Some ideas are repeated so often, we start believing they’re true – particularly when it comes to food. From outdated techniques to more modern conspiracy theories, there’s a lot of culinary misinformation out there that could potentially spoil your supper. Want to separate the myths from the facts? To set the record straight, we've debunked some of the most common foodie misconceptions.

Click or scroll through our gallery to discover 34 so-called food 'facts' that simply aren't true – counting down to the biggest myth of them all.

We've based our ranking on how widespread each food myth is, and on the opinions of our well-travelled (and well-fed) team. The list is unavoidably subjective.

Sorry, broccoli lovers; sadly, this isn't true. For a vegetable, broccoli does indeed have a very high protein content – but you'd have to eat a serious amount of it to get the same boost of protein that a steak would give you. Of course, broccoli is still a healthy ingredient to add to your meals. If you're following a plant-based diet, there are plenty of other ways to get your protein fix, too, including eating plenty of lentils, quinoa and spinach.

There's no need to put an avocado pit in your bowl of delicious guacamole – despite what you may have heard, it won’t prevent your dip from browning. To stop your guac from turning murky, you have two options: wrap it in cling film to prevent oxygen from touching the surface, or add a little acidic lemon or lime juice to slow down the enzyme that causes the brown colour.

Potatoes are a nifty ingredient that can be used to perk up plenty of dishes – but unfortunately, they're unable to selectively soak up salt if you've accidentally used too much. Research shows that adding a potato to soup may absorb some of the salt, but it will also absorb liquid, meaning the salt concentration will remain almost the same. As such, it's always better to season and taste on the go.

Rumours circulated that Subway chicken is mostly made with soy after a Canadian company conducted DNA tests in 2017. However, Subway says that there’s only a small amount of soy protein in its chicken, amounting to 1% or less, which helps it maintain moisture and texture. A different study suggested that Subway tuna wasn’t real, but Subway insists that the chain uses only wild-caught tuna in its sandwiches. A legal case was brought against the company in relation to the supposedly fake tuna, but it was dismissed in 2023.

Castoreum is a substance secreted by beavers’ perineal castor sacs, and it smells strongly of vanilla – which is why it's sometimes used to make food and cosmetics. However, castoreum is extremely difficult to get hold of, and therefore expensive. As such, its use is extremely rare, especially compared to the 20 million pounds (9,071 tonnes) of vanilla that's naturally harvested from real vanilla beans every year. Thankfully, the chances are pretty low that your vanilla ice cream contains any beaver secretions at all.

Forgot to marinate your meat the night before a barbecue?  No problem! While marinades can certainly add a boost of herby or fruity flavour to a meat's exterior, they don't penetrate the meat deeply – so lengthy soaks are pointless. Not only that, but if you leave meat in an acidic marinade for too long, it'll weaken the protein bonds near the meat's surface, turning it unpleasantly mushy.

While James Lewis Kraft (the man behind the boxed mac 'n' cheese) may have popularised this yellow delicacy, American cheese was invented in Switzerland in 1911. The story goes that Walter Gerber and Fritz Stettler first hit upon the formula when they decided to heat Emmental with sodium citrate in an attempt to extend the shelf life of the cheese. However, it's true that Kraft perfected the technique, coming up with the recipe for the processed cheese we all know – and secretly love – today.

When acidic ingredients like tomatoes are cooked in a cast-iron pan for a long time, metallic molecules are released, creating an unpleasant flavour and potentially damaging the pan's seasoning. However, an experiment conducted by America’s Test Kitchen determined that, so long as acidic food is cooked in a cast-iron pan for less than 30 minutes, there will be no ill effects whatsoever. Even better, people with an enamelled cast-iron pan won’t have to worry about the release of metallic molecules at all.

No one wants to spend time sifting flour (and don’t get us started on having to wash up a sieve afterwards). Sifting does have its advantages, though: it allows you to mix dry ingredients properly and get rid of any clumps. But as food production has evolved and flour is milled more evenly, sifting flour is not as necessary as it used to be. Keep in mind that if you're baking a light batter, you should still sift your flour – but for everything else, just stir it with a fork beforehand to break it apart.

For years, turkey has wrongly been accused of sending us into a post–Christmas dinner stupor. This myth stems from the fact that turkey contains the amino acid tryptophan, which promotes good sleep. However, it turns out that cheese contains it too (in fact, it contains more, gram for gram), yet no one seems to be taking cheese naps. The real culprit may just be an excess of booze and carbs – or the fact that a Christmas Day nap has become an annual tradition in homes around the world.

