When we hear the word cancer, one of the first questions that comes to mind is:
Why did this happen?
Most people instantly think it’s because of family history or bad genes. Others assume lifestyle is the only reason.
Truth is, cancer isn’t that simple.
It’s a combination of genetics (what we inherit) and lifestyle (how we live). Both matter — but not equally.
1. Genetics: The Part We’re Born With
Genes act like the body’s instruction manual. Sometimes, people inherit tiny changes (mutations) in those genes that increase the chances of certain cancers.
Common hereditary cancer examples:
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BRCA1 and BRCA2 → linked with breast & ovarian cancer
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APC gene → linked with colorectal cancer
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TP53 mutation → linked with multiple early-age cancers
But here’s the part people don’t always realize:
Only 5–10% of all cancers are caused by inherited genes.
That means 90–95% of cancers are not directly inherited.
So even if cancer runs in the family, it doesn’t guarantee someone will get it. It only increases the risk, not the fate.
Genetics mainly affects:
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Family history
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High-risk gene mutations
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Age at diagnosis (younger age for hereditary cancers)
It’s the part we cannot control, but we can monitor through regular checkups and screenings.
2. Lifestyle: The Part We Can Control (More Than We Think)
Most cancers today are linked to lifestyle and environment — the things we see, breathe, eat, and do every day.
Major lifestyle factors linked with cancer:
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Diet high in processed foods, sugar, and red meat
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Lack of physical activity
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Obesity and hormonal imbalance
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Smoking or secondhand smoke
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Alcohol
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Chronic stress and poor sleep
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Exposure to pollution & chemicals
For example:
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Around 30–35% of cancers are linked to poor diet.
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Smoking causes almost 22% of all cancer deaths worldwide.
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Alcohol increases the risk of breast, liver, and colon cancers.
Lifestyle doesn’t guarantee cancer either, but it shapes the environment inside our body — either helping cells stay healthy or making them vulnerable. Lifestyle contributes to the majority of cancer cases worldwide.
This means there is a lot we can prevent just by living smarter.
Read More: Why Annual Health Checkups Are Important for Cancer Prevention?
So What Matters More: Genetics or Lifestyle?
If we keep it simple:
Genetics loads the gun.
Lifestyle pulls the trigger.
A person may have a genetic risk, but healthy habits can reduce that risk significantly.
On the other hand, even someone with zero family history can develop cancer due to lifestyle and environmental exposure.
Real-life example:
Two sisters may have the same BRCA gene mutation.
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One lives a healthy lifestyle → lower risk
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Other smokes, drinks, has poor diet → significantly higher risk
Same genes, different outcomes.
What We Can Do
Even though we can’t control genetics, we can control our choices:
✔ Eat more fruits, vegetables, and whole foods
✔ Maintain a healthy weight
✔ Exercise at least 30 minutes a day
✔ Avoid smoking completely
✔ Limit alcohol
✔ Manage stress and sleep well
✔ Get regular screenings (especially with family history)
These small habits build long-term protection.
A Human Takeaway
Cancer is never caused by one thing.
It’s almost always a mix of genes, lifestyle, and pure biology.
But here’s the hopeful part:
Most of the factors that increase cancer risk are in our hands.
Our daily choices — what we eat, how we move, how we manage stress — have a much bigger impact than we realize.
Genetics may whisper, but lifestyle decides how loud it gets.
Taking care of your body today is one of the strongest ways to protect your future.
