People from well-educated families are almost twice as likely to suffer from some dangerous food allergies as others — possibly because their bodies’ natural defences have been lowered by rigorous hygiene and infection control, suggests a new Canadian study.

The research from McGill University also found that immigrants were about half as likely to be afflicted by the allergies, perhaps reflecting differences in diet and environment between their countries of origin and Canada.

The study, just published in the Journal of Allergy, was meant to address an enduring medical mystery: Why have so many people in certain industrialized countries developed violent reactions to peanuts, shellfish and other foods in recent decades?

The link to higher education may be explained by what is called the hygiene hypothesis, the unproven idea that smaller families, cleaner homes, more use of antibiotics to treat infections and vaccines to prevent them have curbed development of the immune system, said Dr. Moshe Ben-Shoshan, who led the research. That in turn could make some people more susceptible to allergy.

If the hypothesis does actually explain some food reactions, though, parents may not be able to do much about it, admitted the allergist at Montreal Children’s Hospital. The benefits of such health products as antibiotics and vaccines easily outweigh the risk of children developing serious allergies, said Dr. Ben-Shoshan.
“We can’t suggest we become dirtier and expose our children to more bacteria,” he said. “If the price of having fewer allergies is more infection, I don’t know any parent who would expose their child to more infection.”

The study’s findings are far from conclusive but they, and the hygiene hypothesis as an explanation, seem plausible, said Dr. Stuart Carr, president of the Canadian Society of Allergy and Clinical Immunology. He also cautioned, however, that translating the knowledge into preventive action would be complicated.

So much for the cold-chain.

13 Investigates – the voice of Indiana – found beef, pork, chicken, eggs, milk, and produce being transported in hot trucks that do not have proper refrigeration.

"If it's happening here in Indiana," it's happening in Texas and North Carolina and California," said Capt. Wayne Andrews, who oversees Indiana State Police's Motor Carrier Enforcement Division. "This is not just an Indiana problem and we need to do more to address it."

"It's just not working properly and it had approximately a 94.7 degree reading at the time of the traffic stop," explained ISP Trooper Ashley Hart, standing next to a hot truck she pulled over along Interstate 65 near Lafayette. The truck was carrying raw meat, eggs and produce from a warehouse in Chicago to restaurants in Indianapolis.

"It's absolutely disgusting," she added.

13 Investigates first exposed the problem in July as state police partnered with local health departments to keep spoiled food from hot trucks off Hoosier dinner plates. Since then, the danger has not gone away.

"The problem is growing," said Andrews, whose motor carrier inspectors have found more hot trucks than they ever expected.

Last week, on a 92-degree day, state police stopped a food truck heading northbound on Interstate 69 near Muncie. The truck's refrigeration unit was broken and inside, eggs, pork, shrimp, and fish were found to be 66 degrees. Food safety inspectors from the Delaware County Health Department say that is both dangerous and illegal.

Indiana's effort to crack down on hot trucks is about to get some national exposure. After seeing WTHR's investigation, NBC's TODAY Show has decided to highlight this problem as a national issue. TODAY sent a crew to Indiana last week and will feature a special report on hot trucks September 22 -- this Thursday morning. You can see the report on Channel 13.

An investigation is under way at a U.K. hospital after 10 staff who took part in a food trial were struck down with illness.

Eight of the catering team at Raigmore Hospital in Inverness received treatment in the accident and emergency department.

The workers were testing a new food product aimed at patients with swallowing difficulties, such as stroke victims and dementia sufferers.

Symptoms ranged from temporary loss of vision to facial inflammation. None of the staff was detained in hospital and all are now back at work. No patients were affected and the kitchens were not shut down. It is believed that the illness was not food-related, a spokeswoman for NHS Highland said. The food packaging is the suspected source of the illnesses.

A source, who wished to remain anonymous, said: "Some had lost their vision because their eyes were so swollen, they couldn't open them. It must have been frightening."

"I am surprised the kitchen was not closed down for a while to find out what was going on," the source added.

Raigmore has 577 beds and employs around 3,200 staff. The catering department has 60 staff who provide 2,500 meals a day to patients, staff and visitors.

ABC News set out to find what bystanders would do if they witnessed a waiter drop food on the floor and serve it to unsuspecting patrons. We set up hidden cameras at Holsten's Confectionary in Bloomfield, N.J. -- a popular, well-regarded restaurant that would, of course, never tolerate such behavior from its own staff -- and hired actors to play a clumsy waiter and a hungry couple, out with a hankering for grilled cheese sandwiches. We found people were quick to warn our couple when they saw the disservice. But would anyone alert our couple if they became obnoxious and impolite?

What They Said:
"He picked up the pickles and everything and pit it back on the plate…just dropped it on the floor and brought it over." 

-- a shocked Holsten's customer after witnessing our actor server's spill
"I should have called him on it, but I didn't."

-- a sympathetic customer who was a former waitress
"Why don't you get our food. You're incompetent…I don't care if you're sorry, I just want our food."

-- our "What Would You Do?" offensive couple
"He deserved to eat the food that fell on the floor."
-- a customer that kept quiet about the tainted food
"Let him eat the dirty food. He was being a dirty man."
-- Holsten's patron reacting to our rude actors

Who goes to a restaurant for a grilled cheese sandwich?