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"My grandparents ate meat and lived to 90."
one case doesn't refute millions. Grandparents who lived to 90 are remembered precisely because they lived; those who died young don't come up in the conversation. That's survivorship bias. Population data show that poor diets are among the biggest risk factors for death worldwide, mainly through too much salt and too few whole grains and fruit, and that processed meat is carcinogenic. And even if meat harmed no one, the moral question would still stand.
Short answer
One case doesn't refute millions. Some grandparents smoked and lived to 90, and cigarettes still kill. We remember those who lived long and forget those who died young: that's survivorship bias. Population studies show that poor diets were linked to about 11 million deaths in 2017, mainly from too much salt and too few whole grains and fruit, and processed meat is classified as carcinogenic. And even if meat were healthy, the moral question about the animals would stay the same.
For children
Some people who don't wear seat belts never have an accident. Does that mean seat belts are useless? No! It means those people were lucky. To know whether something is good or bad for us, scientists look at lots and lots of people, not just one.
"If a grandfather who smoked lived to 90, does that prove cigarettes are harmless?"
Como pode aparecer
"My grandparents ate meat and lived to 90."
"My grandmother ate lard and lived to 100."
"Nobody had these diseases back then."
"My grandpa smoked and drank and died at 95."
"Why change what always worked?"
"I know someone who got sick being vegan." (which is G10)
The strongest version
"My grandmother ate lard and lived to 100. Nobody had these diseases back then."
Strongest version (steelman):
- P1Many people of earlier generations ate meat and lived long lives.
- P2If meat were harmful, those people wouldn't have lived so long.
- CSo eating meat isn't harmful, and there's no reason to change.
P1 is true in many cases. P2 is false: risk factors increase the probability of disease but don't make it certain, and individual cases say nothing about the average effect.
The argument is valid. Its soundness fails at P2, and the conclusion ignores that the moral debate doesn't depend on the eater's health.
Full answer
- a
Reconstruction and diagnosis
The argument draws a general conclusion from selected cases:
What the argument uses What it leaves out Grandparents who lived long Relatives who died young of heart disease, stroke or cancer The diet of the past Lifestyle, physical activity and the amount of meat, which were different One generation Data from entire populations - b
Where the argument breaks
1. It's anecdotal evidence.
Individual cases don't show average effects. Risk factors increase the probability of disease, but they never guarantee it.
2. It's survivorship bias.
Grandparents who lived to 90 are remembered precisely for that. Those who died at 50 of a heart attack don't enter the conversation.
3. Population data show something else.
The Global Burden of Disease study estimated that dietary risks were associated with about 11 million deaths in 2017. Most of them came from too much salt and too few whole grains and fruit, not from meat; the figure shows that diet matters, not that meat is the main risk. In 2015, the International Agency for Research on Cancer classified processed meat as carcinogenic to humans and red meat as probably carcinogenic.
4. "Back then" was different.
Earlier generations tended to eat less meat and fewer ultra-processed foods and to be more physically active. And life expectancy was lower, not higher.
5. The argument changes the subject.
Even if meat harmed no one, the question would remain the same: is it just to kill animals when we don't need to?
- c
Data and sources
Source What it says Note GBD 2017 Diet Collaborators, *The Lancet* (2019) Dietary risks were associated with about 11 million deaths in 2017 The main risks were high sodium and low intake of whole grains and fruit IARC, press release No. 240 (2015) Processed meat classified as carcinogenic (Group 1); red meat as probably carcinogenic (Group 2A) Each 50 g of processed meat a day associated with an 18% higher risk of colorectal cancer - d
The strongest counter-reply: the individual risk is small
The most serious version accepts the data, but says the increase in individual risk is small, and that each person may accept that risk, as they accept others.
- e
Why the counter-reply doesn't reach the conclusion
It abandons the original argument.
It no longer says meat isn't harmful, but that the harm is acceptable.
Risk to oneself isn't the heart of the debate.
What's at stake for the animal isn't a risk; it's its whole life.
Personal choice has limits.
Accepting a risk for oneself is different from imposing a certain harm on another (E1).
Reasoning errors
Logical
Is the form valid?
Anecdotal evidence
Epistemological
Does the evidence support it?
Survivorship bias
Confusing risk with certainty
Moral
Is the criterion coherent?
Changing the subject
Biases
Availability bias
Family cases come to mind more easily than statistics
General literature on heuristics
Confirmation bias
Accepts the case that confirms the habit
General literature on confirmation bias
Rosy retrospection
The grandparents' lives are remembered without the illnesses and early deaths
Extrapolations
The principle being tested is: "if someone did something and lived long, it isn't harmful".
If it applied to…CigarettesTap to see
They wouldn't be harmful, because there are long-lived smokers
No one accepts this
If it applied to…Drunk drivingTap to see
It would be safe, because many never had an accident
No one accepts this
If it applied to…Vegan dietsTap to see
They'd also be healthy because there are long-lived vegans
The argument favors neither side
Contradictions
No one concludes smoking is healthy because a grandfather who smoked lived long.
Even knowing many people without one never had an accident.
Earlier generations lived shorter lives on average.
What the argument gets right
What is true
The experience of earlier generations deserves respect, and it's true that many people lived long lives eating meat. It's also true that meat's effect on health depends on the amount, the type and the rest of the diet, and that nutritional alarmism helps no one.
But
But family stories don't replace data from millions of people. And even if meat were perfectly healthy, the question about the animals would remain unanswered.
Connections
Usually comes before
Usually comes after