Key Study 1 (Excitatory neurotransmitter): Kraal et al. (2020)
Aim: To investigate the role of dietary glutamate (in the form of monosodium glutamate (MSG)) in chronic pain and psychiatric disorders such as anxiety and schizophrenia.
Procedure: The researchers reviewed previously published research on the topic as part of their review article. Glutamate is a key excitatory neurotransmitter which, as a dietary source, can be found in the food flavouring additive MSG (which features particularly in cooking which uses a lot of soy sauce but also in parmesan cheese, meat, and many processed foods such as canned soup).
Results: The research reviewed suggests that an excess of dietary glutamate can be harmful to both physical and mental health. Too much dietary glutamate appears to be linked to ongoing chronic pain (pain which is continuous) and to a range of psychiatric disorders such as anxiety, PTSD, OCD, schizophrenia and depression.
Conclusion: Adopting a diet which is low in dietary glutamate such as MSG may lead to a decrease in chronic pain and better mental health.
Evaluation of Kraal et al. (2020)
Strengths
-
- The findings of this review have good application as they can be used to inform preventative/intervention strategies for patients with chronic pain and/or mental illness
- Conducting a review article means that the researcher is able to amass a lot of evidence to assess rather than relying on the results of one study alone
Limitations
-
- A review article uses secondary data which means that the researcher has not been able to exert any control over the conditions in which it was obtained which reduces the reliability of the findings
- It would be very difficult for policymakers such as governments or health committees to insist that people adopt a low-MSG diet which does limit the usefulness of the findings to some extent
Key terms:
- Excitatory neurotransmitter
- Dietary glutamate
- Monosodium glutamate