Like the casino of a Las Vegas resort, our modern food
complex has lost any sense of time, place, and season.
Within a single generation we have gained unprecedented
access to sweet fruit. A pineapple from the tropics, berries
grown in Mexico, and Medjool dates from Morocco are now
flown to our towns and cities so that they may line our
supermarket shelves all year long. These fruits are bred to
be larger, and contain more sugar, than ever before in
history.
We are frequently told that it’s okay—beneficial, even—
to consume “unlimited” fruit, but looked at through an
evolutionary lens, fruit (and particularly today’s cultivated,
high-sugar versions) may be uniquely adept at tricking our
bodies’ metabolisms.^28 This is theorized to be an adaptive,
temporary quality that helped us pack away fat so that we
might survive the winter. In fact, it is thought that our
ancestors developed red-green color vision for the sole
purpose of distinguishing a ripe, red fruit from a green
background—an evolutionary testament to the lifesaving
value of fruit for a hungry forager. Today, 365 days of high-
sugar fruit consumption is readying our bodies for a winter
that never seems to come.
What consequences of gorging on grapes and other
sweet fruit could there possibly be for our brains? A few
large studies have helped to shed some light. In one, higher
fruit intake in older, cognitively healthy adults was linked
with less volume in the hippocampus.^29 This finding was
unusual, since people who eat more fruit usually display the
benefits associated with a healthy diet. In this study,
however, the researchers isolated various components of the