What we eat can affect levels of the happiness hormone serotonin, one of the key brain chemicals that regulate mood.
One study looked at more than 15,000 people and found a diet full of fruit, vegetables, fish, beans, nuts and olive oil, with low levels of processed meats, was associated with lower rates of depression and said more studies were needed to investigate this further.
Boost your mood with B vitamins
B vitamins are sometimes referred to as the 'stress vitamins' as symptoms of deficiency can include irritability, tension and anxiety. They are needed to make brain chemicals, including serotonin.
Some studies have found low levels of folate and B12 in depressive patients. A 2013 Swansea University study concluded high levels of vitamin B supplements may be effective in improving mood states and perceived stress in healthy individuals.
A Cochrane review also found taking B12, folic acid and B6, enhanced and sustained response to antidepressants over a 12-month period. Another review concluded folic acid and vitamin B12 should be tried to improve treatment outcomes in depression.
What to eat: B12 can be found in dairy products, eggs, meat and fish. B6 is in meat, fish, vegetables, such as bell peppers and spinach, baked potatoes, and beans and legumes, such as chickpeas and lentils.
To keep B vitamins topped up, consider taking a supplement.
Eat the right fats
Fatty acids, such as omega 3, are essential for brain health. A study, published by Journal of Affective Disorders, found people who took cod liver oil every day were less likely to have symptoms of depression than those who didn't.
What to eat: Good sources of omega 3 include oily fish including salmon, sardines, mackerel and trout. If you're not a fan of fish, it can be found in flaxseed and walnuts as well. Alternatively, you could take an omega 3 supplement.
Include protein in your diet every day
Protein contains the essential amino acid tryptophan, which the body uses to make serotonin. One study found that a supplement of amino acids (tryptophan and tyrosine) and antioxidants virtually eliminated post-natal baby blues during the peak time.
What to eat: Tryptophan is found in chicken, turkey, walnuts, pork, beef, some cheeses, milk as well as bananas.
Get the 'sunshine' vitamin
Vitamin D, the so-called sunshine vitamin, is produced in the skin on exposure to sunlight, and is vital for healthy bones, teeth, and muscles. Vitamin D3 receptors are also found in the brain and a review of 13 studies published in the British Journal of Psychiatry said their findings supported the hypothesis that low levels of vitamin D were associated with depression, although more trials were needed.
What to eat: Vitamin D is found in egg yolks, oily fish (salmon, mackerel, herring and sardines),dairy products and fortified margarines, and meat (liver and kidney). Sunshine, not food, is the main source though and as we don't get enough in this country in the winter, Public Health England now recommends everyone aged over one takes a 10mcg vitamin D supplement in the autumn and winter months.
Look after your gut
Your brain and gut are closely connected and research reveals that your gut bacteria may affect your brain function. A study, published in Gastroenterology, revealed an improvement in brain function among healthy women who consumed probiotics in yogurt.
What to eat: Fermented foods such as yogurt, miso and sauerkraut are packed with good bacteria. Alternatively, a supplement of probiotics can help to restore the natural balance of bacteria in the gut.
The foods that bring you down
There are foods that can negatively affect your mood too. So, what should you avoid?
Cut back on caffeine and alcohol: Both are stimulants and can affect serotonin pathways to the brain. Having too much of either can disrupt your sleep and leave you feeling anxious and depressed.
- Ditch your sugar habit: Scientists at Emory University found that fructose can alter how the brain responds to stress and may exacerbate anxiety and depression.
- Eat less processed foods: These have limited nutritional value and one study found processed foods such as refined grains, fatty meat, fried foods and sweets, increased the risk of depression, whereas plant foods reduced it.
The good news is that there are several supplements that can support your emotional and mental wellbeing. These include:
Ginkgo Biloba is often used to support cognitive function. One study, published by Physiology & Behaviour, found it improved concentration and mood.
Lecithin may be beneficial to brain functions including memory and some studies suggest it may help treat bipolar disorder, as an add-on treatment.
B vitamins support a healthy nervous system, as well as helping to reduce tiredness and fatigue.