A good reason to trust the FDA is that they have contributed to the safest food in the world! Our strict food regulations in the USA make things like trichinosis very difficult to spread around.
What evidence is there that U.S. food is safer than Japanese food, or even say Canadian food?
I don't have strong evidence but I don't regard U.S. food to be particularly safe relative to most first world countries. It's not terrible by any means and you're right in that you won't get any immediate damage from anything you eat, but I suspect most other first world countries have food and safety and health standards that result in better health outcomes over a long period of time compared to U.S. food.
[EDIT] After doing some minimal research it appears my intuition is correct, at least with respect to foodborne illness, the U.S. is certainly good compared to poverty stricken nations, but compared to most of Europe, Canada, Australia it has much higher rates of foodborne illness:
The deaths in the U.S. is the highest, but what's even more interesting are the hospitalizations. U.S. hospitalizations are among the lowest and one has to wonder why that is given that it has the highest death rate. It wouldn't be unreasonable to suspect that because of how expensive the U.S. health care system is, Americans who do get sick avoid going to the hospital altogether. That is admittedly simplified speculation on my part, but it's a starting point for further investigation.
At a 10x difference, it should clue you in that something is wrong. Choice quotes from a UK Gov page:
> A report published by the FSA has found it is not possible to compare foodborne disease rates effectively between countries.
> The report concludes that attempting to accurately compare different countries’ foodborne disease rates is an almost impossible task. The only way you could attempt this would be for different countries to have the same type of study with the exact same study specifications, over the same time period. Even then, differences in underlying surveillance data available in each country could cause issues, particularly in terms of determining what proportion of IID cases are due to food.
Trichinosis is also very well controlled in many third world countries that just have a bunch of good local regulation agencies. The FDA shines more on the regulation of mass produced packaged food on an unprecedented scale. The only other countries that can independently feed their populations with mass produced packaged nutritious food are some Asian countries that also have rich governments. Even in Europe they piggyback on work that the FDA does via international cooperation.