What Eating Too Much Sugar Does to Your Brain
According to the U.S. Department of Agriculture (USDA), the average American consumes 156 pounds of added sugar per year. Thatâ€™s five grocery store shelves loaded with 30 or so one pound bags of sugar each. Â If you find that hard to believe, thatâ€™s probably because sugar is soÂ ubiquitousÂ in our diets that most of us have no idea how much weâ€™re consuming. Â The Centers for Disease Control (CDC) puts the amount at 27.5 teaspoons of sugar a day per capita, which translates to 440 calories Â â€“ nearly one quarter of a typical 2000 calorie a day diet.
The key word in all of the stats is â€śadded.â€ť Â While a healthy diet would contain a significant amount of naturallyÂ occurringÂ sugar (in fruits and grains, for example), the problem is that weâ€™re chronically consuming much more added sugar in processed foods. Â Thatâ€™s an important clarification because our brains need sugar every day to function. Â Brain cells requireÂ two times the energy needed by all the other cells in the body; roughly 10% of our total daily energyÂ requirements. Â This energy is derived from glucose (blood sugar), the gasoline of our brains. Sugar is not the brainâ€™s enemy â€” added sugar is.
Research indicates that a diet high in added sugar reduces the production of a brain chemical known asÂ brain-derived neurotrophic factor (BDNF). Without BDNF, our brains canâ€™t form new memories and we canâ€™t learn (or remember) much of anything. Levels of BDNF are particularly low in people with an impaired glucose metabolismâ€“diabetics and pre-diabeticsâ€“and as the amount of BDNF decreases,Â sugarÂ metabolism worsens.
In other words, chronicallyÂ eatingÂ added sugar reduces BDNF, and then the lowered levels of the brain chemical begin contributing to insulin resistance, which leads to type 2 diabetes and metabolic syndrome, which eventually leads to aÂ hostÂ of other health problems. Â Once that happens, your brain and body are in a destructive cycle thatâ€™s difficult if not impossible to reverse.
Research has also linked low BDNF levels to depression andÂ dementia. Itâ€™s possible that low BDNF may turn out to be the smoking gun in these and other diseases, like Alzheimerâ€™s, that tend to appear in clusters in epidemiological studies. Â More research is being conducted on this subject, but what seems clear in any case is that a reduced level of BDNF is bad news for our brains, and chronic sugar consumption is one of the worst inhibitory culprits.
Other studies have focused on sugarâ€™s role in over-eating.Â We intuitively know that sugar and obesity are linked, but the exact reason why hasnâ€™t been well understood until recently.Â Research has shown that chronic consumption of added sugar dulls the brainâ€™s mechanism for telling you to stop eating.Â It does so by reducing activity in the brainâ€™s anorexigenic oxytocin system, which is responsible for throwing up the red â€śfullâ€ť flag that prevents you from gorging.Â When oxytocin cells in the brain are blunted by over-consumption of sugar, the flag doesnâ€™t work correctly and you start asking for seconds and thirds, and seeking out snacks at midnight.
What these and other studies strongly suggest is that most of us are seriously damaging ourselves with processed foods high in added sugar, and the damage begins with our brains.Â Seen in this light, chronic added-sugar consumptionÂ Â is no less a problem than smoking or alcoholism. And the hard truth is that we may have only begun to see the effects of what the endless sugar avalanche is doing to us.