I talk about fructose (fruit sugar) here, but sugar is sugar is sugar. As well as fresh fruit and juice, fructose is plentiful in sugary soft drinks, sweets and chocolate, bread, breakfast cereal, most processed and convenience foods, and ‘healthy’ low-fat or fat-free products.
Fructose can dramatically alter your metabolism and your brain chemistry, cause intense cravings and increase your risk for disease.
Looking first at metabolism, fructose can only be broken down by the liver and is stored as fat. In breaking down fructose, a waste product, uric acid is created, raising blood pressure by blocking nitric oxide production. Excess uric acid is deposited in soft tissues causing inflammation leading to gout. Sugar in general is very pro-inflammatory and there are strong links between sugar, inflammation and chronic illness, whether it be heart disease or diabetes, but also linked to neurological problems including depression, anxiety, and autism. Fructose is the most fat-producing carbohydrate and more of the fat it produces is likely to be stored, leading to insulin resistance, diabetes and fatty liver disease.
In terms of brain chemistry, fructose ‘buzzes’ the brain like other narcotics, displaying both dopaminergic and opioid properties, i.e. it’s addictive. Eating sugar has a potent impact on the same parts of the brain that are stimulated by addictive drugs like cocaine or heroin. Why? Because our food environment has changed a lot since we were hunter-gatherers, but our brain hasn’t. Our brains reward centres were shaped by nutritional scarcity. Evolution wired our brains to light up at a prospect of the sort of easy access energy that sugar supplies. What once kept us alive is now slowly killing us.
Fructose is so prevalent today. Sugar in general has become such a pervasive part of our food landscape that we’re chronically overdosing on it and its effects on our brain chemistry are so powerful, that giving it up can be enormously difficult.
But the good news is, within 10 days of quitting sugar your health can improve rapidly, the metabolic and neurological benefits can be substantial. If you find it hard to go cold-turkey, and most likely you will, it’s safer to eat simple sugars like fructose when you’re glycogen depleted, like after moderate to hard exercise or when breaking an intermittent fast (>14 hours women, >16 hours men). The best way to avoid sugar is to focus on eating real, whole, unprocessed foods.