How Your Gut Microbiota is Linked to Both Positive and Negative Aspects of Mental Health

Microbiota composition is linked to both positive and negative aspects of mental health

 

A large-scale study in Belgium and the Netherlands found links between the abundance of certain groups of gut bacteria species and mental health outcomes. Faecalibacterium and Coprococcus bacteria that produce a short-chain fatty acid called butyrate were consistently more abundant in individuals with higher quality of life. In contrast, Dialister, Coprococcus spp, tended to be depleted in individuals with depression. Social functioning tended to be better in individuals with many bacteria capable of producing 3,4-dihydroxyphenylacetic acid in their gut. 3,4-dihydroxyphenylacetic acid is a substance our body produces when processing dopamine, a neurotransmitter associated with experiencing good feelings (Valles-Colomer et al., 2019). The study was published in Nature Microbiology.

 

Social functioning was better in those with bacteria capable of producing a substance our body produces (3,4-dihydroxyphenylacetic acid) when processing dopamine 

 

Humans have known for centuries that there is a link between how our digestive system works and how we feel. Everyone senses from experience that our mental state also deteriorates when our digestive system doesn’t work well. However, in the past century, medical and biological science has advanced enough to allow scientists to examine the gut microbiota in our digestive system and study the interaction between them and the human body in detail.

 

A large-scale study found links between the abundance of certain gut bacteria species and mental health outcomes

 

What is gut microbiota?

The human gut microbiome, often called gut microbiota or gut flora, is a complex community of trillions of microorganisms that reside in the digestive tract, primarily in the colon. These microorganisms include bacteria, viruses, fungi, and other microbes. Gur microbiota is critical in digesting food, absorbing nutrients, and aiding our metabolic activity.

 

Humans have known for centuries there is a link between our digestive system and how we feel

 

Gut microbiota helps maintain a balanced and healthy immune system. The composition and diversity of gut microbiota can vary significantly among individuals and can be influenced by factors such as diet, genetics, and lifestyle. It is increasingly recognized as a crucial factor in overall health and well-being (Heiss et al., 2021; Zhu et al., 2023).

 

Microbiota-gut-brain-axis

A key pathway through which the link between gut microbiota and well-being is achieved is the microbiota-gut-brain axis (MGBA). The microbiota-gut-brain axis is a bidirectional communication system connecting the gut, microbiota, and brain. This axis regulates physiological and psychological processes (Carbia et al., 2023; Zhu et al., 2023).

 

Gut microbiota can vary among individuals and is recognized as a crucial factor in overall health and well-being (Heiss et al., 2021; Zhu et al., 2023)

 

The microbiota-gut-brain axis (MGBA) is based on small proteins called cytokines and several other biomolecules, including the hormone cortisol, short-chain fatty acids (SCFAs), tryptophan, neurotransmitters, and others (see Figure 1). 

 

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Figure 1. Some of the Biomolecules involved in MGBA

 

Emerging studies reveal that the gut microbiota produces substances that can influence the brain’s activity and its responses to stress and emotions. Additionally, the microbiota-gut-brain axis is closely tied to the immune system, influencing the body’s inflammatory responses and potentially contributing to neuroinflammation (Zhu et al., 2023).

 

Gut microbiota produces substances that influence the brain’s activity and its responses to stress and emotions

 

These scientific findings suggest that interventions targeting the gut microbiota, such as probiotics and dietary changes, may positively impact mental health and neurological disorders. This can open a new avenue of treatment for mental health issues and possibly other disorders.

 

The current study

Study author Mireia Valles-Colomer and her colleagues wanted to examine the association between gut microbiota composition and quality of life indicators in the general population. They also wanted to examine links between gut microbiota composition and depression (Valles-Colomer et al., 2019).

They note that recent advances in genetic sequencing technology allowed researchers to start studying the role of the gut microbiota in a broad range of neurological and psychiatric disorders and diseases. Advancements in the field of metagenomics are a particularly important part of this as it allows relatively easy and noninvasive exploration of human gut microbiota composition.

 

Recent advances in genetic sequencing technology allows researchers to study the role of microbiota in neurological and psychiatric disorders 

 

Metagenomics

Metagenomics is a field of genetics and microbiology that involves the study of genetic material collected directly from environmental samples, like soil, water, or the human gut, without the need for isolating and cultivating individual organisms. It employs advanced DNA sequencing techniques to analyze and characterize collective genomes of microorganisms in studied samples and their genetic diversity.

In the case of human gut microbiota studies, researchers typically collect stool samples for this purpose. They then use metagenomics techniques to determine the presence, absence, and abundance of different species of microorganisms in the gut microbiota (see Figure 2).

 

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Figure 2. Metagenomics

 

The procedure – the Belgian Flemish Gut Flora project data

The authors of this study analyzed data from two large-group longitudinal studies in Europe. The first set came from the Belgian Flemish Gut Flora Project (FGFP). It contained data from 1054 individuals on gut microbiota and depression as reported by general medical practitioners. The quality of life of these study participants was assessed using the RAND 36-Item Health Survey 1.0. This assessment covers eight health concepts – role limitations caused by emotional health problems, social functioning, emotional well-being, vitality, physical functioning, role limitations caused by physical health, body pain, and general health perception.  Participants who were using antidepressants but were not diagnosed with depression were excluded from the analysis.

