As with all fields of scientific research, biomedical science is an emergent truth built out of a tapestry of studies, not just one. Often, however, each health-based study is presented by the media as if it’s an indelible fact. Rarely are faults or limits of the study, along with vital additional context, included. Claims are frequently exaggerated or oversimplified.
As Ben Goldacre, a highly respected annihilator of bad medical science once put it in a BMJ editorial: “It is common to find correlational findings misrepresented as denoting causation, for example, or findings in animal studies confidently exaggerated to make claims about treatment for humans.”
Through this pick-and-choose, misrepresentative attitude, health tips given out by TV doctors, outlets, talking heads, and your friends and family can often be closer to horoscopes than scientific facts. These erroneous modicums of advice can either be completely ineffective, specific only to a small demographic, or potentially bad for you. Here’s a look at a handful of them.
“Avoid Dietary Fat”
We need fat to build cell membranes, sheaths surrounding nerves, and it plays a vital role in muscle motion, vitamin absorption, and blood clotting.
For decades, however, fat was made out to be the archenemy of the food groups, the harbinger of all kinds of health-based doom, and the deliverer of weight gain. As time’s ticked on, we’ve learned that it’s far more nuanced than that, and it largely depends on the types of fats you’re ingesting.
As pointed out by Harvard Medical School, you have unsaturated fats, including monounsaturated fats and polyunsaturated fats, which you can get from various oils and oily foodstuffs, like fish and avocados. Their omega-3 fatty acids may help prevent heart disease and stroke.
Then you’ve got trans fats, which are byproducts of hydrogenated oils, found in a wide range of processed foods. “Trans fats have no known health benefits and that there is no safe level of consumption,” the post notes, linking even small consumption levels to heart disease and type 2 diabetes.
You also have saturated fats, found in butter and red meat. Research in the 1950s and 60s suggested saturated fat made you unhealthy, which metastasized into anti-fat dietary advice in general. The meat industry wasn’t keen on saying that saturated fats in their foods were bad for you, so they lobbied the US government just to advise people to eat less fat in general.
Additionally, for decades, the sugar industry – whose own research clearly linked sugar to heart disease – withheld their knowledge from the public. Instead, dietary fats were promoted as the cause of coronary heart disease, something that plenty of the public still readily believe today.
It’s in fact not clear what effect saturated fats have on your health, so right now, the general advice is to moderate your saturated fat intake, as you do with anything else, and stick to the healthier ones. Simply saying eating fat is bad is daft, and cutting it out completely can be unhealthy.
“Feed A Cold, Starve A Fever”
This maxim dates back between 400 and 500 years, which may explain why it’s so frequently repeated. As noted by SciAm, it stemmed from the belief that eating food generates warmth during a “cold” and that, if you have a fever, you shouldn’t be eating food to generate heat at all.
It’s bullshit, as you may expect. When you’re under the weather, you need (healthy) food to give your body energy to fight off the infection.
A fever, as it happens, is normally your body’s response to an underlying infection. By raising your internal temperature, your body is stimulating the immune system, which ultimately makes it more difficult for the pathogens to survive. So keep eating that chicken soup, you sickly human – which, incidentally, gives your body much-needed fluids and nutrients, as well as helps to loosen any dried phlegm you’ve got going on in there.
“You Should Totally Get Your Colon Cleansed”
Cleanses are stupid, but advocates of those primarily involving your poop portal are unequivocally ridiculous. Unless it’s done in preparation for a medically mandated colonoscopy, do not casually flush out your turd tube.
In case you’re wondering, during a colonic, vast amounts of water, along with various infusions, are fired up your rectum. The idea is that such an irrigation removes “toxins” and any lingering poop you can’t pinch out. Some even claim that allergies and weaker immune systems can be effectively treated this way.
As it happens, your colon is perfectly capable of expunging waste itself, and there is no evidence whatsoever to back up the more outlandish health claims. As noted by the Mayo Clinic, the side-effects of such a cleanse can range from the uncomfortable to the dangerous.
