Japan RCT supports γ-tocopherol’s potential to improve some PMS symptoms
Compared to those who did not take γ-toc, significant results were noted for physical symptoms associated with water retention, such as “swelling of the legs” and “heavy legs”; as well as for mood symptoms such as “fatigue” and “irritability/anger”.
Scientists from Otsuka Pharma and two other Japanese hospitals noted that the improvement in PMS symptoms was accounted for by the ability of a γ-toc metabolite to rid the body of salt (sodium) and water.
“γ-Toc intake significantly increased sodium excretion compared with placebo intake. These results suggest that γ-Toc moderately mitigates the accumulation of excessive sodium levels in humans, including during the premenstrual period, as reported by Uto et al. in rats,” the researchers explained.
The study also noted significant results in the morning for the γ-toc group, which the researchers justified that “this could be attributed to the fact that water stored in the lower limbs due to gravity-induced downward water movement during the day is excreted as urine due to position changes during sleep.”
Existing treatments for PMS
The paper reported an undertreatment of PMS despite its prevalence among Japanese women.
Existing treatments span pharmacology such as diuretics, sedatives, oral contraceptives, and herbal medicines, to psycho- and psychotherapies such as counselling, lifestyle guidance and exercise therapy.
Emerging evidence elicited the effects of γ-toc on PMS: “A recent study reported a natriuretic effect of γ-carboxyethyl hydroxychroman (CEHC), which is a metabolite of γ-tocopherol (y-Toc), a natural vitamin E homolog.
“Kato et al. reported that γ-Toc could effectively treat premenstrual pretibial edema; however, the study did not report increased urinary sodium excretion due to γ-Toc intake and did not examine premenstrual symptoms. Therefore, we aimed to investigate the effects of γ-Toc intake on mitigating premenstrual symptoms and natriuresis,” the researchers said.
Study methodology
This was based on a 7-week randomized, double‑blind, placebo‑controlled study done on 51 Japanese women above the age of 20, with premenstrual symptoms induced by water retention during the luteal phase.
Randomised into two groups, the γ-toc group consumed two γ-toc capsules, while the placebo group consumed two capsules containing only Vitamin E-stripped corn oil in a crossover fashion twice a day during the luteal phase of one menstrual cycle.
The γ-toc capsule was supplied by Eisai Food Chemical, and contained 92 mg γ-Toc, 1.7 mg α-Toc, 1.7 mg β-Toc, and 1.0 mg δ-Toc, which was dissolved in vitamin E- stripped corn oil.
Participants were screened a total of three menstrual cycles – one before the intervention, and 2 after the interventions that is spaced three weeks apart.
They had to undergo physical measurements, including taking their urine and blood samples; and complete questionnaires assessing their physical and menstrual symptoms.
“Overall, reducing symptoms related to water retention may mitigate mental symptoms. Since taking 400 mg γ-Toc for 7 days improved edema, we examined whether taking 360 mg γ-Toc for 7 days could improve physical and mental symptoms during the luteal phase.
Concluding the paper, the researchers recommended for future studies to cover multiple cycles with adequate sample size to improve the reliability of the results, and to consider the effect of season on water retention symptoms in future studies.
“γ-Toc may be useful as a nutritional supplement for mitigating PMS symptoms and improving women’s quality of life. Therefore, additional trials of longer duration and larger sample size are required to confirm these beneficial effects of γ-Toc,” the researchers said.
Source: BMC Complementary Medicine and Therapies
“Effect of γ‑tocopherol supplementation on premenstrual symptoms and natriuresis: a randomized, double‑blind, placebo‑controlled study”
https://doi.org/10.1186/s12906-023-03962-5
Authors: Higuchi et al.
