What actually causes PMT?
Although the physiology of the menstrual cycle has been well documented, it’s surprising that the causes of PMT are only now becoming clearer. Scientists have proposed various influencing factors, such as hormone imbalance, vitamin and mineral deficiencies, reactive hypoglycaemia, prostaglandin imbalance, endogenous opiate peptides or hormone ‘allergy’, menstrual toxins, and neurotransmitter imbalance.
Unexpectedly it may not be down to just difference in hormone levels in PMT sufferers that leads to symptoms, but also that the normal fluctuation in ovarian hormones may be the cyclical trigger for biochemical events within the central nervous system.
Neurotransmitters, B6 and PMT
Our mood can be influenced by certain specific chemical messengers in the brain (neurotransmitters), and new research suggests that neuroendocrine imbalances may explain psychological symptoms. This year there has been research into neuroendocrine factors which may contribute to the psychological symptoms of PMT, such as mood disorders, anxiety, insomnia and appetite imbalance.
The ovarian hormones appear to exert their effects on the mood-regulating neurotransmitters seratonin and gamma-aminobutyric acid (GABA). Serotonin receptor concentration actually varies with changes in the oestrogen and progesterone levels and PMT sufferers have lower blood concentrations of serotonin leading to low moods, depression and sleep and appetite disturbances.
So nutrients known to support the synthesis and balance of serotonin and dopamine have demonstrable benefits. This effect is enhanced still further by trials that demonstrated that vitamin B6 is an important “cofactor” for enzymes involved in the synthesis of neurotransmitters and B6 deficiency has been associated with increased nervous irritability. L-tryptophan may also be beneficial when breast tenderness, bloating and water retention are present, even more so when taken with magnesium.
One of many scientific trials
In a randomized controlled clinical trial, 37 patients with premenstrual dysphoric disorder were treated with L-tryptophan 6g per day under double-blind conditions for 17 days from the time of ovulation to the third day of menstruation, during three consecutive menstrual cycles.
RESULTS: the Visual Analogue Scales (VAS) revealed a significant (p = .004) therapeutic effect of L-tryptophan relative to placebo for the cluster of mood symptoms comprising the items of dysphoria, mood swings, tension, and irritability. The magnitude of the reduction from baseline in maximum luteal phase VAS-mood scores was 34.5% with L-tryptophan compared to 10.4% with placebo.
CONCLUSIONS: These results suggest that increasing serotonin synthesis during the late luteal phase of the menstrual cycle has a beneficial effect in patients with premenstrual dysphoric disorder.