Some may experience nothing at all, but cramping and nausea that leads to vomiting are possible. You are also putting yourself at risk of bowel perforations, infections, and electrolyte changes – which, if you have an underlying health problem, can be dangerous. Death via colonic irrigation has occurred.
Stay away from our butts with your coffee enemas and colonic flushes, Paltrow.
“The Paleo Diet Is Great”
We probably don’t have to tell you that fad diets are often based on spurious and unfounded claims taken to their extremes. Take the Paleo diet (PD), for example. Emerging from the work of a gastroenterologist in the mid-1970s, it has a few different versions, but the general ethos is the same: eat as if we still lived in the Paleolithic.
The idea is that, before the agricultural revolution, we used to eat a mixture of meats, fish, eggs, vegetables, fruits, nuts, and seeds. Basically, be modern-day hunter-gatherers and leave out all those cereal grains, legumes, anything processed, anything with added salt, any dairy, and any processed oils.
Advocates suggest that this will not only help you lose weight, but you’ll also reduce your risk of things like diabetes, heart disease, and cancer.
Paleolithic people were hardly the healthiest of humans, though; they often suffered from a range of foodborne diseases. They also happened to eat whatever they could get their hands on, which means their diet was incredibly variable and definitely not balanced. As the British Dietetic Association points out, what they ate is actually based on “educated guesses”.
A 2015 review of the (albeit limited) data on users of the PD found that less salt, moderate intake of carbohydrates, and healthier fats were beneficial and aided weight loss. However, as key food groups (like whole grains) are missing, this diet could lead to potentially dangerous deficiencies that may negatively affect your health unless you take dietary supplements – not very Paleolithic, though.
There’s a chance you’ll lose weight on the PD, sure, but its health claims lack any scientific evidence. If you have a healthy but balanced diet, you’ll also lose weight, but you won’t have to worry about said deficiencies.
“The Early Bird Catches The Worm”
Google searches for why waking up early is good for your health bring up a whole host of unfounded health claims, along with a lot of aggravatingly cheery descriptions of why morning exercise is just the best thing ever.
Your sleep pattern is decided by your chronotype, a genetically controlled preferred sleeping pattern. So-called “clock genes” within your brain release proteins over a 24.2-hour period and this is (in crude terms) what controls when you feel sleepy and when you are at peak alertness. You also have tiny biological clocks in all of your cells elsewhere in the body too.
For many, your sleep schedule fits with society’s work schedule, something that dates back to the Industrial Revolution. If you have a late or early chronotype, however, you’ll be socially jet-lagged, with the more extreme night owls or early birds often experiencing sleep deprivation and related cognitive and physiological problems.
Your chronotype changes a little as you age, but it appears that there’s nothing you can really do to change your chronotype yourself. You’d be at your healthiest and most alert if you could match your work schedule to it, but short of a revolution in education and employment, this is an impossibility for most. So unless you’re already an early bird, forget those “health benefits” to waking up early – it’ll likely do you more harm than good.
“Don't Eat Food X, It Gives You Cancer!”
What is and what is not carcinogenic was epitomized grimly by the recent declaration in California that suggested coffee to be cancer-giving. It isn't, by the way.
This fantastic post from Vox reminds us that individual studies, both well and poorly designed, conclude that certain foods can either cause or protect us against cancer. Depending on which study you read, wine either prevents or causes the affliction, as does butter, milk, and tomatoes. Plenty of things are possibly carcinogenic, but a moderated diet and lifestyle should render much of this risk null and void.
You simply can’t take one study in isolation, just as you can’t take anyone’s claims based on single papers.
Sure, some things are certainly going to increase your risk of cancer, like smoking – that link has been clearly established. Others, ranging from jet fuel to tea, are listed by the International Agency for Research on Cancer as “unclassifiable” as to their carcinogenicity. It’s a spectrum of varying certainty.