Real food is...dangerous??

My mother recently sent me one of those little tidbits of email wisdom that plague the internet from time to time, confusing people. I emailed her my thoughts, but thought I might just as well expose the rest of you my little rant. First, here's the gist of the email:

Written by Zola Gorgon - author of several cookbooks..
Watch out for those spoiled onions. I had the wonderful privilege of touring Mullins Food Products, makers of mayonnaise. Mullins is huge, and is owned by 11 brothers and sisters in the Mullins family....
The guy who gave us our tour is named Ed. He's one of the brothers. Ed is a chemistry expert and is involved in developing most of the sauce formula. He's even developed sauce formula for McDonald's. Keep in mind that Ed is a food chemistry whiz. During the tour, someone asked if we really needed to worry about mayonnaise. People are always worried that mayonnaise will spoil. Ed's answer will surprise you..
Ed said that all commercially-made Mayo is completely safe. "It doesn't even have to be refrigerated. No harm in refrigerating it, but it's not really necessary." He explained that the pH in mayonnaise is set at a point that bacteria could not survive in that environment. He then talked about the quint-essential picnic, with the bowl of potato salad sitting on the table and how everyone blames the mayonnaise when someone gets sick.
Ed says that when food poisoning is reported, the first thing the officials look for is when the 'victim' last ate ONIONS and where those onions came from (in the potato salad). Ed says it's not the mayonnaise (as long as it's not homemade Mayo) that spoils in the outdoors. It's probably the onions, and if not the onions, it's the POTATOES. He explained, onions are a huge magnet for bacteria, especially uncooked onions. You should never plan to keep a portion of a sliced onion. He says it's not even safe if you put it in a zip-lock bag and put it in your refrigerator. It's already contaminated enough just by being cut open and out for a bit, that it can be a danger to you (and doubly watch out for those onions you put in your hotdogs at the baseball park!).....
For some reason, I see a lot of credibility coming from a chemist and a company, that produces millions of pounds of mayonnaise every year.'

First of all, do you really want to take advice about what to eat from the man who invented McDonald's special sauce? Seriously, what's in that stuff? I'll tell ya:

Big Mac® Sauce:
Soybean oil, pickle relish [diced pickles, high fructose corn syrup, sugar, vinegar, corn syrup, salt, calcium chloride, xanthan gum, potassium sorbate (preservative), spice extractives, polysorbate 80], distilled vinegar, water, egg yolks, high fructose corn syrup, onion powder, mustard seed, salt, spices, propylene glycol alginate, sodium benzoate (preservative), mustard bran, sugar, garlic powder, vegetable protein (hydrolyzed corn, soy and wheat), caramel color, extractives of paprika, soy lecithin, turmeric (color), calcium disodium EDTA (protect flavor).

I've bolded the parts that aren't actually food, or that are likely to be genetically modified. Now I'll ask again, are you going eat what this guy tells you to eat?

Chemists know about chemistry. They know how to make something smooth, last for all of eternity, keep it moist, add fake taste, add colour, change the texture. Incidentally, all of these things are already there if you just eat actual food. The fact that a company produces millions of pounds of something every year is not an indication that it's good. It's an indication that they have good marketing. (The sauce above is a great example.) It's also not an indication that it's safe. Think about how much deli meat Maple Leaf produced last year, or how many jars of peanut butter came out of the Peanut Corporation plant in Georgia.

Which brings me to my second point. Are you really going to take advice about what to eat from a man who considers the fact that commercial mayonnaise will never spoil, even if unrefrigerated, a good thing? What does it take to make it last indefinitely, given that mayonnaise is supposed to be made by whipping raw egg yolk, vinegar, and oil (I know, I've made it from scratch). Although the acid in mayonnaise will slow down bacterial growth, its ingredients can spoil, and so they should. I'll take homemade any time, because if something won't spoil, I worry. It's a good general rule to never eat anything that won't spoil, because that's a pretty reliable sign that it's not really food but something a chemist concocted in a lab.

Another good rule for eating (and life for that matter) is to never put anything in your body if you don't know what it is or where it's come from.

To address the safety issue, I suspect what this guy is talking about is the fact that onions grow in the ground and thus get dirt on them. Depending on how you're farming, there could be all sorts of things in that dirt (another good reason to know where your food comes from). Even if the onions are washed off, something could remain on the skin, which will then get into the onion once your slice it from the outside in. Because onions are very moist, they are a great bacteria growing medium. This, however, is not unique to onions. This is why there have been problems in the past with contaminated melons. Slicing moves whatever is on the skin to the inside edible part. I guess we're just more likely to leave a cut onion in the fridge.