Months of short dark days and dreary skies are enough to give anyone a case of the winter blues. But for an estimated two million Brits and 10 million Americans, the lack of sunshine associated with this time of year can cause a set of symptoms that mental-health professionals recognize as ‘seasonal affective disorder’ (SAD)—a type of depression that comes and goes as the seasons change.
In the UK, symptoms—which include tiredness, trouble sleeping, low libido, body aches, lack of concentration and anxiety—usually start between September and November and continue until March or April, but tend to be most severe in January and February.
Says Jenny Scott-Thompson, a SAD sufferer and spokesperson for the Seasonal Affective Disorder Association (SADA),“With the continual lack of light and a long, cold January after the Christmas celebrations, this time of year is the peak time people suffer symptoms of SAD.”
For Jenny, SAD once meant spending half the year hating herself and “wanting to die”. It was a mixture of “exhaustion and misery”, she said, “that seemed out of proportion to what was going on in my life.”
Fortunately, her symptoms improved when she started using a light box, a therapy for SAD generally free of side effects, which was recommended by
“It was incredibly effective,” said Jenny. “2009–10 was the first time in six years that I got all the way from September to April without feeling suicidal at all.”
But light therapy doesn’t work for everyone, and even Jenny found that the benefits diminished over time.
“2013 was particularly difficult despite the light box,” she said. “I vividly remember the frustration of feeling tired all the time, without having done anything to cause it.”
Light therapy is the most researched treatment for SAD, but it’s not the only one worth trying. Growing evidence suggests that, just like non-seasonal depression, diet may have an important role to play in SAD—and making a few simple changes in food choices may be another safe and effective treatment option for SAD sufferers.
If you have SAD or even just a mild case of the winter blues, consider the following dietary changes to boost your mood and energy levels.
Fill up on fish
Diet could explain why Iceland—a country that should have high rates of SAD due to the few hours of daylight it gets during winter—defies all expectations. The country has lower rates of the disorder, according to research, than countries like the UK, Netherlands, US and other countries located at similar latitudes
that have a greater exposure to light in winter.1 Even Canadians of wholly Icelandic descent have low levels
While some speculate that genetics might explain these unexpected findings—others reckon the answer comes down to lots of fish in the diet.
In a letter to the American Journal of Psychiatry, researchers Dr Jerry Cott and Dr Joseph Hibbeln, both interested in the role of essential fatty acids in mental health, agree that fish consumption is the key to why Icelandic SAD is a rarity.3
Icelanders eat, on average, 225 lb of fish per person per year—more than five times the amount we eat in the UK and nine times the amount the Dutch eat. In Japan, another country with high fish intakes (147 lb per person per year), SAD rates are similarly low.
Cott and Hibbeln believe that a high-ish diet may have a protective effect against SAD because it’s rich in omega-3 essential fatty acids, which can help ease depressive symptoms.
In fact, the evidence shows that societies that consume only small amounts of omega-3s have higher rates of depression, and individuals suffering from depression also tend to have lower levels of omega-3s.
A number of clinical trials show that supplementing with omega-3s can have antidepressant effects.4
SAD solution: Eat more fish. Try to include omega-3-rich fish like salmon, sardines, trout and herring in your meals two or three times a week. If you don’t like fish or you’re worried about mercury, take a good-quality omega-3 supplement instead. Aim to get around 10 g of omega-3s per day. If you’re vegetarian or vegan, purslane is an excellent plant source of omega-3.
Cut down on carbs
Cravings for carbohydrates—especially the bad, ‘simple’ kind like sugary cakes and sweets, white bread and processed snacks—is one of the symptoms of SAD.5 And while eating such foods can provide a temporary mood boost, in the long run it can have detrimental effects—and not just on your waistline.
According to a review of the evidence for food effects on mood by Professor Larry Christensen, chair of the psychology department at the University of South Alabama, eating simple carbs may give you a short-term boost in energy, but a decrease in energy and an increase in fatigue over time. This means that SAD sufferers can easily find themselves in a vicious cycle, bingeing on carbs for a quick fix, then eventually feeling worse and craving carbs again.
Christensen suggests that instead of using simple carbs as a form of self-medication, SAD sufferers should simply eliminate these foods from their diets for more long-lasting improvements in mood and fatigue.6
Although studies have yet to be done with SAD patients specifically, a trial of depressed people who cut sugar and caffeine from their diets found that their symptoms improved—and the improvement persisted for three months after the study ended.7
Other studies suggest that processed sugar is the biggest contributor to depression in depressed patients.6
SAD solution: Cut out simple carbs like sweets and processed foods, and choose unrefined ‘complex’ carbs instead.
Oats, brown rice, quinoa, lentils, chickpeas, wholemeal pasta and root vegetables are good meal options (particularly if combined with an omega-3- or tryptophan-rich protein source—see the other SAD solutions in this article), while bananas, nuts and houmous with crudités make good simple snacks.
