1. Mail-order DNA tests don’t provide accurate health info

Aside from discovering your ancestry, a big part of the sales pitch for many direct-to-consumer genetic tests is learning how your genes affect your likelihood of developing certain diseases—which would then allow you to take preventative measures to reduce your risk.

23andMe, one of the most popular options, costs $250 and covers more than 15 areas of health, including BRCA variations (a.k.a. the breast cancer gene), late-onset Alzheimer’s risk and your predisposition to gaining weight.

How reliable are the results

It varies, says Alexis Carere, president of the Canadian Association of Genetic Counsellors. For minor health traits, reliability is low. “Genetics telling you what you should eat, or how best to exercise, or your propensity for sleep—there just isn’t a lot of science behind that,” she says.

Stronger research exists when it comes to determining risks for more serious health issues, like heart disease and diabetes. One major caveat: Accuracy varies across DNA test brands. “Some companies are better than others,” Carere warns. “There are lots out there that don’t use good science.”

The scientific evidence is the strongest when it comes to detecting genes linked with cancer risks, but at-home DNA tests aren’t the final word. Take 23andMe’s test for BRCA mutations. There are thousands of possible BRCA variations that are linked to cancer, but 23andMe only looks at three. “Those are only relevant if you have Ashkenazic Jewish ancestry,” says Carere. “If you’re anyone else in the world, it’s the wrong test for you.”

There is serious concern among geneticists and genetic counsellors that at-home DNA tests might provide the impression that you don’t have a specific risk factor when, in fact, you could. For that reason, they recommend that if you have a true health concern—like a strong history of breast cancer in your family—you should seek genetic testing through a referral from your family doctor, not a kit.

But what’s the harm?

Aside from a false sense of security regarding your risk for certain diseases, the other major downside of home DNA testing is the cost—especially considering that you likely won’t make any long-lasting lifestyle changes based on the results.

When these tests first became available, there was a lot of hand-wringing in the genetics community, says Carere. “Everyone was concerned this test would say you’re not at risk of heart disease and, as a result, you’d stop exercising and start bingeing.”

But as it turns out, we’re so stuck in our lifestyles that at-home DNA testing doesn’t seem to affect us much at all. Studies have shown that people who are told they are at a lower genetic risk of heart disease don’t stop exercising, and those who are told they’re genetically predisposed to lung cancer don’t immediately quit smoking.

The bottom line

“Genetic information obtained from an at-home test doesn’t seem to help people make positive changes,” Carere says.

2. Essential oils aren’t a cure-all

Essential oils are sold everywhere from pharmacies to Facebook—chances are your social media feed contains at least one convert-slash-seller who swears the oils will help balance your gut microbe or ease your anxiety.

So do they work?

It’s complicated. There are a lot of vague claims about how essential oils work, and one theory is that scents trigger the limbic system, which helps regulate our emotions, stress, memory and hormones. But essential oils are definitely not recommended to cure or treat illnesses. In Canada, certain essential oils are regulated as natural health products, meaning they’re generally low-risk products intended to treat minor, non-serious conditions.

There is a bit of evidence to suggest that essential oils can help in some areas. A 2011 systematic review published in the Journal of Alternative and Complementary Medicine found several studies that showed aromatherapy might help reduce anxiety, and other studies have found that lavender might help with sleep.

But in general, “the therapeutic potential of these oils is vastly oversold,” says Timothy Caulfield, a professor of health law at the University of Alberta and the bestselling author of Is Gwyneth Paltrow Wrong About Everything? “There are clinical studies that suggest that they can be beneficial in very particular contexts—particularly when the end point is subjective, like pain and anxiety. But the studies that are done are generally poor.”

Nevertheless, many essential oil products claim they can cure more serious health issues. In 2014, the FDA sent warning letters to multiple companies for advertising that their essential oils could treat specific diseases. One, DoTERRA, claimed its products could help with brain injuries, autism, endometriosis, Alzheimer’s and ADD, as well as cancer and viral infections, including Ebola. (DoTERRA has since instructed its millions of distributors and wellness advocates to stop making these sorts of claims, but not everyone appears to have listened.)

My cousin’s friend swears they work…

“A study from 2016 actually found that a powerful anecdote will overwhelm our ability to think rationally,” cautions Caulfield. And keep in mind that many online testimonials are made by people invested in moving product.

