We are well aware of the major role nutrition and exercise plays in our physical wellbeing. Yet many people are unaware of the role these factors also play in our mental health. Extensive research suggests that there exists a strong link between depression, nutrition and exercise.

Whilst everyone feels unhappy occasionally, depression, often referred to as ‘the flu of mental health’ is characterised by emotions of sadness, low mood, anger or sleeplessness lasting for over two weeks. Depression often presents with social withdrawal, loss of enjoyment in pleasurable activities, a lack of concentration, constant fatigue, a loss or change of appetite, significant weight loss or gain, alcohol or sedative reliance and an increased sensitivity to headaches and muscle pain. All types of depression, including major depression, psychotic depression, dysthymia, mixed depression and anxiety as well as Bipolar disorder can be managed, if not prevented, by sound nutrition and regular physical activity. It is imperative that we have at least a basic knowledge of the five key nutrients which impact depression. These are: omega three, St. Johns Wart, Tryptophan, Folate and Vitamin D.

People who encounter symptoms of depression will often lose the drive to cook for themselves as well as the motivation for feeding themselves well. This may lead them to consume store bought food as well as snack and convenience food. These types of food are often highly processed and may be lacking in the important nutrients that fresh food provides. Research suggests that processed food dietary patterns are a risk factor for depression and do not promote the recovery, or provide the protection from the disease that whole food pattern diets do. It is therefore important that people with depression understand the importance of maintaining a healthy and wholesome diet.

Omega 3

Omega 3 fatty acids are no longer only recognised for their beneficial roles in the prevention of heart disease, high cholesterol and Alzheimer’s in men but are now recognised for the benefits they provide in the management and prevention of depression. It is important that plenty of fish, which is the best source of omega 3, or alternatively red meat and eggs are included in everyone’s diet. Fish oil supplements are also recommended for people with depression. Studies suggest that there is a credible link between the consumption of fish and the rates of depression. A recent study found that people who consumed less fish were at an increased risk of developing major depression and bipolar disorder. Furthermore, the potential of antidepressant medication can be enhanced when consumed in conjunction with omega 3 supplements.

St John’s Wort

St. John’s Wort, a specific variety of herb is often used by people with depression as an alternative to anti-depressant medication. It has been proved to provide sufferers with the same benefits as anti-depressant medications whilst sparing them of some of the irritating side effects including dry mouth, sleepiness and fatigue as well as nausea and insomnia that the consumption of regular medications often result in. St. John’s Wort is a natural and effective method of treatment for people with mild depression however, the lack of regulations and transparency of herbs in Australia mean that not all Wort products are equal and the active ingredient remains unknown. Furthermore, whilst the herb is beneficial when used on its own it should not be taken in conjunction with any other form of anti-depressant.


People with depression are often found to have low folate levels. This is due to the correlation between the consumption of products containing folate and the brain’s production of the hormone serotonin; a neurotransmitter that makes us feel happy. Understandably the happier an individual feels the less depressed they are and hence it is important that people with depression include plenty of folate containing foods including dark leafy greens, citrus fruits and beans, peas and lentils in their diets.


Studies show that at least 45 minutes of exercise undertaken at least three times each week can help to decrease the symptoms of depression. It is recommended that exercise is taken in the form of a structured class such as yoga classes, dance classes, tennis lessons or personal training as opposed to just going for a walk and exercise classes should be undertaken for at least 10 weeks.


Tryptophan is a type of essential amino acid (protein) that has been found to be low in people with depression. There is limited research on the benefits of tryptophan supplements for depression, however some research suggests that it may be beneficial. However, research also shows that even though someones tryptophan levels may increase in the body with supplements, the activity of the tryptophan doesn’t always increase. Furthermore, taking tryptophan (or Hydroxytryptophan 5-HTP) has been shown to have significant side effects, including death, so it is not recommended that this nutrient be taken as a supplement unless under the guidance of a doctor.

However, it is recommended that tryptophan levels are optimised by consuming a healthy diet. As tryptophan is a type of essential amino acid (protein), it is important that we include adequate protein rich foods in your diet each day. High protein diets are not a good choice for people with depression though, as ironically, it has been shown that high protein diets can actually decrease the amount of tryptophan in the brain (because tryptophan has to compete with other amino acids to get to the brain, and the more excess protein that we eat, the more amino acids the tryptophan has to compete with). So having a higher carbohydrate diet (including low GI wholegrain cereals such as pasta, bread, sweet potatoes and milk) is a better method to increase the body’s levels of tryptophan.

Vitamin D

People with low vitamin D levels are more likely to have depression. It is thought that this is because vitamin D helps to decrease the production of cytokines. Cytokines are a protein which cause inflammation, and it is thought that this may have an impact on depression. New research suggests that a poor immune system, and inflammation may actually play a role in the cause of depression.

Whatever the mechanism, we know that vitamin D deficiency is very common in Australia, and vitamin D is a very important nutrient for a range of different reasons. Encourage clients with depression to have their vitamin D levels checked. Their dietitian can then adviseon an appropriate course of supplements if needed.

Nutrition and exercise play an immensely important role in the prevention and management of depression. It is vital that clients with depression consume an optimal intake of the nutrients Omega 3, Folate, Vitamin D and Tryptophan and to have knowledge of the roles they play in both preventing and managing depression. The right diet combined with regular physical activity can make a significant difference. For more information about diet and depression book an appointment to see one of our experienced Dietitians.