Food Myths: Debunking Five Common Claims

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Kombucha in a mason jar -- Food Myths: Debunking Five Common Claims

Nutrition and food are hot topics. With everyone from celebrities to athletes weighing in on what’s good and bad for you, it can be hard to separate food fact from fiction, and frankly, it gets tiring trying to figure out what to eat, especially with a chronic condition like diabetes. Let’s clear up some of the confusion!

Five common food myths: debunked

1. “Drink 8 cups of water every day.”

Water is essential for survival. All of your cells, tissues and organs depend on water in order to do their jobs, which include regulating body temperature, eliminating waste, lubricating and cushioning joints and aiding digestion. And water makes up about 60% of your body weight. So while we all definitely need to drink water, there’s no scientific basis for drinking 8 cups daily. That might be the right amount for you, but some people will need more water, and some will need less.


A good place to start is by following the National Academies of Sciences, Engineering, and Medicine recommendations for daily fluid intake:

• 15.5 cups fluid for men

• 11.5 cups fluid for women

Bottom line: You may need more water if you are an avid exerciser, living in a hot and/or humid climate, are pregnant or breast-feeding, or are ill, say, with a fever or diarrhea. Also, water is the best beverage choice, but other fluids “count,” as well, including tea, coffee, milk and soda. And fruits and vegetables contribute to our fluids needs, too.

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2. “Supplement your diet with protein powder.”

The popularity of low carb, keto, Paleo and plant-based diets has spurred an awareness and even somewhat of a fanatical interest in consuming higher amounts of protein. In addition, some fitness experts and athletes promote the use of protein supplements (often in the form of powders) to build muscle mass and improve performance. As a result, protein has never been more popular. How do you get more protein? Using a protein powder is one way.

There are a number of different types of protein powders on the market; the protein source may come from plants, such as rice, hemp, soy or peas, milk, or egg. Protein powders may contain other ingredients, as well, including vitamins and minerals. Some protein powders contain carbohydrate, while others are pure protein.

Protein powders and supplements can be helpful for some people, including those who:

• Have problems with eating or have a diminished appetite

• Have had recent surgery, a wound that isn’t healing or severe burns

• Are older and are losing muscle mass

Some evidence points to a higher protein intake being helpful for weight management, and individuals with diabetes may find that more protein and less carb helps with blood sugar management.

But, as with any nutrient, it’s possible to overdo protein, and the use of protein powders can easily contribute to protein overload. Too much protein is linked with a higher risk of heart disease, cancer, kidney problems and digestive issues. Also, protein contains calories, so overdoing protein means more calories, which could possibly contribute to weight gain.

Bottom line: Know the risks of using protein powders. They’re not regulated by the FDA, so it’s “buyer beware” when it comes to safety. Some people experience digestive distress, especially with milk-based powders. And always read the Nutrition Facts label, as protein powders can be high in calories and carbs, which can impact your blood sugars. Finally, the Clean Label Project studied 132 protein powders for heavy metals, BPA, pesticides and other contaminants — some brands contained significant amounts of lead, cadmium, BPA and arsenic. Learn more here.

3. “Celery juice is a miracle juice.”

Oh, if only this were true! Years ago, celery was touted as having “negative calories.” Now, it’s thought that celery juice has magical properties, eliminating illness and restoring health. And if you don’t believe it, just visit Gwyneth Paltrow’s website, which features an article written by Anthony William,  originator of the celery juice movement, New York Times best-selling author and acclaimed “Medical Medium” who uses his gift to “read” peoples’ conditions and restore them to health.

Celery is a vegetable that contains decent amounts of vitamins, mineral and antioxidants. It’s also very low in calories and carbs, so it’s a good choice for a snack. In terms of celery juice, a 16-ounce glass of celery juice, as recommended by Mr. William, contains 84 calories, 18 grams of carb, 8 grams of fiber and 430 milligrams of sodium.

Bottom line: Obviously, celery juice contains calories and some carb (mostly from fiber). But miraculous claims about celery juice fighting off autoimmune disorders, chronic fatigue syndrome, viruses, acne and psoriasis (to name a few) are anecdotal and not backed by science. You’re better off eating the actual celery stalk rather than juicing it, which concentrates the calories. And there’s definitely something infinitely more satisfying when you crunch and chew your food versus drinking it.

4. “Drink kombucha to get your probiotics.”

