Sue Bedford (MSc Nutritional Therapist)

It’s that time of year for some people when the darker nights and limited daylight hours can cause them to feel sluggish and for others, the reduction in light can trigger the onset of more severe symptoms of low mood or depression, fatigue, and anxiety.

Seasonal Affective Disorder (SAD) is thought to affect many of us in the northern hemisphere between the months of October and April. Various studies estimate that the prevalence of Seasonal Affective Disorder is anywhere between 1-10%, with prevalence being higher in people who live in northern latitudes. This seasonal form of depression can range from simply a case of the ‘winter blues’, to completely debilitating symptoms of anxiety and depression. A decrease in light seems to be the main contributory factor to SAD, as light is important in maintaining the balance of hormones and neurotransmitters in the brain that affect our mental health and sleep quality. To be diagnosed with SAD, an individual must meet the criteria of depression that coincides with a certain time of the year for at least 2 years. It is thought that other contributing factors could be low levels of serotonin, stress, disrupted body clock, or biological predisposition. Women seem to suffer more as individuals from SAD as well as individuals who have a family history of depression.

Symptoms of SAD include:

• Low energy
• Overeating
•  Weight gain
• Craving sweet and starchy foods
• Social withdrawal
•  Feeling sleepy/sleeping too much

Nutrition and SAD

It is important to optimise your nutrition to help support and nourish your body and brain. Whether you have a mild case of the winter blues or more severe forms of seasonal depression. Here are a few areas of nutrition that may help to boost mood.

Vitamin D: Vitamin D is frequently referred to as the ‘Sunshine Vitamin’ as sunlight is necessary for the synthesis of this Vitamin (which is produced underneath the skin following exposure to sunlight). Vitamin D occurs in two forms: vitamin D2, which is present in a small number of foods, and vitamin D3, which is formed in the skin when exposed to sunlight. Both D2 and D3 are converted into a form that the body can use in the liver and the kidneys. People need varying degrees of vitamin D depending on where they live and their diets.

In the UK (and people living in the northern hemisphere) we don’t get enough of the kind of sunlight that causes our bodies to manufacture vitamin D under the skin. Only one kind of solar radiation does this: UVB sunlight. Vitamin D is synthesised only when we’re exposed to UVB rays – and unless UVB rays are present it doesn’t matter how warm it is, or in fact how brightly the sun is shining: your skin cannot produce vitamin D.  Therefore, individuals who live in darker or colder environments are more susceptible to lower vitamin D levels, as are those with darker skin, those who rarely go outside and those who wear clothing that covers most of their skin. In the UK we are exposed to UVB in reality from April to October.

Low vitamin D is linked to low mood. Choose a supplement that contains vitamin D in the form of D3 (cholecalciferol) as this is the form that is naturally produced in the skin in response to sunlight. To know if you are deficient in vitamin D see a Qualified Nutritional Therapist (check out BANT website) or visit your G.P for advice.

To make vitamin D more available to us, it is added to dairy products, juices, and cereals that are then said to be ‘fortified with vitamin D’. But most vitamin D – 80% to 90% of what the body gets – is obtained through exposure to sunlight. Here are some food sources of vitamin D:

• Egg yolk
• Red meat
• Oil fish such as Sardines, Mackerel, Salmon and Herring
• Tuna
• Liver

Omega 3 fatty acids -Oily fish, nuts, and seeds contain fats that are essential for cognitive function. Omega 3s help mood, memory, and many brain health issues (low levels of omega 3 have been linked to anxiety, depression, and bipolar disorder), but most of us are deficient and as our bodies cannot make omega 3, we need to obtain it from food. Oily fish such as sardines, wild salmon, herring, and mackerel are fantastic sources of omega-3 fatty acids, and meat, eggs, cheese (from grass-fed animals), avocado, and nuts and seeds are good sources too.

Eat good quality lean protein– Our bodies need essential fats and protein for the formation of neurotransmitters like serotonin to help support mood, so aim to have some protein-rich foods at each meal such as eggs, meat, fish, chicken, nuts, seeds, dairy products, pulses, houmous or turkey.

Reduce sugar right down: Although low mood can leave us craving sugary foods and refined carbohydrate, this is not a good choice for supporting mood as quick-release carbohydrates cause our sugar levels to rise sharply and then fall just as quickly often producing a slump in mood. Choose healthier snacks like a handful of seeds and nuts, an oatcake, some homemade guacamole with carrot sticks, or some natural yoghurt instead.

Increase serotonin: Serotonin is the body’s feel-good neurotransmitter, levels of which can be low in those suffering from SAD. 5-HTP (5-Hydroxytryptophan) is a natural precursor to serotonin, which is formed in the body from the amino acid tryptophan, found in oats, milk, yogurt, cottage cheese, red meat, eggs, fish, poultry, sesame, chickpeas, almonds, sunflower seeds, pumpkin seeds, buckwheat and peanuts.

Reduce caffeine and alcohol intake.

Increase berries – they can help to reduce stress as contain an array of vital vitamins and antioxidants. Stress can increase depression symptoms and tire the body. Raspberries, Blueberries, and strawberries may help prevent the release of cortisol, a hormone produced by the adrenal gland. 

B Vitamins – especially B6, B12, and folic acid. There is some evidence to suggest that these important B vitamins can help boost mood and relieve anxiety and depression. Good sources of folic acid can be found in leafy greens, oatmeal, sunflower seeds, oranges, fortified cereals, lentils, black-eyed peas, and soybeans. Low levels of vitamin B12 are associated with depression, and more research is being conducted into this area. Good food sources of vitamin B12 include lean beef crab, wild salmon, eggs, oysters, cottage cheese, natural yoghurt, milk, and fortified cereals.

Eat more Bananas – bananas contain a good amount of Tryptophan, the precursor to Serotonin – the feel-good brain chemical. Bananas may improve sleep and reduce anxiety — two symptoms of SAD. 

Top up on the Turkey! – A small variety of foods contain sources of Tryptophan which is one of the chemicals besides Melatonin that helps to calm and relax the brain. Turkey contains both so is a good food choice during the winter months. It is also packed full of vital vitamins and minerals and is a good source of lean protein.

Boost magnesium –Magnesium is important for balanced mood and energy production, so if you’re feeling down and sluggish then this is one nutrient that you need to include more of in your diet. Found in dark green leafy vegetables, legumes, wholegrain, as well as in nuts and seeds.

And finally…..

Try to exercise outdoors each day -Exercise is a well-known natural anti-depressant. Try and do some each day – brisk walking is particularly beneficial.

Do chat to your GP and Nutritional Therapist/dietician if you are struggling.