The ups and downs of coffee consumption

• New study bodes ill for java lovers but, as is usual, moderation is key

Anew study that links drinking coffee with dementia and stroke may be a bitter brew for keen imbibers to swallow. But it seems that, like with all our legal vices, moderation is the key, and the effects will vary from one individual to another.

The study, done at the University of South Australia and involving 17,702 UK Biobank participants aged 37-73, found that people who drink six or more cups of coffee a day have a 53% increased risk of developing dementia and a higher risk of stroke.

It concluded that high coffee consumption is associated with smaller total brain volumes, leading to an increased risk of dementia.

A degenerative brain condition that affects memory, thinking, behaviour and the ability to perform everyday tasks, dementia affects about 50-million people annually worldwide. SA’s 2011 census shows there are 2.2-million people living with dementia.

Stroke is a condition where the blood supply to the brain is disrupted, resulting in oxygen starvation, brain damage and loss of function. The Heart and Stroke Foundation SA says cardiovascular disease (CVD, including heart disease and strokes) is the leading cause of disabilities and death worldwide, accounting for 17-million deaths a year (31% of total global deaths).

It adds that up to 80% of CVD-related premature deaths in young people (under 65 years) are preventable through a healthy lifestyle — a healthy diet, regular exercise and avoiding smoking.

“Once thought to be a disease associated with the elderly, more than half of deaths occur before age 65. Premature deaths caused by CVD in working age people (35-64) are expected to increase by 41% by 2030.”

The foundation says CVD is responsible for almost one in six deaths (17.3%) in SA, and 215 people die every day from heart disease or strokes.

Quoted in the Journal of Neuroscience, Kitty Pham, the lead researcher of the “High coffee consumption, brain volume and risk of dementia and stroke” study and a Unisa PhD candidate, says.

“Coffee is among the most popular drinks. Yet with global consumption being more than 9-billion kilograms a year, it’s critical that we understand any potential health implications.”

She adds: “This is the most extensive investigation into the connections between coffee, brain volume measurements, the risks of dementia and the risks of stroke — it’s also the largest study to consider volumetric brain imaging data and a wide range of confounding factors.”

Predictably, there was blowback once the study reached social media. People commented that the research said nothing about what consumers were adding to their coffee — sugar, cream, coffee creamers, for example — and queried what size the cups were.

QUALITY

Philippa Bramwell-Jones, a registered dietitian at Johannesburg-based Intuitive Nutrition, says various types of coffee have varying strengths, and it matters whether you drink the barista variety or instant.

“The quality of the coffee we drink plays a big role. A cup of coffee made from coffee grounds could contain as much as 100mg caffeine. Instant coffee contains less, roughly 60mg. A single shot of espresso contains around 65mg. Robusta beans contain around twice as much caffeine as Arabica beans. Then there are variations in the amount we use to brew a cup ... my spoon of grounds may look very different to your spoon.”

But dark forces are at work in determining whether you are the type of person who can happily enjoy a couple of cups of strong java a day, or one of those who will suffer bad effects like anxiety or insomnia, and be at risk of the physical degeneration described in the University of South Australia study. It’s got to do with your DNA, specifically a gene called CYP1A2, and nutrigenomics, the study of the effects of food on gene expression.

“Nutrigenomics is allowing us to learn more about an individual’s ability to metabolise caffeine,” says Bramwell-Jones. “The CYP1A2 gene produces a liver enzyme that is responsible for metabolising more than 90% of ingested caffeine. If you have a mutation on your CYP1A2 gene, you won’t be able to tolerate the effect of caffeine as much as those who don’t.

“We all know those people who can finish off a dinner with a double espresso and sleep like babies. Just as we know those that can’t drink anything containing caffeine after 3pm for fear of counting 1,000 sheep. Genes play a big role.”

She says if someone has a family history of dementia and is interested in finding out how to reduce that risk, they should go for genetic testing and consult a health professional who can relay the results into practical advice. It might seem difficult to predict whether those who are in the espressoafter-dinner camp are as predisposed to developing early dementia as those in the decaf or last-cup-before-noon group.

Dr Craige Golding, a Johannesburg specialist physician, says having a “slow metabolism for coffee” plays an important role. While some of us have responsive livers that eliminate easily, many of us are stuck with more sluggish livers, and therefore toxins remain in the system for longer.

This might explain why people have such varying experiences with coffee, and there are such conflicting views. As Dr Brian Walsh, a naturopathic doctor, writing in Precision Nutrition, says: “Over the ages, some of the greatest composers, thinkers and statesmen have extolled coffee’s virtues, while others have denounced it as a poisonous, mind-corrupting drug”. He concurs that: “In moderation, coffee poses minimal health risks for most people. In some cases, coffee even appears to be protective.”

The problem lies in the vast quantities we are consuming, which can damage our neuroendocrine immune system [composed of the central nervous system, hormonal system and immune system] over the long term, he says.

“For example, many of us know that when we are stressed, we get sick more easily. Emotional and mental demands, especially if prolonged, cause our stress hormones to increase, which means our immune systems don’t work as well.”

Bramwell-Jones says problems can arise when we are tired and stressed, and rely too heavily on caffeine to get up and go every day. Since the advent of Covid-19, she has noticed an increase in coffee intake among her clients. The danger is that “as stress takes its toll, the adrenal glands respond by increasing cortisol production. If this continues over an extended period, adrenal insufficiency and a compromised ability to produce cortisol can occur. The experience is going from being ‘stressed and wired’ to ‘stressed and tired’ and finally to chronic fatigue. This fatigue isn’t normal tiredness; this is emotional, physical and mental exhaustion. In these situations, someone may start relying on more and more caffeine for its stimulant effect. It’s a vicious cycle and can be disastrous in the long term.”

Adding sugar will only worsen this cycle, she says. “Rising cortisol levels lead to increased insulin production. Adding sugar to coffee further increases the release of insulin. Sadly, this means the addition of increased carbohydrate cravings, increased belly fat and weight gain, stress and exhaustion. But there are practical strategies to help.”

JITTERINESS

Walsh concurs that the feelgood effects of drinking coffee can be a duplicitous trap: “Studies in humans have shown that caffeine increases cortisol and epinephrine at rest, and that levels of cortisol after caffeine consumption are similar to those experienced during an acute stress. Drinking coffee, in other words, recreates stress conditions for the body.”

You might feel the effects later in jitteriness and even a dip in your mood and an inability to get to sleep. These are indications you cannot metabolise coffee well and should reduce your intake.

But, we should never forget the benefits of coffee in moderation, says Bramwell-Jones: it’s packed with theobromine, which helps reduce inflammation and tumour formation in the body while increasing blood pressure regulation and airflow to the lungs, helping to improve mood, focus and concentration, as well as reducing water retention due to its diuretic effect.

“As a dietitian, I often recommend good coffee, dark chocolate and organic cocoa for those who may benefit from extra theobromine,” she says.

SINCE THE ADVENT OF COVID-19, SHE HAS NOTICED INCREASE IN COFFEE INTAKE