Every other week, new research claims one food is better than another, or that some ingredient yields incredible new health benefits.

Couple that with a few old wives’ tales passed down from your parents, and each time you fire up your stove or sit down to eat a healthy meal, it can be difficult separating food fact from fiction. We talked to a group of nutritionists and asked them to share the food myths they find most irritating and explain why people cling to them. Here’s what they said.

5 Stubborn Food Myths That Just Won’t Die, Debunked by Science

Myth 1: Never Use Wooden Cutting Boards with Meat

5 Stubborn Food Myths That Just Won't Die, Debunked by Science

This rule, one that I myself have repeated, comes from the notion that using a wooden cutting board will result in tiny scratches and cuts from your knife, and if you use that cutting board with meat-especially raw meat-that all those meat juices will settle into those tiny cuts in the board, and no matter how much you scrub, those germs aren’t coming out. The point has even been made by people as esteemed as Alton Brown. The solution is to use plastic cutting boards, which can be dishwashed and sanitized, and therefore must be safer, right?

Unfortunately, there’s a great deal of research that disputes this notion. One of the most famous studies was conducted at the University of California: Davis, by Dean O. Cliver, Ph.D of the UC-Davis Food Safety Laboratory. His research points out that there’s no significant antibacterial benefit from using a plastic cutting board over a wood one. He notes that even if you apply bacteria to a wooden cutting board, its natural properties cause the bacteria to pass through the top layer of the wood and settle inside, where they’re very difficult to bring out unless you split the board open.

Although the bacteria that have disappeared from the wood surfaces are found alive inside the wood for some time after application, they evidently do not multiply, and they gradually die. They can be detected only by splitting or gouging the wood or by forcing water completely through from one surface to the other. If a sharp knife is used to cut into the work surfaces after used plastic or wood has been contaminated with bacteria and cleaned manually, more bacteria are recovered from a used plastic surface than from a used wood surface.

Dr. Cliver’s study tested 10 different hardwoods and 4 different plastic polymers. In the end, the result was a very scientific one: if you want a plastic cutting board, anti-bacterial properties is no reason to buy one. If you want a wooden cutting board, bacterial infection shouldn’t scare you away. Which is better? That’s a different discussion, but ultimately it’s more important that you take care to properly clean and disinfect whatever board you buy, regardless of what it’s made of. Oh, and don’t fall for plastic or other cutting boards that tout themselves as being coated or made with anti-microbial chemicals or materials, that’s largely junk science as well

Myth 2: Adding Salt to Water Changes the Boiling Point, Cooks Food Faster

5 Stubborn Food Myths That Just Won't Die, Debunked by Science

This is one of those food myths that doesn’t want to die. You’ll hear it repeated by home cooks and professional chefs, but any first year Chemistry student (or in my case, a Physics student taking Applied Thermodynamics) will be able to show you how little the amount of salt you would add to a pot of boiling water in your kitchen actually alters the boiling point.

Yes, strictly speaking, adding salt to water will alter the boiling point, but the concentration of salt dissolved in the water is directly related to the increase in the boiling point. In order to change water’s boiling point appreciably, you would have to add so much table salt (and dissolve it completely) that the resulting salt water would be nearly inedible. In fact, the amount of salt you’re likely to add to a pot of water will only alter the boiling point of water by a few tenths of a degree Celsius at most.

So this is one of those food myths that rings of chemical truth, but only on scales that wouldn’t be applicable for cooking. One thing is for sure though, adding salt to your pasta water definitely makes the resulting pasta tasty.


Myth 3: Low Fat Foods Are Always Better For You

5 Stubborn Food Myths That Just Won't Die, Debunked by Science

Alannah DiBona, a Boston based nutritionist and wellness counselor made this her number one food myth. She said:

“Without fat, the human body is unable to absorb a large percentage of the nutrients needed to survive. Additionally, fat deprivation prevents messages from being passed between neurotransmitters, resulting in all kinds of neural misfiring in the body! While good fats and bad fats do exist, the right fats in the proper amounts can actually aid in weight loss and cholesterol management.”

