In short, food impacts mood.
In recently released research, it was found men who consumed high amounts of added sugar were more likely to experience a mental disorder, such as depression or anxiety, after 5 years.1
Results showed men who consumed the most added sugar – more than 67g (16 teaspoons) per day – had a 23% increased chance of experiencing a common mental disorder after five years compared to the men who consumed less than 39.5g. Results were independent of influences such as health behaviours like smoking or physical activity, socio-demographic and diet-related factors, weight, and diseases such as type 2 diabetes and cardiovascular disease.
“There are numerous factors that influence chances for mood disorders, but having a diet high in sugary foods and drinks might be the straw that breaks the camel’s back,” said lead author Dr. Anika Knuppel.
This study does not describe a definitive cause and effect, but a 23% difference is significant and supports the correlation between high sugary food and drink intake and long-term psychological health, adding more data to an interesting line of research.
And although the results denote high sugar intake may contribute to mental disorder in men, it doesn’t mean women are exempt. Quite the opposite.2
Anecdotally, we know many people – men and women – who feel a marked improvement in mood when cutting back on the sweet stuff.
This, in part, can be due to a simultaneous shift from heavily refined, processed and packaged foods to real, whole foods; eating minimally-messed-with-food provides optimum nutrients to support mental health.
How does the quality of what we eat affect our mental health?
It could be due to chronic, low-grade inflammation. Mental health conditions are associated with neuroinflammation,3 and a heavily processed Western diet lacking health supportive nutrients while being high in added sugar, deep-fried oils and take-out or packaged foods is inflammatory.4 Inflammation throughout the body is further exacerbated by a poor diet’s impact on other body functions including that of the intestinal microbiome.
There are other possible factors within the body related to high added sugar intake that can increase risk of mood disorder, including reduction of BDNF levels in the brain,5 and decreased effects of feel-good neurotransmitters, such as lower levels of ‘happy’ serotonin accessing the brain,6 and increased intolerance (making sugar rather addictive) to the ‘rewarding’ dopamine.7
On top of this, when feeling blue, anxious, tense or frazzled, we are less likely to make healthy food choices. When low or stressed, we can reach for sugary treats to boost mood; though this is quickly followed by a crash in energy and mood.
Or when fatigued from anxiety or depression we are less likely to shop for and cook good food, instead stopping by the local take-out or ringing in UberEATS to feed ourselves with stuff that is often high in added sugar, nasty oils and heavily processed ingredients like refined flours.
“Sweet food has been found to induce positive feelings in the short-term,” Dr. Knuppel says. “People experiencing low mood may eat sugary foods in the hope of alleviating negative feelings. Our study suggests a high intake of sugary foods is more likely to have the opposite effect on mental health in the long-term.”
So, what to take from this?
Where possible, help your body and mind and choose the real, whole food alternative.
Eating mostly real, whole food will inadvertently reduce added sugar intake, as well as other unhelpful foods, while providing the goodies that nourish mind and body. Enjoy real food sources of fibre, some healthy fats and protein for a steady, sustained supply of energy, stabilising blood glucose levels while feeding the brain.
And know that conditions such as anxiety and depression are multifaceted, with diet being one pillar of many in approach to prevention and treatment.
Importantly, if you are experiencing anxiety, depression, or any other sign of mental disorder, please reach out for assistance. There are a plenty of fantastic organisations that are here to help, such as Beyond Blue.
By Angela Johnson (BHSc Nut. Med.)
- Knüppel, A Shipley, MJ Llewellyn, CH & Brunner, EJ 2017, ‘Sugar intake from sweet food and beverages, common mental disorder and depression: prospective findings from the Whitehall II study”, Nature, 7, no. 1, pp. 6287.
- Gangwisch, JE, Hale, L, Garcia, L, Malaspina, D, Opler, MG, Payne, ME, Rossom, RC, & Lane, D 2015, ‘High glycemic index diet as a risk factor for depression: analyses from the Women’s Health Initiative’, The American Journal Of Clinical Nutrition, vol. 102, no. 2, pp. 454-463.
- Cepeda, MS Stang, P & Makadia, R 2016, ‘Depression Is Associated With High Levels of C-Reactive Protein and Low Levels of Fractional Exhaled Nitric Oxide: Results From the 2007–2012 National Health and Nutrition Examination Surveys’, The Journal of Clinical Psychiatry, vol. 77, no. 12.
- Calder, PC, Ahluwalia, N, Brouns, F, Buetler, T, Clement, K, Cunningham, K, Esposito, K, Jönsson, LS, Kolb, H, Lansink, M, Marcos, A, Margioris, A, Matusheski, N, Nordmann, H, O’Brien, J, Pugliese, G, Rizkalla, S, Schalkwijk, C, Tuomilehto, J, Wärnberg, J, Watzl, B, & Winklhofer-Roob, BM 2011, ‘Dietary factors and low-grade inflammation in relation to overweight and obesity’, The British Journal Of Nutrition, vol. 106 Suppl 3, pp. S5-S78.
- Molteni, R, Barnard, R, Ying, Z, Roberts, C, & Gómez-Pinilla, F 2002, ‘A high-fat, refined sugar diet reduces hippocampal brain-derived neurotrophic factor, neuronal plasticity, and learning’, Neuroscience, 112, 4, pp. 803-814
- Kharrazian, D 2013, Why isn’t my brain working?, Elephant Press, Carlsbad, CA
- Avena, NM, Rada, P, & Hoebel, BG 2008, ‘Review: Evidence for sugar addiction: Behavioral and neurochemical effects of intermittent, excessive sugar intake’, Neuroscience and Biobehavioral Reviews, vol. 32, pp. 20-39.