Counterbalancing health effects of coffee consumption

coffee4If you’re an avid coffee consumer you must have been delighted to see in the news lately that coffee can have beneficial health effects. Coffee had previously confusingly been in the bad books blamed for everything from stunting growth to causing heart disease and insomnia.

It had also been shown that high consumption of unfiltered coffee (boiled coffee popular in Scandinavian countries or espresso invented in Italy and spread all over the world) fails to catch a compound called cafestol in the oily part of coffee that can increase the bad cholesterol or LDL.

Not so good.

So what changed?

The good news was based on a scientific review aimed to dispel some of that confusion, examining the evidence presented in 218 previous studies. It’s an example of the ever more popular meta-analysis of existing research that by combining previous findings strengthen the proof of the conclusions.

In synthesising the reported findings the researchers found that coffee consumption was more often associated with benefit than harm for a range of health outcomes across exposures. Three to four cups a day seemed to be optimal.

Drinking coffee was consistently associated with a lower risk of death from all causes and a lower risk of several cancers, as well as type 2 diabetes, gallstones and gout.

Liver conditions, such as cirrhosis, saw the greatest benefit associated with coffee consumption. There also seemed to be beneficial associations between coffee consumption and Parkinson’s disease, depression and Alzheimer’s disease.

Overall, there was no consistent evidence of harmful associations between coffee consumption and health outcomes, except for those related to pregnancy and for risk of fracture in women.

Spoiling the good news story

We shouldn’t spoil a good news story, but we have previously mentioned the presence of toxic acrylamide and furan especially in coffee. Now the European Food Safety Authority has published a new opinion on furan confirming the previous suspicion that furan in food could be harmful to health. Based on animal studies they concluded that liver damage and liver cancer are the most critical health effects.

Although the average intake of food containing furan indicates a low health concern for most consumers, for high consumers exposure is up to three times what would be considered of low concern for public health.

The most exposed group of people are infants, mainly through consumption of ready-to-eat jarred or canned foods. Exposure in other population groups is mainly from consumption of grain-based foods and, here you have it, coffee, depending on age and consumer habits.

coffee_beans_(MarkSweep)The highest concentrations of furan were found in whole roasted coffee beans, with a mean value of 4,579 µg/kg. High mean concentrations of furan were also found in ground roasted coffee (2,361 µg/kg) and instant coffee powder (310 µg/kg). This should be compared to mean values ranging from not detected to 57 µg/kg for most other foods.

All is not lost

There is a serious anomaly between the observational findings that coffee consumption is associated with a lower risk of liver damage, while on the contrary animal studies link the presence of furan in the diet to liver damage. And coffee provides the highest exposure to furan in adults.

What’s to give?

As bad as the concentrations of furan seem to be in solid coffee samples, in preparing the coffee beverage there is both a dilution and an evaporative loss of furan down to typical concentrations of about 60 µg/L in the final beverage. Still bad for heavy coffee drinkers.

But there is more.

Coffee contains a complex mixture of bioactive compounds benefiting health.

It contributes a large proportion of the daily intake of dietary antioxidants, greater than tea, fruit, and vegetables. Chlorogenic acid is the most abundant antioxidant in coffee; though it is degraded by roasting, alternative antioxidant organic compounds are formed. Caffeine also has significant antioxidant effects.

Cafestol and kahweol induce enzymes involved in carcinogen detoxification and stimulation of intracellular antioxidant defence, contributing towards an anticarcinogenic effect.

These antioxidant and anti-inflammatory compounds are likely to be responsible for the  beneficial associations between coffee consumption and liver health, and might neutralise the effects of furan.

coffee drinker

You can still drink your coffee with peace of mind

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Give chai a try

Getting too much caffeine from coffee (Photo: Wikimedia)?

Getting too much caffeine from coffee (Photo: Wikimedia)?

Drinking too much coffee and getting the caffeine jitters? You could of course go for boring decaf coffee but it wouldn’t save you from the acrylamide and furan toxins formed in all roasted coffee.

Acrylamide is the subject of a new opinion from the European Food Safety Authority (EFSA) currently under public scrutiny. The draft report is recommending that acrylamide exposure be reduced as much as possible since it is a proven carcinogen in animal experiments. It is impossible to totally eliminate acrylamide from the normal diet, but since it is a numbers game any significant reduction in acrylamide exposure will similarly reduce the risk of developing cancer. EFSA recently published an excellent consumer guide on how to reduce acrylamide exposure.

Furan is another substance that has proven to be a carcinogen in animal experiments. Since furan formation is linked to the development of the coffee aroma it is an intrinsic component of roasted coffee and cannot be avoided.

And just so you know, coffee substitutes might be even more dangerous. According to levels of acrylamide in food reported by EFSA, coffee substitutes based on chicory carried at least three times more acrylamide than ordinary roasted coffee.

Go for exciting chai

You could go for ordinary tea, but why not try the exciting chai with less than a third of the caffeine content of normal coffee. Chai is a centuries-old beverage which has played an important role in many cultures. Although the word chai is simply the Hindi word for tea, it is much more to it. Chai is a flavoured tea beverage made by brewing black tea with a mixture of aromatic Indian spices and herbs. It can be prepared black, with milk, and with or without sugar. Originating in India, the beverage has gained worldwide popularity, becoming a feature in many coffee and tea houses. Although traditionally prepared by a decoction of green cardamom pods, cinnamon sticks, ground cloves, ground ginger, and black peppercorn together with black tea leaves, retail versions include tea bags for infusion, instant powdered mixtures, and concentrates.