The high-fat/low-fat food myth is one that’s been around for a long, long time. Ultimately, it’s more important to flip over the food you’re about to buy and read the label, see what kinds of fats are in it, and then make an educated decision instead of immediately reaching for the low-fat version of whatever it is you’re planning to buy, thinking it’ll be healthier. In fact, many products that are “low-fat” are low in good fats as opposed to the bad ones, or substitute in other ingredients like sugars and sodium that you don’t want more of in your diet.

Seattle-based Registered Dietitian Andy Bellatti also called out this particular myth. He said, “A good intake of healthful fats is beneficial for cardiovascular health. Prioritize monounsaturated fats (avocados, olives, pecans, almonds, peanuts) and omega-3 fatty acids (hemp seeds, chia seeds, sea vegetables, wild salmon). Virgin coconut oil and dark chocolate (80% cocoa or higher) also offer healthful fatty acids. Many low-fat diets are high in sugar and refined carbohydrates (i.e.: white flour), which are increasingly becoming linked to increased rates of heart disease.”


Myth 4: Dairy Is The Best Thing For Healthy Bones

5 Stubborn Food Myths That Just Won't Die, Debunked by Science

When I asked Andy Bellatti about the most stubborn food myths he’s encountered, he noted that too many people confuse “dairy” with “calcium,” assume they’re the same thing, and think that dairy is the best thing for healthy and strong bones. He explained, “Dairy contains calcium, but so do dark-leafy greens. Milk is fortified with vitamin D, just like all milk alternatives. Additionally, bone health goes beyond calcium and vitamin D. Vitamin K is important for bone health (dark leafy greens have it, dairy doesn’t). Magnesium (present in foods like almonds, cashews, oatmeal, and potatoes, but missing in dairy products) also plays an important role in bone health.”

Ultimately, if you’re concerned about bone health, you should make sure to get enough calcium in your diet, and while milk and cheese are good sources of it, they’re by no means the only sources. It’s important-and can be just as healthy-to branch out and make sure you’re eating dark leafy greens instead of just chugging down milk. Even the Harvard School of Public Health points out that milk isn’t the only, or even the best, source of calcium, as does the University of Missouri’s Nutrition “mythbusters.” If you’re looking for good sources of calcium and Vitamin D, consider collard greens, mustard greens, kale, and bok choy instead of milk.

Myth 5: Everyone Should Drink 64 Ounces or 8 Glasses of Water Every Day

5 Stubborn Food Myths That Just Won't Die, Debunked by Science

This myth is a holdover from a poor attempt by a number of doctors who wanted to wage an ill-researched campaign against sodas and sugary drinks. Their hearts were in the right place, but the fact of the matter is that there’s no uniform rule for how much water a person should drink in a given day. Alannah DiBona explains, “Water’s been touted as the cure for all sins, and in some ways, it’s true—proper hydration is necessary for just about anything body and mind-related. However, sixty-four ounces per day isn’t going to always be the right number for you.”

My old nutritionist explained to me that I should try to drink my body weight in ounces of water, divided in half. She noted that’s a good guideline for most people, but also noted that it’s a goal—not a rule. When I asked her whether there would be real health benefits from it, she explained that it’s not going to make my body work better or somehow stave off disease magically, but it will give me energy, prevent dehydration, get me up away from my desk and walking to the water fountain, and she pointed out that often our bodies interpret thirst signals as hunger. It’s anecdotal, but I have to admit that drinking more water made me feel better by leaps and bounds.

While it’s important to hydrate, it’s not important to stick to an arbitrary rule defining how you hydrate, or how much you drink, or even where you get it, although water is obviously the best source of, well, water. “Nutrition is an individual science, and there will be days when your body and mind require less than the average recommendation,” DiBona explains. “Remember that water is available to you through all liquids, fruits, and vegetables, and that the mark of proper hydration is very light yellow-colored urine.”