New Scientist 28Mar2020

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or charging off in the wmng direction. "I always

say they've losttheirsatnav:• says Lord.

nm is problematic for two reasons.

It reduces the speed and ef6dency of the

defence, giving invaden more time to gain

a foothold. It also causes inflammation.

Imdhaafoundtbatthe blundering

neutrophils ca.use between two and.five

timesasmuchdamageas theircmmades

that still know their way. SUch friendly~

isaleadingcauseofintlammaging, the

generalised low-level inflammation that

c:Meps throughout our bodies as we age.

But the neutropbil satnav can be reset. The

root of the problem is a chronically overactive

enzyme involved in clirect:ional control So

Imdtnc1ceddownsomemstingdruptbat

were known todialdowntbisenzyme. When

she gave one of these drugs to older adults,

she found that it reset their satnav. "Their

neutrophils are rejuvenated, they movelilce

a young person's neutrophils;' she says.

What are these miracle drugs? Stattns,

the ordinary cholesterol-lowering drugs

aheadytaten by millions of people.

"Taking small

daily doses of

vitamin I may

help rejuvenate

immune cells"

Tumingto rea.1 patient data from the

UniversityofBirmingham'sQueenEli7.abetb

hospital, Lord found that people admitted

to hospital withpneumoniaweremuchless

likelytodieiftheywerealreadytakingstatins

to lower their cholesterol. This staggering

result has since been confirmed in a small

clinical trial. It ls too earlyto recommend that

everybody takes statins as anfmmune booster,

says Lord-she and her team are conducting a

bigger c:Unic:al trial. 'nle drugs can also have

serious side effects. But now might be a good

time to have your cholesterol levels tested,

on(.'e your loc:alhealth system has capacity.

'lhere is also a drug-free way to rejuvenate

your neutmphils: exercise. In 2016, Lord and

her colleagues measuml.exett:ise levels and

neutropbil migration in 211 older adults.

IMMUNOLOGY AT A GLANCE

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"Those doing 10,000 steps on average had

neutrophils as good as young adults," she says.

She emphasises thatneutmplUlsaren'tantivhal

so won'tprevent you catclrlng corouavirus or

help you beat it. but they will protect you from

the real danger, which is pneumonia. "Usually

what carries people awaywith these [viral]

infections is secondary infections," she says.

Vital vitamins

Another daas of immune ciells that begin to

misfire as we age are T-cell& These are pivotal

in theadaptiveimmuneresponse-themore

targeted part of the system-but an: blunted in

two ways byimmunosenescence.Aswith

neutmphils,theirintemalsignallingpathways

go awzy, and they are also inhibited by

inflammaging.Buttheremay be a simple way

toundothiadamage.AccordingtoDayongWU,

a nutritionalfmmunologiat at Tufts University

in Boston. the answer ls vttam1n B..

In atUmal. studies, it has long been known

to enhance immune function, butthe

Mlevance of this resea?cll to humans was

overshadowed by studies suggesting

that vitamin E supplementation is toxic.

Wu now says this is inelevant: toxicity only

arises at doses double that needed forT-cell

:rejuvenation. He and his colleagues tested

vitamin ll in older people-giving half of

the fqOresidentsofanunlnghomeasmall

dally dose ofvltamm E and the other half a

placebo-and found significant diff'eMnc:es

in the rate of upper respiratory infections.

A biggercliniml. trial is in the pipeline,

but the evidence is already strong enough

that Wuemmmends peopleover65

:routinely take 200 international units (IUs)

ofvitaminE. "It may help immune function.

It doesn't hurt." he says.

VitammD,meanwhile, appean to do the

11a111.eforthelnnate ann of the immune

system. especially among people living at

latitudes where there isn't enough winter

sunlight for their skin to synthesise the

molecule. A 2017review of the eviden(.'e for

takingvitaminD supplementation concluded

that it prevents upper:respiratory tract

infections. About 1000 to :aooo IUs should

be safe and beneficial, says Wu, but people

shouldn't go higher than that because bJg

doses actually suppress T-ceD.function.

A third supplement with good evidence

forimmune-boostingpowen is zinc. "It is

very effedive for viral infections; says Wu.

Though be adds, "be cautious, the etrec:tM!

windowisnarrowandanoverdosewill

suppressyourimmunesystem". >

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