During
his 25 years as a journalist, he has covered nonprofit organizations
nationwide for The Chronicle of Philanthropy, delved
into media and political matters and the arts for Baltimore's
City Paper, written about pop music for The Baltimore
Evening Sun, and penned stories on business for Warfield's.
He has also reviewed books for The Washington Post.
He is the senior writer at John
Hopkins Magazine where this article originally was published.
Fish,
we're told, is brain food. So are blueberries, as they contain
nutrients that help us remember things. But could it be that
the brain, the hoggish human command center that makes up only
2 percent of our total body weight but requires 20 percent of
the calories we consume, is actually better off when we deprive
ourselves of food altogether?
Scientists
at the National Institute on Aging, led by Mark Mattson, a professor
of neuroscience at the School of Medicine, think so. In several
papers Mattson discussed during a meeting of the American Association
for the Advancement of Science in February, he and other researchers
say that depriving ourselves via fasting twice a week could
significantly lower the risk of developing Alzheimer's disease
or Parkinson's.
The
findings resonate with decades-old studies that show a link
between caloric intake and oxidative rusting -- the stress on
cells that comes when people get older and take in food. "One
of the only ways to slow down the progression of aging that
involves disease or organ malfunctions is to reduce energy intake,"
says Mattson, who has been studying Alzheimer's and the brain
for 20 years and, according to Thomson Reuters' database, is
the most cited neuroscientist in scholarly journals worldwide.
"As is similar to what happens when muscles are exercised,
the neurons in the brain benefit from being mildly stressed.
To achieve the right kind of stress, people might benefit from
severely minimizing their food intake."
Mattson
and others have tested their theories on animal models and small
groups of human subjects. In studies involving experimental
mice, neurons in the brain become more active when the rodents
are hungrily searching for food. What's more, fasting animals
develop protective measures against damage from stroke and other
mechanisms that cause degeneration in the brain. "What
we've discovered in both animal and human studies is that it's
good to submit your brain to challenges, especially in the short
term," Mattson says, citing research done by several groups
in recent years.
But
why fasting? Wouldn't reducing calorie intake overall also help
the brain? Apparently not, or at least not as much. Sticking
to an intermittent crash diet, with no more than 500 calories
two days per week, primes the brain for protection, he says.
Studies show that keeping calories at around that level stimulates
two messaging chemicals that operate at the cellular level and
are key to the growth of brain cells in animals and humans,
Mattson explains. The shock of fasting leads the brain to create
new cells. As neurons are coaxed to grow, the brain becomes
more resistant to the effects of protein plaques that underlie
cases of Alzheimer's, or the damage inflicted by Parkinson's.
"Fasting
imposes more stress on the cells, but in a good way," he
adds. "There's an increase in adaptive stress responses
when people intermittently fast that is good for maintaining
the brain."
Dietary
changes have long been known to have an effect on the brain.
Children who suffer from epileptic seizures have fewer of them
when placed on caloric restriction or fasts. It is believed
that fasting helps kick-start protective measures that help
counteract the overexcited signals that epileptic brains often
exhibit. (Some children with epilepsy have also benefited from
a specific high-fat, low-carbohydrate diet). Normal brains,
when overfed, can experience another kind of uncontrolled excitation,
impairing the brain's function, Mattson and another researcher
reported in January in the journal Nature Reviews Neuroscience.
The
intermittent fasting advocated by Mattson and others for overall
brain health may be linked to how humankind has evolved. There
are reasons why the intermittent shocks of hunger do a brain
good. "Our ancestors undoubtedly had to go without food
for stretches of time," Mattson explains. "It hasn't
been that long since humanity lacked regular supplies of food.
When you search for food when you're hungry, the brain is really
engaged. The individuals who survive the best -- the ones whose
brains are more attuned to predators and who can remember where
food sources are -- are the ones who've survived."
Partly
because he is worried people might not be able to stick to it,
Mattson isn't promoting a strict, water-only fast. He advises
people to drink plenty of water or unsweetened tea and to eat
no more than 500 calories per fasting day via fiber-rich vegetables.
He warns, however, that fasting is not recommended for the very
young, who need many more calories to keep them growing, or
people over 70, whose brains seem to derive little benefit from
intermittent food deprivation.
