Climate change and food safety


global-warming1What has global climate change to do with food safety you ask? Well quite a lot is the unfortunate answer. In a previous blog we have already described the increased risk of finding toxic levels of arsenic in rice due to global warming. Not convinced yet? Maybe the following quotes from a range of official global organisations can provide some compelling information for you to change your mind.

Opinions expressed by some official agencies

The world Health Organization (WHO) writes:

Climate change is likely to have considerable impacts on food safety, both direct and indirect, placing public health at risk. With changing rainfall patterns and increases in extreme weather events and the annual average temperature we will begin to face the impacts of climate change. These impacts will affect the persistence and occurrence of bacteria, viruses, parasites, harmful algae, fungi and their vectors, and the patterns of their corresponding foodborne diseases and risk of toxic contamination. Alongside these impacts, chemical residues of pesticides and veterinary medicines in plant and animal products will be affected by changes in pest pressure. The risk of food contamination with heavy metals and persistent organic pollutants following changes in crop varieties cultivated, cultivation methods, soils, redistribution of sediments and long-range atmospheric transport, is increased because of climate changes.

The European Food Safety Authority (EFSA) writes:

Climate change poses significant challenges to global food safety. Long-term changes in temperature, humidity, rainfall patterns and the frequency of extreme weather events are already affecting farming practices, crop production and the nutritional quality of food crops. The sensitivity of germs, potentially toxin-producing microorganisms and other pests to climate factors suggests that climate change has the potential of affecting the occurrence and intensity of some foodborne diseases. Also, changing conditions may favour the establishment of invasive alien species harmful to plant and animal health. Surface seawater warming and increased nutrients input leads to the profusion of toxin-producing algae causing outbreaks of seafood contamination.

The transmission of infections or diseases between animals and humans (“zoonotic diseases”) is a major source of food safety risks. Environmental factors such as temperature, rainfall, humidity levels and soil can help to explain the distribution and survival of bacteria.

The European Food Information Council (EUFIC) writes:

There is a growing consensus that human activities may be changing our planet’s climate. These changes in climate have a number of possible implications for human health and welfare, one of which could be the safety of food.

It is impossible to accurately assess the full impact of climate change on food safety. However, it is likely that some effect on microbiological and chemical hazards will be seen. The extent of the risk posed by these hazards will depend on the type of hazard and the local conditions and practices.

The Food and Agriculture Organization (FAO) writes:

Climate change does not only imply increased average global temperature. Other effects of climate change include trends towards stronger storm systems, increased frequency of heavy precipitation events and extended dry periods. The contraction of the Greenland ice sheet will lead to rising sea-levels.

These changes have implications for food production, food security and food safety. It is widely understood that the risks of global climate change occurring as a consequence of human behaviour are inequitably distributed, since most of the actions causing climate change originate from the developed world, but the less developed world is likely to bear the brunt of the public health burden.

There is reason to believe that climate change can affect infection of crops with toxigenic fungi, the growth of these fungi and the production of mycotoxins. Given the great importance of this hazard, it is necessary that we understand what changes we might expect in order to better prepare ourselves to deal with this critically important issue.

Changes in climate may be creating a marine environment particularly suited to the growth of toxic-forming species of algae. Toxin-producing algal species are particularly dangerous to humans. A number of human illnesses are caused by ingesting seafood (primarily shellfish) contaminated with natural toxins produced algae; these include amnesic shellfish poisoning (ASP), diarrheic shellfish poisoning (DSP), neurotoxic shellfish poisoning (NSP), azaspiracid shellfish poisoning (AZP), paralytic shellfish poisoning (PSP), and ciguatera fish poisoning. These toxins may cause respiratory and digestive problems, memory loss, seizures, lesions and skin irritation, or even fatalities in fish, birds, and mammals (including humans).

Like EFSA, FAO also comments on zoonotic diseases such a hot topic with COVID-19 a prescient example:

Climate change is one of several ‘global change’ factors driving the emergence and spread of diseases in livestock and the transfer of pathogens from animals to humans.

The United States Environmental Protection Agency (EPA) writes:

Climate change will have a variety of impacts that may increase the risk of exposure to chemical contaminants in food. For example, higher sea surface temperatures will lead to higher mercury concentrations in seafood, and increases in extreme weather events will introduce contaminants into the food chain through stormwater runoff.

The United States Department of Agriculture (USDA) writes:

The assessment finds that climate change is likely to diminish continued progress on global food security through production disruptions leading to local availability limitations and price increases, interrupted transport conduits, and diminished food safety, among other causes. The risks are greatest for the global poor and in tropical regions. In the near term, some high-latitude production export regions may benefit from changes in climate.