From this group, study authors selected 80 participants with clinically diagnosed depression (40 were using antidepressants) and 70 healthy participants as controls, matched with them on age, sex, body mass index, and stool consistency for in-depth analysis using shotgun metagenomic sequencing. Shotgun metagenomic sequencing is a method that involves sequencing all the genetic material present in a microbial community sample, providing a comprehensive view of the genes and organisms within that community.

 

The Lifelines Cohort data and controls

Researchers used another sample to verify their findings – the Lifelines Cohort. The Lifelines Cohort is a large-scale, three-generation longitudinal study in the Netherlands. It contains a large amount of medical and psychological data from over 167,000 participants so far. The Lifelines cohort study was started in 2006 and aimed to include 10% of the northern population of the Netherlands of all ages. The authors of the Lifelines Cohort study hope to be able to follow these individuals for 30 years and collect follow-up data during this time.

In this study, the authors used data from 1063 individuals from the Lifeline Cohort. The quality of life of this group was assessed in the same way as in the Belgian sample. Participants self-reported depression. Researchers asked participants to indicate the disorders they have or have had, and depression was on the list. Participants also reported on their use of antidepressants in the last three months.

The study authors used gas chromatography-mass spectrometry (GC-MS) to determine butyrate levels in stool samples from this dataset. Butyrate is a short-chain fatty acid produced by certain species of bacteria in the gut during the fermentation of dietary fiber (see Figure 3). It is an important energy source for the cells lining the colon and helps maintain their integrity and function. Additionally, it has anti-inflammatory properties and has been associated with various health benefits. Butyrate potentially reduces the risk of inflammatory bowel diseases and promotes overall gut health.

 

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Figure 3. The Short-Chain Fatty Acid Butyrate

 

Additionally, study authors collected and sequenced seven stool samples from patients suffering from major depressive disorder resistant to treatment. Participants in this sample were diagnosed with moderate-to-severe depression and inadequate response to at least two therapies with antidepressants. Inadequate response means that symptoms of depression persist after treatment.

 

Gut microbiota composition was related to quality of life

Results revealed multiple associations between microbiome characteristics and all aspects of quality of life (see Figure 4). Study participants with better quality of life indicators tended to have more Faecalibacterium and Coprococcus bacteria in their guts. Those with better physical functioning tended to have fewer bacteria from the Flavonifractor group of species (genus). This group of bacterial species was also increased in individuals suffering from major depressive disorder (MDD).

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Figure 4. Associations between microbiome characteristics and all aspects of quality of life (as outlined earlier)

 

Study authors note that Faecalibacterium and Coprococcus bacteria produce the short-chain fatty acid butyrate. Butyrate levels in the gut are generally reduced in individuals with inflammatory bowel disease and those with depression. They examined the Lifelines cohort data to verify this finding, and the results showed that the abundance of these bacteria is indeed associated with butyrate concentrations in the stool.

 

Butyrate levels in the gut are reduced in those with inflammatory bowel disease and depression

 

Coprococcus and Dialister bacteria are depleted in the guts of individuals suffering from depression

Study authors identified 4 groups of bacterial species that were consistently depleted in individuals suffering from depression (depleted in this case, means that they are present in numbers significantly lower than those found in typical healthy individuals).

However, further analyses revealed that antidepressants can substantially affect the composition of gut bacteria. When study authors controlled for the use of antidepressants, only Coprococcus and Dialister groups of species remained associated with depression. There were significantly fewer bacteria from these groups in the guts of individuals suffering from depression than healthy individuals (see Figure 5). This finding was held in the Flemish Gut Flora and the Lifeline Cohort data.

 

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Figure 5. Microorganism abundances linked to Quality of Life and Depression

 

Bacteria producing 3,4-dihydroxyphenylacetic acid are more abundant in individuals with better social functioning

Next, the study authors examined the gut-brain modules, i.e., they looked for groups of bacteria that produce substances that could affect mental states and their links to quality-of-life indicators. These analyses showed that bacteria producing 3,4-dihydroxyphenylacetic acid (DOPAC) were more abundant in participants with better social functioning scores.

The potential for producing this substance was the most strongly associated with Coprococcus group of bacteria. DOPAC is produced from dopamine, an important neurotransmitter, and researchers believe it can reduce the proliferation of colon cancer cells. Reduced DOPAC levels are a potential biomarker of Parkinson’s disease (Valles-Colomer et al., 2019).

 

Bacteria involved in the degradation of glutamate and production of GABA tended to be depleted in participants with depression

Additionally, bacteria involved in glutamate degradation tended to be depleted in participants with depression. Glutamate is an amino acid that plays a role in various metabolic and signaling pathways in the body. However, it is also the primary excitatory neurotransmitter in the central nervous system. This means that it increases the likelihood of neurons generating a nerve impulse.

Microorganisms involved in synthesizing gamma-aminobutyric acid (GABA) also tended to be depleted in participants with depression. GABA is an important inhibitory neurotransmitter. It makes neurons less likely to fire a nerve impulse (see Figure 6).

 

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Figure 6. Link of microbial substance to the quality of life and depression

 

Conclusion

Overall, the analysis of two large sets of gut microbiome samples from two different (although neighboring) countries confirmed specific links between gut microbiota composition and mental health indicators. Individuals with better quality of life indicators tended to have more Faecalibacterium and Coprococcus bacteria in their gut. Those with better physical functioning tended to have fewer bacteria from the Flavonifractor species group. Bacteria from Coprococcus and Dialister groups of species tended to be much less present in the guts of individuals suffering from depression. 