But what’s the harm?

As long are you’re using essential oils safely, there’s not too much of a risk. Yes, there’s the cost—vials range between $6 and $300—as well as the possibility of developing a rash from an allergic reaction. The biggest potential issue is that your kids will get into your stash and ingest them, which can be poisonous; eucalyptus oil, for example, can cause seizures. And there is also the potential for harm if you’re delaying treatment for a medical problem by using essential oils to treat it.

The bottom line

If you enjoy dabbling in essential oils, that’s great. But they’re not going to solve any medical issues. “Go in with your eyes open,” says Caulfield. “Be very skeptical and be aware that there is a lack of evidence to support their use.”

3. Cleanse diets can be dangerous

Cleanses and detoxes come in many varieties, from a daily celery juice to the original Master Cleanse to the Wild Rose detox-in-a-box. But no matter the form, the premise remains the same: Detoxes promise to cleanse your body of the toxins it’s been exposed to, like pollutants, heavy metals, preservatives and pesticides. Most of these diets involve extreme calorie restriction. Some also employ laxatives.

Do detoxes work?

2014 review in the Journal of Human Nutrition and Dietetics looked at the claims of eight of the most popular detoxes and found there wasn’t much evidence there—only a handful of studies supported them, and the methods used were pretty poor.

Beyond that, claims that your body is dirty or full of toxins are patently false. That’s because you’re already the owner of the best all-natural, cutting-edge, science-backed detox system around: your large intestine, liver and kidneys. And they can get the job done just fine on their own.

Finally, while detox diets may lead to weight loss, results are temporary. “Weight loss happens, but the majority of what you lose is water,” says Curley. “As soon as you stop taking that laxative, you go through a few days of not having any bowel movements, and then you’re right back to where you started.”

But what’s the harm?

In the same 2014 review, researchers found that detox diets can cause serious harm, especially those that severely restrict calories, like liquid-only cleanses. (One of the diets the researchers examined only contained enough daily protein for someone who weighed less than 50 pounds!)

“With liquid cleanses, you’re not giving the body the carbohydrates, fats and protein it needs to function,” says Curley. That’s why detox diets often come with side effects like headaches, nausea, diarrhea and tiredness. And they can lead to more significant issues, like dehydration and disordered eating. As a result, Dietitians of Canada recommends that children and teenagers avoid them entirely.

The bottom line

If you feel like you’ve overindulged lately, try to cut back. Drink plenty of water, add more fruits, vegetables and other high-fibre foods to your diet, eat less processed food, drink less alcohol and do more physical activity. “That’s more effective than a cleanse,” says Curley, “and it’s probably easier, too.”

4. Exercise alone isn’t an effective way to lose weight

There’s a rule that gym rats like to share: For every 3,500 calories you burn working out, you’ll lose a pound. (You may be at the gym right now, labouring away under this assumption!) But research has found it’s not that simple.

Wait, what?

Dozens of studies have looked at the relationship between working out and losing weight. One of the most important is a large 2011 review from the American Journal of Medicine. In it, researchers synthesized the best evidence and found aerobic exercise alone isn’t an effective way to lose weight.

“If we look at the association between exercising and weight, it would seem that people doing 150-plus minutes a week gain slightly less weight than people who are doing nothing,” says Yoni Freedhoff, an associate professor of family medicine at the University of Ottawa and founder of the Bariatric Medical Institute.

Why “calories in, calories out” doesn’t work

The problem with this equation is that it leaves out how we subconsciously compensate after exercise. Studies have shown that we move less in the afternoon if we hit the gym in the morning and we also tend to eat back the calories we burn.

“Sometimes we eat more because we feel virtuous exercising; sometimes we get hungry if we exercise significantly; and sometimes we’ve been told we need to refuel afterwards,” says Freedhoff. But it all has the same result: “In 30 seconds, you can eat back what you’ve burned in an hour. That’s not a fair equation,” he says.

If you’re tracking what you eat through an app or diet program, Freedhoff suggests that you don’t log your exercise, since it could encourage you to eat more on workout days.

But what’s the harm?

“Exercise is the world’s best drug,” says Freedhoff. “It’s just not a weight-loss drug.”

If you want to get in shape, don’t make weight loss your goal. Research has found you’re more likely to quit working out if you aren’t losing weight. Instead, concentrate on the enormous health benefits of physical activity: better sleep, greater resilience to stress and a lower risk of diabetes, cancer and heart disease.

