罗马的天主教大学研究人员发现，限制热量的饮食通过触发CREB1通路而激活
很多和长寿和脑健康有关的基因。
Eating Less Keeps the Brain Young
December 20, 2011
Overeating may cause brain aging while eating less turns on a molecule that
helps the brain stay young.
A team of Italian researchers at the Catholic Univ. of Sacred Heart in Rome
have discovered that this molecule, called CREB1, is triggered by "caloric
restriction" (low caloric diet) in the brain of mice. They found that CREB1
activates many genes linked to longevity and to the proper functioning of
the brain.
The work was led by Giovambattista Pani, Faculty of Medicine at the Catholic
Univ. of Sacred Heart in Rome, and directed by Prof. Achille Cittadini, in
collaboration with Prof. Claudio Grassi of the Institute of Human Physiology
. The research appears this week in the Proceedings of the National Academy
of Sciences USA (PNAS).
"Our hope is to find a way to activate CREB1, for example through new drugs,
so to keep the brain young without the need of a strict diet," Pani says.
Caloric restriction means the animals can only eat up to 70 percent of the
food they consume normally, and is a known experimental way to extend life,
as seen in many experimental models. Typically, caloric-restricted mice do
not become obese and don't develop diabetes; moreover they show greater
cognitive performance and memory, are less aggressive. Furthermore they do
not develop, if not much later, Alzheimer's disease and with less severe
symptoms than in overfed animals.
Many studies suggest that obesity is bad for our brain, slows it down,
causes early brain aging, making it susceptible to diseases typical of older
people as the Alzheimer's and Parkinson's. In contrast, caloric restriction
keeps the brain young. Nevertheless, the precise molecular mechanism behind
the positive effects of an hypocaloric diet on the brain remained unknown
till now.
The Italian team discovered that CREB1 is the molecule activated by caloric
restriction and that it mediates the beneficial effects of the diet on the
brain by turning on another group of molecules linked to longevity, the "
sirtuins". This finding is consistent with the fact that CREB1 is known to
regulate important brain functions as memory, learning and anxiety control,
and its activity is reduced or physiologically compromised by aging.
Moreover, Italian researchers have discovered that the action of CREB1 can
be dramatically increased by simply reducing caloric intake, and have shown
that CREB is absolutely essential to make caloric restriction work on the
brain. In fact, if mice lack CREB1 the benefits of caloric restriction on
the brain (improving memory, etc.) disappeear. So the animals without CREB1
show the same brain disabilities typical of overfed and/or old animals.
"Thus, our findings identify for the first time an important mediator of the
effects of diet on the brain," Dr. Pani says. "This discovery has important
implications to develop future therapies to keep our brain young and
prevent brain degeneration and the aging process. In addition, our study
shed light on the correlation among metabolic diseases as diabetes and
obesity and the decline in cognitive activities."
