These are my daily CDMs, or caffeine-delivery-mechanisms, a term used by author Murray Carpenter to refer to ‘convenient, stigma-free vessels by which we funnel caffeine into our bodies’.
In his new book, Caffeinated: How Our Daily Habit Hooks, Helps and Hurts Carpenter says caffeine has all the hallmarks of a drug of abuse.
“It alters mood. As little as 100mg a day is all it takes to get us hooked to the point where most people would have withdrawal symptoms if they were to stop using it abruptly.”
But talking about it as a drug is uncomfortable for those of us who need our daily hit. “It’s easier to talk about how we love our tea, coffee, coca-cola than it is to say, ‘I really love the drug caffeine’,” says Carpenter.
Caffeine lovers will recognise what Carpenter calls “that gentle buzz” that hits your brain 20 minutes after you’ve drunk a caffeinated beverage. Caffeine stimulates your central nervous system. It blocks upload of neurotransmitter adenosine, which tells our brains we’re drowsy. Blood pressure may rise slightly. Your heart may race. “Caffeine is a psychoactive drug. It’s a stimulant. It reduces fatigue, decreases reaction times and sharpens focus,” says Dr James McIntosh, toxicologist with Safefood.
It’s a psychoactive drug but it’s culturally acceptable. Sales of coffee have risen here in the last 10 years, says Conor Minogue, Irish Coffee Council secretary. They’ll reach €71.7m by the end of 2014. Last year, we drank 3,992 tons of coffee.
“There’s been a coffee revolution here in the last five years. People have become more aware, knowledgeable and sophisticated — they’re interested in the art of coffee, where it comes from, different bean types and brewing methods,” says Minogue.
Coffee accounts for 32% of Ireland’s drinks market. Tea is still number one. Tea’s 44mg of caffeine per cup is a gentler hit compared with coffee’s 78mg (cup of instant) and 111mg for a brewed cup). Tea also contains the caffeine-mitigating compound, theobromine.
A 250ml can of Red Bull has 80mg of caffeine. We consumed 50m cans of Red Bull here in 2013. In 2010, a Health Impact Assessment, produced by the Dept of Health for the proposed sugar-sweetened drinks tax, predicted that, between 2011 and 2014, 7 to 7.5 litres per year per person would be drank by consumers of energy drinks.
Carpenter says most people don’t know how much caffeine they’re getting daily. He cites a 2003 study by Baltimore forensic toxicologist, Bruce Goldberger, which “analysed contents of coffee drinks and found huge caffeine differences, not only between coffee brands, but also between coffees from the same shop.”
Moderate, daily coffee intake is 300-500mg. Consultant dietician, Aveen Bannon, recommends a maximum of 300mg. “For some people, 300-500mg shouldn’t impact on health, but if you’re routinely having more than 400mg a day, that’s a lot,” she says.
Pregnant women shouldn’t have more than 200mg daily. “Whether caffeine causes miscarriage is debatable,” says McIntosh, but he refers to a concern of the Food Standards Agency, in London, that unborn babies fail to reach proper growth potential due to caffeine exposure. “Risk starts to get significant above 200mg a day,” he says.
Most experts agree that 600mg a day of caffeine is too much. “You’d be jittery, on edge, sleep-deprived, you might get palpitations. Why would anybody want to inflict that on themselves?”
Ted Dinan, pharmacologist and professor of psychiatry at UCC, says caffeine has a long half-life in the body. It takes four or five hours for caffeine concentration to drop by 50%. “Loading up on a lot of coffee during the day can impact on sleep. There are many causes of insomnia but, undoubtedly, high caffeine intake is a very significant cause,” Dinan says.
Carpenter cites findings from 2000 that caffeine affects later stages of sleep, “which account for about 20% of our sleeping time and include some of our most restful, restorative sleep”.
John Greden, of the University of Michigan, links caffeine and anxiety. Greden says the first-line treatment for anxiety in a caffeine-user is to eliminate the caffeine and see how the patient responds, before prescribing anti-anxiety medication.
Excess caffeine intake “can cause nausea, abdominal discomfort, and irritability and can elevate heart rate and blood pressure”, says Bannon. But for the average adult, drinking a few cups a day has no real long-term consequences, says Dinan. “You’re not more likely to get heart disease or cancer,” he says.
There are benefits. “Does it make you jump higher, run faster or swim longer?” asks McIntosh. “There are claims and counter-claims. When the European Food Safety Authority was asked if caffeine improved sports performance, they looked, in 2011, at different types of exercise. They found no evidence that caffeine improved performance in short-term, high-intensity exercise like sprinting. But with endurance sports, like marathons, they concluded that 225mg of caffeine, consumed an hour prior to exercise, did improve performance.”
