Can Diet Prevent Seasonal Affective Disorder (SAD)?

This time of year, I’ve pretty much had it with winter. My body and brain are craving an outdoor jog, a walk to the park with the kids, running an errand without having to put on 10 pounds of warm clothing (sigh). Most of all, I long to wear footwear that is not a boot! 

The long hours of darkness can certainly affect mood and attitude, but when symptoms begin to affect sleep patterns and weight, it could mean seasonal affective disorder or SAD. 

Also known as seasonal depression or the winter blues, SAD is associated with dramatic changes in mood, depression, and low energy. Although rare, it can occur during the summer months too, with symptoms presenting as anxiety, weight loss and trouble sleeping.

The changes in mood seem to be related to light. In the winter, less direct exposure to sunlight and reduced physical activity contributes to a shift in the production of the hormone melatonin, affecting the circadian rhythm (sleep cycle) and serotonin production. This can cause us to oversleep and have trouble waking up in the morning, a lack of energy and reduced motivation, and strong cravings for carbohydrates, leading to overeating and weight gain.

But for about 6 percent of Americans, the ‘winter blues’ are serious. Changes in season can trigger a severe form of clinical depression that returns and disappears at the same time every year. If you recognize this pattern and it has occurred for two consecutive years or more, seek medical attention.

SAD is more common in women than in men, and cravings for carbohydrates – foods like potato chips, pasta, bread – are one of the main indicators of the condition. It’s normal to crave carbs when you’re feeling down. Carbs raise serotonin levels promoting a better mood. Since SAD can cause changes in appetite and eating behaviors, food and specific nutrients can help combat symptoms too. Here are some mood-boosting strategies:

Improving Mood with Food

The key foods to include in your diet during the glum winter months include:

Fish: SAD is lower in countries with high fish consumption, such as Iceland and Japan, suggesting that low omega-3 intake may be behind the symptoms. That makes sense considering the relationship of omega-3 to mood and depression. Research indicates that omega-3 in fish can help improve symptoms of all forms of depression, from mild to serious, and is critical for a well-functioning central nervous system. Cold-water fatty fish like salmon, mackerel, anchovies and sardines provide the most omega-3. If you prefer to supplement, choose products with more DHA (Docosahexaenoic acid). Flax seed oil, raw nuts and seeds and nut butters also provide some omega-3.

B vitamins: This group of vitamins is critical to mental and emotional health. Leafy greens (like spinach and kale) and whole grains are the richest sources of B vitamins, with the exception of vitamin B12, which is found exclusively in animal foods and by-products (yogurt, cheese, eggs, etc.). Keep a variety of washed leafy greens on hand for quick salads. If you can tolerate grains, prepare homemade muffins from oats and whole grain flour, and center meals around brown or black rice. Have your vitamin B12 tested If you frequently experience low energy levels and lethargy. Low levels of B12 are linked to depression and could result in serious illness. Keep in mind that B vitamins are depleted by stress, caffeine, alcohol, nicotine and refined sugars. Yikes!

Protein: Amino acids in protein make neurotransmitters (brain chemicals) that have an immediate impact on your mood and behavior. The amino acid tyrosine, for example, increases dopamine and norepinephrine levels, making you feel more alert and energized. It’s also necessary for healthy thyroid function. SAD can affect the thyroid in women, contributing to fatigue and weight gain. Start each day with about 20 grams of protein. Eggs, high-protein cereals, nut butters or a high-quality protein shake are excellent sources.

Vitamin D: There is some evidence that low levels of vitamin D may contribute to symptoms of SAD. This is not surprising, since the sun is our most direct source of the vitamin, but studies have been inconsistent. Nonetheless, vitamin D is linked to a host of other diseases including cancer, osteoporosis, heart disease and autoimmune disease. Take at least 1,000 IU of vitamin D daily, especially during the winter months when you aren’t regularly exposed to direct sunlight. Better yet, have your vitamin D levels tested to determine if, in fact, you are deficient, and base your daily supplementation dose on the results. Food sources of vitamin D include fatty fish like salmon, mackerel and tuna, fish liver oils (cod liver oil, we’re talking about you!) and egg yolks.

Probiotics: While information about the relationship between probiotics and SAD is frightfully lacking, since most of our serotonin (about 90 percent) is located in the gut and new research strongly suggests that gut flora has a profound effect on mental health, it makes sense to encourage the growth of good intestinal bacteria. Serotonin influences mood, sleep, appetite and memory. Fermented foods, such as yogurt, kefir, kimchi and sauerkraut, as well as probiotic supplements, should be part of our daily diet and supplementation protocol.

Melatonin: Studies show that supplementing with melatonin can significantly improve symptoms of depression if the supplement is taken at the correct time of day. For those who go to bed sometime between 9 p.m. and midnight, taking melatonin in the middle of the afternoon appears to regulate the sleep cycle and can reduce symptoms related to SAD.

Exercise: Physical activity, especially when exposed to bright lights or sunny days for at least 20 minutes, appears to be effective for treating symptoms of depression.

Finally, since sleep plays an important role in the development or prevention of SAD, establish a good sleep routine. Avoid any screens – computer, tablet, or TV within an hour of bedtime, and instead, spend that hour preparing for restful sleep.