A bleak future

As you can see a fairly bleak uniform view from many official agencies. Global efforts to reduce greenhouse emissions and regional measures to adapt to changing climatic conditions will be important to mitigate the impact on food and feed safety in relation to human health and nutrition, animal and plant health, and the environment.

The previous blog on arsenic was used as an example of a an increasing human health problem of a contaminant due to climate change. In some future blogs we will cover the the increased prevalence of algal and fungal toxins due to global warming.

Lead – up to no good


Lead in petrol an earlier culprit in lead poisoning.

Lead has been used for thousands of years because it is widespread, easy to extract, and easy to work with. It is highly malleable and easily meltable. Equally, lead poisoning has been documented since ancient Rome, ancient Greece and ancient China. It is thus clear that, ingested or inhaled, lead is poisonous to animals and humans. Still we were foolish enough to add it to petrol starting in the 1920s and use lead pigments particularly in white but also in yellow, orange, and red paint to spread its occurrence even further.

We have lived with the consequences ever since. Lead poisoning typically results from ingestion of food or water contaminated with lead, but may also occur after accidental ingestion of contaminated soil, dust, or lead-based paint. It is a neurotoxin that accumulates both in soft tissues and the bones, damaging the nervous system and causing brain disorders. Lead has been shown many times to permanently reduce the cognitive capacity of children at extremely low levels of exposure. Lead exposure in early childhood has also been linked to violent crime.

But there is more

As if that was not enough, new research has shown that early life exposure can alter the composition of the gut microbiota (remember one of my favourite topics), increasing the chances for obesity in adulthood. So far at least in mice. Lead was added to the drinking water of female mice prior to breeding through nursing their young. The lead levels used  were designed to be within past and present human population exposure levels. Thus the lowest dose used of 5 µg/dL is the same as the current US blood lead action level, while the higher dose mirrored exposure levels during the 1960s and 1970s to be able to evaluate both current and historically relevant lead levels.

Once weaned, the offspring were raised to adulthood without additional exposure, and then tested for lead effects acquired from their mothers. The guts of both males and females exposed to lead had all of the similar complexity in microbiota as those not exposed. The differences were in the balance of the different groups of microorganisms. Due to differences in their gut microbiota, adult male mice exposed to lead during gestation and lactation were 11 percent heavier than those not exposed. But not females, although the researchers speculate that females might have shown effects on obesity if they had followed them longer.

Although improving, it is not over yet


Lead exposure linked to obesity in mice.

So now we have obesity added to the long list of potential harm caused by lead contamination. Fortunately, by the mid-1980s, a significant shift in lead end-use patterns had taken place with lead use phased out from petrol in many countries and banned from paint, but still remaining in some grades of aviation fuel, and in some developing countries.

Although the situation has improved, it is not over yet. Lead may be introduced to foods from the use of lead containing pottery or lead crystalware. Another source is water from lead containing pipes. And wild game that has been shot with lead pellets. Not to forget some odd Chinese herbs found to contain high lead levels.

So vigilance is still needed.

Can honey make you sick?


The safety of honey questioned (Photo: Hillary Stein)

Is the world mad when Irish scientists focus their attention on Australian honey and find high levels of pyrrolizidine alkaloids? And the results are sensationalised by the Australian press a year later, talk about a slow response! Headlines in January 2016 proclaimed that “Australian honey could make us sick” and the article stated that “Australian honeys are the most contaminated in the world with natural poisons linked to chronic disease including cancer”. If that didn’t frighten you, what would?

And truely, pyrrolizidine alkaloids are natural toxins linked to chronic disease including cancer. Typically the compounds affect the liver and in some cases the lungs causing serious illness. Animal experiments have also shown that certain pyrrolizidine alkaloids are genotoxic carcinogens, the worst of the worst of toxins.

So what are they?

Pyrrolizidine alkaloids are produced as a protection against herbivores by about 6,000 plant species, representing 3% of all flowering plants, most of which are weeds. There is a great variety of compounds with more than 500 different pyrrolizidine alkaloids known to date. Besides in honey, pyrrolizidine alkaloids in food have been detected in products of plant origin, for example, in herbal teas and supplements, cereals, and salads. Cases of elevated contamination in wheat are known to have occurred in Afghanistan associated with illness and similarly contaminated salad in Germany.

