Vegan and Vegetarian Diets and Their Impact on Mental Health
Like many people around the world this month, I have switched to veganism for Veganuary. I have joined this initiative as an almost life-long vegetarian who is curious to see if veganism makes any difference to how I feel physiologically and mentally. There are, of course, valid ethical and environmental reasons for taking up this dietary regimen, as well as proven health benefits.
Diet Can Positively Influence Mindset
An incidental consequence of eating a vegan and vegetarian diet is that it can contribute to better physical health, lowering the risk of heart disease, strokes, and cancers. Moreover, many studies have shown that veganism and vegetarianism can have a positive influence on mindset and can help improve mental health and wellbeing.
Good vs Bad Fats Can Influence Emotion
A study in the Nutrition Journal entitled, ‘Vegetarian Diets Are Associated with Healthy Mood States’ found that ‘…vegetarians reported less negative emotion than omnivores … and … had lower scores on depression tests and mood profiles when compared to fish and meat eaters’ (2010). The study concludes that this positive mindset among vegans and vegetarians could be due to a low intake of saturated and trans fats obtained from red meat, dairy and eggs, and a higher intake of polyunsaturated fats. These fats, found in olive, sunflower and coconut oil, can help reduce bad cholesterol levels in your blood, lowering the risk of heart disease and strokes.
Just as eating polyunsaturated fats can be responsible for better health and an improvement in mood, studies have shown that there is also a direct link between eating trans fats, leading to poor health, cardiovascular disease, and a risk of depression. This is illustrated in the article, ‘Dietary Fat intake and the risk of Depression’:
A detrimental relationship was found between TFA (trans fatty acids) and depression risk, whereas weak inverse associations were found for … PUFA and olive oil. These findings suggest that cardiovascular disease and depression may share some common nutritional determinants to … fat intake. (2011)
However, there isn’t always widespread agreement among scientists and researchers that a plant-based diet is good for you. There is a school of thought that believes that the opposite is true: that there is a connection between vegetarianism and depression. Many have conducted extensive studies to support the view that vegetarianism and veganism can contribute to poor mental health and lead to depression.
In an article in Psychology Today, ‘The Baffling Connection Between Vegetarianism and Depression’, Dr Hal Herzog discusses a series of peer-reviewed studies which link vegetarian and vegan diets with depression. One of the studies he refers to from the International Journal of Behavioral Nutrition and Physical Activity(2012) maintained that ‘Vegetarians displayed elevated prevalence rates for depressive disorders, anxiety disorders and somatoform disorders.’
In Pursuit of Tangible Evidence
Having reviewed many articles that straddle both arguments, I have reached the conclusion that the scientific studies aiming to prove that there is a link between a plant-based diet and depression have struggled to produce tangible evidence that this is the case. They are unconvincing at best and appear to be biased against the vegetarian and vegan diet.
These studies have proven that it is difficult to provide any causal link between vegetarianism and veganism and poor mental health and depression. In fact, the tenuousness of this argument can be seen in the conclusions drawn by many of these researchers whose findings can be attributed to the possibility that vegetarians are by nature ‘sensitive’ humans with a propensity to care for living creatures: ‘The experience of a mental disorder may sensitize individuals to the suffering of other living beings, including animals’ (Michalak, et al. 2012).
There is also compelling scientific evidence (Timko et al., 2012) to indicate that those who are less committed to a vegetarian/vegan diet (semi-vegetarians), who dip in and out of the dietary regime, are more likely to be associated with ‘disordered eating’, in other words, avoiding particular foods and restricting intake in order to control weight. As Timko et al. suggests: ‘Vegetarianism may be a precursor to the development of an eating disorder.
Many committed vegans and vegetarians would refute the idea that they dip into and out of their dietary regimen and would not classify themselves as semi-vegetarians and their dietary choices as fickle. Therefore, it would be unfair and inaccurate to draw generalized conclusions that committed vegans and vegetarians are prone to depression. Rather, it would appear that researchers are bending the truth to make their argument via their studies.
In her doctoral thesis, ‘The Social and Psychological Well-Being of Vegetarians: A Focused Ethnography’ (2017), Jacqueline Torti does a thorough review of many of the research out there contending that veganism/vegetarianism is correlated with poor mental health. She also finds that the link between negative mood and vegetarianism is tenuous:
There is little available evidence on the psychological well-being of vegetarians. Most studies have high risk of bias…. Further research is needed to investigate whether a causal relationship exists between vegetarianism and mental health…. Others may not agree with their diet choice and this can affect their self-perceived social well-being. However, the self-perceived benefits to psychological well-being associated with adopting a vegetarian diet seem to outweigh any of the perceived threats to their social well- being. (Torti 2017)
There appears to be a bias against vegans and vegetarians evidenced in these research studies, especially as there is compelling evidence to the contrary, suggesting that ‘… vegetarian groups tended to be … more highly educated and more likely to be married, to drink less alcohol, to smoke less, to exercise more and to be thinner’.
All in all, vegetarians and vegans are fiercely protective of their decision to eat plant-based products to maintain good health and to live a more sustainable life. They continue to reap the benefits by enjoying better health, living longer lives, and helping to save the planet:
A vegetarian diet has been found to reduce the risk of heart disease, obesity, hypertension, type 2 diabetes and some types of cancer. (Brazier 2017)
Concomitant to these benefits of living a healthier lifestyle is the sense that vegetarians and vegans are doing themselves and our planet good, and therefore maintaining a healthier mental state and a positive mindset.
 Bonnie Beezhold, Carol Johnston, Deanna Raigle, ‘Vegetarian diets are associated with healthy mood states’, Nutrition Journal (1 June 2010), https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2887769/
 Almudena Sanchez-Villegas, Lisa Verberne, Jokin De Irala, Miguel Ruiz-Canela, Estefania Toledo, Lluis Serra-Majem, Miguel Martinez-Gonzalez, ‘Dietary Fat intake and the risk of Depression: The SUN Project’, Plos ONE (26 January 2011), https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3027671/
 Johnannes Michalak, Xiao Chi Zhang, Frank Jacobi, International Journal of Behavioral Nutrition and Physical Activity, ‘Vegetarian diet and mental disorders: results from a representative community survey’ (2012): https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3466124/.
 C. Alix Timko, Julia Hormes, Janice Chubski, Appetite, ‘Will the real vegetarian please stand up? An investigation of dietary restraint and eating disorder symptoms in vegetarians versus non-vegetarians’ (14 Feb 2012).
 Jacqueline Torti, Doctoral thesis: ‘The Social and Psychological Well-Being of Vegetarians: A Focused Ethnography’, Public Health University of Alberta (2017).
 JAMA Network Journals, ‘Vegetarian diets associated with lower risk of death’ (3 June 2013): https://www.sciencedaily.com/releases/2013/06/130603164147.htm.
 Yvette Brazier, ‘What to know about the vegetarian diet’, Medical News Today (10 March 2017).