Hot or iced coffee? Expert explains which is healthier - and more likely to give you a buzz

As heat waves spread across the US, many of us are ditching hot coffee for iced coffee or cold brew. 

But while the chilled version might help cool you down, it could change the impact of the drink on your health.

According to Dr Majid Basit, a cardiologist at Memorial Hermann Sugar Land Hospital in Texas, a piping hot cup of Joe might have more disease-fighting nutrients than iced coffee. 

Additionally, the strong aroma of a steaming cup has been shown to improve mood and reduce feelings of fatigue.

However, cold coffee may still have some advantages, including being less acidic and even helping to regulate blood sugar. 

Research suggests that coffee can boost health by preventing chronic diseases and improving metabolism. But it's long been debated if it's better to drink it hot or iced

Research suggests that coffee can boost health by preventing chronic diseases and improving metabolism. But it's long been debated if it's better to drink it hot or iced

'Hot coffee has been shown to have higher amounts of antioxidants, which may offer health advantages,' Dr Basit told HuffPost.  

Antioxidants are molecules that attack free radicals, unstable compounds that increase oxidative stress throughout the body. 

Too much oxidative stress has been shown to damage cells and lead to long term health issues like heart disease, Alzheimer's, kidney failure, and even some forms of cancer

A 2018 study in the journal Scientific Reports, for example, found that hot coffee had higher levels of antioxidants compared to cold brew. This is because brewing coffee with hot water extracts more nutrients from the beans than cold water. 

Other antioxidant rich foods include berries, green tea, dark chocolate, beans, and artichokes, among others.

Some research also suggests that hot coffee may give you a bigger boost of energy as well. A 2020 study from the American Chemical Society, for example, found that hot brewing methods led to slightly higher caffeine levels than cold brewing coffee. 

Jordan Karchner, a coffee expert and founder of Grounds & Hounds Coffee Co, told Bustle that cold brew 'contains less caffeine, which is a benefit for those who really crave a second cup of coffee but feel a little shaky.' 

And even getting a whiff of hot coffee could make you feel more relaxed, as hot coffee has a stronger aroma than iced drinks. 

A study published in the Journal of Agricultural and Food Chemistry using rodents suggested that a single whiff hot coffee reduced tiredness and stress levels. 

And 2021 research found that people who inhaled coffee aromas before undergoing dental procedures were less anxious and more relaxed than those who did not.  

'Since hot coffee has more vapors emanating from it, it is possible this effect may be heightened with hot coffee versus cold coffee,' Dr Basit said. 

And a 2009 study found that participants who held a cup of coffee for a few minutes were more likely to see others as generous, caring, and warm than those who were asked to hold an iced coffee. 

Drinking coffee in moderation could be good for you, according to researchers. The caffeinated drink has been linked to reducing your risk of type-2 diabetes, Alzheimer's, heart disease and liver disease, among other benefits

Drinking coffee in moderation could be good for you, according to researchers. The caffeinated drink has been linked to reducing your risk of type-2 diabetes, Alzheimer's, heart disease and liver disease, among other benefits

However, iced coffee may have its own advantages.

For instance, cold coffee tends to be less acidic than hot coffee, as heat increases the acid content. Drinks that are more acidic can upset your gut's healthy bacteria, leading to digestive distress.

Dr Eva Cwynar, an endocrinologist based in Beverly Hills, told First for Women: 'Acidic coffee upsets your natural gut flora, which actually makes you feel sluggish.'

Cold brew coffee has also been shown to contain higher levels of magnesium and antioxidants called chlorogenic acids. These can helps regulate blood sugar and lower blood pressure, which decreases the risk of developing heart disease. 

However, Dr Barit has cautioned that research is limited, and much is still unknown about which coffee temperature is better. 'More research needs to be done,' he said.