To be fair to the Irish, the study was all about developing better analytical methods for detecting multiple pyrrolizidine alkaloids and the scientists probably selected Australian honey to be certain of having positive samples. They could as well have selected South American samples also known for containing high levels of pyrrolizidine alkaloids.

Nevertheless, their results showed that 41 of the 59 honey samples were contaminated by pyrrolizidine alkaloids with a mean total sum of 153 µg/kg. This is on average four times more pyrrolizidine alkaloids than in European honeys and is quite high as an average level. Echimidine and lycopsamine were most common and found in 76% and 88%, respectively, of the positive samples. The scientists also attempted to calculate possible average daily exposure based on the results and found that adults could have an exposure of 0.051 µg/kg bodyweight per day and children 0.204 µg/kg bodyweight per day of pyrrolizidine alkaloids.

What does it mean?

It is debatable if all pyrrolizidine alkaloids should be treated equally when considering their toxicity due to their expected cumulative effects or if some of the compounds could be considered to be less toxic.


Scientists cannot agree on how to assess safety of honey.

Conveniently the Australian authority, Food Standards Australia New Zealand, considers that echimidine is less toxic and used a Tolerable Daily Intake approach in establishing a safe level of exposure of 1 µg/kg bodyweight per day. This was calculated by applying an uncertainty factor of 10 to what was considered to be a human no-observed-effect level of 10 µg/kg bodyweight per day for liver failure due to veno-occlusive disease. But carcinogenic effects were not considered. Using this approach the Irish exposure estimates are well within safe limits.

Not so says a number of national and international organisations like the World Health Organization International Programme on Chemical Safety, the Dutch Rijksinstituut voor Volksgezondheid en Milieu, the UK Committee on Toxicity of Chemicals in Food, Consumer Products and the Environment, the German Bundesinstitut für Risikobewertung, and the CONTAM Panel of the European Food Safety Authority. They have all concluded that 1,2-unsaturated pyrrolizidine alkaloids may act as genotoxic carcinogens in humans (that is they may cause cancer and damage DNA, the genetic material of cells).

The safety of genotoxic carcinogens should be evaluated using the Margin of Exposure approach and not the Tolerable Daily Intake approach. A benchmark dose lower confidence limit for a 10% excess cancer risk (BMDL10) of 70 μg/kg bodyweight per day for induction of liver haemangiosarcomas by lasiocarpine in male rats was calculated as the reference point for comparison with the estimated dietary exposure. As a Margin of Exposure of 10,000 or higher, based on a BMDL10 from an animal study, is considered to be of low concern from a public health point of view, exposure to 0.007 µg/kg bodyweight per day or less of pyrrolizidine alkaloids would not be a worry. But the Irish presented much higher exposure estimates.

What margin is safe?

The different interpretations of what is a safe exposure to pyrrolizidine alkaloids is confusing to scientists and the public alike. Honey consumption has a long and varied history as a remedy for several health afflictions. Although, due partly to low numbers and questionable quality of human studies, some of the suggested health benefits of honey have been difficult to prove scientifically. Nevertheless, the public perception is that honey is a wholesome and natural product beneficial to health and a tastier alternative to refined sugar. There is a small committed group of consumers that regularly consume relatively large amounts of honey. So the findings of pyrrolizidine alkaloid contamination is disturbing.


Paterson’s curse is a common source of pyrrolizidine alkaloids in honey.

However, there are som alleviating factors to reassure honey consumers. The presence in honey of lasiocarpine used to calculate the BMDL10 is rare and most other pyrrolizidine alkaloids are at least a magnitude less toxic. This could raise the level of exposure of no concern to 0.07 µg/kg bodyweight per day. Also retail honeys are often mixed from several sources to reduce the overall level of pyrrolizidine alkaloids in the consumer-ready product. And finally the Australian honey industry is claiming that they have reduced access of bees to Paterson’s curse, a main source of pyrrolizidine alkaloids in Australian honey. But the future will tell if that is right.

So some caution is justified for regular honey consumers. Vary your source of honey to limit exposure and hopefully you will be fine. For now.


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.

What’s that smell?

This is going to be a bit of a smelly blog, but don’t feel offended. Some of the smelly foods are natural, others are manmade. Some of the foods make you smell. But be aware that smell is a very individual experience. Something that would be revolting to one person could be a delicatessen to another. Each to their own senses. If you read to the end you will find a surprising fact about strong tasting foods.

