12 | F RIDAY, AUGUST 2, 2019 THE NEW YORK TIMES INTERNATIONAL EDITION
well
Weight training may have benefits for
brain health, at least in rats. When rats
lift weights, they gain strength and
also change the cellular environment
inside their brains, improving their
ability to think, according to a notable
new study of resistance training, ro-
dents and the workings of their minds.
The study finds that weight training,
accomplished in rodents with ladders
and tiny, taped-on weights, can reduce
or even reverse aspects of age-related
memory loss. The finding may have
important brain-health implications for
those of us who are not literal gym
rats.
Most of us discover in middle age, to
our chagrin, that brains change with
age and thinking skills dip. Familiar
names, words and the current location
of our house keys begin to elude us.
Much earlier research indicates that
regular aerobic exercise, such as walk-
ing or jogging, can prop up memory
and cognition. In these studies, whichhave involved people
and animals, aerobic
exercise generally
increases the num-
ber of new neurons
created in the brain’s
memory center and
also reduces inflam-
mation. Unchecked,
inflammation in the
brain may contribute
to the development of dementia and
other neurodegenerative conditions.
Far less has been known, though,
about whether and how resistance
training affects the brain. A few studies
with older people have suggested that
weight training may be linked to im-
proved cognition, but the studies have
been small and the linkages tenuous.
While researchers know that lifting
weights builds muscle, it is not yet
clear how, at a molecular level, it might
affect the cells and functions of the
brain.
So, for the new study, which was
published last month in the Journal of
Applied Physiology, Taylor J. Kelty, a
Ph.D. candidate at the University of
Missouri in Columbia, began to con-
sider rats and ladders. He and his
collaborators knew that to closely
study brain changes related to resist-
ance training, they would need to
induce animals to lift weights. But
how?
Mr. Kelty’s solution, a modification of
methods used in some earlier studies,
involved a 100-centimeter-long ladder(a little over three feet) and bags of
weighted pellets gently taped to the
rats’ rear ends. The animals received a
Froot Loop when they reached the top
of the ladder and soon started climbing
willingly, even without rewards. After
several weeks, the climbers showed
increased muscle mass, indicating that
the activity was effective weight train-
ing.
Next, to test the training’s brain
effects, Mr. Kelty and his colleagues
injected a separate group of animals
with a substance known to induce
inflammation in the brain, creating a
rodent form of mild cognitive impair-
ment or early dementia.
Half of these rats then began a
weekly program of weight training. As
the climbing became easier, the mass
of the pellets in their bags was in-
creased, just as people progressively
add to the weight they lift at gyms.
After five weeks, all of the animals,
including an untouched control group,
were loosed individually into a brightly
lit maze with a single, darkened cham-
ber. Rodents gravitate toward dark
places and during repeated visits to
the maze, the animals would be ex-
pected to learn the location and aim for
that chamber.
But their success differed. In the
first few tests, the control animals
were fastest and most accurate, and
the rodents with mild cognitive impair-
ments faltered. With a little practice,
though, the weight-trained animals,
despite their induced cognitive impair-
ments, caught up to and in some cases
surpassed the speed and accuracy of
the controls.
The weight training had “effectively
restored” their ability to think, Mr.
Kelty said.
The untrained animals with mild
cognitive impairments, meanwhile,
continued to lag far behind the others
in their ability to find and recall the
chamber.
Finally, to better understand how
ladder climbing might have changed
the rats’ brains, Mr. Kelty and his
collaborators microscopically exam-
ined brain tissue from each of the
groups. As expected, they found signs
of inflammation in the brains of the
animals that had been injected.
But they found, too, that the memory
centers of the brains in the weight
trainers teemed now with enzymes
and genetic markers that are known to
help kick-start the creation and sur-
vival of new neurons, while also in-
creasing plasticity, which is the brain’s
ability to remodel itself.
In effect, the brains of the weight-
trained rats were remaking themselves
to resemble those of brains that had
not been inflamed and impaired.
Of course, this was a study with rats,
and rats are not people. We rarely
weight train by climbing ladders with
heavy bags strapped to our rears, for
one thing. So, it is impossible to know
from this experiment if our brains will
respond in quite the same way to
lifting weights.
The study also cannot tell us
whether aerobic exercise leads to
similar, differing or complementary
molecular changes in our brains, or if
healthy people gain the same benefits
as those with impairments.
But the findings are suggestive, Mr.
Kelty said.
“I think it’s safe to say that people
should look into doing some resistance
training,” he said. “It’s good for you for
all kinds of other reasons, and it ap-
pears to be neuroprotective. And who
doesn’t want a healthy brain?”Brain may get a lift
from weight training
Several inconclusive studies have sug-
gested that weight training may be linked
to improved cognition.REBECCA BLACKWELL/ASSOCIATED PRESSFitness
GRETCHEN REYNOLDSWeight
training
“effectively
restored” the
test animals’
ability to
think.Since my cancer diagnosis, I have lived
intimately with thoughts of death.
Cancer patients of all ages and stages,
as well as people with other ruinous
conditions, often experience “a double
frame of mind,” as the polemicist
Christopher Hitchens once put it.