Bacteria capable of producing 3,4-dihydroxyphenylacetic acid or DOPAC were more abundant in participants with better social functioning scores. DOPAC is produced from dopamine, an important neurotransmitter in the human body, and it plays various important roles in the body’s functioning. Bacteria involved in the degradation of glutamate and the production of GABA, two important neurotransmitters, tended to be depleted in individuals with depression (see Figure 7).

 

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Figure 7.  Summary

 

While these findings are only correlational and do not allow for cause-and-effect conclusions, future research can be expected to map causal pathways responsible for the observed associations. This could open a new avenue of mental health treatments to achieve improved mental outcomes by affecting the gut or adjusting gut microbiota composition. It is also not hard to imagine scientists in the future using genetic techniques to create microorganisms that could influence mental health or mental states when placed in the gut.

The paper “The neuroactive potential of the human gut microbiota in quality of life and depression” was authored by Mireia Valles-Colomer, Gwen Falony, Youssef Darzi, Ettje F. Tigchelaar, Jun Wang , Raul Y. Tito, Carmen Schiweck, Alexander Kurilshikov , Marie Joossens, Cisca Wijmenga, Stephan Claes, Lukas Van Oudenhove, Alexandra Zhernakova, Sara Vieira-Silva , and Jeroen Raes.

To learn more about this topic,, CNP has developed two university-level continuing education courses exploring the evidence based interconnections in the microbiota-gut-brain axis diet-mental health relationship (MGBA-DMHR). See our course pages here

References

Carbia, C., Bastiaanssen, T. F. S., Iannone, F., García-cabrerizo, R., Boscaini, S., Berding, K., Strain, C. R., Clarke, G., Stanton, C., Dinan, T. G., & Cryan, J. F. (2023). The Microbiome-Gut-Brain axis regulates social cognition & craving in young binge drinkers. EBioMedicine, (In press), 104442. https://doi.org/10.1016/j.ebiom.2023.104442

Heiss, C. N., Mannerås-Holm, L., Lee, Y. S., Serrano-Lobo, J., Håkansson Gladh, A., Seeley, R. J., Drucker, D. J., Bäckhed, F., & Olofsson, L. E. (2021). The gut microbiota regulates hypothalamic inflammation and leptin sensitivity in Western diet-fed mice via a GLP-1R-dependent mechanism. Cell Reports, 35(8). https://doi.org/10.1016/j.celrep.2021.109163

Valles-Colomer, M., Falony, G., Darzi, Y., Tigchelaar, E. F., Wang, J., Tito, R. Y., Schiweck, C., Kurilshikov, A., Joossens, M., Wijmenga, C., Claes, S., Van Oudenhove, L., Zhernakova, A., Vieira-Silva, S., & Raes, J. (2019). The neuroactive potential of the human gut microbiota in quality of life and depression. Nature Microbiology, 4(4), 623–632. https://doi.org/10.1038/s41564-018-0337-x

Zhu, X., Sakamoto, S., Ishii, C., Smith, M. D., Ito, K., Obayashi, M., Unger, L., Hasegawa, Y., Kurokawa, S., Kishimoto, T., Li, H., Hatano, S., Wang, T. H., Yoshikai, Y., Kano, S. ichi, Fukuda, S., Sanada, K., Calabresi, P. A., & Kamiya, A. (2023). Dectin-1 signaling on colonic γδ T cells promotes psychosocial stress responses. Nature Immunology. https://doi.org/10.1038/s41590-023-01447-8

 

 

The Diet-Mental Health Relationship in Astronaut Performance

The discipline of nutritional psychology is consolidating evidence worldwide on how dietary intake can impact various aspects of psychological, behavioral, cognitive, and functional performance in work environments (see the Diet and Human Performance research category within the NPRL). This includes how we think, behave, and perform in many workplace environments — from shift workers in hospitals (Leedo et al., 2017) and long-haul truck drivers (Ge et al., 2021) to students in the classroom (Barchitta, 2019), pilots in the cockpit (Lindseth, et al., 2011), and astronauts aboard space stations (Douglass, 2022).

NASA’s Human Exploration Research Analog (HERA) experiment compared the psychological and health effects of the standard diet currently served to astronauts on the International Space Station (ISS) with a new, enhanced diet formula. Results showed that study participants who ate a diet containing more fruits, vegetables, fish, and foods rich in flavonoids and omega-3 fatty acids had lower levels of cholesterol, reduced stress (as indicated by the hormone cortisol), better cognitive speed, accuracy, attention, and a more stable composition of gut microorganisms compared to participants who ate the standard International Space Station diet. The study was published in Scientific Reports.

 

Adding more fruit, vegetables, fish, and foods rich in flavonoids and omega-3 fatty acids to astronauts’ diets improves psychological, cognitive, and health-related outcomes.

 

What do astronauts eat?

Since the start of spaceflight over half a century ago, the food available to astronauts during space missions has improved dramatically. Early astronauts had very limited dietary choices, typically consisting of prepackaged foods served in either squeeze tubes or bite-sized cubes coated in gelatin to prevent the formation of crumbs. This was crucial in the confined environment of a space vessel, where loose food particles could pose a serious long-term health threat (Perchonok & Bourland, 2002).

Food options for astronauts have dramatically increased, as have the number of days astronauts routinely spend in orbit during a single mission. Longer duration missions, like those on the International Space Station (ISS), have increased the importance of spaceflight menus, allowing astronauts’ diets to be as Earth-like as possible. Today’s space foods include various food items packed in single-serving containers.

