Food & mood - how nutrition affects mental health

We’re well-aware of how important food choices are when it comes to maintaining our bodies and preventing disease, but there’s expanding research delving into the impacts of nutrition on mental health. Kelly Scholtz, a registered dietitian and spokesperson for ADSA (The Association for Dietetics in South Africa), says, “There are many established links between nutrition and mental health related to specific nutrients and their effects on the brain. There is also a significant amount of ongoing research about nutrition and mental health because nutrition has been clearly identified as an area that is independently associated with mental health. This means that dietary approaches can be used as a complementary intervention along with treatment for mental health issues even in situations where other significant variables cannot be changed. For instance, it may be easier to make dietary adjustments than to fix social situations or other sources of stress in the case of depression and anxiety. Mental healthcare professionals are increasingly including a healthy diet as one of the essential steps in the management of mood disorders, and nutrition can play a role in protecting mental health during times of both acute and chronic stress.”

While a healthy diet can enhance our mental well-being; it’s also true that poor food choices can trigger mood disorders. Sugary foods and drinks, as well as meals or snacks that are mostly comprised of refined carbohydrates cause our blood sugar and insulin to spike, then crash. Low blood sugar often leads to irritability or could possibly trigger symptoms of anxiety. Diets deficient in nutrients such as vitamin B12 and folate can make you vulnerable to the development of depression. Skipping meals can leave us feeling tired and weak, and starves the brain of the energy that we need to think clearly and concentrate. There is also a growing body of evidence showing links between our gut health and brain function which is important for mental health because we want to avoid disruptions to the brain’s normal release of ‘feel-good’ hormones such as serotonin.

Another ADSA spokesperson and registered dietitian, Kgadi Moabelo says, “It’s important to understand that the relationship between nutrition and mental health is complex. Our physical health and mental well-being are inextricably linked. Therefore, when we eat well for our bodies, we’re inevitably also eating well for our minds. It can be typical for a person experiencing depression, anxiety, mood disorders or psychiatric illness to lose focus on making healthy eating choices which can not only worsen their mental health condition but then also impact negatively on their physical health. There’s a significant number of studies linking overweight and obesity to mental health disorders, particularly depression but also anxiety, bipolar disorder, post-traumatic stress syndrome (PTSD) and attention deficit disorder (ADD). Overweight and obesity are then also linked to cardiovascular disease and diabetes. This makes it essential for a dietitian to be part of a multi-disciplinary team helping a patient to address the nutritional challenges that can improve both physical and mental health.”

How stress impacts on eating

Moabelo says: “Stress, through a complex pathway in the brain, can cause increased production of the ‘hunger hormone’ called ghrelin, which can lead to over-eating. Stress can also lead to reduced physical activity which over time sets you on a path to overweight and obesity and metabolic syndrome resulting in the development of depression. Development of stress-related psychiatric disorders such as PTSD and depression have an effect on eating habits, including binge eating and making poor food choices where nutrient-poor high fat meals and sweet foods are favoured over fruits and vegetables. This could be the reason for the association between mental disorders and cardiovascular diseases, diabetes and obesity as well as changes in metabolism.”

Eating well for better mental health

Scholtz points out that as with most health conditions, there is no single food or nutrient that can prevent or cure mental health conditions. “However,” she says, “an overall focus on good nutrition will support health in every way. While the Mediterranean diet has been shown to optimise mental health; and in some cases, even treat clinical depression, other healthy traditional diets do show similar reductions in risk of depression and anxiety. The key characteristics of these diets are an emphasis on whole foods, specifically whole grains, vegetables, fruits, legumes and healthy fats from nuts and seeds, fish and olives.”

Together, Scholtz and Moabelo recommend:


• Eat a variety of foods – the best way to avoid nutritional deficiencies that can trigger mood disorders or exacerbate mental health conditions is to eat a variety of different foods every day. It is also important to have regular meals and use healthy snacks to maintain brain and body energy levels.
• Enjoy vegetables and fruits daily – these are vital sources of the vitamins and minerals we need for optimal functioning of our brains and bodies. A nutrient-rich diet includes a minimum of five vegetables and fruits every day.
• Choose carbohydrates wisely – avoid refined carbohydrates and opt for whole-grain varieties such as wholewheat breads, pasta and brown rice.
• Focus on fibre-rich – gut health, which impacts on brain functioning, is maintained by eating high-fibre foods. Vegetables, fruits, legumes (such as beans, lentils or chickpeas) and whole-grains are important sources of dietary fibre.
• Opt in when it comes to healthy fats – choose healthier plant oils, such as nuts, seeds, olive or canola oil and avocados, instead of animal fats. Omega-3 fatty acids are particularly important for brain health, and these are found in certain nuts, seeds, oily fish (such as pilchards, sardines, tuna or salmon) and some fortified eggs or dairy.
• Go for quality protein – amino acids, the building blocks of proteins, are used by the brain to regulate thoughts and feelings. Our daily diets need to include protein, and healthy sources include lean meat and poultry, fish, soya-based foods, nuts, seeds, legumes, eggs and dairy.

To find a registered dietitian in your area, please visit www.adsa.org.za