The spiky durian

The terrible smell of durians (Photo: Wikimedi)

The terrible smell of durians (Photo: Wikimedi)

First out is the durian, a fruit native to Brunei, Indonesia and Malaysia, although now grown in several other countries with Thailand the major exporter. If you see something looking like a hedgehog (or echidna if you’re Australian), that is the durian. Its edible flesh has a strong and distinctive odour even with the skin intact. Some people regard the durian as pleasantly fragrant and the flesh is praised in Southeast Asia for its nutty, custardy taste.  However, others find the aroma overpowering and revolting and  describe it  as rotten onions, turpentine, raw sewage, or gym socks.  Because of the smell it is actually illegal to carry this exotic fruit on public transport in Singapore. Like many stinky foods, people often love it or hate it.  Connoisseurs say that durian is worth the stench and that bad breath can be overcome by using freshening mints or toothpaste after consumption.

The strong odour of the durian can be detected from far away by animals.  Squirrels, mouse deer, pigs, orang-utans, elephants, and even carnivorous tigers eat the fruit and as a result dispose the seeds in the surrounding environment to the benefit of the plant. Thiols or mercaptans are compounds which give faeces, rotting flesh and the spraying of skunks their awful smells. They were earlier believed to also be responsible for the smell of durians, however, new findings pinpoint a complex mix of up to 50 different chemicals.

In case you want to try a durian be aware that it inhibits the liver enzyme aldehyde dehydrogenase important in the detoxification of alcohol. This might account for stories that getting intoxicated while eating durians can lead to death.

Ancient garlic making its mark

Nothing surprising here. Garlic is widely used around the world for its pungent flavour as a seasoning or condiment. It has been used as both food and medicine in many cultures for thousands of years, dating at least as far back as when the Giza pyramids were built. Garlic is still grown in Egypt, but the Syrian variety is the kind most valued now. The garlic bulb is the most commonly used part of the plant. Garlic bulbs are normally divided into numerous fleshy sections called cloves. Garlic cloves are used for consumption (raw or cooked) or for medicinal purposes. The pungent, spicy flavour mellows and sweetens considerably with cooking.

Garlic is known for causing bad breath, as well as causing sweat to have a pungent ‘garlicky’ smell. This is caused by allyl methyl sulphide. It is a volatile liquid that travels with the blood to the lungs and further to the mouth, causing bad breath, and to the skin, where it is exuded through skin pores. Washing with soap is only a partial solution in that most of the smell stays. The bad breath might be neutralised by drinking milk at the same time as consuming garlic. Plain water, mushrooms and basil may also reduce the bad breath but are not as effective as milk.

Where is the smell coming from?

Smelly urine - it is the asparagus (Photo: Mundoo)

Smelly urine – it is the asparagus (Photo: Mundoo)

Asparagus has been used as a vegetable and medicine, owing to its delicate flavour and diuretic properties. The finest texture and the strongest and yet most delicate taste is in the tips. The effect of eating asparagus on the eater’s urine has long been observed and described as a filthy and disagreeable smell. There is debate about whether only some people produce the odour since not everyone can smell it. It was originally thought this was because some of the population digested asparagus differently from others, so some people excreted odorous urine after eating asparagus, and others did not.

However, it has now been proven through genetic testing that most people produce the odorous compounds after eating asparagus, but only about 22% of the population have the genes required to smell the ammonia and various sulfur-containing degradation products.

You can test yourself if you belong to the exclusive one fifth of the population. Just sniff away.

Inulin is found naturally mostly in root vegetables. It is a soluble fibre, one of three types of dietary fiber including soluble, insoluble, and resistant starch.Tiny amounts are found in onions and garlic, while much larger amounts are found in starchy roots such as chicory root and Jerusalem artichokes. Inulin is indigestible by the human enzymes ptyalin and amylase, which are adapted to digest starch. As a result, inulin passes through much of the digestive system intact. It is only in the colon that bacteria metabolise inulin, with the release of significant quantities of carbon dioxide, hydrogen, and methane. This will result in flatulence, exacerbated if you belong to about 30–40% of the population in Central Europe suffering from fructose malabsorption since inulin is a fructan.

To avoid embarrassment it might be wise to consume inulin-containing foods in moderation.

Disgusting varieties of fermented fish

Surströmming is a foul smelling fish (Photo: Stefan Leijon)

Surströmming is a foul smelling fish (Photo: Stefan Leijon)

There seems to be as many varieties of fermented fish as there are fishing nations in the world, and several of them have a disgusting stench.

Indigenous to northern Sweden, surströmming is herring that is fermented in barrels for a couple of months, then put into tin cans for up to another year. The fermentation is so strong that the can actually bulges from pressure, and it has been banned by some airlines who say that it is an explosive safety hazard. It is best enjoyed in the outdoors because of the strong odours released when the can is opened, often compared to rotten eggs, vinegar, and rancid butter.

