10 Popular Health Myths Debunked

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10 Popular Health Myths Debunked

Last updated: Monday, February 1, 2021 | 10 min reading time
Dr Leong Hoe Nam

Infectious Disease Physician

Dr Loi Shen-Yi Kelly

Obstetrician & Gynaecologist

Sugar makes you hyper and MSG gives you cancer. Are these myths true? Experts break down 10 of the most common health myths.

Myth 1: Alkaline foods improve your health by reducing your body's acidity

Alkaline diet

The truth: While the 'alkaline diet' is generally quite healthy – encouraging a high consumption of fruits, vegetables and plant foods while restricting processed foods – the thinking that it can help to neutralise your body's acidity is a myth.

Here are the facts. Your blood is slightly alkaline, while your stomach is acidic in order to break down food. The food you eat does not affect the way your body alkalises itself or balances its acidity. Your kidneys and lungs do it – they control your system's acid-alkali balance and keep your blood pH constant. If they didn't, you would be seriously ill by now. 

Myth 2: MSG can cause cancer

MSG and cancer

The truth: The popular flavour enhancer has earned a bad rep with supposed links to a variety of health issues, from migraine to cancer. However, researchers have not found any definitive evidence of monosodium glutamate (MSG) being bad for health. The Food and Drug Administration (FDA) in the US has also classified MSG as a food ingredient that is 'generally recognised as safe'.

MSG is a combination of sodium and the amino acid glutamate, which is one of the most abundant amino acids in nature. Glutamate can be found in tomatoes, cheeses, mushrooms, seaweed and soy. Excessive intake of glutamate may damage nerve cells and the brain. However, dietary glutamate should have little to no effect on the brain as it cannot cross the barrier between the blood and the brain in large amounts.

While a small proportion of people may have adverse reactions to MSG such as headaches or nausea, these symptoms are generally mild and do not require treatment. Instead of focusing on whether something contains MSG, it is probably more helpful to look at the general nutritional value of what you're eating – for example, processed foods like instant noodles are bottom-line unhealthy, with or without MSG.

Myth 3: Eating too much sugar causes diabetes

Sugar and diabetes

The truth: Contrary to popular belief, sugar does not cause diabetes. Eating too much sugar, however, can make you put on more weight, and being overweight increases your risk for type 2 diabetes. The best way to reduce your risk of diabetes is to watch your weight. That means not only moderating the amount of sugary food you take in, but watching your intake of fatty food as well.

As for type 1 diabetes, there is no way that sugar, or anything in your diet can be a cause, because this type of diabetes only happens when insulin-producing cells in your pancreas are destroyed by your immune system.

Causes of diabetes

The causes of type 1 diabetes are still not fully understood. Scientists think that genes and environmental factors, such as viruses, may trigger the disease.

There are several factors that cause type 2 diabetes, including:

  • Being overweight or obese
  • Physically inactive
  • Insulin resistance, a condition in which muscle, liver and fat cells do not use insulin well
  • Genes and family history

People who have excessive weight, live a sedentary lifestyle, and have a family history of type 2 diabetes are at increased risk of developing the disease. Having certain medical conditions such as high blood pressure and cholesterol, gestational diabetes, polycystic ovary syndrome, depression, or a history of heart disease or stroke also make a person more prone to developing type 2 diabetes.

Diet and lifestyle remedies

Pay attention to the following measures to keep diabetes in check:

  • Eat healthy and avoid sugar-sweetened beverages to keep blood sugar, blood pressure and bad cholesterol as close as possible to normal levels
  • Lose weight and stay at a healthy weight
  • Stop smoking
  • Do at least 30 minutes of physical activity a day

Myth 4: It's good to go on a detox to cleanse your body of toxins

Detox diets

The truth: Detox diets, juices and treatments are hugely popular, but the very idea that we can take steps to detox our own bodies is a myth. From a medical point of view, there is no need for anyone to detox their systems, as our bodies are built to get rid of toxins way better than any diet or treatment can. (If it were true that toxins could build up in our systems without our bodies being capable of excreting it, we would either be dead or in need of serious medical intervention by now.)

As such, there is no need to take diets, drinks or treatments to 'cleanse' or 'detox' your body. Probably the best way to protect your body's detoxification process would be to take care of the liver and the kidney, which are the body's main organs in detoxification. To do so, avoid processed and packaged foods like fries, limit your intake of sugary foods, fatty foods and alcohol (these foods will cause fatty liver), and drink plenty of water.

