Animals react to the changing seasons with changes in mood, metabolism and behaviour people and human beings are just the same. Many people find they eat and sleep slightly more in winter and dislike the dark mornings and short days and this is commonly referred to as 'winter blues' or 'winter depression'. Others have symptoms that are more severe, often making it difficult to cope with work and putting strain on relationships. This is a recognised problem known as Seasonal Affective Disorder that's usually shortened to SAD (sometimes also called SAD syndrome or SAD disorder).

What are the symptoms of SAD and winter blues?

If you suffer from either SAD or winter blues symptoms you will probably start to notice the difference around September and may not feel like your normal self until April. The main symptoms are listed below; you may not experience all of them, particularly with milder winter blues: 

• Sleep problems - oversleeping but not refreshed, cannot get out of bed, needing a nap in the afternoon
• Overeating - carbohydrate craving leading to weight gain
• Depression, despair, misery, guilt, anxiety - normal tasks become frustratingly difficult
• Family / social problems - avoiding company, irritability, loss of libido, feeling emotionally 'numb'
• Lethargy - too tired to cope, everything an effort
• Physical symptoms - often joint pain or stomach problems, lowered resistance to infection
• Behavioural problems - especially in young people

Who does it affect?

The standard figure says that around 2% of people in Northern Europe suffer badly, with many more (10%) putting up with milder symptoms (sub-syndromal SAD or winter blues). Across the world the incidence increases with distance from the equator, except where there is snow on the ground, when it becomes less common. More women than men are diagnosed as having SAD. Children and adolescents are also vulnerable.

What causes SAD?

The problem stems from the lack of bright light in winter. Researchers have proved that bright light makes a difference to the brain chemistry but why some people suffer and others don't is not clear.

Nerve centres in our brain controlling our daily rhythms and moods are stimulated by the amount of light entering the eyes. As night falls, the pineal gland starts to produce a substance called melatonin that tells our body clock it's night time; bright light at daybreak is the signal for the gland to stop producing this melatonin. But on dull winter days, especially indoors, not enough light is received to trigger this waking up process. Light is also linked to serotonin (also known as or 5HT), a neurotransmitter in the brain. This makes sense because low serotonin levels can cause depression and if you're depressed it can be difficult to concentrate and complete what would normally be simple tasks. Evidence has shown that serotonin levels increase with exposure to bright light - SSRI drugs such as Prozac have the same effect, but without getting into prescription drugs, a simple course of Vitamin D can be an effective counter balance.

MCI was defined by the following criteria:
1. Objective memory impairment for age
2. Largely preserved general cognition
3. Essentially normal activities of daily living
4. No dementia.

Mild cognitive impairment is common and thought to be caused by reduced blood flow causing a physical shrinking of the brain. This is largely due to raised levels of a natural chemical, or amino-acid, called homocysteine. Too much homocysteine can encourage the arteries in the body to harden, fur-up and, in turn, reduce the free flow of blood to the brain and other areas such as the heart. This reduced blood flow causes the brain to ‘shrink’ making it hard for the brain to function optimally, especially for cognitive tasks such as memory and problem solving. Research shows that these patients may also be at an increased risk of developing dementia, including Alzheimer’s disease.
For the purposes of the study the participants received a mixture of the B vitamins B12, folic acid and B6 or placebo, for two years. The results showed that B vitamins appear to slow cognitive decline by reducing this raised homocysteine and equally, due to the duration period, illustrated the ability of B vitamins to intervene in disease progression and development of dementia or alzheimers.

This is just one of many studies that have suggested that B vitamins could help to reduce memory loss as we get older. In fact, previous research has shown that high homocysteine has a direct correlation to low folate (folic acid) or vitamin B12 levels in the blood. As a result improving the body’s provision of these nutrients, including Vitamin B6, can slow the rate of brain shrinking by up to 50% by converting homocysteine into other non-harmful substances.

What can you do to reduce your homocysteine levels?

The good news is that, whatever your homocysteine level is, you can lower it with the right combination of nutrients, dietary and lifestyle changes to reduce your risk.

• Eat less fatty meat, more fish and vegetable protein.
• Eat your greens. Have at least five servings of fruit and evegatbles per day. Vary your selections from day to day
• Have a clove of garlic a day or take a garlic supplement.
• Don’t add salt to your food
• Cut back on caffeine
• Limit alcohol to four glasses of wine a week or two pints of beer.
• Address your stress levels.
• Stop smoking
• Supplement with a B vitamin complex and a Multivitamin & Mineral combination supplement each day.
• Get exercising at least three times a week
• Balance your hormones, if post-menopausal, with soya foods and herbs such as black cohosh.
• For extra memory support consider well-researched natural supplements such as gingko biloba and 1000mg of Fish Oils.

*where neither the researchers nor the participants knew whether they were being given the placebo or the B vitamins.