In fact, the idea that you can flush impurities out of your system by cleansing it with juices, tablets or tinctures is eschewed by registered dietitian Zannat Reza.
Many detoxes people sign up for are simply low-calorie potions or juice cleanses.
"Like, what are you getting there? Not much of anything," she says. "Definitely not calories, not enough nutrients, no probiotics."
In fact, the result can be dehydration, headache, dizziness, nausea, vomiting and lack of energy. Harmful effects include low blood sugar, low or high blood pressure, detrimental interaction with medications, and vitamin and mineral deficiencies, Reza says, citing research from organizations including Dietitians of Canada and the Mayo Clinic.
"And for people who are looking to lose weight what it does is it actually slows down your metabolism, so your body thinks it's starving. Slowing down your metabolism really is not the smartest thing to do to lose weight," she says.
"You may feel great after three days because basically you've lost water and you've lost some muscle and you've lost your body's carbohydrate store, which is glycogen. But after three days if you go back to eating refined foods, processed foods and all that, any so-called weight loss that you've experienced, it's going to come right back and probably even more because you've also slowed down your metabolism."
Instead, the Toronto dietitian suggests "clean eating," with a focus on fruits and vegetables, whole grains and lean proteins, which will also help boost the immune system, especially at this time of year when cold and flu bugs are rampant.
But healthy food is only one piece of the puzzle. It's also important to get enough sleep, exercise and wash hands well in warm soapy water.
Most Canadians don't eat enough fruits and vegetables. The recommendation is to fill the plate with fruits and vegetables at every meal and snack.
"It doesn't have to be just the coloured ones. Cauliflower is just as good and mushrooms are great because they're really high in selenium which is key in terms of acting as an antioxidant in your body," says the mother of two.
Whole grains supply B vitamins and folate. Those with celiac disease or an intolerance to gluten will want to avoid wheat, barley and rye but can consume whole grains that don't contain the protein composite in brown, black and wild rice, amaranth, buckwheat, millet and teff and seeds like quinoa.
Vitamin D is added to milk, soy and rice beverages, orange juice and margarine and is also found in salmon and sardines, egg yolks and fortified yogurts.
"Because it's wintertime one of the recommendations is to take a vitamin D supplement just because we don't get enough sunlight and our skin doesn't get enough exposure to make vitamin D in the winter months," Reza says.
Probiotics, or good bacteria in the gut that help keep your immune system healthy, and prebiotics are both needed.
Probiotics are in supplements, some yogurts (check the label) and fermented foods that have been produced or preserved using good bacteria, such as sauerkraut, kimchee (Korean pickled cabbage), miso, tempeh, injera (sourdough-risen flatbread), fish sauce, sour cream, soy sauce and Worcestershire sauce.
"The prebiotics are actually strands of carbohydrate that we don't digest, but they're actually food for the probiotics because they have to eat something," explains Reza.
Prebiotics are in artichokes, asparagus, bananas, tomatoes, garlic, onions, leeks, whole grains and roots like chicory and dandelion.
Boosting the immune system with healthy food needs to be done all season long rather than just as you're beginning to feel ill. If you do fall ill, stay hydrated with lots of water along with fruits and vegetables high in water, like watermelon, celery and cucumbers.
"That's where soups come in really nicely because there's flavour to them, but also they give you that hydration," says Reza.
Soups packed with vegetables, protein and fibre are filling and comforting. Ingredients with anti-inflammatory properties like turmeric and ginger inject great flavour.
Some people find taking a zinc supplement when they start getting a cold can help reduce some symptoms. But talk to your health-care professional or pharmacist first.
"There have been some studies that show that if you dose really high on zinc it actually can suppress your immune system. It's one of these things where too much of a nutrient is not good. My preference is to get the zinc from food — lentils, baked beans, pumpkin seeds."
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