 

Longer space missions require more earth-like food items and menus to address astronauts’ psychosocial and psychological needs.

 

Modern spaceflight menus are typically organized into 6 or 7-day rotations, consisting of four meals per day – breakfast, lunch, dinner, and a snack. Food menus are planned based on the astronauts’ weight to provide the calories and nutrients required to maintain their health.

In the early days of spaceflight, experts believed they could calculate the ideal food composition for astronauts based solely on nutritional requirements for survival in space. However, the current perspective recognizes that “ideal food cannot ensure psychosocial comfort, while a grandma-style pie can” (Bychkov et al., 2021). Longer space missions have highlighted the importance of food beyond just nutritional survival needs, taking into account the diet-mental health relationship. This includes considering the psychological, cognitive, behavioral, and psychosocial value of food for the well-being of astronauts.

With this in mind, modern astronauts can select around 20% of their food items and beverages, while around 80% of their diet comes from a shared standard set of foods (Douglas et al., 2020).

 

Consistent with nutritional psychology-related factors, “Ideal food cannot ensure psychosocial comfort, while a grandma-style pie can” (Bychkov et al., 2021).

 

How is the food for astronauts prepared?

Food items are specially prepared on Earth before a flight to make them easy to use in a weightless environment and to minimize the risk of spillage. Spillage is dangerous in weightlessness as spilled material will not drop to the ground but disperse around the room or form free-floating bubbles. Crumbs or very small granules can also be dangerous and difficult to collect. For example, salt and pepper are available to astronauts in liquid form.

The food items need to be shelf-stable, either in their natural form or preserved by removing water and sterilized using heat or radiation. On the International Space Station, resupply vehicles arrive several times a year, bringing fresh fruits and vegetables and some semi-shelf-stable specialty items. Astronauts report that these deliveries provide profound psychological benefits (Douglas et al., 2020).

 

Astronauts report that these deliveries [fresh produce] provide profound psychological benefits (Douglas et al., 2020).

 

While NASA has successfully provided food for missions of up to 11 months in low Earth orbit (Douglas et al., 2020), plans for future deep-space manned exploration missions make space nutrition a topic of intense scientific research.

What is HERA?

The Human Exploration and Research Analog or HERA is a two-story building at the NASA Johnson Space Center (JSC) in Houston. Its purpose is to simulate the isolation, confinement, and remote conditions of space exploration scenarios. The building contains four habitats that simulate a space vessel with its simulated airlock and hygiene module.

HERA is used for studies that consist of 4 crew members living in the enclosed space of the simulated vessel for up to 45 days. One such stay is called a mission. During a mission, study participants stay in the habitat, spending their time in the way they would spend on a real space mission (with the difference that they are not weightless).

The simulation vessel crewmembers did not have access to the internet, social media, or communication outside mission control. They could communicate privately with their family, medical personnel, or a psychologist once a week. There was a limited selection of movies or music through a controlled account. HERA research studies last up to 68 study days (NASA ROI – Flight Analogs Human Research Program, 2019) and involve 16 days of preparation before entering the habitat and 7 days of follow-up after leaving it.

 

Plans for future deep-space manned exploration missions make space nutrition a topic of intense scientific research.

 

The study of health and psychological effects of an enhanced menu

A new study by Grace L. Douglas — an experienced researcher on the health effects of spaceflight working at the Human Health and Performance Directorate of the NASA Johnson Space Center in Houston — and her colleagues explored whether the diet of astronauts can be further improved (Douglas et al., 2022). They reasoned that studies investigating the effects of spaceflight nutrition conducted thus far have focused only on a limited number of nutrients and outcomes. They wanted to test how further increasing the variability and availability of healthy, shelf-stable, space flight-compatible foods that included fruits, vegetables, fish, and other foods rich in flavonoids and omega-3 fatty acids would affect the immune system, gut microbiome, nutritional status, and cognitive outcomes of future astronauts.

Study participants and procedure

The study participants were sixteen individuals with an average age of 40 and body mass indexes that placed them in the healthy weight range. Ten of the study participants were men, and 6 were women. These sixteen individuals participated in four 45-day HERA missions (four people per mission) conducted in 2017 and 2018. Each participant participated in a single mission. They were instructed to keep logs of the food and beverages they ate and drank 15 days before the mission.

After they entered the HERA habitat and started the mission, participants were not allowed to select any menu components. Trading food items was also not permitted. This is because the researchers wanted to make the study as consistent as possible with real-life situations in future space exploration missions. Food and beverages that the participants were expected to consume during the mission were stowed in the habitat at the beginning of the mission. All participants received the same base menu in each mission.

The standard International Space Station menu and the new enhanced menu

The menu was designed to provide the nutrients required to stay healthy with approximately 2300 calories daily. An additional 100 to 200 calories per person were provided “to ensure adequate provisioning with minimal choice.” Participants were instructed to consume the base menu before consuming additional calories.

Researchers randomly selected two missions to receive the new enhanced menu they designed, while the other two missions received the standard International Space Station menu. Study participants were not told which menu they were receiving during the mission they participated in.

Measures and assessments

After each meal, participants recorded actual food consumption using the International Space Station Food Intake Tracker iPad App. Researchers recorded the use of antibiotics and medications. Weight and height were measured before the mission and weight measurements were taken before breakfast each day during the mission.

Researchers collected blood, stool, urine, and saliva samples from each subject at 5-time points – twice before and 3 times during the mission. The collection of samples during the mission was done in a special HERA chamber and transferred out through a pass with minimal to no contact between the study participants (HERA “crew”) and the support team.

