Above: Image © istockphoto.com/julos
Did you know? The hippocampus is an area of the brain involved in forming memories, controlling emotions, and storing information. You can buy soft drinks just about anywhere and you probably see people drinking them all the time. So it’s not surprising that when New York City tried to restrict the sale of large-sized sodas in 2012, a lot of the public reaction was negative. On the other hand, although the New York City soda ban has since been officially struck down, a lot of the news about the health impacts of soft drink consumption is pretty negative as well.
|A rodent in a Barnes maze. Click image to enlarge (Bd008)
The soda ban, championed by then-mayor Michael Bloomberg, was promoted as a way of reducing obesity and related health problems, including diabetes. Indeed, researchers have repeatedly linked diabetes and obesity to consuming too many sugary drinks. However, new research suggests that sugar-sweetened drinks are also very bad for your brain, especially if you are a teenager.
Researchers at the University of Southern California have identified a link between a diet high in sugar and cognitive impairment. The research focused on adolescence, a critical period of development when negative effects can be particularly significant. Adolescent rats that consumed a high fructose corn syrup (HFCS-55) solution displayed impaired learning and memory when compared to rats that consumed either a sucrose (table sugar) solution or plain water. The water-drinking group performed the best.
Did you know? On average, American teens consume about 34 teaspoons of sugar daily—that's up to seven times the daily recommended intake!The rats’ cognitive abilities were tested using a Barnes maze, which measures a rodent’s ability to learn and remember a location using visual cues. The rats that performed worse on the cognitive tests were also found to have higher levels of cytokines. These small molecules help initiate immune responses in the hippocampus, an area of the brain important for memory. The researchers behind the study stressed how sensitive the hippocampus is to environmental factors, including diets high in saturated fat and processed sugar.
Meanwhile, researchers at Lund University in Sweden have shown that, in addition to cognitive impairment, the over-consumption of sugary beverages may also interfere with neurogenesis in the hippocampus. In other words, it prevents new neurons and other brain cells from developing. This study also involved rats, and those that were given a fructose solution showed high rates of apoptosis (cell death) in the hippocampus.
Taken together, these two studies strongly suggest the sugary drinks can have harmful effects on health, especially the health of adolescents, when consumed in large quantities. So even if soft drinks taste great and New Yorkers are free to drink whatever sized soda they want, you might want to consider what sugary drinks can do to your hippocampus before buying one. Instead, try a healthier alternative such as green tea, vegetable juice, soy beverages, or even (unsweetened) flavoured water!
10 Soda Alternatives (2014)
Adrienne Rayski, Everyday Health
Article listing healthier alternatives to sugary soft drinks.
T. M. Hsu, V. R. Konanur, L. Taing, R. Usui, B. D. Kayser, M. I. Goran & S. E. Kanoski. (2014). Effects of sucrose and high fructose corn syrup consumption on spatial memory function and hippocampal neuroinflammation in adolescent rats. Hippocampus doi: 10.1002/hipo.22368.
Article by University of Southern California researchers on negative effects of sugary drinks on learning and memory. An abstract is available on the publisher’s website but a subscription is required to view the full text.
K. van der Borghta, R. Köhnkeb, N. Göranssonb, T. Deierborga, P. Brundina, C. Erlanson-Albertssonb & A. Lindqvistc. (2010). Reduced neurogenesis in the rat hippocampus following high fructose consumption. Regulatory Peptides 167(1), 26-30.
Article by University of Lund researchers on the negative effects of sugary drinks on hippocampal neurogenesis. An abstract is available on the publisher’s website but a subscription is required to view the full text.