Top up your tryptophan
l-Tryptophan is an amino acid the body needs to make serotonin, the so-called ‘happy hormone’ that some evidence suggests is involved in SAD.8 Supplements of l-tryptophan appear to help some SAD sufferers. In one small trial, SAD patients who responded poorly or not at all to light therapy were given 3 g/day of l-tryptophan for two weeks in addition to the light therapy. Nine of the 14 SAD sufferers showed “very good clinical responses” to this combined treatment, with few side effects.9
In another study, l-tryptophan was pitted against light therapy and a placebo in 13 SAD sufferers. Both l-tryptophan and light proved equally effective at improving SAD symptoms—and both were better than a placebo.10
This suggests that a tryptophan-rich diet may be helpful against SAD. However, according to nutritionist Natalie Savona in her book The Kitchen Shrink, for tryptophan in food to be converted to serotonin in the brain, you need a healthy supply of other nutrients, such as vitamins B3, B6 and C, folic acid and zinc.
You also need a good balance between carb and protein intakes, she says, as too much protein could mean tryptophan ends up competing with other amino acids trying to reach the brain.
SAD solution: Eat plenty of tryptophan-rich foods like bananas, chicken, turkey, fish, sunflower seeds, oats, milk, dried dates, peanuts and cottage cheese, and make sure your meals are supplying equal amounts of carbs and protein. Also, vary your diet to make sure you’re getting a full spectrum of nutrients, or take a multivitamin/mineral supplement. If that doesn’t work, consider an l-tryptophan supplement. Doses of 2 to 6 g/day have been used in studies.
Light the way
Light therapy is the most studied treatment for SAD, and it’s a great option if you can stick with it. It has an overall positive treatment response of up to 70 per cent and virtually no side effects.1
The treatment usually involves sitting in front of a light box, which gives off bright light that mimics natural outdoor light. Another form of light therapy that can be effective is ‘dawn simulation’, where a bedside light such as the Lumie Bodyclock (www.lumie.com) gradually increases its intensity as morning approaches. This form of light therapy may be easier to incorporate into your life than the traditional light boxes.
Another take on light therapy treatment is the Valkee (www.valkee.com), a headset similar to an iPod that channels bright light into the brain through the ear canal. It sounds like it can’t work, but the manufacturer actually has a clinical trial to back it up.2
Natural light—if you can get it—can also be an effective SAD-buster, especially when combined with exercise. One Swiss study showed that a daily one-hour walk outdoors in natural light was more effective that an artificial light box for improving SAD symptoms. The walking group also spent less time in bed, got up earlier and even ate fewer carbs.3
Other ways to beat SAD
St John’s wort (Hypericum perforatum). This popular herb is a well-known treatment for depression, with numerous studies reporting success. Although only a few trials have specifically looked at its potential for treating seasonal depression, the evidence has been promising—suggesting that it can improve low mood, fatigue, anxiety, lethargy, sleep and other symptoms of SAD.
In a study carried out in Vienna, 900 mg of St John’s wort led to significant improvements in SAD severity after just a month. Interestingly, when light therapy was added to the treatment, there wasn’t much of an improvement .1
Suggested dosage: 900 mg in three divided doses (but consult a qualified herbalist first)
Vitamin D. If SAD is triggered by a lack of sunlight, then the ‘sunshine vitamin’, vitamin D, seems like an obvious solution. In one trial, SAD sufferers were given either 100,000 IU of vitamin D as a one-off dose or two hours of bright-light therapy every day for a month. The researchers reported a significant improvement in depression in the vitamin D group, but not in the light therapy group.2
Another study looked at whether vitamin D supplements could improve mood in healthy people during winter. The results showed that vitamin D—whether at doses of 400 IU or 800 IU—was significantly more effective than not taking any vitamin D.3
However, a much larger study of more than 2,000 healthy elderly women found that supplementing with vitamin D (800 IU daily) failed to prevent the common wintertime mood slump.4
This suggests that vitamin D may only help people with genuine SAD, and not much the milder forms of winter blues. Or, perhaps vitamin D is only beneficial if blood levels of the vitamin are initially low, as was the case with some studies of SAD sufferers. In any case, as D supplements are also good for your health overall—particularly in winter when there’s often not enough sunlight to get a decent dose of D the natural way—they might be worth a try.
Suggested dosage: For best results, consult a qualified practitioner to find out if your vitamin D levels are low; if so, they can recommend a therapeutic dosage. Otherwise, try doses of 800–5,000 IU/day of vitamin D3
Cognitive behavioural therapy (CBT). This involves talking to a specially trained therapist over several weeks or months to change the way you think and behave. Recent studies suggest this ‘talking therapy’ can be just as effective as light therapy or even superior to it in the long term.5