From these samples, researchers assessed levels of vitamins, flavonoids, calcium, and bone health, cardiovascular and fluid regulation, metabolic, oxidative stress, reproductive hormones, and iron and blood cell concentrations. They also conducted immunological analysis and assessed levels of the hormone cortisol and viruses from saliva. Researchers determined the composition of the gut microbiome from stool samples of participants and conducted a study of gene expressions of these microorganisms. The latter procedure is called metatranscriptomic analysis.

As part of a broader Cognition test battery (see Figure 1), participants completed vigilant attention assessments using the Psychomotor Vigilance Test (PVT) twice before the mission and three times per week during the mission. 

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Figure 1. Crewmember measures and assessments protocol

 

Nutritional intake was improved for participants consuming the enhanced diet

Results showed that study participants in both groups did not fully consume their menu items. However, participants in the enhanced menu missions consumed more servings of fruits and vegetables per day, and ate more fish per week and more servings of tomato-based foods.

The participants receiving the enhanced diet took in more calcium, potassium, daily fiber, and omega-3 fatty acids than participants on the two standard menu missions (see Figure 2). The importance of omega-3 fatty acids comes from the fact that they are an integral part of cell membranes in the human body. They are also starting points for producing hormones that regulate blood clotting, contraction and relaxation of artery walls, and inflammation.  Intakes of protein, sodium, and iron were similar in the two groups.

Crewmembers on the enhanced diet took in more calcium, potassium, fiber per day, and omega-3 fatty acids than participants on the standard menu missions. 

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 Figure 2. Enhanced menu missions consumption

 

The enhanced menu and health indicators

General health status was similar in participants consuming the two diets. However, cholesterol status was improved in participants consuming the enhanced diet. They also had higher physiological flavonoid concentrations in urine and more stable fatty acid concentrations in the blood (see Figure 3).

The concentration of the hormone cortisol in the blood was higher in participants on standard diets. Cortisol is a hormone produced by adrenal glands. It regulates the body’s response to stress. Higher concentrations are indicative of higher stress levels.

The diversity and richness of gut microbiota were reduced in participants consuming the standard diet. Researchers also detected changes in the abundance of several species of gut microorganisms that were associated with the differences in the diet. Additionally, gene expression profiles, i.e., metatranscriptomic profiles of the gut microbiome, were more stable for subjects consuming the enhanced diet.

Cognitive speed, accuracy, and attention were better for subjects consuming the enhanced diet

Psychological assessments showed that cognitive speed, accuracy, and attention were better for subjects consuming the enhanced diet. The reaction speeds in the tests of study participants consuming the enhanced diet were higher than the average reaction speeds of participants on the standard diet and improved compared to their pre-mission results.

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 Figure 3. Enhanced vs Standard diet

 

Conclusion

The study showed that a specific diet rich in fruits, vegetables, and omega-3 fatty acids produces significant health and performance benefits in a simulated space exploration mission environment. Countering the physiological deterioration of astronauts’ health during long space missions is an ongoing goal for researchers and mission planners. These results can help achieve this goal by better planning food resources and astronauts’ menus and lend credence to the importance of the diet-mental health relationship on human performance and within work environments.

The paper “Impact of diet on human nutrition, immune response, gut microbiome, and cognition in an isolated and confined mission environment” was authored by Grace L. Douglas, Diane DeKerlegand, Holly Dlouhy, Nathan DumontLeblond, Eden Fields, Martina Heer, Stephanie Krieger, Satish Mehta, Bridgette V. Rooney, ManolitoG.Torralba, Sara E. Whiting, Brian Crucian, Hernan Lorenzi, Scott M. Smith, Millennia Young, and Sara R. Zwart.

 

References

Barchitta, M., Maugeri, A., Agrifoglio, O., Favara, G., La Mastra, C., La Rosa, M. C., Magnano San Lio, R., & Agodi, A. (2019). Dietary patterns and school performance: evidence from a sample of adolescents in Sicily, Italy. Annali di igiene : medicina preventiva e di comunita, 31(2 Supple 1), 72–80.

Bychkov, A., Reshetnikova, P., Bychkova, E., Podgorbunskikh, E., & Koptev, V. (2021). The current state and future trends of space nutrition from a perspective of astronauts’ physiology. International Journal of Gastronomy and Food Science, 24, 100324. https://doi.org/10.1016/J.IJGFS.2021.100324

Douglas, G. L., DeKerlegand, D., Dlouhy, H., Dumont-Leblond, N., Fields, E., Heer, M., Krieger, S., Mehta, S., Rooney, B. V., Torralba, M. G., Whiting, S. E., Crucian, B., Lorenzi, H., Smith, S. M., Young, M., & Zwart, S. R. (2022). Impact of diet on human nutrition, immune response, gut microbiome, and cognition in an isolated and confined mission environment. Scientific Reports, 12(1), 1–22. https://doi.org/10.1038/s41598-022-21927-5

Douglas, G. L., Zwart, S. R., & Smith, S. M. (2020). Space food for thought: Challenges and considerations for food and nutrition on exploration missions. Journal of Nutrition, 150(9), 2242–2244. https://doi.org/10.1093/JN/NXAA188

Ge, Y., He, S., Xu, Y., & Qu, W. (2021). Effects of dietary patterns on driving behaviours among professional truck drivers: the mediating effect of fatigue. Occupational and environmental medicine, 78(9), 669–675. https://doi.org/10.1136/oemed-2020-107206

