Sugar and Depression, Another Endless Cycle

Sweet or salty?

The question is easy for me. I have a sweet tooth....a mouth full of them in fact! I eat pretty healthy....protein, complex carbs, lots of vegetables...but it's the dessert. I can't say no. My obsession lately has been cake from Loblaws. They make these "critter cupcakes". It's basically a cupcake surrounded by icing. Most people can't handle the sweetness, but I love it. It's the only thing that seems to pick me up these days.

Critter Cupcake...I love these!

There have been a lot of articles recently about the food-mood connection, how blood sugar and brain chemistry are related. To my dismay, sugar is bad for you. I'm not talking about all sugar. Your body does, after all, need some sugar to function properly. I'm talking about too much sugar....like my icing. It doesn't have to be dessert to be considered too much sugar. Everyday foods like rice, bread, soda or fruit juice can put you over the top too.

People with low levels of serotonin (like those with depression) crave sugar. Too much sugar exacerbates mental health problems. Yes, another another endless cycle that those with mental illness have to fight. It's not fair is it? At least now I know why I've always been a sugar addict.

Carbohydrate cravings have been linked to lower serotonin levels. Ingesting sugar releases insulin from the pancreas. Insulin alters the ratios of amino acids in the body causing there to be more tryptophan available and less of other amino acids. This means there is less competition for tryptophan to cross the blood-brain-barrier. In the brain, tryptophan is can be converted into serotonin, the feel-good neurotransmitter that is often low in those with depression. This explains why I reach for cake as soon as I start feeling down. The relief is only temporary though. Eventually things return to normal and less tryptophan is available to be converted to serotonin. Keep in mind, this is just a fragment of a hugely complex picture.

Sugar has the potential to be addicting too. The more you eat it, the more you crave it. Sugar floods the brain with another feel-good neurotransmitter, dopamine. Studies have show that sugar activates the same areas of the brain as cocaine and we all know how addictive cocaine is known to be. How's that for scary?

There are 3 potential mechanisms through which too much sugar can be a burden on mental health.

1. Insulin and leptin resistance. Insulin resistance can impair signaling between brain cells. You know that foggy feeling you get when you are feeling low. You can't really concentrate and you're having trouble remembering things....insulin resistance contributes to that. Leptin is released to tell the brain you are full, building up a resistance can lead to constant overeating which leads to weight gain. And that always makes us feel great about ourselves right?


2. Chronic inflammation. Too much sugar triggers a set of reactions that lead to a low level of chronic inflammation. This doesn't cause problems right away, but in the long term, chronic inflammation leads to things like heart disease, Alzheimer's and macular degeneration. Inflammation in the brain is also thought to exacerbate depression.
    
3. Less Brain-derived Neurotrophic Factor (BDNF). BDNF is necessary for healthy neurons. Sugar suppresses the production of BDNF. Studies comparing those with depression to those without have found that generally, people with depression have significantly lower levels of BDNF. So sugar just lowers it even more. Ugh!

 So I guess sugar is my best friend and my worst enemy. Sigh, maybe I'll think twice about having my critter cupcake this week. Or maybe I'll just join a Google+ baking community and drool over their creations instead.

Cookie Monster Critter Cupcake

Sources:
Neurology
Diabetes Care
Food for the Brain