cigarettes affect the body?
Cigarettes aren’t good
for us. That’s hardly news. We’ve known about the dangers of smoking for
decades. But how exactly do cigarettes harm us?
Let’s look at what happens as their
ingredients make their way through our bodies,
and how we benefit physically when we finally give up
smoking. With each inhalation, smoke brings its more than 5,000 chemical substances
into contact with the body’s tissues. From the start, tar, a black, resinous material, begins to coat the teeth and gums, damaging tooth enamel, and eventually causing decay.
Over time, smoke also damages nerve-endings in the
nose, causing loss of smell. Inside the airways and lungs, smoke increases the
likelihood of infections, as well as chronic diseases like bronchitis
and emphysema. It does this by damaging the cilia, tiny hairlike
structures whose job it is to keep the airways clean. It then fills the
alveoli, tiny air sacs that enable the exchange of oxygen and carbon dioxide
between the lungs and blood.
A toxic gas called
carbon monoxide crosses that membrane into the blood, binding to haemoglobin
and displacing the oxygen it would usually have transported around the body.
That’s one of the reasons smoking can lead to oxygen deprivation and shortness
of breath. Within about 10 seconds, the bloodstream carries a stimulant called
nicotine to the brain, triggering the release of dopamine and other neurotransmitters
including endorphins that create the pleasurable sensations which make smoking
Nicotine and other
chemicals from the cigarette simultaneously cause constriction of blood vessels
and damage their delicate endothelial lining, restricting blood flow. These
vascular effects lead to thickening of blood vessel walls and enhance blood
platelet stickiness, increasing the likelihood that clots will form and trigger
heart attacks and strokes.
Many of the chemicals
inside cigarettes can trigger dangerous mutations in the body’s DNA that make
cancers form. Additionally, ingredients like arsenic and nickel may disrupt the
process of DNA repair, thus compromising the body’s ability to fight many
cancers. In fact, about one of every three cancer deaths in the United States
is caused by smoking. And it’s not just lung cancer.
Smoking can cause cancer
in multiple tissues and organs, as well as damaged eyesight and weakened bones.
It makes it harder for women to get pregnant. And in men, it can cause erectile
dysfunction. But for those who quit smoking, there’s a huge positive upside
with almost immediate and long-lasting physical benefits. Just 20 minutes after
a smoker’s final cigarette, their heart rate and blood pressure begin to return
to normal. After 12 hours, carbon monoxide levels stabilize, increasing the
blood’s oxygen-carrying capacity. A day after ceasing, heart attack risk begins
to decrease as blood pressure and heart rates normalize.
After two days, the
nerve endings responsible for smell and taste start to recover. Lungs become
healthier after about one month, with less coughing and shortness of breath.
The delicate hairlike cilia in the airways and lungs start recovering within
weeks and are restored after 9 months, improving resistance to infection. By
the one-year anniversary of quitting, heart disease risk plummets to half as
blood vessel function improves. Five years in, the chance of a clot forming
dramatically declines, and the risk of stroke continues to reduce. After ten years,
the chances of developing fatal lung cancer go down by 50%, probably because
the body’s ability to repair DNA is once again restored. Fifteen years in, the
likelihood of developing coronary heart disease is essentially the same as that
of a non-smoker.
There’s no point
pretending this is all easy to achieve. Quitting can lead to anxiety and
depression, resulting from nicotine withdrawal. But fortunately, such effects
are usually temporary. And quitting is getting easier, thanks to a growing
arsenal of tools. Nicotine replacement therapy through gum, skin patches,
lozenges, and sprays may help wean smokers off cigarettes. They work by
stimulating nicotine receptors in the brain and thus preventing withdrawal
symptoms, without the addition of other harmful chemicals. Counselling and
support groups, cognitive behavioural therapy, and moderate-intensity exercise
also help smokers stay cigarette-free. That’s good news since quitting puts you
and your body on the path back to health.
Source: TED Ed – By Krishna Sudhir