Leedo, E., Beck, A. M., Astrup, A., & Lassen, A. D. (2017). The effectiveness of healthy meals at work on reaction time, mood and dietary intake: a randomised cross-over study in daytime and shift workers at a university hospital. The British journal of nutrition, 118(2), 121–129. https://doi.org/10.1017/S000711451700191X

Lindseth, G. N., Lindseth, P. D., Jensen, W. C., Petros, T. V., Helland, B. D., & Fossum, D. L. (2011). Dietary Effects on Cognition and Pilots’ Flight Performance. The International journal of aviation psychology, 21(3), 269–282. https://doi.org/10.1080/10508414.2011.582454

NASA ROI – Flight Analogs Human Research Program. (2019). Human Research Program Human Exploration Research Analog (HERA) Facility and Capabilities Information (Issue July). https://www.nasa.gov/sites/default/files/atoms/files/2019_hera_facility_capabilities_information.pdf

Perchonok, M., & Bourland, C. (2002). NASA Food Systems: Past, Present, and Future. Nutrition, 18(10), 913–920. https://doi.org/https://doi.org/10.1016/S0899-9007(02)00910-3

How Much Do Nutritional Psychologists Really Make? And How Do I Become One?

A Guide to the Field of Nutritional Psychology: Education, Salary, and More

To see a more updated version of this article, visit here. Note: This guide was written by the developer of the field of Nutritional Psychology, and reviewed by The Center for Nutritional Psychology (the founding organization of Nutritional Psychology), with the purpose of providing individuals with accurate information reflecting the state of the field. Nutritional Psychology was first defined in 2005, taught in university courses in 2008, and The Center for Nutritional Psychology was founded later in 2015 to foster NP’s growth and set the foundation for the field. Due to the source of the information provided in this article, it is considered an accurate reflection of the history, development, and direction of the field of Nutritional Psychology.

What is Nutritional Psychology?

NP is the area of study examining how dietary intake patterns affect mood, behavior, and mental health. Nutritional Psychology examines the psychological, behavioral, cognitive, perceptual, interoceptive (sensory), and psychosocial changes we experience in relation to our dietary intake patterns.

Each Nutritional Psychology element is defined here in more detail:

Diet and Psychological element: The relationship between our dietary-nutrient intake patterns and our psychological moods, emotions and affect (e.g., resilience, flourishing, creativity, negativity).

Diet and Behavioral element: The behaviors, reactions, and choices in which we engage that result from thoughts and emotions influenced by our dietary intake and food environment (e.g., increased reactive behavior or changed dietary behavior patterns).

Diet and Perceptual element: Our interpretation of food-related information stemming from our society, familial, and cultural dietary environment (what foods we are exposed to and how that influences our choices).

Diet and Interoceptive element: The internal physiological sensations we experience in response to our dietary intake patterns (discomfort, pain, energy, fatigue, craving, and wanting).

Diet and Cognitive element: The relationship between dietary-nutrient intake and our cognitive functions and capacity, including memory, attention, learning, and appetite control.

Diet and Psychosocial element: Examining the role that family, culture, community, society, and socioeconomic status play in relationship to our dietary-nutrient intake patterns.

All mental health professionals can benefit from understanding the elements of Nutritional Psychology, and when taken together, these elements form conceptualization in the Diet Mental Health Relationship.

 

How can I become a “Nutritional Psychologist”?

The formal title of “Nutritional Psychologist” does not yet exist. The first academic training in Nutritional Psychology resided in the John F. Kennedy University in the Continuing Education department from 2008 through 2020. This program provided academic training to hundreds of mental health professionals, nutritionists and dietitians, students, nurses, and counselors in the field of Nutritional Psychology. Those completing the program are trained in providing psycho-educational tools that assist clients in understanding of the diet-mental health relationship (DMDHR). The next-generation curriculum in NP is in development and will be available through The Center for Nutritional Psychology in 2021.

What is the scope of practice for those trained in Nutritional Psychology?

The intended scope of practice for Nutritional Psychology is dependent on the accompanying certification or license of the practitioner (Nutritionist, LCSW, LPCC, MD, Licensed Psychologist, etc.). It is a subset of information and tools designed to deepen the awareness and effectiveness through a better understanding of the DMHR.

Nutritional Psychology provides education, rather than intervention, treatment, or diagnosis. Training and certification in Nutritional Psychology do not provide professionals with the ability to give dietary advice or intervention if they do not already have a license to do so. If one does not have a state-sanctioned license, then the person must work in conjunction with professionals whose scope of practice includes providing nutritional intervention to affect health outcomes.

Those who received formal education and training in Nutritional Psychology, and who can provide education within their scope of practice, may provide educational information on how diet affects mental health, and use NP psycho-educational ‘tools’ to increase awareness of the effects of diet on psychological, cognitive, behavioral, perceptual, interoceptive and psychosocial functioning.

How much do Nutritional Psychologists make?

No salary data for jobs in Nutritional Psychology currently exists. Rather, the psycho-educational tools within Nutritional Psychology serve as an adjunct to previously established mental healthcare methods. Nutritional Psychology provides an additional, and increasingly important tool for professionals to incorporate that helps their clients be better able to achieve their goals, which in turn, can increase the demand for their services, which can (as does any specialty) result in increased services offerings and generated revenue.

Where can I get a degree in Nutritional Psychology?

