Nutritional Psychiatry : How Does Food Affect Our Mood?
You probably have already heard of the following analogy: “food is fuel for the body”. Undoubtedly, food ultimately is energy for our body, but can it affect our mood? Absolutely !
Although some of the mood effects of food can be related to pleasure and reward (i.e. chocolate), others can be due to their nutrient content. Vitamins and minerals play a fundamental role in your energy levels, ultimately affecting your mood and brain functions. For instance, whole grains (i.e. whole wheat bread, brown rice, oatmeal) are rich sources of B vitamins, an essential coenzyme for the metabolism of macronutrients into energy. A diet low in such foods can therefore lead to feelings of tiredness, feeling depressed or irritable.
Glucose is vital for brain function, as it is its main source of energy. Low levels of blood glucose can make you feel weak and tired, which poses a special risk with the rise of popular trends such as low-carb diets.
Furthermore, caffeine acts as a stimulant and can counter the effect of fatigue by increasing alertness. However, too much caffeine can lead to feelings of grumpiness. To know more about the good and the bad of consuming coffee, check out our previous article “Calling all fellow coffee addicts: How much is too much?” here: https://www.dhnusmcgill.com/single-post/calling-all-fellow-coffee-addicts-how-much-is-too-much
Nutritional psychiatry, an emerging field looking at the effects of food on mental health, shows promising research for prevention and treatments of psychological disorders.
Studies have shown a 25-35% decrease in the risk of depression in individuals eating a Mediterranean or Japanese diet, compared to a typical Western diet (processed foods, refined grains and sugars). This is mainly due to the high content of “vegetables, fruits, unprocessed grains, and fish and seafood, and to [...] modest amounts of lean meats and dairy”.
We often hear of our gut being “second brain.” The lining of our gastrointestinal (GI) tract is composed of hundreds of millions of nerve cells, allowing for synthesis of different neurotransmitters. The GI tract communicates back and forth with our brain by sending signals to the central nervous system, therefore altering our mood. This Gut-Brain connection is so strong that about 95% of serotonin, a neurotransmitter playing a key role in stabilizing our mood, is produced in the gut.
The production of this “happy hormone” is also influenced by our microbiome. The “good bacteria” in our gut aids in absorption of key nutrients by limiting inflammation, but also by activating such neural pathways to affect our mood.
In summary, food can affect our mood emotionally and physically. It is important to consume enough fruits, vegetables and whole grains to assure optimal energy levels. Further research is needed to provide information about the underlying causality mechanisms of nutrition and mental health.
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Johns Hopkins Medicine. The Brain-Gut Connection. Retrieved on March 12th 2021, from: https://www.hopkinsmedicine.org/health/wellness-and-prevention/the-brain-gut-connection
Adan et al. ScienceDirect. Nutritional psychiatry: Towards improving mental health by what you eat. December 2019. Volume 29, Issue 12, pages 1321-1332. Retrieved on March 12th 2021, from: https://www.sciencedirect.com/science/article/pii/S0924977X19317237