The new research was published in the journal Molecules. It was the work of a large team of researchers associated with institutions in France, Italy, Kazakhstan, Norway and Pakistan.
Dance of the neurotransmitters
It has long been understood that dietary changes can affect mood states, depending on the individual. The researchers noted that the modern understanding of this effect has to do with how some nutrients can impact the production of neurotransmitters. More than 200 neurotransmitters have been identified, and the complex interplay of these substances form the energy currency of the brain. They comprise the chemical basis of cognition and emotions via processes that are still only dimly understood.
“Food intake, diet changes, and nutritional supplements are known as outstanding options for complementary and alternative medicine, as they can either support or substitute traditional therapies. Current areas of medicine, like neuroscience and psychiatry, show a growing inclusion of alternative medicines in the modern therapeutic panorama. Health care practitioners continue to incorporate dietary changes with beneficial outcomes on some medical disorders, such as headaches,” the researchers noted.
But, they said, more precise definitions and treatment modalities are called for, because, at the moment, almost anything goes, giving rise to the genre of online advertising telling viewers to ‘do this one thing before bedtime’ as an answer to a host of ills.
“These alternative medicines are often misused by patients beyond their therapeutic purpose, thus actually causing side effects, drug reactions, and waste of time and money,” they said.
The researchers combed through the abstracts of more than 1,100 papers to arrive at 72 for further review. In the end, 13 papers met their inclusion criteria.
The authors looked at what these papers had to say about the effects of dietary inputs on the following neurotransmitters: dopamine, acetylcholine, serotonin, gamma-aminobutyric acid (GABA), glutamate, norepinephrine, epinephrine, histamine and aspartate.
Blood-brain barrier complicates equation
The authors noted that it is not a simple plug and play option for the levels of chemicals in the brain as it is for the blood stream in general. If an individual is suffering from low vitamin C, for example, eating citrus fruits or other foods high in vitamin C is a quick fix. But the blood-brain barrier prevents most constituents of foods and supplements from entering the brain directly, so increasing neurotransmitter levels has to be approached via the supply of precursors and paying attention to other mediating agents.
For example, increasing the level of dopamine in the brain could be approached from a nutritional standpoint by consuming more foods or supplements that supply L-dopa, a dopamine precursor. Extracts of velvet bean (Mucuna pruriens) is one example of such a dietary source. In addition, however, attention would need to be paid to the level of the amino acid tryptophan in the body, which is a key part of the assembly of dopamine in the brain, aided by other cofactors.
The authors said a greater understanding of the interplay of dietary intakes with brain biochemistry could go a long way in improving outcomes for patients.
“This review article has highlighted some food sources that contain NTs and the positive effects of NTs on the nervous system. Medication can cause some side effects, so nutritional NTs would be useful in such cases. This article focused on the role of plant, vegetable, and animal foods, including dairy products, in order to adequately compensate the body requirement of these NTs,” the authors concluded.
2023, 28(1), 210; https://doi.org/10.3390/molecules28010210
Neurotransmitters Regulation and Food Intake: The Role of Dietary Sources in Neurotransmission
Authors: Gasmi A, et al.