There is currently no degree program leading to an undergraduate or graduate degree in Nutritional Psychology. The first university-based curriculum in Nutritional Psychology began at John F. Kennedy University from 2008-2020 and was accredited for Continuing Education credits by the American Psychological Association (APA), The California Board of Behavioral Sciences (BBS), and the California Board of Registered Nursing (BRN). The Center for Nutritional Psychology is working to develop a university-level curriculum in Nutritional Psychology that will be available in 2021-2022.

Where can I find education in the field of Nutritional Psychology?

The Center for Nutritional Psychology (CNP) is working to develop the field of Nutritional Psychology by consolidating research, developing an educational curriculum that informs learners of the appropriate methods, concepts, and tools, publishing the first textbook in Nutritional Psychology, setting practice guidelines and standards for certification and licensure in Nutritional Psychology.

Isn’t there currently a Certificate in Nutritional Psychology available for mental health professionals?

Yes, however, the current certificate program in Nutritional Psychology at JFKU is being ‘taught out’, which means the authors of the program have decided to phase it out although it currently has students enrolled. These students will be allowed to complete the program, which remains accredited until they have completed the program. No new students can be enrolled in the JFKU Certificate in NP. CNP is developing a new curriculum to replace this program, which will be available through CNP sometime in early 2021.

Can I obtain a license in Nutritional Psychology?

There is currently no licensing or certifying organization that provides formal credentialing leading to the title of “Nutritional Psychologist”. The John F. Kennedy Certificate in Nutritional Psychology provided formalized education in Nutritional Psychology along with the scope of practice guidelines, but this program is currently being replaced by the next-generation curriculum in Nutritional Psychology available through The Center for Nutritional Psychology (CNP) in 2021-2022.

Aren’t all Mental Health Professionals trained in Nutritional Psychology?

Psychologists and mental health professionals already address the psychological, cognitive, psychosocial, and behavioral knowledge that contributes to positive mental health, but the current model is not considering the Diet-Mental Health Relationship (DMHR) as a contributor to mental health issues.

Conversely, dietitians and nutritionists already address the dietary knowledge that contributes to positive dietary intake and practices. But formal training in the DMHR is not included for those in these fields.

The field of Nutritional Psychology is developing in response to the growing need to equip mental health professionals and nutritionists alike with knowledge of how dietary patterns interact with psychological, cognitive, behavioral, perceptual (interoceptive), and psychosocial functioning to impact both physical and mental health.

Does a professional with Nutritional Psychology skills provide dietary or mental health treatment and/or intervention?

Nutritional Psychology training does not qualify professionals to write nutrition-focused treatment plans or implement specific nutritional interventions. Nutritional Psychology provides professionals with psycho-educational tools and information designed to increase client awareness of how dietary factors can influence their mental health outcomes.

Who should get involved in Nutritional Psychology?

Students in high school and college, licensed professionals, and anyone interested in understanding more about the Diet Mental Health Relationship (DMHR). Typical backgrounds of interested people include psychology, counseling, marriage and family therapy, dietetics, health coaching, nutrition, nursing, and other health-related professions.

Does Nutritional Psychology give me the ability to diagnose or treat mental health problems?

No. Nutritional Psychology does not provide intervention or diagnosis. Rather, it provides psycho-educational tools that engage individuals in understanding the relationship between their dietary intake patterns and their mood, behavior, and mental health.

Is there a difference between the fields of Nutritional Psychiatry and Nutritional Psychology?

While the research informing these two fields at times overlap, the fields of Nutritional Psychology and Nutritional Psychiatry are distinct.

The innovative and emerging field of Nutritional Psychiatry is generally concerned with researching the connection between diet and mental health, including possible clinical intervention (diagnosis and treatment) in patients who suffer from psychiatric disorders including depression and anxiety. This field has been instrumental in leading the way forward in the Diet-Mental Health Relationship.

Nutritional Psychology is focused on the development of methodology, is applied, and includes research informing the following areas:

 Diet and…

  • Psychological functioning
  • Mood (affect)
  • Behavior
  • Cognition
  • Interoception/sensory
  • Perception
  • Performance
  • Psychosocial
  • Brain Function

Any aspect of the relationship between daily dietary intake patterns and their effects on the “Diet Mental Health Relationship” (DMHR) form the basis of Nutritional Psychology and the exploration of the ways in which diet is a positive or negative contributor to psychological functioning.

Is Nutritional Psychology different from Health Psychology?

Nutritional Psychology is distinct from Health Psychology. Nutritional Psychology examines the psychological, behavioral, cognitive, perceptual, interoceptive, and psychosocial factors that occur in relationship to human dietary intake patterns. NP is aligned with principles of integrative health, and the newly emerging transformational approach to health and wellbeing is referred to as ‘Whole Health’. Whole health empowers and equips people to take charge of their physical, mental, and spiritual well-being, and live their lives to the fullest.

Health psychology examines how biological, social, and psychological factors influence health and illness. Health psychologists use psychological science to promote health, prevent illness and improve health care systems. These fields have developed independently from each other though no doubt can benefit from one another.

Is there evidence to support the field of Nutritional Psychology?

There is a growing body of research demonstrating the link between dietary intake and the psychological, behavioral, cognitive, perceptual, interoceptive, and psychosocial aspects of mental health. The Center for Nutritional Psychology (CNP) consolidates this research into three different research libraries:

Nutritional Psychology uses evidence-based research to inform and guide the development of the field, and research substantiates the process of providing education/psycho-education designed to help people understand and implement dietary changes. The specific NP tools, methods, and concepts developed thus far have not yet been validated through research.

