Pond snails that consumed epicatechin found in chocolate developed long-term memories. Image: Kenneth Lukowiak
Turns out that flavonoids make snails smarter.
If you love chocolate, a new study published in the Journal of Experimental Biology may help you justify your dietary choice. Professor Kenneth Lukowiak and fellow researchers from the University of Calgary have identified a component found in cocoa and green tea that can enhance the length and strength of a snail’s memory.
To test the effect of the flavonoid epicatechin (epi), researchers tested one group of pond snails (Lymnaea stagnalis) in standard pond water and another group in pond water with an epi solution (15 milligrams per litre). The concentrated epi level did not alter the snails’ homeostatic behaviour and is considered the equivalent of what humans regularly consume.
The molluscs went through a 30 minute training sessions that involved teaching them to keep their breathing tubes closed in deoxygenated water. The snails usually breathe through their skins, but when immersed in water with low oxygen levels they change their breathing behaviour by extending their breathing tubes above the surface. After the training, Lukowiak and his team found that the control group formed intermediate-term memories lasting less than 3 hours, but the snails exposed to epi developed long-term memories that lasted up to 72 hours. The researchers found that epi directly affected the neurons that store memories, thus demonstrating that cognitive abilities in mammals can be enhanced with the use of flavonoids.
“I think it is important because it again shows that materials we can get from plants can alter how the nervous system functions,” explains Lukowiak. “I believe that if a substance has an effect on snail neuron it probably also has an effect on my neurons.” To test the strength of the memories, the researchers used a process called extinction, in which they override the stored memory with a new memory. This time, in the attempt to extinguish the first memory, they taught the “epi-trained” snails to open their breathing tubes, but instead of learning this new memory, they kept their snorkels shut. It took three training sessions for these snails to demonstrate extinction — the control group only required one.
Whether the results of the research can be applied to humans is yet to be known. Lukowiak says: “Would eating 100 grams of dark chocolate improve people’s ability to form a memory, I don’t know but it is worth the try. People might be happier!”
Source: Journal of Experimental Biology
