What's wrong with eating sugar?

Will you trust me if I just answer: "everything"?

OK, fine. I'll try not to get too technical since other, more learned people have done a better job than I could, but it's still going to be a long discussion.

I have four big problems with sugar. Before I lay them out for you, remember that sugar == carbohydrates, so I'm talking about not just the white stuff here but all processed carbs and even some "unprocessed carbs" that turn to sugar as soon as they get into our digestive system (grapes, I'm looking at you here).

These are my three big problems with sugar:
1. Sugar is addictive.
2. Long-term, chronic consumption of sugar initiates a cascade of health problems termed "metabolic syndrome".
3. Sugar sneakily tricks our brains into eating more of it.
4. The sugar and processed foods industry is evil.

#1: Sugar is addictive.
Our brains have a system called the "reward" system that helps us learn what we like and don't like so we can do it again. When you do something pleasurable (eat, hang out with friends, have sex), your reward system sends out a signal to the parts of your brain that help you remember and control your behavior. If we could translate that signal from the language of neurons it would sound something like: "That was totally awesome. Do it again."

This system is pretty basic. Even worms and flies have reward systems in their brains. Trying to stop it from working is like trying to stop yourself from breathing. You can control it for a little while but eventually your body is going to take over and there's nothing you can do about it. Those of you who have tried to go on a diet know what I'm talking about here. Willpower will only take you so far when your reward system kicks in.

The reward system is naturally activated by pleasurable things that are good for us (eating, hanging out with friends, having sex). But it is also activated (highly) by drugs like cigarettes, alcohol, heroin, cocaine, marijuana, etc. In fact, the reward system can be activated 2-10x more powerfully by drugs than by natural rewards.

As you can imagine, activating the system that gets us to repeat behaviors -- the same one we have very little control over -- 2-10x more than usual is generally not a good thing.

Sugar activates the brain in a similar manner to how drugs activate the brain. Neuroscientists have shown fancy colored pictures of brains so it must be true (I'm joking about trusting a result from a study just because it has a picture of a brain, but it is true that sugar highly activates the reward system).

Science is showing so much evidence that sugar is addictive that a couple of years ago, some prominent scientists came together and published an opinion paper in one of the top scientific journals in the world stating sugar should be regulated in the same way that drugs and alcohol are regulated because sugar is addictive and, like cigarettes, drugs and alcohol it has seriously negative consequences for public health.

There are many more studies that explore the addictiveness of sugar, and some day I'll post links to them, but for now if you want to hear a real nutrition scientist talk about sugar and processed foods and why they are evil, take 90 minutes to watch Dr. Robert Lustig's "Fructose 2.0" talk. For the less technical audience watch the movie "Fed Up", and for the less technical audience that's short on time, watch this 3-minute clip (which is also great for kids).

#2. Long-term, chronic consumption of sugar initiates a cascade of health problems termed "metabolic syndrome".
Metabolic syndrome is a set of risk factors that put us at risk for many nasty health conditions including heart disease, stroke, and diabetes. It results from a diet that is chronically too high in sugars.

Our bodies are not made to have a high sugar intake for a long period of time. Our body has systems in place to regulate the amount of sugar in our blood, so that when we eat something very sugary it won't overwhelm our bodies. But when we are sugar-addicted, our bodies are chronically attacked by sugar and after a while those natural mechanisms to safely dispose of sugar stop working (much like many of us with 9-5 jobs cease to function by the time 4pm rolls around).

One way our body gets rid of excess sugar is by storing it as fat. Yes, you read that right: sugar makes you fat. In the long term, after a decade or two (or more) of excess sugar consumption, your body is no longer able to efficiently process sugar and you start seeing effects on your cholesterol and triglyceride levels (markers of heart disease), not to mention your waistline.

#3. Sugar sneakily tricks our brains into eating more of it.
Our fat cells secrete a hormone called leptin when they get full. Our hypothalamus (part of our brain) detects leptin and uses leptin levels to regulate how much we eat. When we don't have enough fat in our bodies leptin levels are low, leading to our feeling hungry and eating uncontrollably. When we have too much fat in our bodies, leptin levels are high, leading to our feeling full and not wanting to eat.

Guess what blocks leptin?

Yes! Sugar.

Sugar blocks the leptin signal to our hypothalamus. If our hypothalamus doesn't get the leptin signal, it tells us to keep eating. Sugar tricks our brains into eating more than we need.

As with the reward system, this food regulation system is not one to be trifled with. The hypothalamus is a basic part of our brain, one that is evolutionarily quite old. We never would have made it this far as a species without a solid system to regulate our food intake. You might be able to stop yourself from eating temporarily, but unless you're on a hunger strike for a very good reason you're not going to hold out for very long before you start eating uncontrollably (one of the big reasons diets don't work).

#4. The sugar and processed foods industry is evil.
Remember the reward system? It plays a big role during puberty and adolescent development. During puberty, and with a lot of help from our reward system, our brains lay down the pathways that will influence the rest of our lives. More so than at any other time in our life, what we choose to do as young adults sets in place patterns and habits that will exert a lot of influence on our future selves. If you're triggering your reward system with addictive substances during adolescence (cigarettes, drugs, alcohol, sugar), you're more likely to get hooked than if you waited until adulthood, and if you do get hooked your habit is going to be harder to break if you start as an adolescent than if you start as an adult. This is one reason why tobacco companies had to be stopped from marketing to kids.

The sugar and processed foods industry is the tobacco industry of our children's generation, on steroids. Anyone growing up prior to 1990 saw cigarette marketing that directly targeted kids (remember Joe Camel)? We knew cigarettes were bad for our health but the cigarette industry didn't care that they were poisoning entire generations. They just wanted to make money off of our addiction.

Like tobacco did 20-30 years ago, the sugar and processed foods industry strongly markets to kids. If you don't believe me, take a trip down any of the interior aisles in your grocery store. How many boxes and containers are brightly colored? How many have cartoon characters? How many have toys inside or offer "free online games"?

Maybe there are some adults who like brightly colored cartoon characters on their foods and still enjoy playing with toys, but it's pretty obvious to whom these companies are trying to sell their poison. Get a kid hooked on sugar early on, and not only are you likely to have a customer for life, but you also have a customer whose sugar tolerance will only grow over time. In other words, if you get a kid hooked on sugar you have a customer for life who will keep buying more and more of your products as they get older, even when it's killing them. Evil, right?