By Maia Szalavitz
http://www.time.com/time/health/article/0,8599,1951240,00.html?xid=rss-topstories
Dr. Vincent Felitti, founder of
Kaiser Permanente's Department of Preventive Medicine and director of its
obesity-treatment program, was seeing some good results. His
patients were losing 50, 80, even hundreds of pounds. He
might have considered the program a success, if not for the fact that the
participants who were doing the best — those who were both the most obese and
losing the most weight — kept dropping out.
Felitti was baffled. Why, invariably, did so many patients quit just as they
approached their healthy goal weight? Ella, for
instance, a middle-aged woman who entered the program in the mid-1980s morbidly
obese at 295 lb., had managed to whittle her frame by 150 lb. over six months. "Instead of being happy, she was having anxiety
attacks and was terrified," Felitti says. (See "The Year in Health 2009: From A to Z.")
He asked Ella what she thought was going on. "Finally, the story comes out," he says. "She had been molested as a child, both within her
family and outside it. She tried to escape by marrying
at 15, at her mother's urging. It was a disastrous
marriage — her husband was crazy jealous. They divorced
in two years. She remarried. Her
new husband was also jealous. He was convinced that
when she was out hanging the laundry, she was sexually posturing to attract the
neighbors."
When Ella was overweight, Felitti
learned, her husband was less suspicious. And her fear
of his rage — perhaps he saw her new slimmer weight as a provocation? — was probably spurring her anxiety. (See a special report on the science of appetite.)
Felitti wondered if there was
something similar barring weight loss in other patients — or causing obesity
itself. In the late '80s, he began a systematic study
of 286 obese people, and discovered that 50% had been sexually abused as
children. That rate is more than 50% higher than the
rate normally reported by women, and more than triple the average rate in men. Indeed, the average rates of sexual abuse are themselves
unsettling: according to a large 2003 study conducted by John Briere and Diana Elliott of the
In recent years, studies by both Felitti
and others have largely confirmed the association between sexual abuse — as
well as other types of traumatic childhood experience — and eating disorders or
obesity. A 2007 study of more than 11,000
Discoveries by Felitti and
colleagues have also helped give rise to broader work linking stressful
experiences early in life — as early as in the womb — to effects on health and
behavior later on, such as an increased risk of heart disease or becoming
addicted to drugs. Scientists are finding that such
effects are not only long-lasting, but can even be inherited by future
generations. (Watch a video about obesity and social networks.)
In decades of experiments with rats, for instance,
neuroscientist Michael Meaney at McGill University in
Canada and his colleagues have shown how such environmentally induced traits
can be passed down — then undone, also by environment. Meaney studied rats with differing maternal styles — some
were naturally nurturing (they licked and groomed their pups constantly),
others were less attentive and even neglectful (mother rats placed in stressful
environments like isolation had greatly decreased capacity for nurture). What researchers found was that these behavioral traits
were passed down to future generations: pups born to neglectful mothers endured
stressful childhoods and grew up to become neglectful mothers themselves. But when babies born to stressed or less attentive mothers
were instead placed with nurturing, affectionate mothers, that early experience
changed the pups. They adapted quickly to the new
mothering style and grew up to tend carefully to their own offspring. These pups' adaptation was then passed to successive
generations as well.
When Felitti first presented his
Kaiser Permanente data connecting obesity with child molestation at a national
meeting on obesity in 1990, most colleagues dismissed him immediately (one even
claimed that obese people made up such stories to justify their "failed
lives"). David Williamson, an epidemiologist at
the Centers for Disease Control and Prevention (CDC), was the lone exception. He said that a large epidemiological study was needed to
determine whether there were any implications of Felitti's
findings for public health.
Felitti knew that he had just the
right data set: Kaiser Permanente has the largest medical-evaluation facility
in the developed world, diagnosing some 58,000 patients annually. Even if only a minority agreed to discuss their childhoods
and allow anonymous use of their medical records, that would be a huge sample. And so the Adverse Childhood Experiences (ACE) study was
born, as a collaboration of Felitti and another CDC
researcher, Dr. Robert Anda.
For the past several decades, the ACE study has recorded
reports of negative childhood experiences in more than 17,000 patients. Adverse experiences include ongoing child neglect, living
with one or no biological parent, having a mentally ill, incarcerated or
drug-addicted parent, witnessing domestic violence, and sexual, physical or
emotional abuse. The researchers then searched for
correlations between these experiences and adult health and the risk of
disease.
