subjects’ diets and found that fruit didn’t seem to be doing
their memory centers any favors. Another study from the
Mayo Clinic saw a similar inverse relationship between fruit
intake and volume of the cortex, the large outer layer of the
brain.^30 Researchers in the latter study noted that excessive
consumption of high-sugar fruit (such as figs, dates, mango,
banana, and pineapple) may induce metabolic and cognitive
derangements on par with processed carbs.
DOCTOR’S NOTE: WHEN YOU REALLY NEED TO
RESTRICT FRUIT
People have a wide tolerance for carbohydrates, but for
diabetics, it’s pretty open-and-shut that sugar, even from
fruit, needs to be dramatically restricted. I have my diabetic
patients consume fruit in half-serving quantities—even a
single orange can spike the blood sugar into an
unacceptable range for hours after eating it. But all is not
without hope! Once insulin sensitivity is restored, exercise
has become a habit, and the system has had time to restore
energy balance and metabolic flexibility, unprocessed carb
sources can be reintroduced.
Fruits, however, do contain various important nutrients.
Luckily, low-sugar fruits are among the most concentrated
sources of these nutrients. Some examples include coconut,