Medical science on "diet" sucks

I've been looking for proof that ham and bacon cause bowel cancer. Well - there is none I can find - not any allowable for a mere ordinary person to read. I did find a lot of studies on other eating habits - involving thousands of people with who filled in questionnaires? about their food.One wonders how other influences (other than eating habits) are accounted for. Diet must be a very difficult science to study - and maybe that is why we are faced with varying and conflicting 'results'.

Colonic cancer is rare in primitive populations. In western populations it was uncommon in the past, but now accounts for about 3% of all deaths. We study diet to explain its rise - but what about dish washing liquids - detergents?

When I was little, Grandma (we lived with grandma for quite a few years), collected up bits of sunlight soap, with which we washed clothes and dishes, and put them in a mutton cloth bag. When granddad washed up after a meal, he swizzled the bag in the hot water in a basin in the sink. If we had had fish, he always washed the plates and cutlery twice, and he rinsed it all after washing. I can remember really grey, greasy water in the washing up bowl!

When I first married, we could buy a sort of plastic swizzle device which you could fill with bits of soap - or use a round, bright red dish washing soap re-fill. One always battled with the grease! But that was the old days when bowel cancer was rare....So when detergent became available it seemed like a gift from heaven - amazing science again!

But just like the foot X-ray machines I looked at my feet in disappeared from shoe shops when we learned better - maybe re-assessing the effect cleaning materials have on us would be an excellent scientific study! But who would PAY?