The bottom line

It’s simple. When it comes to weight loss, says Freedhoff, “keep your focus on your kitchen, not on the gym.”

5. You don’t need an obsessive gym routine to be active

The benefits of exercise are vast: It decreases the risk of heart disease, stroke, diabetes, breast cancer, osteoporosis and even Alzheimer’s. It can lessen depression and anxiety, and reduces inflammation. It can increase self-esteem and helps with sleep. Some studies have even found that exercise makes sex more pleasurable.

That said, getting to the gym can be a challenge. So what’s a busy woman to do?

Cardio is king

If you have to prioritize one thing, pick cardio, says Jack Goodman, professor of cardiac health and exercise at the University of Toronto’s Goldring Centre for High Performance Sport. “If you want to be healthy, the evidence is that a physically active lifestyle that includes aerobic exercise trumps all,” he says. “It’s very difficult to accrue anywhere close to the same health gains and chronic risk reduction from strength training alone.”

Think outside the gym

Cardio doesn’t have to mean a 6 a.m. spin class. Any workout counts if it’s hard enough to quicken your breathing and make you sweat after 10 minutes. That means biking to work or hiking on the weekend can be effective. Even mowing the lawn, shovelling snow or giving your house a deep clean can count as exercise. If you’re older, overweight or just starting to get active, a brisk walk is often enough to raise your heart rate.

“Any way you can enjoy cardio or tolerate it—that’s the ticket,” says Goodman. “I’m a runner, but my wife can’t stand it, so I don’t advocate it to her. You need to find something you like.”

Break it up

The Canadian Society for Exercise Physiology says the minimum length of time for a workout to count is only 10 minutes: think biking to the corner store instead of driving, or running around with your kids at the park. Or try adding a harder burst to everyday activities, like speed walking for a few blocks during a longer walk.

But what’s the harm?

There is none. If you don’t mind paying for a gym membership and can make the time to get there, you do you.

The bottom line

While heart-pumping cardio may be the best form of exercise, increasing your general activity during the day helps your health, too. “I can’t tell you how laughable it is when you watch people try to park in the closest spot to the gym,” says Goodman. “Taking the stairs instead of the elevator, getting off the bus a stop early—it all counts.”

6. IgG tests are widely considered to be useless

When you’re not feeling well—be it from migraines, brain fog or bloating— it’s hard to resist anything that might end the agony. That’s a huge part of the appeal of IgG testing. This simple blood test gives you a detailed list of exactly how sensitive you are to common foods. The idea is that if you cut out the foods you can’t tolerate—wheat or eggs or dairy or blueberries or garlic or all of them at once—your symptoms should resolve.

How does an IgG test work?

The test measures the amount of immunoglobulin G, a type of antibody in your blood that the body produces in response to foreign substances like food. An IgG test can cost between $400 and $700, and is usually prescribed by a naturopath or other alternative health providers.

Is there a hitch?

There sure is: Most health experts say IgG testing doesn’t work. That’s because IgG production is an absolutely normal response to food. Generally, the more of a certain food you eat, the more IgG your body will make, and the more likely it is that those foods will show up as positives on the test. So if you usually eat a couple of eggs for breakfast, they’ll show up as a food that you should avoid. Those high IgG levels don’t mean you’re intolerant to those foods, just that you eat them regularly.

“Every allergy and immunology society in the developed world has taken the stance that these tests are useless when it comes to a diagnosis of food sensitivities,” says Abby Langer, a registered dietitian in Toronto.

Does that mean food sensitivities are fake?

Not at all. Food sensitivities are real and often cause pain and bloating in your gut.

But what’s the harm?

Restricting your diet—whether based on the results of an IgG test or any other reason not supported by sound medical advice—can often lead to more harm than good. For instance, studies have found that g-free diets tend to have less fibre, vitamins and nutrients than diets that don’t restrict gluten. Why deprive yourself of healthy stuff if you don’t have to?

The bottom line

If you suspect you have sensitivities, ask a dietitian whether you should consider an elimination diet. The one with the most evidence behind it is called a FODMAP diet, which separates foods into common potential irritants, like lactose, sorbitol or fructose. You cut out all of these foods, then slowly reintroduce them to pinpoint what’s causing problems—leaving you with the least restrictive diet possible.