Hákarl is fermented shark meat and is an Icelandic delicacy. It tastes like ammonia and causes humans to gag when they put it in their mouth. Sharks get rid of their urine by changing it into urea and passing it through the skin. When a shark dies, the urea in its body turns into ammonia and this is what give hákarl its unique taste. I am assured that it tastes better than it smells, as long as you can keep it down.

A similar Korean speciality is hongeo hoe, or hongeo sashimi, rotten raw skate fish that equal to the shark bathe in its urine to give the flesh a smell of ammonia. Hongeo fans rave about its unique flavour, but it is an acquired taste that is usually masked by mixing it with other foods or drink, like makkeolli – a kind of Korean rice wine. The smell in hongeo specialty restaurant can stick to your clothes and be with you for some time.

Finally the kusaya, a Japanese fish that is soaked in salted fish juice, then dried in the sun. It doesn’t sound like a problem until you’re told that the same brine is used again and again and again. The best kusaya is supposed to come from brine that has been in continuous use for many years. The brine is never refrigerated and could have been fermenting in a container for centuries. Translated, the name indicates what you experience close up, kusaya means ‘that stinks’.

Efforts to make cheese stink

Stinky cheese is not for everyone (Photo: Andrew Eick)

Stinky cheese is not for everyone (Photo: Andrew Eick)

There seems to be a bit of a competition in making the absolute stinkiest cheese. The Vieux-Boulogne was named the world’s stinkiest cheese by a team of researchers at Cranfield University in 2004 using an electronic nose and 19 human testers. Thus it should be an objective test. It out-stank a number of close competitors, including the Epoisses de Bourgogne, Napoleon’s favourite that is now banned from all French public transport, and the Limburger, the previous owner of the stinky crown. As a matter of fact, one of the bacteria that creates human body odour, Brevibacterium linens, is that same bacteria used to ferment the Limburger. As a result, when people say Limburger smells like dirty human feet they are scientifically correct. So disappointment in the German camp, at least they had tried hard.

The British seemed equally disappointed. They thought their Stinking Bishop, officially Britain’s smelliest cheese, should have got the dubious honour. It’s one of the oldest types of cheese in the world, dating back to the time of the Cictercian monks. It’s washed with pear juice, which makes the rind orange and really sticky. The smell is only in the rind, not in the actual cheese.

And the Italians voted for the Casu Marzu, or “rotten cheese,” a Sardinian sheep’s-milk cheese whose secret ingredient is thousands of writhing maggots hidden beneath the rind.

But despite the stink, some people still eat them all with enjoyment.

And other stinky foods

Stinky tofu or chòu dòufu is a form of fermented tofu that has a strong odour. It’s a popular dish at night markets in China, Taiwan and Southeast Asia. Fresh tofu is added to a brine made from fermented milk, meat, vegetables and sometimes seafood. The brine fermentation can take as long as several months. The brine can be so rotten that it will be infested with maggots – even people who like it often admit its smell resembles rotten trash or faeces. It’s usually served deep fried, often drizzled in sauce and topped with sour pickled vegetables.

Kombucha is a form of tea that gets its special punch from yeast, which is allowed to ferment in the warm beverage for a month. The result is a drink that has long, green strands of gunk floating in it, and that smells like compost. There are wild health claims associated with drinking kombucha but no scientific evidence that the drink can help liver function, immunity or anti-cancer activity. However,  what is clear is that this beverage can cause upset stomachs, infections and bad breath.

Nattō is a traditional Japanese food made from soybeans fermented with Bacillus subtilis. It has a very slimy consistency, looking quite off-putting, and a raw fermented smell, but is not as pungent as stinky tofu. Nattō may be an acquired taste because of its powerful smell, strong flavor, and slimy texture. However, this one might actually be good for you being a rich source of proteins and vitamin K2. The perceived flavour of nattō can differ greatly between people. Some find it strong and cheesy and they use it in small amounts to flavour rice or noodles. Others find the taste bland and unremarkable, requiring the addition of flavoring condiments such as mustard and soy sauce.

Century egg or pídàn is a Chinese dish made by preserving duck, chicken or quail eggs in a mixture of clay, ash, salt, quicklime, and rice hulls for several weeks to several months, depending on the method of processing. Through the process, the yolk becomes a dark green to grey colour, with a creamy consistency and an odour of sulphur and ammonia, while the white becomes a dark brown, translucent jelly with little flavour.