The fast food world is tough for vegetarians and vegans. Beef burgers and chicken nuggets dominate menus, making it hard to find a plant-based meal. You might think that fries are safe; after all, they’re just made from potato. But the reality is that many fast food fries are cooked in lard or fried in the same oil that's used for meat products. In the US, McDonald’s uses beef flavouring in the oil used for its fries – which, although it’s meat free, contains dairy elements. As such, it's always best to check before ordering a portion of fast food fries (or any other fast food potato product).

Milk is a fantastic source of calcium, which is good for your bones – so you could be forgiven for falling for this foodie myth, which has been doing the rounds for generations. However, Stanford nutritional scientist Christopher Gardner says that while drinking milk can help to improve bone density, it doesn’t actually prevent bones from fracturing. His advice? Strengthen your bones via regular physical activity instead.

You may have heard rumours that extra-virgin olive oil has a lower smoke point than most oils – which, supposedly, causes it to start breaking apart and releasing harmful compounds when it's heated to high temperatures. However, research conducted in 2018 showed that extra-virgin olive oil was not only safe when cooked at an extremely high heat, but that it was more stable at that temperature than other cooking oils.

American celebrity chef Julia Child once said that the secret to cooking delicious mushrooms is to never crowd the pan. However, her advice isn't as foolproof as you might think. According to food scientist Harold McGee, author of On Food and Cooking, crowding the pan stops mushrooms from becoming too porous, meaning they'll soak up less oil as they cook – resulting in a better taste. Sorry, Julia!

While we're on the subject, we might as well tackle another mushroom myth. Although some people say otherwise, you can wash mushrooms before cooking them – they won’t lose any flavour in the process. A second Harold McGee experiment found that soaking mushrooms before cooking is another way to prevent them from absorbing too much oil. Not only that, but giving your mushrooms a rinse will remove any lingering dirt still clinging to the stems.

Ever heard the phrase 'simmer the wine to allow the alcohol to evaporate' in a cookery show? As it turns out, studies have proven that it takes a very long time for alcohol to evaporate fully. Of course, during cooking, some of it does burn off – but certainly not all of it. This is something to be mindful of when cooking for children or people avoiding alcohol for ethical, personal or health reasons.

We often associate oranges and other citrus fruits with vitamin C (ascorbic acid), a vital nutrient that supports the body’s healing process, among other things. Oranges are a good source of vitamin C, but they’re not the fruit that packs the highest amount. If your aim is to boost your vitamin C levels, you’re better off going with strawberries, which have 57mg per 100g, compared to 42mg per 100g – the amount contained in an easy peeler orange. You only need to eat around seven strawberries to get your recommended daily dose.

You may have heard that cooking vegetables is a sure-fire way to destroy the nutrients they contain – but this isn’t always the case. Studies have proven that cooking some vegetables allows for their nutrients and antioxidants to be better absorbed by our bodies. Meanwhile, other vegetables, such as broccoli, are healthier when raw. The simplest answer: serve your vegetables both ways, and eat lots of them!

Here's another foodie 'fact' to add to the pile of urban legends from the internet. For decades, rumours have been swirling that KFC uses genetically engineered chickens to make its products. However, there's no truth to this at all; in fact, KFC once sued three Chinese companies for spreading misinformation when they claimed that the fast food chain was breeding chickens with six legs and eight wings.

A chilli pepper's seeds are hotter than its flesh, which is why removing them is a good way to cool things down. However, they're not the spiciest part of the pepper – the pith and ribs are. This is because they're where most of the pepper's capsaicin, which is responsible for the heat, is stored. The seeds simply get their spiciness from being nearby.

The idea that you can burn calories while snacking might appeal (as long as you like celery). Unfortunately, it’s a myth that eating celery will burn more calories than you gain. Celery is still great to eat though, with plenty of fibre and moisture, so don’t let that stop you munching on a stick. To up the flavour factor, dip it in some hummus or cover it in peanut butter.

It's easy to assume that a product with no discernible animal origins might be vegan, but unfortunately, this isn't always the case. If you want to avoid consuming more than you bargained for, it's important to read and understand the label; some wines use animal products like egg whites, gelatine, casein (a substance derived from milk) and fish bladders in a clarification process called fining. Though vegan-friendly alternatives do exist these days, every winemaker has a different approach – so it's always best to double-check.