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The connections became clear: compared with a person with no
adverse childhood experiences, or ACEs, a person with
four or more has almost double the risk of obesity. Having
four or more ACEs more than doubles the risk of heart
attack and stroke, and nearly quadruples the risk of emphysema. The risk for depression is more than quadrupled. Although many of these outcomes could reflect the
influences of genes and other environmental influences — beyond those occurring
in childhood — the tight relationship between increasing ACE numbers and
increasing health risks makes the role of child trauma clear.
Dr. Jack Shonkoff, director of Harvard's
Center on the Developing Child, calls the research "a tremendous
contribution."
But how does the psychological experience of childhood
neglect cause physical effects like obesity, heart attack or stroke? There are at least two interconnected pathways — one
physiological, the other psychological. (See the top 10 scientific discoveries of 2009.)
The psychology is relatively straightforward: being abused
or otherwise traumatized is painful, and food can be a numbing or comforting
escape. Hence, abused children may turn to overeating,
which causes obesity. Indeed, ACEs
are also strongly linked with other types of unhealthy
"self-medication": for instance, cigarette smoking (which accounts
for the increased rate of emphysema among high ACE scorers) and drug abuse
(having four or more ACEs increases the risk of injectable-drug use by a factor of 10). As
Felitti puts it, "Being fat [or having other
unhealthy behaviors] is not the problem. It's the
solution."
The psychological effects often exacerbate health problems
that the physiological stress response has already caused. High
ACE scorers who do not overeat, smoke or take drugs still have high rates of
obesity, heart disease, depression and diabetes. The
mechanism for these risks appears to lie in the biology of the stress-response
system and in the way environment affects a person's genetic activity.
For most of human evolution, a stressful world would have
been marked by famines or periods of starvation, and that environment might
have resulted in a particular pattern of gene expression that would have
prompted the body to store more fat in preparation for the next bout of
scarcity. Today, of course, the same response to
stress would result in obesity. This theory of a
thrifty fat-storing system that kicks in under high levels of early stress was
originally proposed by British physician David Barker. (See pictures from an X-ray studio.)
If, for instance, a modern child's early life experience —
in the womb and during the first five years, particularly — is constantly
stressful, it would be incredibly energy-consuming, says Dr. Bruce Perry,
senior fellow at the
"Early adverse experience can disrupt the body's
metabolic systems," says Shonkoff. "One of the cornerstones of biology is that our
body's systems when they are young are reading the environment and establishing
patterns to be maximally adaptive."
Researchers also posit that high levels of stress hormones
caused by ACEs can wear down the body over time. A temporary spike in blood pressure in response to a
stressful event may be useful to power an adaptive fight-or-flight response,
but over the long term constant high blood pressure could raise a person's risk
for heart attack and stroke. Studies have also found
that consistently elevated levels of stress hormones, like cortisol, can lead
to permanent damage in certain brain regions linked to depression.
Recently, scientists have discovered that these changes can
themselves be passed down from one generation to the next — a burgeoning new
area of study called epigenetics. Such
research may have significant and long-term implications for the prevention of
obesity, addiction and other illnesses related to early life stress. After all, reducing childhood exposure to trauma in one
generation may further benefit that generation's children and grandchildren. (See 25 people who mattered in 2009.)
Some initiatives, such as the nurse home-visiting program and President Obama's proposed Promise Neighborhoods program, already put
this theory into practice, by offering support and services to low-income
parents in order to reduce child abuse, increase access to prenatal care and
provide parenting education and high-quality day care.
The goal is not only to improve conditions for the current
participants of such programs, but also hopefully to reduce the risk of
problems in successive generations, including major causes of death and disability
like obesity, heart disease and stroke. "It's not
a secret that there is a growing epidemic of obesity and there's no question
that the way we eat and the way we exercise, or do not exercise, is
contributing to it. But it's a huge mistake to
attribute it just to the need to close down fast-food restaurants and turn off
the TV. There's important biology here early in life
that needs attention," says Shonkoff.
Szalavitz is co-author,
with Dr. Bruce Perry, of the forthcoming Born for Love: Why Empathy Is Essential
and Endangered
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