We know that sugar is not good for our waistline. We keep it out of our children’s diets for fear of cavities. But did you also know that eating a diet full of excess sugar - particularly high fructose corn syrup - is also really bad for the brain?
High fructose corn syrup (HFCS) is a common added sweetener in processed foods and beverages. Research studies have yielded mixed results about possible adverse effects from consuming too much of the additive, especially cardiovascular risks. However, consumption of excess sugar overall has been linked to health ills such as weight gain, dental caries (cavities), poor nutrition, and high triglyceride levels.
In a new study, Fernando Gomez-Pinilla PhD of the University of California-Los Angeles and colleagues studied the effects of high-fructose corn syrup in laboratory rats. Two groups of animals were given HFCS as part of their water supply; however, one group was additionally given omega-3 fatty acids as part of their diet. The rats were trained on a maze prior to the diet changes and evaluated again after six weeks.
The rats who were fed HFCS only were slower navigating the maze than those who had omega-3 fatty acid supplementation. The researchers also noted a decline in brain activity in those with the high sugar diet alone. They theorize that insulin resistance prevented synaptic responses in the brain from working properly. Synapses are the chemical connections between brain cells that enable learning and memory.
High Fructose Corn Syrup has also been linked to high blood pressure, also bad for brain health.
"Our findings illustrate that what you eat affects how you think," said Dr. Gomez-Pinilla, a professor of neurosurgery at the David Geffen School of Medicine at UCLA and a professor of integrative biology and physiology in the UCLA College of Letters and Science. "Eating a high-fructose diet over the long term alters your brain's ability to learn and remember information.
The average American consumes over 40 pounds of high-fructose corn syrup each year, according to the US Department of Agriculture. Some researchers believe that this particular type of sugar is metabolized differently in the body than regular table sugar (sucrose), leading to high blood sugar and increased insulin secretion. But keep in mind that added sugar from any source is not recommended by health experts, especially those at the American Heart Association. The AHA recommends that men should consume no more than 150 calories per day from added sugar (about 9 teaspoons) and women, no more than 100 calories per day (6 teaspoons).
Cutting back on processed and packaged foods can cut back on a number of unhealthy nutrients, including excess sugar and high fructose corn syrup. Instead, snack on vegetables, fruit, low-fat cheese, whole-grain crackers and low-fat yogurt. Also, trading sugar sweetened beverages for water is more healthful overall.
But, even if you enjoy a treat now and then, the researchers note that the simple addition of Omega-3 fatty acids may help limit some of the damage that HFCS does to the brain. This healthful fat may help to reinforce the synapses and protect them. Craving a soda or a baked dessert? Be sure to also eat foods high in omega-3’s such as salmon, flax seed oil, and walnuts.
R. Agrawal, F. Gomez-Pinilla. 'Metabolic syndrome' in the brain: deficiency in omega-3 fatty acid exacerbates dysfunctions in insulin receptor signalling and cognition. The Journal of Physiology, 2012; 590 (10): 2485 DOI: 10.1113/jphysiol.2012.230078