An interesting study using a natural substance, Marmite, was released in April, demonstrating GABA-ergic manipulation by a nutraceutical. GABA plays a role in controlling brain activity in processes such as depression and seizures. There are no real oral sources of natural foods that can be digested and absorbed into the CNS to increase GABA levels until Marmite was found in this study. Marmite is a derivative of a yeast extract that is high in B!@ and pyridoxine (B-6) as well as glutamate. Fourteen subjects were studied in this clinical trial, each being fed a teaspoon of Marmite a day for a month with a control group being fed peanut butter. EEG demonstrated a down-regulation of evoked visual responses in the brain , the occipital lobe, which is highly GABA dependent for inhibition. It was determined that the Marmite did have an ability to decrease the visual response of the brain based on EEG, thereby was modifying the GABA control of the brain.
Using a steady-state EEG paradigm, we found that a dietary intervention had a significant effect on the brain’s response to visual stimuli, compared with consumption of a placebo. This was unlikely to be a consequence of attentional lapses, and the effects were reduced after 2 months of resuming a normal diet. These findings are consistent with an increase in the availability of GABA in visual areas of the brain that inhibits the excitability of neurons responsive to the stimulus.
This raises the possibility that dietary interventions geared towards increasing GABA concentration might reduce excitability to normal levels, and potentially alleviate some symptoms of the disorder such as seizure frequency (particularly for photosensitive epileptics). This might be of particular utility in treating patients who either do not respond to traditional medication, or who cannot take it for other reasons (e.g. pregnancy, or interactions with other drugs). The apparent involvement of GABA in other neurological and mental health conditions (Honig et al., 1988; Nemeroff, 2003; Robertson et al., 2016) suggests further potential for deployment of dietary interventions.
Of note, the vitamin content of marmite :
Vitamin B6 0.57 mg/100 g
Vitamin B12 (Cyanocobalmin) 29 mcg/100g
Glutamic Acid (Glutamate) 2.8 g/100g