What are the Educational Requirements for a Career in Nutritional Psychology?

There are currently no educational requirements for a career in NP because there is no official title, license, or degree associated with this field. In order to make good use of the information and tools of NP, we recommend pursuing:

– A graduate-level degree in psychology, counseling, nutrition, or health science, or

– A four-year degree program consisting of electives, core study courses relating to nutrition, psychology, counseling, social work, or mental health;

– Formal education in Nutritional Psychology (available through CNP in 2021-2022).

The following areas of disciplines would help:

Psychology

Counseling

Health Studies

Health Coaching

Nutrition

Nutrition Education or consulting

Dietetics

Social Work

School counselor

Wellness coaching

Substance abuse Counselor

Can Nutritional Psychology be used to cure mental disorders?

Nutritional Psychology is designed to be complimentary and an addition to standard mental health interventions and treatments. For individuals who possess an appropriate license to diagnose and treat mental disorders, NP can provide tools to assist in the treatment. This information and tools from NP can provide a piece of the puzzle for supporting mental health, but is never to be used as a substitute for psychiatric, therapeutic, or medical interventions.

What recommendations do you have regarding incorporating Nutritional Psychology into one’s practice?

Professionals incorporating Nutritional Psychology into their practice must have:

  • Formal training in NP (available through CNP in 2021), which includes an understanding of the relationship between dietary and nutrient intake on all aspects of psychological, behavioral, cognitive, perceptual, interoceptive, and psychosocial functioning;
  • Advanced knowledge commonly found in a Master’s degree education or higher in psychology, social science, or the health science that includes advanced courses in psychology, along with electives in anatomy and physiology;
  • Formal education in nutrition in the form of certification or license from a credentialed program;
  • Demonstrated competency in how NP education can be incorporated into their work in a manner that is consistent with their profession’s scope of practice. They must also demonstrate awareness of competencies that extend beyond their profession’s scope of practice and determine when a referral for a psychological or nutritional diagnosis, intervention, or treatment is necessary;

The courses will be suitable for nutritionists and dieticians who seek additional training in mental health from accredited institutions, as well as psychology-minded practitioners requiring coaching on implementing nutritional techniques.

What Does the Future Hold for Nutritional Psychology?

All areas of specialty that can benefit from Nutritional Psychology training are experiencing projected rates of employment growth faster than average, including jobs as nutritionists and dietitians, psychologists:

For nutritionists and dietitians, The BLS (Bureau of Labor Statistics) expects the field to grow by 11% by 2028. The BLS attributes this growth to “the role of food in preventing and treating diseases, such as diabetes”. This is also undoubtedly to address the most recent NHANES findings on obesity in the U.S. adult population (42.4%) (NHANES is a cross-sectional survey designed to monitor the health and nutritional status of the civilian non-institutionalized U.S. population). Dietitians and nutritionists will be needed to provide care for patients in improving their overall health.

Additionally, the Bureau of Labor Statistics indicates that those close to retirement age are demanding more nutritional services. Assisted living facilities, hospitals, nursing homes, and private clinics are expected to add more positions in this field. This need is consistent with research connecting diet with age-related brain disorders.

The employment of psychologists is projected to grow 14 percent from 2018 to 2028, much faster than the average for all occupations. Job prospects should be best for those who have a doctoral degree in an applied specialty.

Employment of marriage and family therapists is projected to grow 22 percent from 2018 to 2028, much faster than the average for all occupations. Growth is expected due to the increasing use of teams for treatment, in which these therapists work with other counselors to address patients’ needs.

Employment of substance abuse, behavioral disorder, and mental health counselors is projected to grow 22 percent from 2018 to 2028, much faster than the average for all occupations. Employment growth is expected as people continue to seek addiction and mental health counseling.

A recent study published in The Lancet estimates that “one in five deaths globally — equivalent to 11 million deaths — are associated with poor diet, and that diet contributes to a range of chronic diseases in people around the world”. And that “the urgent need for coordinated global efforts to improve the quality of human diet” is needed, and that “given the complexity of dietary behaviors and the wide range of influences on diet, improving diet requires the active collaboration of a variety of actors throughout the food system, along with policies targeting multiple sectors of the food system (Lancet 2019).”

Future Education and Training Benefits in Nutritional Psychology

Collectively, these projected job statistics along with the rise in chronic diet-related and mental-health-related conditions, indicate the added knowledge professionals gain from education and training in Nutritional Psychology could quickly highlight their job skills in an increasingly competitive field, and may fast-track career progression.

While both the nutrition and mental health fields have existed independently for many years, nutrition and mental health are only recently beginning to be combined. The demand for nutritional psychology services is likely to increase as individuals become more aware of and interested in the connection between diet and mental health. This is particularly as research validates the link between diet and mental health.

Research is demonstrating that diet is playing an increasingly important role in the mental health of individuals and societies around the globe. The development of the field of Nutritional Psychology provides mental health and nutrition professionals with a much-needed structure through which to address mental health issues.

Visit The Center for Nutritional Psychology (CNP) to keep current with what’s happening in the field of Nutritional Psychology.

References:

  1. GBD 2017 Diet Collaborators. Health effects of dietary risks in 195 countries, 1990–2017: a systematic analysis for the Global Burden of Disease Study 2017. The Lancet, April 3, 2019; DOI: 10.1016/S0140-6736(19)30041-8

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