The tenets of a healthy diet are increasingly fluid these days. But whether you’re in the low-carb, Paleo, vegan or eat-everything-in-moderation camp, chances are you’ve cut out all foods that we know to be “bad.”
Unfortunately, sometimes even those good foods can be harbouring dangers.
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“When it comes to nutrition, you have to keep context in mind,” says Sarah Goldstein, a Toronto-based holistic nutritionist. “The food you’re eating may be inherently nutritious, but the way it’s raised or prepared could be harmful. It’s not an all-or-nothing idea.”
While you should be proud of yourself for replacing potato chips with popcorn and hot dogs with salmon, these healthy foods could be exposing you to harmful chemicals that are linked to cancer. You don’t necessarily need to cut them out of your diet altogether, Goldstein says, but be mindful of how often you eat them.
As far as satisfying snacks with none of the guilt go, you can’t beat popcorn. It’s delicious, comforting, rich in fibre and only packs 30 calories in a cup. But microwave popcorn harbours some nefarious compounds.
There’s been a debate about its link to cancer, although a 2013 study published in the journal Environmental Health Perspectives found an association between kidney and testicular cancer and exposure to perfluorooctanoic acid (PFOA), a chemical used in the manufacturing of microwave popcorn bags, among other things.
But if the cancer link isn’t definitive, this one is: it can cause lung damage or something researchers have dubbed “popcorn lung.” Microwave popcorn uses a synthesized chemical called diacetyl to give it its buttery flavour and smell. It’s often listed in the ingredients simply as “artificial flavour.” The medical term is bronchiolitis obliterans and it was found in popcorn factory workers who developed respiratory problems.
Although the casual microwave popcorn eater shouldn’t be too concerned about it, experts also caution that you should avoid popcorn varieties made with trans fats, which put you at elevated risk for heart disease, stroke and diabetes. Air or stove-top popping is always better.
We know fish is good for us and packed with healthy omega-3 and -6 fatty acids, but you need to be very careful about the waters your fish has been swimming in.
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Farmed fish swim in what’s called persistent organic pollutants (POP). The waters contain carcinogenic compounds like dioxins and PCBs, which have been linked to negative effects on the nervous, immune and endocrine system, reproductive function and cancer.
“The ratio of fat in farmed fish is also problematic,” Goldstein says. “To be anti-inflammatory, fish has to have a one-to-one ratio of omega-3 to -6. In farmed fish, there are more omega-6 compounds, which make it pro-inflammatory.”
Eating fish, farmed or wild, one or twice a week has not been shown to have adverse effects, but more than that and you may want to consider sticking with wild varieties.
The B.C. Salmon Farmers Association notes that B.C. farm-raised salmon of the Chinook, Coho and Atlantic varieties feature low levels of polychlorinated biphenyls (PCBs) and other contaminants, and that their mercury content isn’t high enough to threaten consumers’ health.
Canada’s farmed fish industry is regulated by the Canadian Food Inspection Agency, which enforces quality and safety standards.
Sliced meats are a great source of protein, not to mention a fast, easy and convenient way to get food on-the-go. But you need to be mindful of how often you eat them.
Processed meats, like cold cuts, jerky and bacon, have been linked to colorectal and stomach cancers. The problem derives from the smoking, curing and preservation processes the meats undergo, and the chemicals (like nitrates) that are released throughout.
However, experts are quick to point out that in this case, moderation is key.
“We should be limiting red and processed meat to help reduce colon cancer risk, and possibly, the risk of other cancers,” Colleen Doyle, American Cancer Society managing director of nutrition and physical activity, said in a statement. “The occasional hot dog or hamburger is okay.”
It’s also very easy to find organic or chemical-free meats, if you’re concerned about the amount you consume.
When cooking with oils, you’ll want to leave the corn, sunflower, palm and soya bean varieties in the cupboard — they’ve been linked to various cancers and neurogenerative diseases like Alzheimer’s.
“This is a controversial food because we know that vegetable oil has a high smoke point,” the temperature it can reach before it burns off its beneficial nutrients and starts to release free radicals, Goldstein says.
However, a study published in Toxicology Reports noted that rats that were fed repeatedly heated cooking oil (RHCO) showed significant damage to the colon and liver. The concern is that once heated, vegetable cooking oils release free radicals that lead to oxidative stress, and cellular and molecular damage.
If you’re going to cook with oil, choose healthier options like olive or coconut, both of which are proven to withstand high cooking temperatures.
Much like microwave popcorn, the issue with canned tomatoes (and canned vegetables in general) is the BPA in the aluminum. Bisphenol A is an industrial compound that’s used inside things like the linings of cans (and plastic bottles) to prevent corrosion and breakage, and preserve the food inside. It’s been linked to diabetes, obesity, cardiovascular disease and reproductive development issues, and is considered an endocrine disruptor.
“There is a lot of evidence, and it’s growing, that BPA can have an affect on the human body even at very low levels,” Lynn Ladbrook, chief executive of Breast Cancer UK, said to the Telegraph. “We believe there is no safe dose of BPA.”
However, it’s fairly easy and increasingly common to find BPA-free cans and bottles in your grocery store.