There is a direct link between mood and blood sugar balance. All carbohydrate foods are broken down into glucose and your brain runs on glucose. The more uneven your blood sugar supply the more uneven your mood. In fact, our experience at the Brain Bio Centre is that poor blood sugar balance is often the single-biggest factor in mood disorders amongst the people that seek our advice.
Eating lots of sugar is going to give you sudden peaks and troughs in the amount of glucose in your blood; symptoms that this is going on include fatigue, irritability, dizziness, insomnia, excessive sweating (especially at night), poor concentration and forgetfulness, excessive thirst, depression and crying spells, digestive disturbances and blurred vision. Since the brain depends on an even supply of glucose it is no surprise to find that sugar has been implicated in aggressive behaviour, anxiety, and depression, and fatigue .
Lots of refined sugar and refined carbohydrates (meaning white bread, pasta, rice and most processed foods,) is also linked with depression because these foods not only supply very little in the way of nutrients but they also use up the mood enhancing B vitamins; turning each teaspoon of sugar into energy needs B vitamins. In fact, a study of 3,456 middle-aged civil servants, published in British Journal of Psychiatry found that those who had a diet which contained a lot of processed foods had a 58% increased risk for depression, whereas those whose diet could be described as containing more whole foods had a 26% reduced risk for depression.
Sugar also diverts the supply of another nutrient involved in mood – chromium. This mineral is vital for keeping your blood sugar level stable because insulin, which clears glucose from the blood, can’t work properly without it. There is more on chromium below.
The best way to keep your blood sugar level even is to eat what is called a low Glycemic Load (GL) diet and avoid, as much as you can, refined sugar and refined foods, eating instead whole foods, fruits, vegetables, and regular meals. The book, the Holford Low GL Diet Bible, explains exactly how to do this so this is a great resource if you really want to improve your blood sugar balance. Caffeine also has a direct effect on your blood sugar and your mood and is best kept to a minimum, as is alcohol.
Where’s the evidence? Click here for a list of scientific studies on sugar, caffeine and depression.
And here is a list of 147 reasons to give up sugar.