So what is all that leading to? Well, science has the answer.

The benefit of strong aromas

Bite size related to taste intensity (Photo: horizontal integration)

Bite size related to taste intensity (Photo: horizontal integration)

We take bigger bites of foods we are familiar with and smaller bites of those that require more chewing. Scientists have shown that small bites are a good thing since they actually make your stomach feel fuller faster, reducing the amount of food eaten and thus calorie intake.

Now it has been found that people take smaller bites of food when it’s accompanied by stronger aromas. Scientists designed an interesting eating contraption to separate smell from other factors that affect how big of a bite participants take. They found that when food was associated with strong aromas people took smaller bites.

It probably doesn’t matter if the the aroma is pleasant or unpleasant, it is the strength that counts. When a strong smell is presented to the nose, eating is paired back to reduce the amount of flavour experienced. Combining aroma control with portion control could fool the body into thinking it was full with a smaller amount of food, aiding weight loss.

Maybe the stinky cheese is not that bad after all.

Related articles

Beer drinking benefits – yes benefits!


Healthy beer in moderation (Photo: Tim Dobson)

We have all seen the massive beer belly that we commonly associate with drinking too much beer, as is implied in the name. And we might have first hand experience of loutish behaviour after excessive beer consumption. Both negative aspects of beer drinking. No joke, but there are actually benefits from drinking beer as well, of course only in moderation. If you thought red wine, which we covered in a previous blog, was the healthy alternative, think again. Beer is giving wine a run for its money. Beer in moderation can actually be a healthier beverage choice than soft drinks or sugary fruit cocktails.

Beer has been brewed for just about as long as humans have been cultivating crops and is actually made with some very healthy ingredients. Those ingredients are hops, brewer’s yeast, barley and malt. Several beer brands can trace their origin to monasteries. Trappist monks drank beer to sustain themselves during their Lenten fasts. They called their beer “liquid bread.” Benjamin Franklin probably said it best: “Beer is living proof that God loves us and wants us to be happy.” But you don’t have to be religious to enjoy the health benefits of beer.

Health benefits of beer consumption

Studies have suggested that, when consumed in moderation, beer has many health benefits. It has long been known that moderate alcohol consumption may lower a drinker’s risk of illnesses such as cardiovascular disease, Alzheimer’s disease or diabetes, and can even reduce weight gain. Alcohol can increase good cholesterol and lower the bad, as well as lowering blood pressure. But some research suggests that other specific components in beer may play a role in fending off disease, irrespective of the alcohol content.

Beer is a surprising source of many nutrients. It is packed with B vitamins like niacin, pantothenic acid, folate, riboflavin, and vitamins B6 and B12. The folate found in beer may help to reduce homocysteine in the blood and lower homocysteine levels mean a lower risk of cardiovascular disease.

A bottle of beer, usually between 330-375 mL depending on country and brand, can contain 92 mg of potassium, 14 mg of calcium and 48 mg of phosphorus, all minerals that are essential to a healthy diet. It is also rich in silicon, a nutrient that is said to help strengthen bones. A 2010 study by scientists at the University of California’s department of food science and technology suggests that drinking beer moderately may ward off osteoporosis due to the silicon, which is important for bone growth and development.

One of the most effective forms of soluble fibre for lowering cholesterol is betaglucan, which is the predominant form of fibre in beer. One bottle of beer contains around 1-3 gram of soluble fibre. This is equivalent to around 10% of the recommended daily fibre intake.  Beers with high malt content like craft beers may even provide up to 30% of the recommended daily fibre intake.

Hops provide healthy chemicals

Hops provide healthy antioxidants

Beer contains polyphenolic antioxidants, which help reverse cellular damage and thus help reduce cancer risks. Dark beers tend to have the most antioxidants. Studies suggest that xanthohumol, a plant compound found in hops, may be one of the more important compounds that help prevent cancer. As an antioxidant it is 200 times more potent than resveratrol found in red wine.

If you like to be exclusive, you might up your antioxidant intake even further by selecting microbrews because they are made with more hops than mass-produced beers.

Further proof of health benefits

In a meta-study published in 2011, researchers at Italy’s Fondazione di Ricerca e Cura when reviewing 16 previous studies involving more than 200,000 participants found that people who drank about 500 mL of beer a day had a 31% reduced risk of heart disease. Consuming more alcohol, either beer, wine, or liquor, reversed the benefit.

A 2011 Harvard study of 38,000 middle-aged men showed that consuming one or two glasses of beer a day reduced the risk of developing type 2 diabetes by 25 percent. There was, however, no noted benefit from drinking more than two beers a day.

