Sugar consumption and human memory
Consuming too much sugar-rich foods could slow learning and memory while taking omega-3 fatty acids could improve such problems, say researchers.
According to a new study, a diet that is consistently high in fructose “slows” the brain and hinders memory and learning and that taking more omega-3 fatty acids can improve the former and latter.
Professor Fernando Gomez-Pinilla, from the University of California, Los Angeles (UCLA), said: “Our findings illustrate that what you eat affects how you think.
“Eating a high-fructose diet over the long term alters your brain’s ability to learn and remember information. But adding omega-3 fatty acids to your meals can help minimise the damage”.
As part of the research, rats were given both fructose and the mega-3 fatty acid docosahexaenoic acid (DHA) actually managed to recall the route of a maze quicker than the ones given fructose.
Prof. Gomez-Pinilla said that the rats who consumed fructose demonstrated a decreasing synaptic activity and their brain cells had trouble signalling each other, “disrupting the rats’ ability to think clearly and recall the route they’d learned six weeks earlier”.
“DHA is essential for synaptic function – brain cells’ ability to transmit signals to one another,” he added. “This is the mechanism that makes learning and memory possible. Our bodies can’t produce enough DHA, so it must be supplemented through our diet”.
He thinks that fructose is responsible for the rats’ brain dysfunction implying that consuming lots of sugar could prevent insulin from regulating the way cells use and store sugar for energy needed to process thoughts and emotions.
He said: “Insulin is important in the body for controlling blood sugar, but it may play a different role in the brain, where insulin appears to disturb memory and learning. Our study shows that a high-fructose diet harms the brain as well as the body. This is something new”.
Fructose can be found in cane sugar (sucrose) and high-fructose corn syrup, a liquid sweetener. The former is used commonly in a lot of items such as processed foods, soft drinks, and condiments. The average American roughly consumes 47 pounds (21.3kg) of cane sugar and 35 pounds (15.8 kg) of high-fructose corn syrup each year.
Prof. Gomez-Pinilla added: “We’re less concerned about naturally occurring fructose in fruits which also contain important antioxidants. We’re more concerned about the fructose in high-fructose syrup which is added to manufactured food products as a sweetener and preservative”.
The US-based Corn Refiners Association pointed out that the study did not examine high-fructose-corn-syrup but investigated the intake of fructose being fed to rats in water.
Dr John White, a sweetener expert and president of White Technical Research, said that studies in rats “often do not translate well to human physiology, anatomy or nutrition”.
He said: “Since one of the most important differences between humans and rats is brain anatomical structure, the applicability of rat brain research to humans must be questioned”.
Dr White said that, according to the study data, rats were fed seven grams of fructose per day which is – compared to an adult human being – taking in more than one kilogram each day.
“A consumer would have to eat 66 apples or drink 51 cans of soda per day to reach that level. Clearly this is a highly exaggerated and distorted version of the typical human diet,” he said.
Whilst gathering research, Prof. Gomez-Pinilla and his team investigated two groups of rats that were fed a fructose solution as drinking water for six weeks.
The second group were also given omega-3 fatty acids in the form of flaxseed oil and docosahexaenoic acid (DHA) – which are enabled to protect against damage to the chemical connections between brain cells that enable memory and learning.
The rats were also given standard rat chow and trained on a maze two times everyday for five days before the experiment started.
UCLA examined how the animals managed to navigate through the maze, including numerous holes but one exit. Visual landmarks were added so the rats can remember the way much easier.
Six weeks later, the research team tested the rats to see if they can remember the route and were surprised with the results.
Prof. Gomez-Pinilla said: “The second group of rats navigated the maze much faster than the rats that did not receive omega-3 fatty acids.
“The DHA-deprived animals were slower, and their brains showed a decline in synaptic activity… Their brain cells had trouble signalling each other, disrupting the rats’ ability to think clearly and recall the route they’d learned six weeks earlier”.