Photo courtesy LFS Learning Centre
With all the messages of what to eat, super foods, supplements, and wonder nutrients, it is easy to forget the most important way to eat healthy is to be sure our food is safe.
Richmond’s Dr. Brent Skura, recently retired from UBC’s Faculty of Land and Food Systems, has spent his career studying food science and food safety.
Originally intending to study insects as an entomologist, things changed one day in a university food science lecture.
Skura was hooked from that day on: “It was exactly what I was looking for.”
The work of scientists like Skura has meant lives saved. Even then, we have a ways to go.
According to the federal government: “Every year, a total of about four million (1 in 8) Canadians are affected by a food-borne illness. Of these, there are about 11,600 hospitalizations and 238 deaths.”
Throughout his career, Skura worked to reduce those numbers with research and education.
Skura says many illnesses are actually spread by people who don’t wash their hands after using the toilet.
He calls it the fecal-oral route of spreading illness: “It can be from a surface to hands to the intestinal tract, or a person touching food and the food is then consumed.”
Other than not washing hands, Skura cites other causes of illness from food:
“Not holding food at proper temperatures, leaving perishable foods out, not refrigerating foods properly, and the issues of potential cross-contamination.”
He says that means spreading bacteria from one food to another, often from an uncooked item to other things ready to eat. One example is frying up raw hamburger but using the same flipper for the raw meat as the cooked. Any bacteria from the uncooked burger will be spread back onto the cooked, and otherwise safe, meat.
In naming some of the main culprits, the bugs in food that can make us sick, like Hepatitis A, something spread from human fecal or sewage contamination, Skura cautions against uninspected raw seafood. Shellfish are filter-feeders and one thing they can filter out of the water is bugs like the Hep A virus. Even touching the infected food can be enough to pass the virus on to consumers. Hep A is very contagious.
As is Norwalk virus. Spread by the same route from someone who didn’t wash their hands properly so the virus ends up on surfaces or food, and from there, flows into a body to make the person very ill. This virus can live on surfaces thus the decontamination cleaning required when this fast-acting and dramatic virus infects a cruise ship of passengers.
And if you have ever had the 24-hour flu, chances are, says Skura, that you actually had a food-borne illness.
“People often think that it’s the flu but really it is caused by Norovirus or bacteria like Clostridium perfringens or Staphylococcus aureus.”
Sometimes, illness is caused by eating a type of bacteria that has changed its form slightly such as the one from farm animals, E. coli O157, that can cause devastating disease. The symptoms can include bleeding from the intestines and the kidneys. It can cause death or life-long disability.
Though outbreaks are often caused by undercooked hamburger, the most recent in Canada came through Romaine lettuce. The thought being that someone with E. coli O157 didn’t wash their hands properly before handling the lettuce destined for market.
An outbreak’s cause can be hard to nail down.
“It’s like looking for a needle in haystack,” says Skura because the amount of contamination isn’t evenly spread throughout a product or a shipment and Skura says, “Not all people who eat the same food are going to become ill.”
Some bugs make us sick because they produce a toxin. That’s why home canning has to be done following reputable instructions and not by using mom or grandma’s old recipes.
Botulism toxin is produced by a naturally-occurring bacteria but only where there is no oxygen and little acid, as is the case with some home canned foods.
Eating this bacteria itself doesn’t hurt adults; we probably eat a fair bit of it. It’s safe because we have strong acid in our stomachs, but for babies, who don’t have very acidic stomachs, it’s a serious hazard. For that reason, experts recommend not feeding babies honey or corn syrup. They can contain spores that will grow, producing toxin in an infant’s stomach. Even pasteurized products can still contain the spores. Also, since modern tomatoes are much lower in acid, you have to add a known amount of acid to them for safe canning. The government of Canada website has an excellent home canning safety site.
While some food contaminants cause the typical food poisoning symptoms, others have different tricks up their sleeves. Botulism is actually a nerve poison and it takes very little to start to paralyze people. In fact, doctors use miniscule amounts of the purified toxin to relax the muscles of people suffering from painful muscle spasms, such as after a stroke. It is also used cosmetically to paralyze facial muscles so wrinkles are less obvious.
Listeria can be responsible for typical symptoms of food borne illness like nausea and diarrhea but is also notorious for causing miscarriages. Outbreaks are often, but not always, found in unpasteurized dairy products like milk and cheese.
Some bugs that can make us very ill don’t make the food smell, look or feel different. Skura says if in doubt, throw it out.
The time it takes to get sick from a food-borne pathogen varies. With some, like the one that grows on warm but not hot rice, it is as little as eight hours while for others, it can be up to 10 days, making figuring out the source all the harder.
With some food contaminants, safe handling techniques and thorough cooking are enough to render them safe to eat. With others, like the toxin produced by one variety of Staph aureus, heat won’t kill them.
Skura also cautions that commercially prepared foods we used to keep on the shelf may now need refrigeration: “We follow the recommendations to reduce salt to reduce hypertension but that can have impacts on food safety.”
The salt and sugar that once made foods shelf-stable have been cut, making them healthier to eat, as long as they are stored properly. We need to read the label. If it says “refridgerate after opening” then do.
Skura’s desire for food safety continues.
Today, in our community, he still teaches and monitors the food safety of those working at the booths at the Family Fall Fair, held every September at South Arm United.
“You always have to be vigilant all of the time,” he says.
So what does a scientist who says, “I was always been fascinated by the food system,” recommend where our health is concerned?
“Everything in moderation. Eat a variety of food. Practise good personal hygiene and make sure your foods are handled, cooked and stored properly.”