Does junk food make you sad?
Does Junk food make you sad?
Have you ever returned from an indulgent holiday and felt post-holiday blues? It may be the return to reality of course, but have you thought about what you eat when you are on holiday and how this could affect your mood?
It seams eating a hotel buffet breakfast everyday followed by burger and chips for lunch and then pasta for dinner doesn’t exactly leave you feeling light and full of energy physically.
You might notice feeling bloated after eating a meal out or after eating junk food, but have you ever considered what affect a change in your diet is having on your mental health?
Your gut is full of bacteria and viruses which help it function well. This is known as the gut microbiota. This collection of bacteria and viruses impacts certain chemicals (such as serotonin) made in the gut which can affect your mood.
Serotonin is a neurotransmitter which is thought to have a good influence on your mood, emotion and sleep. A rise in serotonin can improve symptoms of depression and mental health conditions (1) and gut provides approximately 95% of total body serotonin. Although serotonin has intrinsic roles in the intestines and peripheral metabolism, it can also activate nerve endings that are connected directly to the central nervous system.
For the gut to be healthy and perform its functions (such as produce serotonin), there should be a healthy microbiota.
So what is a healthy microbiota?
We know that having a diverse range of bacteria and viruses is a good thing for your gut. How do you achieve this? By eating a rainbow of fruit and vegetables and avoiding too much junk. Changes to your gut microbiota can occur within days of changing your diet.
It is thought that the consumption of a diet that is high in saturated fat and added sugars negatively impacts cognitive function (2). Evidence suggests that your eating these things can significantly change the proportions of “normal” bacteria that lives in your gut and therefore can influence your cognitive function (2).
Anxiety, depression as well as autism spectrum disorders now all have well established links to a disturbance in your GI tract (3). Additionally, GI disease often also involve psychological comorbidities which are linked to the alteration of your gut microbiome (3).
Up to date research so far suggests that a plant-based diet may be an affective way to achieve a healthy and diverse gut microbiome (4). Fibre is also is a key nutrient for a healthy microbiome (5).
Conclusion
The effects of eating processed food or food that is high in saturated fat and sugar can have negative impact on your gut microbiome which can be linked to issues with mood. Eat plenty of fruit, vegetables and fibre containing foods in order to feed your gut microbiome for a healthier happier you.
NHS : Overview - Selective serotonin reuptake inhibitors (SSRIs). Available from: https://www.nhs.uk/mental-health/talking-therapies-medicine-treatments/medicines-and-psychiatry/ssri-antidepressants/overview/
Noble EE, Hsu TM, Kanoski SE. Gut to Brain Dysbiosis: Mechanisms Linking Western Diet Consumption, the Microbiome, and Cognitive Impairment. Front Behav Neurosci. 2017 Jan 30;11:9. doi: 10.3389/fnbeh.2017.00009. PMID: 28194099; PMCID: PMC5277010.
Appleton J. The Gut-Brain Axis: Influence of Microbiota on Mood and Mental Health. Integr Med (Encinitas). 2018 Aug;17(4):28-32. PMID: 31043907; PMCID: PMC6469458.
Tomova A, Bukovsky I, Rembert E, Yonas W, Alwarith J, Barnard ND, Kahleova H. The Effects of Vegetarian and Vegan Diets on Gut Microbiota. Front Nutr. 2019 Apr 17;6:47. doi: 10.3389/fnut.2019.00047. PMID: 31058160; PMCID: PMC6478664.
Valdes A M, Walter J, Segal E, Spector T D. Role of the gut microbiota in nutrition and health BMJ 2018; 361 :k2179 doi:10.1136/bmj.k2179