Food and mental health
For many of us, feeling hungry makes us feel grumpy, and a good meal enjoyed with friends gives us a lift. But does the food we eat have a more fundamental effect on our mental health? We took a look at the research and talked to some experts to see whether it's possible to eat yourself happy.
Healthy diet, healthy mind?
Research has shown a link between eating a healthy diet, and good mental health. In 2014, researchers reviewed 12 studies that looked at the diets and mental health of children and young people. They said there was a 'significant' relationship between poor diet and poor mental health in this age group, and that a good diet was linked to better mental health. Another study looked at the relationship between depression and diet in adults. It found that people with a healthy diet - lots of fruit, vegetables, fish, and wholegrains - were less likely to have depression than those eating a 'Western' diet which included more processed food.
While these studies sound convincing, this type of research can't prove that good diet actually causes better mental health. It's quite likely that some of these links could have worked the other way around - for example, people who are happier are more likely to eat a healthy diet, and people who have depression are more likely to rely on convenience or fast food.
Also, diet might be a sign of other things, too - for example, the children with unhealthy diets might live in families where people don't have the money, time, or facilities to prepare healthy food every day. Food itself might be less important than the family situation. Older people with poor diets may be more likely to have depression, but they are also more likely to be socially isolated, in poor health generally, and on lower incomes. Any of these things could make them more likely to be depressed.
Psychiatrist Stephen Lawrie, professor of psychiatry at Edinburgh University, is sceptical about research linking diet to mental health: "I don't think there's anything convincing at all [about food and mental health]. Too much alcohol is bad for you, starvation is bad for you. Other than that, I really don't think there's much evidence," he says.
While agreeing that "there's not a vast amount of evidence", Stephen Buckley, head of information at Mind mental health charity, says: "Most people we talk to know instinctively that what they eat and drink has an impact on what they feel, more or less immediately. It can be very personal, how people experience moods and feelings, which is not easy to test in RCTs [randomised controlled trials, a type of clinical study]."
Ursula Arens, dietitian and features editor of NHD, a magazine for dietitians, says the research about food and mental health is "less strong than in other areas", partly because mood is difficult to measure. "Mood is influenced by a million things and food is far down the list."