Laboring to survive in the present, we
simultaneously imagine our future
demise. Of course, feelings and beliefs
about mortality range widely. But a
number of thinkers have set out to help
those who suspect that introspection
about this state of mind may be the
most important work we can under-
take.
If you want to evaluate your own
perspective on death, try filling in the
Death Attitude Profile — Revised
questionnaire developed by the psy-
chologists Paul T.P. Wong, Gary T.
Reker and Gina Gesser. A series of 32
propositions, the survey measures
death anxiety: worries about self-loss,
missed opportunities, stolen moments,
the prospect of your or your survivors’
suffering, the unknown. It also gauges
death acceptance: satisfaction at hav-
ing led a good life, at acknowledging a
natural ending, at escaping physical
pain or gaining a desirable afterlife or
merging with the cosmos.
When my husband and I compared
our responses to this test, what struck
me was how complicated we all are.
The prospect of my own death arousesmore fright in me than his does in him,
but he is more convinced than I that
death is a grim experience. What, then,
do the psychologists really tell us?
After taking the quiz, the palliative
care nurse Sallie Tisdale found her
score was “all over the place, internally
contradictory.”
To encourage people to ponder their
own extinction, Ms. Tisdale, the author
of “Advice for Future Corpses (and
Those Who Love Them),” recommends
the Japanese film “After Life.” In a
posthumous state, the dead in this
movie pick a single memory in which
to live forever. With delicacy, its direc-
tor, Hirokazu Kore-eda, implicitly asks,
what memory would you choose?
This is a difficult assignment for me.
Should I choose a joyous holiday get-
together with the extended family?
Well, those events often disintegrated
into mayhem. Maybe I should select
the occasion of a professional success.
Unfortunately, those moments were
often fraught with tension. Besides, do
I believe in an afterlife?
Yet watching the movie and consid-
ering its premise — or reading Ms.
Tisdale’s book or taking the question-
naire — equip the mind with the dou-
bled frames through which many
imperiled patients view the world. Not
unlike the double consciousness W.E.B.
DuBois ascribed to African-Americans,
the double consciousness that I experi-
ence can devolve into debilitating
self-division. However, it can also
evolve into an intoxicating clarification
of the human condition.
The drawbacks of living in the
present with corrosive dread about a
diminished or canceled future seem
abundantly clear. When the substanceof the everyday is drained of reality,
leached by visions of impending debili-
tation and disappearance, double
consciousness leads to depression.
As fatigue or nausea take over, I am
torn asunder by the morbid conviction
that this might very well be the last
time I travel, that soon I won’t have the
strength to prepare the meal that I am
cooking or rise from the bed I am
making. Will I survive long enough to
finish the next project? Worse, why
start the next project, if it cannot be
completed? Riven by contrary im-
pulses, I want to live today, but trepi-
dations about tomorrow render the
present flimsy or vacuous. Intimations
of mortality rob us of confidence in our
autonomy before the dying process
finishes that job.
One coping route involves tackling
the logistics of the looming loss: ob-
taining a will, signing advance direc-
tives, deciding how and where to dis-
pose of the remains, composing letters
to survivors or an obituary. Such ef-
forts — focusing the mind on our per-
ishable bodies — rarely erase dread.
Yet they make good use of time, con-
ferring upon us the dignity of taking
actions within perilous circumstances.
Sophie Sabbage, the author of “The
Cancer Whisperer,” is hardly the sole
survivor who believes that dying
should be “the firstthing to come to
terms with when you’re diagnosed
with cancer, not the last.” She goes on
to explain that “We cannot control
what happens to us, but we can control
how we perceive what happens and
how we choose to respond.”
Taking seriously such an insight
entails making meaning from unavoid-
able truths. Most religions — Bud-dhism, Judaism, Christianity, Islam —
encourage believers to contemplate
the dust we will become, to deliberate
on the Latin phrase memento mori,
meaning “remember you must die.”
Endangered patients have a head start
on the steep fork in the road of memen-
to mori, which (as my mom used to
say) is not for patsies, though a
glimpse of its scenery turns out to be
breathtaking.
For at higher altitudes, intimations
of tomorrow’s mortality can shrink
today’s fatigue and nausea into trifles,
or oddly into exultant evidence that,
hey, I’m not dead yet! Some find that
the darkness of the future heightens
the brightness of the present. If this is
the last time I will travel or cook or get
out of the bed, I will relish the experi-
ence to its fullest. Others discover in
an awareness of death the potency of
their own integrity. If the next project
might not be finished, I will pursue it
just as I see fit.
Patients lucky enough not to be
obliterated by pain can learn to bal-
ance on the precarious edge of the
discerned present and an incalculable
future. No longer an ailment, double
consciousness becomes a vertiginous
high-wire act.
Personally, I shift from negative to
positive modes of double conscious-
ness, and back again, in the passage of
time it took you to read these words. It
doesn’t make me the easiest individual
in the world to hang out with.JAIME JACOBDeath as a close companion
A cancer patient strives
to live in the present but
still imagines the futureBY SUSAN GUBARSusan Gubar, who has been dealing
with ovarian cancer since 2008, is dis-
tinguished emerita professor of English
at Indiana University. Her latest book is
“Late-Life Love.”Little heralds the arrival of summer like
the smell of open water, smoky grills and
sunscreen.