Those Instagrammers having breakfast in a pool in Bali certainly don’t think you need to delay your dip – and they’re right, despite what our mothers may have told us. Nutritionist Rebecca Scritchfield told the Washington Post that while it's possible to get a slight cramp after eating and swimming (due to blood moving to your muscles instead of your digestive system), doing so won't disable anyone enough to drown them.

Pay no attention to that old wives' tale – there's no need to worry about accidentally swallowing chewing gum (though it shouldn't be given to young children). While you shouldn't do it on purpose, rumours that gum will remain undigested in your stomach are completely unfounded; when eaten, it will pass through your digestive system at exactly the same rate as any other food.

This one is a real no-no. Washing raw chicken is completely unnecessary, as any bacteria it contains will be destroyed when the chicken is cooked. Furthermore, studies have shown that washing your chicken increases the chances of spreading bacteria – including salmonella and campylobacter, the two leading causes of bacterial foodborne illnesses – all over your kitchen surfaces.

Images of McDonald’s burgers that have barely changed, despite being made weeks, months or sometimes even years ago, regularly circulate online. It’s often claimed that the chain’s food is so full of preservatives that it won’t show any signs of decay. McDonald’s disputes this notion, suggesting that the unspoilt burgers in the photos may simply have been kept in the right environment; when kept moisture free, burgers dry out, and mould and bacteria is prevented from growing.

This is perhaps one of the most widespread culinary myths out there – which is why food scientist Harold McGee made it his mission to debunk it. He found that the only factor that will directly affect the juiciness of meat is the temperature it's cooked to. That said, searing is a fantastic way of adding more flavour, all thanks to the Maillard reaction: a foodie phenomenon that sees new flavour compounds released as meat browns.

Used as a flavour-boosting additive – particularly in Asian and Latin American cuisines – MSG (or monosodium glutamate) is a controversial ingredient. The idea that it's bad for our health is not only inaccurate, but rooted in a racist term coined in 1968: Chinese Restaurant Syndrome, a so-called malady that blamed Chinese restaurants and MSG for causing diners to develop symptoms like palpitations and numbness. However, there's no conclusive scientific evidence to back up this claim; MSG is present in many common foods such as Parmesan, and it's perfectly safe to eat.

It's true that carrots – which are packed with a form of vitamin A known as beta carotene – are good for your overall eye health. However, eating them won’t give you night vision or improve your eyesight. This myth first appeared as part of a military strategy; during World War II, to disguise the fact that the British Royal Air Force was using a new type of radar technology, a propaganda campaign claimed that regular consumption of carrots was improving pilots’ eyesight. Somehow, the world believed it.

A very sharp knife can seem like a scary tool to wield; however, they tend to be safer and easier to use than blunt knives. A dull blade means you'll have to exert more force when chopping your ingredients – and this is when most accidents happen. Sharp knives are also easier to control as you can sense when they're about to slip, then adjust your grip accordingly

This one's been repeated so often that it's widely accepted to be true; however, a 2022 study conducted by the University of Wisconsin-Madison in the US found that it's yet another myth. Researchers measured the water intake of over 5,600 people from 26 different countries and noted that the amount of water needed to stay healthy varied considerably. There's no one-size-fits-all guideline we should follow – other than if you're thirsty, have a drink!

Thankfully, there's no need to forgo the odd chocolate treat for the sake of your skin – there's no evidence to suggest that snacking on the sweet stuff will cause you to break out in spots. Acne is mostly caused by hormones and the effect they have on glands in the skin, not by the foods we eat; however, a poor diet consisting of lots of refined carbohydrates may increase the body's production of spot-triggering hormones.

Contrary to popular belief, adding oil to your pasta water will do nothing to prevent pasta from sticking together – in fact, the oil will simply sit on the water's surface, having no effect on the pasta at all. The only thing that won’t be sticking to the pasta is the sauce; when the pasta is drained, it'll get coated in the oil, making it slippery. The result? Well-sauced pasta bowls and tasteless spaghetti. A better way to prevent your pasta from sticking is to stir it occasionally as it cooks.

Anyone who's ever experienced the unbridled chaos of a children's party may find this one difficult to believe, but the idea that sugar causes hyperactivity was disproven years ago. In a study conducted in the 1990s, mothers who were told their children had been given a large dose of sugar rated them as significantly more hyperactive – though the kids had only been given a placebo.

Now discover the handiest food hacks of all time

Last updated by Laura Ellis.