Living in the higher latitudes of the northern hemisphere I, like the locals, have learnt to view the weather in a different light. “At least it’s not bitterly cold,” we say. As we fully submerge ourselves into winter grey and indulge in hot toddies, hot ports and warm hearths, some of us may unfortunately feel like a storm cloud has descended on us. People will describe low moods, feeling foggy and physical symptoms that are worse in the damp weather such as lung and joint problems. Whilst a seasonal decline in energy and mood is normal for many of us, some of us may actually be suffering from Seasonal Affective Disorder (SAD) or the winter blues.
The symptoms of SAD can include serious mood change when the seasons change, excessive sleep, fatigue and craving for sweets and high carbohydrate foods. Herbal medicine, nutritional supplementation, dietary and lifestyle approaches can treat this condition naturally, without the use of pharmacological drugs.
What causes SAD?
The causes, although unclear, are thought to be related to too little serotonin (our feel good hormone), excess melatonin (our sleep inducing hormone) and increased levels of cortisol (our sugar making hormone). This results in depression, excess fatigue and cravings for carbohydrates. SAD is thought to be a result of a misalignment of the sleep-wake phase known as our circadian rhythm combined with decreased blood levels of vitamin D, a hormone we make in our skin, due to lack of sunlight. Whilst antidepressants increase serotonin and treat SAD, there are alternative options to popping a pill. Let’s have a look at them.
Vitamin D and SAD
“Sunshine on my shoulders makes me happy”
It’s a fact. The sun makes us happy. Serotonin is our feel good hormone. Serotonin synthesis is dependent on the duration of sunlight exposure in summer. Epidemiological evidence shows an association between reduced sun exposure and an increase in mental illnesses such as schizophrenia, bipolar disease and depression. These are all associated with low vitamin D and serotonin levels in the blood.
Sunshine makes our bones strong
When the sun hits our skin our bodies make a vitamin (which is actually a hormone) called vitamin D. After sun exposure, Vitamin D is converted to the active form by the liver and then the kidneys where it is known as calcitriol. Calcitriol increases calcium absorption in the intestines and bone production by cells called osteoblasts. This is why sunshine is good for our bones. Conditions like osteoporosis are as much to do with deficient sunlight, as they are to do with deficient calcium in the diet.
Sunshine boosts our immune systems
The sun boosts our immune systems. It does this as there are Vitamin D receptors (VDR) on most of our immune cells. When these VDRs are activated this has potent anti-proliferative and pro-differentiative effects, meaning vitamin D prevents the excess cell growth seen in cancer and allows for proper recognition of cancer cells by our immune cells in order that they be zapped. Vitamin D is also said to modulate the immune system, meaning it has both immune-enhancing and immunosuppressive effects. This is important in not only in immune deficiency diseases such as cancer but also in conditions of a hyperactive immune system such as seen in auto-immune diseases including Multiple Sclerosis (MS), Systemic Lupus Erythematosus (SLE) and Rheumatoid Arthritis etc. Vitamin D deficiency increases the risk of infections, such as influenza and tuberculosis, which of course is even more relevant now with Swine flu.
Sunshine and cancer prevention
The less sun, the more cancer. Studies show an inverse relationship between the risk of developing cancer and sun exposure. In 2005, scientists released a metastudy, which found a beneficial correlation between vitamin D intake and prevention of cancer. Drawing from a meta-analysis of 63 reports, the authors showed that intake of an additional 1,000 international units (IU) of vitamin D daily reduced an individual's colon cancer risk by 50%, and breast and ovarian cancer risks by 30%. Research has also shown a beneficial effect in patients with advanced prostate cancer. Imagine if there was a drug that did this?
Sunshine and the prevention of heart disease
Research indicates that vitamin D may play a role in preventing or reversing heart disease. As with cancer incidence, an inverse relationship exists between heart disease and vitamin D levels in the blood. Low Vitamin D means a higher incidence of heart disease. Gardeners in the UK have lower cholesterol levels in summer. Heart attacks peak in winter and decline in summer in temperate but not tropical latitudes.
Groups at Risk of Vitamin D Deficiency
Obtaining sufficient vitamin D from food alone can be difficult. For many people, consuming vitamin D rich foods and being exposed to sunlight are essential for maintaining healthy vitamin D levels. In some groups, supplements might be required.
Vitamin D requirements cannot be met by human milk alone. The sun is the best source of vitamin D, but of course we are advised to keep infants out of direct sunlight and for them to wear protective clothing and sunscreen. This winter, when your child is sleeping, place it next to a window in full sunlight.
People aged 50 and older are at increased risk of developing vitamin D insufficiency. As we age, our skin cannot synthesise vitamin D as efficiently and the kidneys are less able to convert vitamin D to its active form.
People with limited sun exposure
Homebound individuals, people living in northern latitudes (such as us here in Ireland), women who wear Burkas and people with occupations that prevent sun exposure are unlikely to obtain adequate vitamin D from sunlight.
People with fat malabsorption
As a fat-soluble vitamin, vitamin D requires dietary fat in the gut for absorption. Individuals who have a reduced ability to absorb dietary fat require vitamin D supplement. Fat malabsorption is associated with a variety of medical conditions including some forms of liver disease, cystic fibrosis, Crohn's disease and ulcerative colitis.
People who are obese
Obese people have less vitamin D in their blood. Obesity does not affect skin's capacity to synthesise vitamin D, but greater amounts of fat sequester more of the vitamin and alter its release into the circulation.
Food Sources of Vitamin D
Very few foods in nature contain vitamin D. That is why sun exposure is so important. Good sources of vitamin D are butter, cheese, cream, yoghurt, milk and eggs but these are also good sources of calories and cholesterol. The richest sources of vitamin D are salmon, tuna, mackerel, halibut and cod.
Vitamin D supplement
Try a Vitamin D supplement. 4000IUs per day is recommended in healthy adults. For pregnant women the dose is 2000IU. Cod liver oil is also a good old-fashioned source of vitamin D, A and omega 3. Get one without mercury! The bottom line Yes the sun is good for you as it is necessary to manufacture vitamin D in our skin. Get your bum in the sun. Holiday in southern Europe! Spend as much time as possible in direct sunlight. Even in Galway most mornings are sunny. When it’s cold, allowing for exposure on your face and the backs of your hand while walking the prom or letting the sunshine on your skin by the window is sufficient. Another reason to leave the car at home, Bus it, Bike it, Walk it!
Herbal Medicine for SAD
Besides sunshine and Vitamin D, to treat SAD, I prescribe the use of herbs known as adaptogens contained in my Energy Tonic. Adaptogenic herbs produce an increase in power of resistance against all stress whether it is physical, chemical, biological or emotional. Adaptogens restore and normalise physiological functions in the event of stress, including the stress that winter has on our circadian rhythm and hormone patterns. Adaptogens are specifically prescribed to prevent the effects of SAD as they increase serotonin, decrease melatonin and lower excess levels of cortisol.
The Adaptogens in Carahealth Boost Performance;
- · Lower cortisol levels during times of stress
- · Boost immunity
- · Increase energy levels
- · Improve resistance to stress
- · Improve concentration and memory
- · Improves symptoms of SAD
Carina Harkin BHSc.Nat.BHSc.Hom.BHSc.Acu.
Cert IV TAE.