What foods actually increase cancer risk, and should you eat them at all?

The issue isn't really with the products themselves, but with how we eat them and in what quantities. Research often takes a group of people who eat red meat every day by the kilogram and compares them with vegetarians - and then it turns out the first group has a bunch of other risk factors: they move less, smoke more, sleep worse. Correlation, as you correctly pointed out, isn't causation.

What's more or less proven: processed meat (sausages, smoked meats, bacon) really is linked to increased risk because of preservatives and the processing method. With red meat, the situation is milder - if you're not frying it until it's charred on high heat and not eating half a kilo a day, the risk stays low. Alcohol, especially in large amounts - now that's been studied long and well. Sugar and simple carbs are linked through obesity and inflammation, not directly.

You should change your diet, but not out of panic. Just eat varied foods, don't get hung up on one product, prepare things without going overboard with processing methods. If you normally eat fine, don't smoke, and do at least some exercise - a single portion of red meat or even something sweet won't be a deciding factor. The hysteria around every study is more about media and the food industry, which then sells you alternatives.

I've actually looked into this myself - when you start reading the research, you realize the key word is everywhere: quantity and frequency. It's not about eating a steak or processed meat once a month, it's about systematic consumption in large amounts. The same goes for hot drinks above a certain temperature or alcohol - if it's not every day and in moderate doses, the risk statistically stays low. Instead of chasing the perfect diet, it makes sense to just diversify your diet, not obsess over one product, and remember physical activity - that works way more reliably than cutting out some single dish.

Have you noticed yourself how they say the opposite thing about the same product a couple of years later? That's because in reality the link is often weak and multifactorial.

As for whether it's just about quantity - I partly agree, but not entirely. Yeah, kilos of sausage a day is an extreme. But WHO research calls even moderate consumption of processed meat a risk factor, and it's not just about volume here. Processed meat (smoked, salted, with nitrites) - that's really not the same thing as fresh red meat, even though both are considered dangerous.

The key is that the increase in risk in absolute numbers is often small. If a person's cancer risk over their lifetime is 20% anyway, and red meat raises it by 10-15%, that sounds scary, but in absolute terms it's a difference of a couple of percent. So you don't have to turn your life upside down to completely give up steak. But cutting down on processed meat or balancing red meat with vegetables - that makes sense.