Foods good for the liver

Foods that are good for the liver contain active compounds that fight against inflammation and oxidative stress, reduces fat buildup, and regulate liver enzyme levels. These include:

  • Coffee. Reduces fat buildup and increases antioxidants in the liver and helps liver enzymes rid the body of cancer-causing substances.
  • Green tea. Helps to reduce overall fat content, fight against oxidative stress, and reduce other signs of nonalcoholic fatty liver disease (NAFLD).
  • Whole or steel-cut oats. Beta-glucans from oats help to fight inflammation.
  • Garlic. Reduces body weight and fat content in people with NAFLD.
  • Berries. Dark berries such as blueberries, raspberries, and cranberries contain antioxidants called polyphenols, which may help protect from liver damage and stimulate the immune system.
  • Grapes. The fruit including its seeds are a rich source of antioxidants that may help reduce liver inflammation and damage.
  • Grapefruit. Contains 2 primary antioxidants: naringin and naringenin that may help reduce inflammation.
  • Prickly pear cactus. May help reduce inflammation.
  • Plant foods. A large number of plant foods may be helpful for the liver. These include, avocado, banana, barley, beets, broccoli, brown rice, carrots, leafy vegetables, lemon, papaya, and watermelon.
  • Fatty fish. Omega-3-fatty acids in fatty fish help reduce inflammation, prevent the buildup of excess fats and maintain enzyme levels in the liver.
  • Nuts. The unsaturated fatty acids, vitamin E, and antioxidants in nuts help reduce inflammation and oxidative stress.
  • Olive oil. Its high level of unsaturated fatty acids helps reduce oxidative stress and improve liver function.

Foods good for the kidneys

Foods that are good for the kidneys contain nutrients and compounds that fight inflammation and reduce risk factors that lead to kidney disease. These foods include:

  • Water. The kidney uses water to filter out toxins to be transported out of the body through urine.
  • Fatty fish. Omega-3 fatty acids in fatty fish help reduce fat levels in the blood and lower blood pressure, thus protecting from kidney disease.
  • Sweet potatoes. Potassium in sweet potatoes help balance sodium levels in the body and reduce its effect on the kidneys.
  • Leafy green vegetables. Dark leafy greens contain many vitamins, fibres, minerals and antioxidants that are protective.
  • Berries. Dark berries, such as strawberries, blueberries, and raspberries contain nutrients and antioxidants that help protect cells in the body from damage.
  • Apples. Pectin in apples is a fibre that helps reduce blood sugar and cholesterol levels, which are risk factors for kidney damage.

Myth 5: Brown sugar, honey, maple syrup or agave nectar are healthier substitutes for sugar

Honey and maple syrup

The truth: These sugars are no better for you than refined sugar – all offer empty calories and barely any nutrients. While unrefined sugar may retain some minerals such as calcium, iron and potassium, it contains them only in trace and insignificant amounts. These 'healthier' sugars don't provide any significant nutrition over refined white sugar, and all sugars are almost identical in terms of calories. You should watch your sugar intake regardless of what type it is.

Sugar nutrition facts

The following lists the nutrient content in one teaspoon (4g) of granulated sugar:

  • Calories: 15.4kcal
  • Fat: 0g
  • Sodium: 0mg
  • Carbohydrates (sucrose): 4g
  • Fibre: 0g
  • Protein: 0g

Myth 6: Eggs contribute to high cholesterol

Eggs and cholesterol

The truth: Eggs have gotten an undeserved bad rap. There is insufficient data to show that consumption of dietary cholesterol (such as that in eggs) affects our blood cholesterol levels. Our harmful cholesterol levels are more influenced by the consumption of saturated and trans fat. It is more important to keep your cholesterol in check by monitoring these fats in your diet.

On the other hand, eggs are an inexpensive source of many nutrients, including omega-3 fatty acids, zinc, iron, antioxidants and vitamin D. Nevertheless, eggs contain saturated fat and should be eaten in moderation – a healthy person can eat up to 6 eggs each week, as a guide.

Cholesterol levels

Cholesterol levels that are recommended for adults are as follows:

  • Total cholesterol: < 200 mg/dL
  • LDL ('bad cholesterol'): < 100 mg/dL
  • HDL ('good cholesterol'): > 60 mg/dL

Cholesterol in eggs

Are eggs good or bad for your cholesterol levels? Chicken eggs are naturally high in cholesterol. One large egg has 186mg of cholesterol, all of which is found in the yolk. However, it does not appear to raise blood cholesterol levels. Most healthy people can eat an egg a day without increasing their risk of heart disease. Some studies show this may even prevent certain types of stroke and a serious eye condition called macular degeneration.