A 2005 study involving 11,000 older women showed that those who had one beer a day had better mental function than those who didn’t. In fact, they decreased their risk of mental decline by as much as 20 percent.

An Emory University study published in 2001 involving over 2,200 elderly men and women discovered that those who consumed at least 1.5 drinks daily had up to a 50% lesser risk of suffering from heart failure.

The other side of beer consumption

If one beer is good for you, it doesn’t mean that three or four beers must be better. Most of the studies cited above point to one beer per day as being beneficial, not drinking all seven beers in one day per week. Drinking more than one beer or any alcoholic beverage per day can put too much alcohol in your system harming the liver. This is the organ that removes toxins from the body. In the liver, enzymes first convert alcohol into acetaldehyde. During this step, a molecule called NADH (nicotinamide adenine dinucleotide) is also produced. Acetaldehyde is further metabolised into acetic acid, and then water and carbon dioxide that we breathe out.

Unfortunately, in people who drink daily, the body might not be able to metabolise the toxic acetaldehyde fast enough. To make matters worse, heavy drinking can elevate the levels of NADH, which can lead to the accumulation of fat in the liver in a condition called fatty liver. A liver clogged with fat is not only less efficient in performing its duties, it can also reduce oxygen and nutrient access for the liver cells. Left untreated, this causes liver cells to die and form fibrous scar tissue leading to liver cirrhosis.

And that’s not all. The energy content of beer can lead to obesity in those who drink excessively. Being obese, in turn, carries a lot of health risks, including heart disease and diabetes.

So as usual the adage “everything in moderation” holds true.

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Big issue – hormone disrupting chemicals

Make no mistake, you will soon hear more about hormone disrupting chemicals, or endocrine disruptors as they are also called since hormones constitute the body’s endocrine system. So we thought that now is a good time to give you a brief introduction to this growing problem issue for public health and the environment.

World Health Organization changes its mind on endocrine disruptors (Photo: Wikimedia)

World Health Organization changes its mind on endocrine disruptors (Photo: Wikimedia)

If we first go back about ten years in time international organisations had a rather cavalier attitude to endocrine disrupting chemicals. Scientists had started to sound warning bells, but there was yet no critical mass of information. Thus, in 2002 a report published by the International Programme on Chemical Safety (IPCS), which is a joint programme of such esteemed authorities like the World Health Organization (WHO), the United Nations Environment Programme (UNEP) and the International Labour Organization, raised the problem. However, they basically dismissed it due to lack of evidence of causal links between observed changes and actual levels of the chemicals.

The tone is different in a new report published in 2012. In the intervening period, organisations like the Endocrine Society, the European Commission and the European Environment Agency have published scientific reviews drawing renewed attention to concerns to public and wildlife health. Further, the European Society for Paediatric Endocrinology and the Pediatric Endocrine Society have called for action on endocrine disruptors and their effects. In an update to the initial IPCS report, it is now claimed that increasing scientific evidence suggests that endocrine disrupting chemicals actually are a cause for global concern, and that more research is critically needed to understand these chemicals and their human health effects in more depth. It is also stated that their environmental health impacts could be of similar concern with negative effects on organisms like fish in polluted water and plants living near industrial sites. Effects on early development of both humans and wildlife are highlighted as special concerns, as these effects are often irreversible and may not become evident until later in life.

Endocrine disrupting chemicals mimic hormones in the human body and have the capacity to interfere with tissue and organ development and function. This effect may alter susceptibility to different types of diseases throughout life. It can cause pregnancy complications, cancers, thyroid disorders and metabolic problems in adults. In infants and young children the impact of such chemicals is more severe because their bodies and brains are developing so quickly that endocrine disturbances have a disproportionate impact. It is clear that a large number of non-communicable diseases have their origin during development with exposure to endocrine disrupting chemicals one of a number of important risk factors for disease. Included are some of the major human diseases that are increasing in incidence and prevalence around the world.

Around 800 chemicals are expected endocrine disruptors (Photo: tk-link)

Around 800 chemicals are suspected endocrine disruptors (Photo: tk-link)

This sounds like doom and gloom as we are exposed to perhaps hundreds of environmental chemicals at any one time. Potential endocrine disrupting chemicals can be found in a huge range of consumer products as well as pesticides, herbicides, industrial pollution and more. Close to 800 chemicals are known or suspected to be capable of interfering with hormone receptors, hormone synthesis or hormone conversion. However, only a small fraction of these chemicals have been investigated in tests capable of identifying overt endocrine effects in intact organisms. That makes addressing their presence in the environment difficult. The United Nations is suggesting tighter regulations on the use of such chemicals, reminiscent of bans on compounds like PCBs in the past. These bans were used to limit new emissions of compounds known to be harmful to human or environmental health, and could be used again to prevent exposure to hormone disruptors and protect the environment.

