Taking stock of a year of blog posts

We have now been blogging for more than a year and published 70 blogs on a range of food safety topics. I have started to lose track of all the blogs and thought it was about time for both you and me to list them all to jog our memories. Thus you can now find a list of blogs in the top most menu.

Blogging efforts (Illustration: Francesco Pozzi)

Blogging efforts (Illustration: Francesco Pozzi)

So far we have been sparse with coverage of bad bugs with only 4 published blogs. This is of course an important food safety topic but covered extensively by many others.

Bad bugs not extensively covered (Photo: Wikimedia)

Bad bugs not extensively covered (Photo: Wikimedia)

Dangerous foods and not so dangerous foods have been more fun to write about. This has resulted in 21 blogs published so far and this seems to be the most popular topic on this website. Rucola and coffee-leaf tea have been the most visited topics. Kale received the most comments both on the blog and in private emails.

Rucola received a lot of interest

Rucola received a lot of interest

Debated additives have also received limited coverage with only 5 published blogs. Additives are often high up on the public risk list but are in most cases strictly regulated. Aspartame has been covered in several blogs but has now received a conclusive opinion by EFSA. If that will prove sufficient is still to be seen.

Aspartame and additive debated a lot

Aspartame and additive debated a lot

Nasty chemicals is an area close to my heart and this has resulted in 24 blogs published so far. Sometimes these blogs can cover quite complex issues difficult to digest. Most official opinions are difficult to read so I have attempted to simplify the issues without compromising on the science. Not an easy task but you be the judge if I have been successful.

Infant development

Juvenile brain development can be hampered by lead contamination

There has been a lot of activity in relation to health claims assessment in Europe with new legislation enforced. Here we have covered what we have called spurious health claims in 16 blogs. Some have been valid claims, some still not proven, but many just old tradition.

Healthy kale (Photo: Mike)

Healthy kale (Photo: Mike)

I would be happy to take requests for new blog topics, just add a comment in the bottom of this blog.

With this summary it is time to celebrate the festive season and take a break from blogging. We will come back in the new year with renewed vigour.

Many thanks for your interest and please come back many times.

Aspartame deemed safe after a mammoth effort

Aspartame - EFSA's most comprehensive risk assessment ever

Aspartame – EFSA’s most comprehensive risk assessment ever

After its most extensive effort ever the European Food Safety Authority (EFSA) deemed aspartame to be safe at current use levels in an opinion just published in December 2013. This is a mammoth effort not only reviewing most of the available literature on aspartame and its breakdown products, but also consulting widely with the public before finalising the opinion. It will be seen as a breakthrough effort in improving consumer confidence in the scientific process of evaluating controversial food additives. But of course not everyone will be pleased, that is the nature of the beast.

The question could be raised why EFSA didn’t do as thorough a job in its previous evaluations of aspartame, but why be critical now when it is done. The work raises the bar for future opinions and I am thinking in particular of the Bisphenol A opinion in the immediate pipeline. That issue will be even more difficult to resolve with the low-dose hypothesis causing considerable angst among scientists. Another question is if EFSA can spend so much time on only one opinion without hampering overall progress on the many issues on EFSA’s plate. But that is an issue for their political masters.

So what did EFSA find

We all know that aspartame (E 951) is a sweetener authorised for use as a food additive in many countries. It is used extensively in diet soft drinks in particular. Chemically it is a dipeptide, that is the molecule is formed by the two amino acids, aspartic acid and the methyl ester of phenylalanine, binding together. In the gastro-intestinal system it is rapidly hydrolysed and fully degraded into its primary constituents of aspartic acid, phenylalanine and methanol with little or no aspartame available to be absorbed by the body. The amount of intact aspartame that enters the bloodstream has actually been reported as undetectable. Thus  potential toxic effects must be caused by any or all of these three major metabolites.

EFSA stated that it was clear from their literature review that the acute toxicity of aspartame as tested in mice, rats, rabbits and dogs was very low. Similarly, sub-acute and sub-chronic studies did not indicate any significant toxic effects in rats, mice or dogs. Neither did available data indicate a genotoxic concern for aspartame. Results from three chronic toxicity and carcinogenicity studies in rats and one in mice revealed no aspartame-related increase in any type of neoplasms at the doses tested.

There was a caveat though with debate raging about tumour findings reported by the European Ramazzini Foundation. However, EFSA and other authorities are of the view that many of the malignant neoplasms and the lymphoid dysplasias diagnosed in the studies were hyperplasias related to unknown chronic infection in the animals and not related to aspartame intake. Also hepatic and pulmonary tumour incidences reported fell within the institute’s own historical control ranges for spontaneous tumours.

There was also a problem with birth weight data from several reproductive and developmental toxicity studies performed in rabbits. However, EFSA stated that the findings were confounded both by a decrease in feed intake in the treated group and poor health of the animals.

What about human studies?

Artificially sweetened soft drinks a common source of aspartame

Artificially sweetened soft drinks a common source of aspartame

Looking at human studies, EFSA noted that there was no epidemiological evidence for possible associations of aspartame with various cancers in the human population.

A large prospective cohort study in Denmark found no consistent association between the consumption of artificially sweetened beverages in general (of which some might have been using aspartame) during pregnancy and the diagnosis of asthma or allergic rhinitis in children. Though they did find a small but significantly elevated risk of medically induced pre-term delivery in women with higher reported consumption of artificially sweetened drinks. This was countered by findings in another prospective study in Norway showing a barely discernible association between pre-term delivery and artificially sweetened soft drinks but a stronger association with consumption of sugar-sweetened soft drinks.

And the metabolites specifically

Methanol was cleared from any effects after aspartame consumption since it only contributes to a very small part of methanol exposure. Fruit and vegetables play a more important part in methanol exposure and it is also naturally produced by the body. It is only toxic at fairly high levels, such as from consumption of some home-distilled alcoholic spirits.

Neither did aspartic acid raise any human safety concerns. The body can convert aspartic acid into the neurotransmitter glutamate which, at levels very much high than can be derived from aspartame consumption, can have harmful effects on the nervous system.

Phenylalanine is the remaining potential culprit. It is known to be toxic at high intake levels, in particular to the developing foetus in women suffering from the medical condition phenylketonuria (PKU). EFSA considered that it was plausible that phenylalanine could be responsible for some or all of the adverse effects reported for aspartame in rat and rabbit developmental toxicity studies. However, phenylalanine blood levels reached after realistic dietary intake of aspartame were well below conservative estimates of the levels necessary to cause harm.

So all clear for everyone except PKU patients where total control of dietary phenylalanine intake is necessary to manage the risk from elevated phenylalanine blood levels. Fortunately, it is a requirement in many countries that products containing aspartame should indicate through labelling that they contain a source of phenylalanine to protect the small minority unable to metabolise the compound.

And the conclusion?

All-in-all EFSA considered aspartame safe at normal use levels and retained an Acceptable Daily Intake of 40 mg/kg bodyweight. Some dubious results remain but scientific studies are seldom perfect. It seems clear that all doubtful results can be explained without casting a shadow over aspartame. At least according to the EFSA evaluation.

Related articles

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.

Related articles