You should, however, be cautious of the types of foods you would typically eat with eggs, such as bacon, sausages and ham, and cook eggs with less oil. Also remember to keep intake of cholesterol within the recommended intake of 300mg a day.

Myth 7: Drinking soya sauce makes wounds darker

Soy sauce

The truth: If you've ever suffered from a case of chicken pox or had a nasty scar from a bad wound, you might have heard the warning to avoid taking soya sauce. The belief is that the dark pigment in soya sauce will result in scabs turning dark and leaving lasting scars. However, scarring only results from scratching that interferes with the healing process – not by what we ingest. Even TCM experts have confirmed that this is a myth. If you want to avoid scarring from a wound, it is best to just keep the wound clean and avoid scratching it.

Myth 8: Don't give your kids too much sugar, they'll become hyperactive

Children and sugar

The truth: While regulating your children's sugar intake is the correct thing to do, the reasoning behind why parents do this isn't always right. Many believe that too much sugar can lead a child to become hyperactive – however, there is no scientific evidence for sugar causing attention deficit hyperactivity disorder (ADHD) or worsening ADHD symptoms.

Increased sugar intake can cause a quick increase in blood sugar

Increased sugar intake can cause a quick increase in blood sugar and thus an adrenaline-like rush that looks like hyperactivity, but studies have found no relation between sugar and a child's behaviour or cognition. Nevertheless, it is good practice to provide healthier, low-sugar options for your kids, such as fruit-infused water over a canned drink or sugar-sweetened drink.

Myth 9: Eating spicy food can give you stomach ulcers

Spicy foods and stomach ulcers

The truth: It is no secret that many like their food spicy, so this is probably good news for many – contrary to popular belief, spicy food is not one of the causes of stomach ulcers. Stomach ulcers are usually the result of infections due to the Helicobacter pylori (H. pylori) bacteria, not spicy food. Other factors like family history, smoking and excessive alcohol also influence your risk of developing ulcers. It is important to note though, that if you already have an ulcer, it is still best to avoid spicy food.

Myth 10: Drink 8 glasses of water a day


The truth: Despite it being a belief widely held onto for its supposed multiple health benefits (including better skin and the prevention of gallstones), the age-old mantra of drinking 8 glasses of water a day is medically unfounded. While water is essential to keep you hydrated, there is no need to drink minimally 8 glasses a day. This is because water is not the only source of hydration – our body gets its hydration from the water found in fruits, vegetables, and even in juice and coffee.

Furthermore, there is also no scientific evidence that drinking more water has health benefits for otherwise healthy people. That being said, water is still the healthiest drink to consume – you just do not have to drink 8 glasses of it a day. The best gauge of how much water to drink is simply to drink as and when you feel thirsty.

MSG (Monosodium Glutamate): Good or Bad? (2018, November 19) Retrieved December 04, 2020, from https://www.healthline.com/nutrition/msg-good-or-bad#fact-vs-fiction

Symptoms & Causes of Diabetes (2016, December) Retrieved December 04, 2020, from https://www.niddk.nih.gov/health-information/diabetes/overview/symptoms-causes

Risk Factors for Type 2 Diabetes (2016, November) Retrieved December 04, 2020, from https://www.niddk.nih.gov/health-information/diabetes/overview/risk-factors-type-2-diabetes

Diabetes Diet, Eating, & Physical Activity (2016, December) Retrieved December 04, 2020, from https://www.niddk.nih.gov/health-information/diabetes/overview/diet-eating-physical-activity

What Foods Protect the Liver? (2020, January 23) Retrieved December 04, 2020, from https://www.medicalnewstoday.com/articles/323915#12-best-foods

What Foods Are Good for Kidneys? (2019, June 05) Retrieved December 04, 2020, from https://www.medicalnewstoday.com/articles/325390

Sugars, Granulated. (2019, December 16) Retrieved December 04, 2020, from https://fdc.nal.usda.gov/fdc-app.html#/food-details/746784/nutrients

What Should My Cholesterol Level Be At My Age? (2020, January 05) Retrieved December 04, 2020, from https://www.medicalnewstoday.com/articles/315900#treatment-options

Eggs: Are They Good or Bad for My Cholesterol? (2020, January 09) Retrieved December 04, 2020, from https://www.mayoclinic.org/diseases-conditions/high-blood-cholesterol/expert-answers/cholesterol/faq-20058468
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