Skip to main content



A heart doctor tells why he eats 100g of dark chocolate every week

SINGAPORE — Despite having a “terribly sweet tooth”, heart doctor Michael MacDonald tries to avoid consuming too many sweet and sugary treats for health’s sake. Once a week though, the 44-year-old who professes to be a “big fan of chocolate” permits himself a small bar of dark chocolate.

A heart doctor tells why he eats 100g of dark chocolate every week
Follow us on Instagram and Tiktok, and join our Telegram channel for the latest updates.

  • Eating chocolate at least once a week is linked to a lower risk of heart disease, a new study has found
  • Protective benefits may lie in its key ingredient cocoa
  • Cocoa contains heart-healthy compounds such as flavonoids, an antioxidant
  • The darker the chocolate, the higher the cocoa content and the greater the benefits
  • A heart doctor recommends consuming no more than 30g of dark chocolate a day


SINGAPORE — Despite having a “terribly sweet tooth”, heart doctor Michael MacDonald tries to avoid consuming too many sweet and sugary treats for health’s sake. Once a week though, the 44-year-old who professes to be a “big fan of chocolate” permits himself a small bar of dark chocolate.

Dr MacDonald is a senior consultant cardiologist at The Harley Street Heart and Vascular Centre in Gleneagles Hospital.

The delicious melt-in-the-mouth treat does more than satisfy his sweet-tooth cravings; the latest research has concluded that it also has heart-friendly benefits.

“Although chocolate has been vilified for its unhealthy qualities, this perception is changing because of its potent antioxidants and cardiac-protective effects,” Dr MacDonald said.  

Eating chocolate at least once a week is linked to a reduced risk of coronary heart disease, based on a meta study published in the European Journal of Preventive Cardiology last year. 

To confirm whether chocolate benefits or harms the coronary arteries, the blood vessels supplying the heart, a team of researchers from the United States looked at many studies over the past 50 years involving more than 330,000 participants.

Those who ate chocolate at least once a week had an 8 per cent reduction of risk in getting coronary artery disease compared to those who ate chocolate less frequently.

This makes it a promising preventative measure against cardiovascular disease, Dr MacDonald said.

Cardiovascular disease is one of the leading causes of death in Singapore, accounting for around three in 10 deaths in 2019.

Dr MacDonald said that the heart health benefits could lie in the key ingredient in chocolate: Cocoa.

Cocoa contains heart-healthy compounds including the antioxidant flavonoids, healthy fat, theobromine, caffeine as well as minerals such as potassium, copper, iron, phosphorous, magnesium and zinc.

Dr MacDonald also pointed out that cocoa contains higher concentrations of flavonoids than tea and wine.

“Flavonoids are powerful antioxidants that fight free radicals, allowing your body to function more efficiently, while protecting it against daily toxins and stressors. These compounds have been found to also improve insulin sensitivity, high blood pressure and endothelial function, reducing the risk of diabetes, atherosclerosis and cardiovascular disease,” he said.

In addition to heart health benefits, chocolate is considered a brain food, too. Some of the compounds in it have been linked to better cognitive function, memory and learning as well as reduced stress, he added.


Before you start eating copious amounts of chocolate, however, there is a major caveat: Eating the wrong types of chocolate is likely to do more harm than good.

Chocolates with fillings and other ingredients that are high in sugar and cream should not be eaten frequently. Photos: Pixabay

Senior clinical dietitian Rddhi Naidu said: “Not all forms of chocolate can be considered equally healthy.

“Processing and heating cocoa can cause it to lose its beneficial properties. Chocolate is also often treated with alkaline to reduce bitterness, which may result in up to a 60 per cent decrease in flavanol content.”

Ms Rddhi (pronounced as “rid-dee”), who practises at Arden Metabolic Centre in the Cairnhill Road area, is also the founder of Nutriology, a digital nutrition clinic. 

Dr MacDonald said that the health benefits of chocolate do not depend on whether it comes from a fancy chocolatier or the supermarket. What matters is its cocoa content.

“With chocolate, I go for the darker, less sweet varieties.”

He added: “The rule of thumb is, the darker the chocolate, the higher its cocoa content, which means greater levels of antioxidants and other beneficial compounds.

“Conversely, the lighter the chocolate, the higher its fat and sugar content, which can increase risks of cholesterol accumulation, weight gain, high blood pressure, and diabetes.”


