After living in the dark for so long, a glimpse of the light can make you giddy

Though the way antioxidants work in the brain is not well known, Dr Gómez-Pinilla says it is likely they protect the synaptic membranes. Synapses are the junctions between nerve cells, and their action is central to learning and memory. But they are also, he says, the most fragile parts of the brain. And many of the nutrients associated with brain function are known to affect transmission at the synapses.

An omega-3 fatty acid called docosahexaenoic acid (DHA), for example, provides membranes at synaptic regions with “fluidity”—the capacity to transport signals. It also provides “plasticity”—a synapse’s capacity to change. Such changes are the basis of memory. Since 30% of the fatty constituents of nerve-cell membranes are DHA molecules, keeping your DHA levels topped up is part of having a healthy brain. Indeed, according to the studies reviewed by Dr Gómez-Pinilla, the benefits of omega-3s include improved learning and memory, and resistance to depression and bipolar disorder, schizophrenia, dementia, attention-deficit disorder and dyslexia.

Omega-3s are found in oily fish such as salmon, as well as in walnuts and kiwi fruit, and there is a strong negative correlation between the extent to which a country consumes fish and its levels of clinical depression. On the Japanese island of Okinawa, for example, people have a strikingly low rate of mental disorder—and Okinawans are notable fish eaters, even by the standards of a piscivorous country like Japan. In contrast, many studies suggest that diets which are rich in trans- and saturated fatty acids, such as those containing a lot of deep-fried foods and butter, have bad effects on cognition. Rodents put on such diets show declines in cognitive performance within weeks.

Cognition Nutrition: Food for Thought

Image: Ellen von Unwerth, Vogue Italia 1990

Title: The Good Girl