Sure, protein is “hot,” but so are probiotics. If you’re not familiar, there are good bacteria that live in your gut and help with digestion, keeping harmful bacteria at bay and even promoting a healthy immune system. Certain factors and conditions can affect the balance of helpful microorganisms in your digestive tract, including taking antibiotics and an unhealthful diet.

You can restore the balance of bacteria in your gut by including foods and beverages that contain probiotics (good bacteria), including yogurt, kefir and fermented foods such as sauerkraut and pickles. Another probiotic source is kombucha, which is a fermented, fizzy tea drink containing bacteria, fungi and sugar that has surged in popularity due to its probiotic content. You’ll find it everywhere now, including your local grocery store.

Of course, health claims abound when it comes to kombucha. Now, to be fair, kombucha does contain probiotics, and it also contains B vitamins and antioxidants. But read the Nutrition Facts label and you’ll also see that, on average, an 8-ounce serving contains 30 calories, 7 grams of carb and 2 grams of sugar. (Granted, sodas, fruit juices and sweetened iced tea contain far more. But continuously swig down kombucha, and those carbs will add up.) Kombucha is purported to fight cancer and heart disease, promote liver health, help with weight loss and even boost mental health. Of note, many of the studies supporting these claims were done in test tubes or rats, not in humans. And some of the claims are extrapolated from the overall possible benefits of probiotics, not specifically kombucha.

If you’re curious about this fizzy drink, it’s important to know that, besides its calories and carbs, it contains very small amounts of caffeine and alcohol, and due to its acidity, there’s a chance that it could affect tooth enamel. Not everyone tolerates kombucha, and it may cause nausea, diarrhea and headaches in some people.

Perhaps more importantly, you should check with your doctor before drinking kombucha if you are pregnant or breastfeeding, or if you have a compromised immune system, as the bacteria in this drink could be harmful. And be very careful about making your own kombucha, as it may ferment for too long and can easily become contaminated if you’re not extremely careful about keeping a sterile environment.

Bottom line: Kombucha is not a miracle potion. What it’s got going for it is its probiotic content, which may very likely boost gut health. Keep in mind that you can get your probiotics from other sources.

5. “Apple cider vinegar helps lower blood sugars.”

Apple cider vinegar has been used for centuries as a folk remedy to treat a host of different ailments. Made from fermented apple cider, the main component of apple cider vinegar is acetic acid; it also contains, in small amounts, B-vitamins and polyphenols, a type of antioxidant.

Apple cider vinegar may indeed be beneficial for people with diabetes. In a study published in the journal Diabetes Care in 2004, subjects with and without diabetes were given either apple cider vinegar or a placebo (inactive treatment), and then fed a meal of a bagel, butter and orange juice. Compared with the placebo, the vinegar improved insulin sensitivity, and glucose levels were improved in the subjects with insulin resistance.

Perhaps not surprisingly, apple cider vinegar is claimed to help with weight loss; in a study of 175 people who consumed a drink of 0, 1 or 2 tablespoons of vinegar daily, those who had the most vinegar lost 2 to 4 pounds after 3 months compared to those who had no vinegar (hardly a result to write home about). There’s also some evidence that apple cider vinegar may improve blood fats. But more evidence is needed before routinely recommending apple cider vinegar for weight management.

While there’s nothing wrong with using apple cider in your diet — say, on a salad — it’s not without its risks. The high acid content can damage tooth enamel, worsen acid reflux, and, because it contains a fair amount of potassium, should be used with caution if you have kidney disease.

Want to learn more about eating well with diabetes? Read “Improving Your Recipes: One Step at a Time,” “Top Tips for Healthier Eating” and “Cooking With Herbs and Spices.”

(Image by Brent Hofacker/Shutterstock)

Amy Campbell, MS, RD, LDN, CDCES

Amy Campbell, MS, RD, LDN, CDCES

Amy Campbell, MS, RD, LDN, CDCES on social media

A Registered Dietitian and Certified Diabetes Educator at Good Measures, LLC, where she is a CDE manager for a virtual diabetes program. Campbell is the author of Staying Healthy with Diabetes: Nutrition & Meal Planning, a co-author of 16 Myths of a Diabetic Diet, and has written for  publications including Diabetes Self-Management, Diabetes Spectrum, Clinical Diabetes, the Diabetes Research & Wellness Foundation’s newsletter,, and

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