Coffee kick: The health benefits of your morning espresso

A major 15-year study of more than half a million participants showed that people who drank more coffee were less vulnerable to a range of chronic illnesses. Photo / 123RF

Whether we have an espresso shot, a frothy cappuccino or a milky latte, many of us are as reliant on a caffeinated pick-me-up as we are on our alarm clock. But now there is an increasing amount of evidence to suggest that the many ingredients within coffee could help with aspects of our health.

The latest data have emerged from the University of Verona, where researchers showed that doses of espresso could prevent a toxic protein called tau from clumping together in cells in a petri dish. This is particularly interesting because the steady accumulation of tau in the brain is a contributing factor to Alzheimer’s disease.

Dr Federica Amati, a medical scientist and nutritionist at Imperial College London, has been intrigued by the various benefits of coffee for many years. She refers to a major 15-year study of more than half a million participants, known as the European Prospective Investigation into Cancer and Nutrition (Epic), which showed that people who drank more coffee were less vulnerable to a range of chronic illnesses.

“Data keep coming out which show that coffee drinking is protective for health,” she says.

“Whether you have milk or not doesn’t seem to make a difference, but as soon as [coffee is] sweetened with sugar, you start losing the beneficial effects,” Dr Federica Amati says. Photo / Thinkstock

However, there are caveats. “Whether you have milk or not doesn’t seem to make a difference, but as soon as it’s sweetened with sugar, you start losing the beneficial effects,” she says. “Some studies also suggest that espresso drinking is the best.”

So, how much should you drink? Experts at Nutritank, who provide medical education to healthcare professionals on food, nutrition and lifestyle medicine, say that Harvard University recommends two to five cups of coffee daily.

It is also not necessarily suitable for everyone. People with irritable bowel syndrome, or genetic factors that mean they cannot process caffeine so well, will likely not benefit from coffee.

“It is important to remember that UK guidelines are that no more than about two and a half cups of coffee are consumed in one sitting, or five cups per day,” says Dr Ally Jaffee, NHS doctor and co-founder of Nutritank. “Daily consumption of more than seven and a half cups of coffee has been suggested to have a negative impact on heart and brain health.”

So, what can coffee do for you?

Reduces risk of colorectal cancers

One of the findings of the Epic study was that coffee lowered the risk of colorectal cancers. Dr Amati says this is likely to be because it encourages bowel turnover, helping to flush toxins through the system.

“Coffee has a laxative effect when you drink it,” she says. “Essentially, it’s really good to promote regular bowel movements and that is very important.”

Coffee drinkers have also been found to have different species of bacteria in their gut microbiomes compared with non-coffee drinkers. This is believed to be one of the strongest protective factors against colorectal cancers.

Dr Francesca Jackson-Spence, an NHS doctor who provides medical information on her Instagram channel @drfrankiejs, says that coffee contains chemicals called polyphenols, which protect against inflammation in the body and repair damage to cells. These chemicals are found in decaffeinated coffee, too, which has also been found to have health benefits.

“These plant-based chemicals act as prebiotics and soluble fibre to feed the various species of microbes in the gut and support gut microbiome diversity, which has been shown to have an important role in our long-term health,” she says.

Improves brain function in later life

While it is far too early to say that coffee drinking can prevent a highly complex disease such as Alzheimer’s, researchers feel there is an association between coffee drinking and better cognition in later life.

Mariapina D’Onofrio, a researcher at the University of Verona who led the recent study into tau protein accumulation, believes that coffee may help to promote normal brain functioning in middle age and later life. “I believe that the components in coffee may be helpful in maintaining neuronal activity and plasticity,” she says.

Helps prevent Type 2 diabetes

At the Karolinska Institute, in Stockholm, Mattias Carlström, professor of cardiorenal physiology, has been fascinated by how coffee drinking appears to reduce the risk of Type 2 diabetes, one of the strongest associated health benefits.

He points to numerous epidemiological studies which have found that drinking three to five cups of caffeinated or decaffeinated coffee per day appears to lower the risk of this chronic health condition. Indeed, below six cups, each mug of coffee seems to decrease the risk of Type 2 diabetes by 6 per cent.

We are still attempting to understand why, but the complex mixture of minerals and chemicals within coffee, from magnesium to chlorogenic acid, seem to potentially alter how the body produces and uses insulin.

“Some studies have shown that caffeine intake may improve insulin sensitivity, which is a crucial factor in preventing Type 2 diabetes,” says Professor Carlström. “Enhanced insulin sensitivity means that the body can use insulin more effectively to regulate blood sugar levels. Chlorogenic acid, the main polyphenol in coffee, is a type of antioxidant that may have anti-inflammatory and blood sugar-regulating properties. It may help reduce glucose absorption in the intestines and improve glucose metabolism in the body.”

Boosts your metabolism

Dr Amati points to research that suggests caffeine might be able to increase metabolic rate – the number of calories we burn every day. “I saw one estimate that coffee increases this by 100 calories a day, and if that’s true, it would help to maintain a healthy weight,” she says.

However, the connection between coffee and weight management is also likely to be due to its impact on the gut microbiome, which is thought to play a role in regulating appetite.

“When you have a gut microbiome with lots of helpful bacteria, you are more efficient at producing the hormone feedback that helps you control your hunger,” Amati says.

Protects the central nervous system

While caffeine is known to help keep us focused and alert, improving concentration through increasing the level of a brain chemical called dopamine, it may also help prevent the abnormal build-up of toxic proteins that have been associated with neurodegenerative disorders such as Parkinson’s disease.

Dr Jackson-Spence points to research in mice that suggests the way caffeine interacts with certain brain receptors could help to prevent the abnormal brain wiring and death of crucial brain structures called synapses that occur in diseases such as Parkinson’s.

“Additionally, there is increasing research supporting the diversity of the gut microbiome in protecting from neurodegenerative conditions, so the benefits of coffee may be twofold,” she says. “Both by the direct chemical effects on the brain and also by the prebiotic effects on the gut microbiome.”

Helps prevent depression

Some population studies have indicated that the mood-boosting properties of caffeine may help to mitigate the risk of depression. A 2018 study in Spain found that people who drank at least four cups of coffee a day had a significantly lower risk of depression compared with those who drank less than one cup per day.

However, scientists say that we still need to learn much more about how true this relationship is. “The mechanisms through which coffee may reduce the risk of depression may be due to the antioxidant content and anti-inflammatory action, as inflammation is a key mechanism in depression,” says Alice Benskin, nutrition education lead at Nutritank.