WEBVTT

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While regaling you with daring 
stories from her youth,

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it might be hard to believe your 
grandmother used to be a trapeze artist.

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However, the bad backs, elbow pain, 
and creaky knees so common in older people

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is more than just “old age."

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In fact, the source of this stiffness 
plagues many young people as well.

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The culprit is arthritis:

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a condition that causes inflammation 
and pain in the joints

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of over 90 million people 
in the U.S. alone.

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But are stiff, creaky joints 
really inevitable?

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What makes arthritis so pervasive,

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and why haven’t we found a cure for 
this widespread condition?

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The first hurdle is that arthritis 
is actually a spectrum

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of over 100 different arthritic 
conditions.

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All these conditions share symptoms 
of joint pain and inflammation,

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but the origin and severity of those 
symptoms vary widely.

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Even the most common type, 
osteoarthritis,

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is trickier to prevent than 
one might think.

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It’s a general misconception that 
arthritis is confined to old age.

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The origins of osteoarthritis can often 
be traced to a patient’s early life,

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from any seemingly ordinary joint injury.

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Following impact, immune cells rush in 
to help clean and repair the damaged site

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and begin pumping out enzymes,

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including matrix metalloproteinases 
and aggrecanases.

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These enzymes clear out the damaged 
tissue and contribute to inflammation.

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But while this rapid swelling helps 
protect the joint during recovery,

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inadequately healed tissue can cause these
immune cells to overstay their welcome.

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The continuing flood of enzymes starts 
to degrade the cartilage,

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weakening the joint and leading 
to arthritis later on.

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Not all forms of arthritis can simply 
be traced to an old sports injury.

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Take rheumatoid arthritis, which 
affects 1.3 million U.S. adults.

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This condition is actually an 
autoimmune disease

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in which autoantibodies target 
natively produced proteins,

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some of which are secreted 
by cartilage cells.

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We still don’t know what 
causes this behavior,

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but the result is that the body treats 
joint tissue like a foreign invader.

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Immune cells infiltrate the joint despite 
there being no tissue damage to repair.

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This response leads to chronic 
inflammation,

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which destroys bone and cartilage.

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Yet another condition, 
spondyloarthritis,

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has similarities to both of the 
conditions we’ve covered.

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Patients experience continuous 
inflammation in the joints

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and at the sites where ligaments and 
tendons attach to bones,

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even without any initial injury.

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This leads to the flood of enzymes and 
degradation seen in osteoarthritis,

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but is driven by different inflammatory 
proteins called cytokines.

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As the enzymes eat away at cartilage,

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the body attempts to stabilize smaller 
joints by fusing them together.

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This process sometimes leads to 
outgrowths called bone spurs,

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which also cause intense stiffness 
and joint pain.

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With so many factors causing arthritis,

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our current treatments are tailored 
to tackle specific symptoms

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rather than underlying causes.

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These range from promising 
MACI techniques,

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which harvest cells from small pieces 
of cartilage to grow replacement tissue.

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To a technique called microfracture,

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where surgeons create small 
holes in the bone,

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allowing bone marrow stem cells to 
leak out and form new cartilage.

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As a last resort,

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people with withered cartilage can 
even undergo full joint replacements.

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But outside these drastic measures,

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the underlying drivers of 
autoimmune arthritis

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still present a unique 
treatment challenge.

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Scientists are making progress with 
therapies that block TNF-alpha,

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one of the primary proteins causing 
inflammation in rheumatoid arthritis.

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But even this approach only treats the 
symptoms of the condition, not the cause.

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In the meantime, some of our best defenses
against arthritis are lifestyle choices:

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maintaining a healthy weight to 
take pressure off joints,

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low-impact exercises like yoga or cycling,
and avoiding smoking.

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These arthritis-fighting behaviors 
can help us lead longer lives

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as we continue to research 
cures and treatments

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for the huge diversity of 
arthritic conditions.