Harris Liebermann, psychologist with the US Army Research Institute of Environmental Medicine, has studied caffeine for 30 years. He found “moderate doses of caffeine can improve cognitive function, including vigilance, learning memory and mood”.
Other US research says coffee can ward off depression. Coffee drinkers, in a 2000 study, had a lower incidence of Parkinson’s disease. A 2012 study linked coffee-drinking with longer life — drinking three or more cups was associated with a 10% lower risk of death in 400,000 Americans aged 50 to 71.
Caffeine is a quirky compound, as Carpenter shows: morning people (larks) are more susceptible to caffeine’s sleep-disrupting effects than owls. Extroverts get more cognitive enhancement from it. Women on birth-control pills get double the kick from the same amount of caffeine. And smokers get half the caffeine hit.
So, why isn’t caffeine regulated and why aren’t levels marked on products, like units of alcohol, grams of sugar or calories? Why haven’t heavyweights like the FDA (US Food and Drug Administration) put their foot down?
Carpenter says the FDA has long practised a dual regulatory role for caffeine — regulating it when it’s packaged as over-the-counter medication and ignoring it when it’s blended into drinks.
“If the FDA were to regulate caffeine in energy drinks and colas, which have far less caffeine than coffee, what would it do with coffee? It’s tricky. This is a drug most Americans take daily — automatically it’s in a different category to most other drugs,” Carpenter says.
But the FDA is investigating products with added caffeine, such as energy drinks. “These drinks tend to be cocktails with ingredients other than caffeine — taurine, sugars, ginseng. Do these collectively, synergistically, create health risks that caffeine alone doesn’t?” Carpenter asks.
It’s 10 years since any comprehensive independent review was done on energy-drink consumption in Ireland. In 2002, a review on the Health Effects of Stimulant Drinks involved a sample group of 11- to 35-year-olds who were asked about their consumption. Results showed 37% of us took stimulant drinks — more commonly in a single session with alcohol. Peak consumers of energy drinks were aged 19 to 24. “Some were drinking eight cans a day — 640mg of caffeine. These individuals were literally bombing on eight cans a day — that’s some serious caffeine consumption,” says McIntosh.
It’s debatable whether tea or cola is a child’s first introduction to caffeine. Should parents stop giving caffeinated drinks to children?
“We don’t recommend children consume any fizzy drinks, especially those containing caffeine — they don’t offer any nutritional health. They contain sugar calories and can displace milk and water intake,” says Bannon.
In Ireland, the label on any beverage that contains more than 150mg of caffeine per litre must state ‘high caffeine content’. From December 2014, new legislation will require such labels to read ‘high caffeine content, not recommended for children or pregnant or breast-feeding women’. Foods and food supplements that exceed 150mg per litre/kg must be labelled ‘high caffeine content, not recommended for children or pregnant women’.
Does Carpenter want caffeine labelled a drug of abuse? “That’s probably too strong. Some people have problems with caffeine, but the vast majority handle it quite well. What’s not to like about caffeine? In moderate doses, it tends to make you feel good. It increases alertness, decreases fatigue, increases feelings of sociability, wellbeing and mood. But I do think it’s important we all have more respect for its psychoactive powers,” he says.
For his book, he tried out numerous caffeinated products. Coffee remains his caffeine of choice. “I’m still an avid coffee drinker. I take three to four cups a day of good, strongly-brewed coffee — about 300-400mg. I like it drip-brewed with milk and cream.”
Since writing Caffeinated, he has often been asked ‘please tell me there’s nothing wrong with my coffee habit?’ He tells people: “If you’re sleeping well, not anxious, not pregnant and you’re happy, keep it up.”
My sentiments exactly — make my next one a cappuccino.
¦ Cup coffee, brewed – 111mg (range 102-200mg)
¦ Cup coffee, instant – 78mg (range 27-173mg)
¦ Cup coffee, decaffeinated – 4mg (range 3-12mg)
¦ One shot espresso – 40mg (range 30-90mg)
¦ Cup tea, brewed – 44mg (range 40-120mg)
¦ 500ml bottle Pepsi – 32mg
¦ 500ml bottle Diet Coke – 64mg
¦ 500ml bottle Coke – 48mg
¦ 500ml bottle 7-up (diet and regular) – 0mg
¦ 250 can Red Bull – 80mg
¦ Cup hot cocoa – 8mg
¦ Bar milk chocolate – 11mg
¦ Bar dark chocolate – 31mg
¦ Lemsip Cough & Cold Capsules – 25mg.
¦ Information adapted from Centre for Science in the Public Interest.
¦ Exact amount of caffeine will vary according to cup size, brewing methods and brand.
1 cup = 200ml;
1 shot = 30ml;
1 bar = 45g.