Since the late 1970s, after medical re-
searchers linked sun exposure to skin
cancer, Americans have been told to du-
tifully slather, spray and rub on sun-
screen as part of a broader package of
sun protection. But does it make sense
for me, a dark-skinned black woman, to
wear it?
With record-breaking heat this sum-
mer it’s an especially relevant question,
and you might even expect the answer
to be “absolutely.” It’s more complicated
than that.
The American Academy of Dermatol-
ogy’s official position on sunscreen,
which is echoed by the Food and Drug
Administration, is that everyone, re-
gardless of skin tone, should wear it be-
cause, “anyone can get skin cancer, re-
gardless of age, gender or race.” But be-
cause people of color are often left out of
clinical trials and treatments, there is
very little research available about
dark-skinned people and skin cancer,
which raises questions about who is be-
ing considered when organizations
make these public health recommenda-
tions.
Medicine, they say, is about balancing
risks, and it turns out that the benefits
and risks of wearing sunscreen when
you have dark skin can be murky. Many
experts believe that there is no clear link
between sun exposure and skin cancer
among people with dark skin, and there
is also a growing body of research to
suggest that using certain types of sun-screen may actually be harmful, no mat-
ter who uses it.
Black people experience sunburn that
can be painful and cause peeling. When
their skin is exposed to too much sun-
light, black people can suffer from hy-
perpigmentation and visible signs of ag-
ing, just like people with other skin
types. And, of course, black skin comesin a variety of shades, some of which are
more sensitive to the sun than others.
The way skin researchers often quan-
tify different skin tones is by using a
subjective measure called the Fitz-
patrick scale, which breaks skin tones
into six categories based on color and
how easily skin tans instead of burning
when exposed to sunlight. On the Fitz-patrick scale, I, a person who has never
had a painful sunburn in her life, rate a
six.
Dr. Martin Weinstock, a professor of
dermatology and epidemiology at
Brown University in Providence, Rhode
Island, was an author of a study in the
Journal of the American Medical Associ-
ation that looked at the relationship be-tween ultraviolet light exposure, skin
color and skin cancer. The study found
that while such a relationship exists
among people with lighter skin tones,
there’s no such relationship between
sun exposure and skin cancer and dark-
skinned individuals.
People whose skin is naturally brown
when it has not been exposed to sunlight
“are quite resistant to skin cancer,” Dr.
Weinstock said.
When dark-skinned people do get
skin cancer, as Bob Marley did on his big
toe, it tends to appear on “the palms of
the hand and the sole of the feet,” said
Dr. Adewole Adamson, a dermatologist
and the director of the pigmented lesion
clinic at the Dell School of Medicine at
The University of Texas at Austin.
According to Dr. Adamson, the fact
that dark-skinned people are most likely
to get skin cancer on the areas of the
body that are least likely to be exposed
to sunlight suggests that this cancer is
unrelated to sun exposure.
“If UV exposure was such a problem
for skin cancer, you’d see a massive epi-
demic in sub-Saharan Africa,” he added.
“They don’t have the same level of sun-
screen promotion that they do here. And
you hear nothing about it, because there
probably is no association.”
Melanin is humankind’s inborn sun-
screen. Everyone has melanin, but
much like swagger, some of us have
more of it. Melanin is also believed to de-
lay the visible signs of aging. It’s why
“black don’t crack.”
Dark-skinned people don’t have more
melanocytes, the cells that produce mel-
anin, than lighter-skinned people. But
the melanocytes that we do have tend tobe more productive. And it’s because of
melanin that some scientists believe
darker skin tones absorb between 50 to
70 percent less of the sun’s ultraviolet
light than paler skin tones. Exactly how
much less is not well understood, be-
cause fewer studies look at how darker
skin reacts to the sun.
This is not to say that dark-skinned
people shouldn’t pay attention to their
moles and get periodic skin checks —
they should. Among dark-skinned peo-
ple, skin cancer actually tends to be
deadlier, in part because it often goes
undiagnosed for longer. It’s just that, ac-
cording to these experts, the cause of
that cancer isn’t necessarily the sun.
Dr. Adamson thinks there needs to be
more discussion around the particular
risks and benefits of wearing sunscreen,
especially for people with dark skin.
“As I was looking at all this stuff, I’m
like, there’s nothing on people of color in
here and yet I see this messaging say-
ing, ‘Hey, wear your sunscreen,’ ” Dr. Ad-
amson said.
In a statement, the American Acad-
emy of Dermatology said that “while
there is strong evidence to show all skin
types benefit from sun protection to re-
duce sunburn and aging, research is
emerging that explores the relationship
between sun exposure and skin cancer
in people of color.”
The organization has appointed a
working group to review current sci-
ence in the area, and to “assess our mes-
saging on skin cancer and skin of color
based on the latest research.”
In telling everyone to wear sun-
screen, Dr. Adamson said, “we’re not
messaging right for black people.”Should black people wear sunscreen?
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