Milk chocolate may or may not have nuts and other fillings. Photo: Jurgen Brandes/Pixabay

Milk chocolate

Milk chocolate has a lower ratio of cocoa to milk solids (10 percent cocoa to 12 per cent of milk solids).

Dr MacDonald advised eating milk chocolate in limited amounts since it has more sugar and fat than cocoa, which can increase your risk of diabetes, atherosclerosis, heart disease and cardiovascular disease.

White chocolate has no cocoa content at all. Photo: Jerneja Ribnikar/Pixabay White chocolate

A derivative of chocolate, white chocolate contains absolutely no cocoa. Made of 20 per cent cocoa butter, milk solids and a whopping 55 per cent sugar content, white chocolate is mostly sugar and fat, offering little to zero nutritional content, Dr MacDonald said.

That is why it is advisable to eat as little of it as possible, preferably none at all.

Dark chocolate is the best for heart health. Photo: Charisse Kenion/Unsplash

Dark chocolate

Also called semi-sweet chocolate, the experts said that dark chocolate offers the best cardio-protective effects because it contains the highest level of cocoa, flavonoids and nutritional compounds.

For it to be called “dark chocolate”, it must contain at least 35 per cent cocoa, Dr MacDonald said.

The remainder is made of a combination of cocoa butter, sugar, flavourings and milk for texture.

However, for those who wish to eat chocolate every day, he recommended choosing those with at least 70 per cent cocoa content and avoiding those that contain fillings such as fruit.

Ms Rddhi said that choosing dark chocolate of at least 70 per cent cocoa would also mean less sugar is added.

She suggested the following extra tips when buying dark chocolate:

  • Read the ingredient list to ensure that cocoa is listed as the first ingredient

  • Look for Stevia-sweetened dark chocolate. Stevia is a plant-based sweetener

  • Ensure there is no trans fat in the product; avoid it if the words “hydrogenated” or “partially hydrogenated oil” appear in the ingredient list

  • If you prefer some crunch, then choose chocolates with nuts. Avoid caramel or those with fruit paste fillings.

  • Avoid alkalised chocolate or Dutched dark chocolate. Dutching is a method to reduce the bitter flavour, which lowers the flavanol content drastically.


Although dark chocolate is packed with heart-healthy nutrients, Dr MacDonald said that it is essentially still “candy” because it contains sugar and moderate amounts of milk solids or saturated fat to soften its texture.

And while dark chocolate is lower in energy content than milk or white chocolate, it still contains 150 to 170 calories for each 30g serving, or about 500 to 600 calories for every 100g.

Dr MacDonald, who eats 100g of dark chocolate each week, said: “Various studies researching the effects of dark chocolate suggest that eating 20g to 30g of dark chocolate a day delivers various cardio-protective effects.

“For this reason, I recommend that adults consume no more than 30g of dark chocolate a day as it can still contribute to weight gain if eaten excessively.”

An even healthier way to reap heart health benefits is to add unsweetened cocoa powder to a lower-calorie beverage such as low-fat milk or almond milk.

Ms Rddhi suggested mixing raw unsweetened cocoa powder to smoothies, oats or chia seed puddings to create a chocolate-infused snack or drink.

Raw cocoa powder may also be sprinkled over a platter of cut fruit or berries, which helps to reduce some of its bitter taste. 


To keep your heart healthy, Ms Rddhi said that having a healthy diet that is high in fibre but low in saturated fats and sodium is equally paramount.

A great way to start a heart-healthy diet is to include more wholegrains, fruit and vegetables while reducing intake of deep-fried items and processed foods.

For instance, include oats into a breakfast meal and replace white rice and bread with wholegrain varieties.

Have some fruit in between meals and order at least two servings of vegetables when dining out, she said.

“Have a variety of colourful fruit and vegetables because different fruits have different types of antioxidants that can be beneficial to you. Choose plant-based foods like legumes, beans and lentils, which are good sources of protein and fibre,” Ms Rddhi said.

“Eating moderate amounts of healthy food that has unsaturated fat is also great. For example, avocados, nuts and fatty fish (such as salmon, mackerel, tuna, cod, and sardines). Include seeds such as flaxseeds, chia seeds or sunflower seeds for good fats and fibre.”

Related topics

chocolates Heart Health cocoa antioxidant

Read more of the latest in



Stay in the know. Anytime. Anywhere.

Subscribe to get daily news updates, insights and must reads delivered straight to your inbox.

By clicking subscribe, I agree for my personal data to be used to send me TODAY newsletters, promotional offers and for research and analysis.