Eating a healthy, varied and well-balanced diet can improve brain function, helping us to think clearly, feel more alert and to concentrate for longer periods. In contrast, a poor diet can disrupt our brain chemistry, leading to fatigue, low mood, anxiety, poor sleep and more. Eating well is thus particularly important for those undertaking demanding postgraduate research.
Knowing what and how to eat can be difficult given the sheer volume of often conflicting nutritional information available. Below is a quick guide of evidence-based tips to eat healthily and support your physical and mental wellbeing.
Eat plenty of vegetables
During busy or difficult periods, it’s common to reach for sugary processed foods that offer a quick dopamine rush. In the longer term, though, these foods can leave use feeling worse than we started. Diets high in refined sugars have been shown to cause oxidative stress in the brain, which impairs brain function and worsens mood disorders such as depression. Conversely, eating foods rich in vitamins, minerals and antioxidants nourishes the brain.
To boost your mental health, focus on eating plenty of fruits and vegetables along with foods rich in omega-3 fatty acids, such as salmon. Dark green leafy vegetables, in particular, are brain protective. Nuts, seeds and legumes, such as beans and lentils, are also excellent brain foods.
Stay hydrated
Water loss of only 2% can negatively affect mental functioning, causing brain fog, poor concentration and memory, and tiredness. Aim to drink 6–8 glasses of fluid each day to avoid dehydration. It is recommended that at least half of your fluid intake should be water; however, tea, coffee, juices, milk and smoothies all count towards your intake as well (though you should bear in mind that some of these may also contain caffeine and sugar).
Eat regularly
The brain relies on a constant supply of glucose for optimal function. Eating regular, balanced meals helps to provide a steady stream of energy to the brain, supporting cognitive functions such as concentration, memory and mental alertness. To maintain steady blood sugar levels, opt for foods that release energy slowly, such as whole grains, legumes, nuts and seeds, and starchy vegetables.
Get enough protein
Protein contains amino acids, which make up the chemicals your brain needs to regulate your mood, attention, motivation and overall cognitive function. Protein also helps to modulate blood sugar levels and keeps you feeling fuller for longer. Ensure your diet contains plenty of protein-rich foods such as lean meat, fish, eggs, cheese, legumes, soya products, nuts and seeds.
Eat the right kinds of fat
While we should try to avoid trans fats and partially hydrogenated oils (found in many shop-bought cakes and biscuits), fats play several essential roles in maintaining the structure and function of the brain (which itself is composed of approximately 60% fat). Omega-3 fatty acids are particularly important for brain function. These are found in oily fish, poultry, nuts (especially walnuts and almonds), olive oils, seeds (such as sunflower and pumpkin), avocados, milk, yoghurt, cheese and eggs.
Limit caffeine
Moderate caffeine intake (approximately three cups of coffee per day, or 250 milligrams of caffeine) is not associated with any recognised health risk. However, caffeine is a stimulant, meaning that if you consume too much it may leave you feeling anxious, wired or depressed and can interrupt your sleep.
Look after your gut health
Taking care of your gut is crucial for supporting your mental health because the gut and brain communicate closely through a network known as the gut-brain axis. For instance, you might notice that emotions such as stress and anxiety can cause your digestive system to speed up or slow down. If you're feeling stressed and you think it is affecting your gut, you could try some of the mindfulness techniques listed on this webpage.
To support gut health and mental wellbeing, focus on eating a varied, balanced diet with fibre-rich foods and fermented foods such as kimchi and sauerkraut, manage stress, stay hydrated, and limit processed foods and sugars.
Get enough vitamin D
Adequate levels of vitamin D are crucial for cognitive functioning and reducing the risk of mental health disorders such as depression and seasonal affective disorder. To ensure you’re getting enough, make sure you are exposing your skin to sunlight for 5 to 15 minutes two to three times per week during the summer months and eating vitamin D-rich foods such as fatty fish and fortified dairy.
Sources and further reading
(opens in a new window)Feeding your brain – The Wellbeing Thesis
(opens in a new window)Eating healthily to improve mental health – HSE
(opens in a new window)Maintaining mental health: food – St Patrick's Mental Health Services
(opens in a new window)Achieving a balanced diet with the food pyramid – spunout
(opens in a new window)Who can I trust for nutrition and fitness advice? – spunout
(opens in a new window)Vitamin D and the sun – Irish Cancer Society