There has been a phenomenal growth in the popularity and interest in chai in the Western world over the last decade. As chai has become very common at over-the-counter specialty coffee and tea shops, it is now as easy to order a chai latte as it is a cafe latte or a cappuccino. Many industry analysts are predicting that chai will eventually become as popular and common as coffee is now.

Great variety of spices used

chai_tea_(Wikimedia)

A great variety of spices used in producing chai (Photo: Wikimedia)

Drinking chai is part of life in India and most Indian’s are amazed at all the current fuss in the West. The spices used vary from region to region and among households in India. Traditionally, cardamom is a dominant note, supplemented by other spices such as cloves, ginger, or black pepper; the latter two add a heat to the flavour and the medicinal aspect of the drink. Other spices include cinnamon, star anise and/or fennel seeds.

In Western India, cloves and black pepper are expressly avoided, while the Kashmiri version of chai is brewed with green tea instead of black tea and has a more subtle blend of flavourings including almonds, cardamom, cinnamon, cloves, and sometimes saffron. Other possible ingredients include nutmeg, mace, chilli, coriander, rose flavouring (where rose petals are boiled along with the loose-leaf tea), or liquorice root. A small amount of cumin, also considered a “warm” spice in Ayurveda and traditional Chinese medicine/cuisine, is also preferred by some people. A pinch of turmeric may be added to aid those suffering from a fever.

The warm, aromatic flavours of chai have their roots in ancient Ayurvedic traditions. Ayurveda, meaning “life science” in Sanskrit, is a traditional system of medicine that includes the practice of yoga and the use of healing herbs and spices. It is said that Indian chai produces a warming, soothing effect, acts as a natural digestive aid and gives a wonderful sense of well being.

I tried a Hari Hai Chai

I had the benefit of trying a chai latte curtesy Hari Hai Chai recently. I am not vouching for the health claim aspects but it was difficult to resist a second cup and with so much variety possible it might take many months to explore fully.

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Skip the third cup of coffee – or not

A cup of coffee to raise the spirit.

A cup of coffee to raise the spirit.

Do you need a cup of coffee in the morning like me to start functioning? To kick-start the brain and get the spirit up. Do you also have a refill after lunch? To be honest I am tempted to have a third cup in the afternoon as well, but then I remember the furan issue.

You haven’t heard about furan? Lucky you. If you read on I am going to destroy the enjoyment of your final cup of coffee for the day – or not.

You might have read the previous blog on acrylamide formation in which you had to take most of the blame for this toxic compound found in your toast. With furan it is actually a shared responsibility between you and the coffee roaster unless you roast your own coffee. And not many would do that.

First some technical facts about furan

Furan is a highly volatile substance formed in foods and beverages due to the degradation of naturally-occurring sugars, polyunsaturated fatty acids and ascorbic acid (vitamin C) during heating. It is actually an integral component contributing to the sensory properties of the heated product and is seen as an important coffee flavour component. However, in 2004, the US Food and Drug Administration (FDA) raised concerns about the presence of furan in food and beverages.

Already in 1993 furan was subject to comprehensive toxicological evaluation within the US National Toxicology Program (NTP). Results showed that furan was carcinogenic and mutagenic in animal experiments. High doses of furan given to rats and mice caused the formation of liver tumours. It is also expected to be genotoxic, a particular danger sign, and a warning has been issued that it might be a possible human carcinogen. More research is underway to confirm the previous findings, but overall currently not good news on this front.

Furan levels in coffee

Roasted coffee beans have the highest furan levels (Photo: MarkSweep)

Roasted coffee beans have the highest furan levels (Photo: MarkSweep)

Although furan can be formed in different heated foods and beverages, coffee is the outstanding contributor to furan exposure in adults. A survey by the European Food Safety Authority found that roasted whole coffee beans have the highest levels of furan, followed by roasted ground coffee and instant coffee powder. The darker the roast, the higher the furan levels. So that’s the industry side and it is not much they can do while retaining the coffee aroma.

But as it happens it is also important how you prepare the coffee brew. When Spanish researchers compared the effect of different brewing methods they found the highest furan levels in coffee made from capsules followed by commercial bean-to-cup machines in which the coffee was prepared from start to finish in a largely enclosed environment. Less furan was found in coffee made in drip coffee machines and the least in instant coffee.

There is an easy explanation to the findings. The hermetically-sealed capsules prevent the highly volatile furan from being released, and the coffee machines used to brew this coffee use hot water at higher pressures, which leads to more of the compound being extracted into the brew. Similarly, the enclosed system in automated espresso machines transfers more furan to the final brew. This is great for the coffee taste but may be bad for health.

But there are some good news

Because of the volatility of furan, the longer the coffee brew is exposed to air in cups or jugs the more of the furan will evaporate. So maybe you should let the coffee cool down a bit before drinking it. You might also avoid to take a sniff of the newly brewed coffee though, as good as the smell might be.

And there is more. Confusingly, a recent review of epidemiological data found that three cups of coffee per day actually reduced liver cancer risk by more than 50%. It was speculated that this favourable effect might have been mediated by coffee’s proven prevention of diabetes, a known risk factor for the disease, or for its beneficial effects on cirrhosis and liver enzymes. A further epidemiological study showed that four or more cups of coffee a day was associated with a lower risk of prostate cancer recurrence and progression. Men who drank that much coffee daily had a 59% reduced risk for prostate cancer recurrence or progression, compared with those who drank one or fewer cups per week.

So what to believe? It is proven that coffee contains phytochemical compounds with beneficial effects on health. That include anti-inflammatory and antioxidant effects and modulation of glucose metabolism, but also some anti-cancer effects. Could that weigh up the potential negative effects of furan?

Maybe I should have the third cup of coffee anyway.

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