplementation on Inflammatory Markers in Individuals Susceptible to Depression: A Systematic Review

Abstract

Folate has been proposed to be an efficacious treatment strategy for depression. The mandatory fortification of flour with synthetic folic acid (FA) in over 80 countries has yielded improvements in folate intake; however, depression is still a considerable public health concern. While there are established benefits of FA fortification in reducing risk of neural tube defects, the implications regarding depression are unclear, especially in individuals with certain genetic polymorphisms. Therefore, a systematic review was conducted to examine the effects of folate to treat depression. Following PRISMA guidelines, a systematic review was conducted of electronic databases (PUBMED, Scopus, CINAHL, and Cochrane Library) to identify human clinical trials examining the effects of folate (including FA) supplementation in the management or prevention of depression, the impact on inflammatory markers and if genetic polymorphisms were considered. Ten trials met the inclusion criteria. Seven trials examined effects of either adjunctive FA or L-methylfolate (L-MTHF) supplementation with antidepressants in the management of depression and three examined effects of FA supplementation alone for prevention of depression. No benefit of FA was found compared to placebo (all, p > 0.05). The single L-MTHF trial that explored the interplay of genetic polymorphisms and methylation status found benefit in the Hamilton depression rating scale from adjunctive treatment with 15 mg/day of L-MTHF compared with placebo (−6.8 ± 7.2 vs. −3.7 ± 6.5; p = 0.017) and improvement with L-MTHF for most genetic markers. Currently, there is no evidence to support FA supplementation for the management or prevention of depression. More research is required to determine the efficacy of L-MTHF and folinic acid in certain clinical populations.

The Effects of Green Tea Amino Acid L-Theanine Consumption on the Ability to Manage Stress and Anxiety Levels: a Systematic Review

“…Given the growing interest and prevalence of green tea bioactives consumption globally [23], future human trials of L-THE consumption should be conducted over a more extended period (ten weeks or longer) with the combination in identifying the therapeutic doses required for different population sub- symptoms, and cognition [65,66]. Further, studies should be conducted to ascertain whether L-THE binds to food matrixes before consumption as the health effects of L-THE may vary depending on the type of food and/or compounds in which L-THE has been combined with.…”

The Effect of Natural Therapies in Combination with Usual Care for Depression: A Narrative Review

“…The synthetic form of folic acid occurs as the completely oxidized pteroylmonoglutamic acid that has more stability than the natural form [26]. Folate acts as a cofactor in the pathways associated with the synthesis of various neurotransmitters involved in depression [27] such as dopamine, serotonin, and noradrenaline [28]. It acts as a methyl donor for the conversion of homocysteine to methionine, which leads to the production of S-adenosylmethionine (SAMe) [29].…”

The association between protein consumption from animal and plant sources with psychological distress in older people in the Mediterranean region

“…As part of a relatively new field termed nutritional psychiatry, dietary intake and patterns have emerged as having strong influence on symptoms of depression and anxiety, yet the specific components and the underlying mechanisms are unclear [2]. To date, several dietary nutrients have been investigated for their effects depression and anxiety including Bvitamins [6][7][8], omega-3-fatty acids [9], and minerals including iron, zinc and selenium [10]. However, despite some benefits of supplementation with individual nutrients, it is now widely recognised that the overall quality of the dietary pattern represents a more robust and substantial influence on overall health [11].…”