So… I’m not great at eating fruit. I buy it and watch everyone else eat it. I think it’s a great idea in theory but in practice I never quite find I’m in the mood. Apples annoy me. Don’t ask me why, but they do. Luckily my partner has instilled a great love of fruit, and to some extent vegetables in the kids. This is especially good because according to nutritional psychiatry (yup, it’s a thing) diet not only affects your physical health but is related to improved feelings of wellbeing – a diet rich in fruit and vegetables is associated with increased happiness and well-being.
On the other hand, poor diets are linked to poor mental health. It’s perhaps not that surprising given brain function depends on certain nutrients being available – if it’s going to work well it needs the right food. What might be more surprising is that gut bacteria are also affected by diet and can in turn influence your mental health. Your gut, as it turns out, is crucial to your response to stress, anxiety and depression. It’s possible a good diet helps regulate your gut bacteria reducing stress and inflammation in the brain. Studies have shown that high fibre diets and lots of fruit and veg promotes diverse gut bacteria and reduces the likelihood of depression.
Not only that but being deficient in some vitamins impairs cognition – the strongest links are with B12 which causes fatigue, depression and poor memory if you don’t have enough and folic acid where deficits are associated with increased depression during adulthood. There is also some evidence to suggest vitamin D can reduce depression and ADHD. Diet affects your mental health across your life as well, with a good childhood diet reducing the likelihood of experiencing mental health problems later in life and a good adult diet reducing the likelihood of cognitive decline as you get older – for instance high fat, high sugar diets are associated with a poorer memory.
With every study that looks at diet and mental health, the evidence stacks up that annoying as they are, I should probably start eating apples.