But they would take time and energy to implement. Even as some companies have chosen voluntarily to start refraining from use of chemicals like bisphenol A and phthalates, others have lagged behind, and eliminating them from the environment could be a lengthy process. The United Nations report points to the simultaneous need for more action to address immediate known issues, and more research to uncover issues that haven’t been identified yet, in the hopes of staying one step ahead.

This is a global threat that needs to be resolved. The European Food Safety Authority was given a mandate in 2012 to define scientific criteria to identify endocrine disruptions in humans and the ecosystem. It is providing its contribution to this area in a soon to be published opinion and a stakeholder meeting. The opinion will feed into the current review of the European Union’s strategy on endocrine disruptors as well as EFSA’s ongoing and future scientific work in assessing substances such as food contact materials, pesticides and contaminants in food and feed.

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Opium for free with food

Old opium den (Illustration: Wikimedia)

Old opium den (Illustration: Wikimedia)

I know opium is not the must popular drug these days. It has the connotation of a Chinese den from the 19th century. Opium dens in China were frequented by all levels of society, and their opulence or simplicity reflected the financial means of the patrons. But what about if you can get it for free as part of your food supply, no financial means needed? Interested now?

Opium is normally harvested from the milky sap of the opium poppy (Papaver somniferum L.) together with other narcotic agents like morphine and codeine. They are collectively called opium alkaloids and have been used by man for the treatment of severe pain for generations – and of course misuse. The milky sap can be found across the plant and particularly in the pericarp of the capsule, but normally not in the seeds. Although the seeds of the poppy plant do not contain the milky sap, they can become contaminated with alkaloids as a result of insect damage to the capsule, or through poor harvesting practices.

And herein lies the conundrum since poppy seeds are used as food in bakery products, on top of dishes, in fillings of cakes and in desserts and to produce edible oil.  Consumption of foods containing poppy seeds that are contaminated with opium alkaloids can lead to adverse health effects and to detectable contents of free alkaloids in blood as well as measurable concentrations in urine, sufficient to interfere with drug abuse testing.

To some extent harvesting of poppy seeds is in conflict with harvesting for opium. Poppy seeds of superior quality are harvested when they are ripe, after the seed pod has dried. Traditionally, opium is harvested while the seed pods are green and their milky sap is abundant, but the seeds have just begun to grow. Poppy varieties especially bred with high alkaloid content intended for pharmaceutical purposes are also used for production of poppy seeds for food use in some countries. However, low morphine varieties are available particularly for food use.

Poppy seed consumption varies broadly around the world. Poppy seeds are widely used in Austrian, Czech, German, Hungarian, Lithuanian, Polish, Romanian, Russian, Slovak, Turkish and Ukrainian cuisines. In some cultures, such as in Central and Eastern European countries, it is traditional to use poppy seeds in foods, and in specific instances sometimes in high amounts in bread, fine bakery ware, desserts and other dishes. In other countries poppy seeds are commonly used as a condiment or decoration only at very much lower levels.

Whole poppy seeds (Photo: Wikimedia)

Whole poppy seeds (Photo: Wikimedia)

Whole poppy seeds are used as a spice and decoration in and on top of many baked goods like bagels, muffins and cakes, for example, sponge cake. Buns and soft white bread pastries are often sprinkled on top with black and white poppy seeds. Fillings in pastries are sometimes made of finely ground poppy seeds mixed with butter or milk and sugar. The ground filling is used in poppy seed rolls and some croissants and may be flavoured with say lemon or orange zest.

The data on the pharmacology of morphine, codeine and the other opium alkaloids in poppy seeds indicate that morphine is the most pharmacologically active opiate compound, with codeine as the second. They cause a number of different effects, both in the central nervous system and in the peripheral nervous system like sedation and respiratory depression.

The European Food Safety Authority (EFSA) issued an opinion on public health risks related to the presence of opium alkaloids in poppy seeds in 2011. It concluded that for poppy seeds consumed as condiments or decoration in bread and fine bakery ware acute symptoms would be rare but might possibly affect toddlers. On the contrary, a considerable proportion of consumers of foods that contain large amounts of poppy seeds, such as are common in Central and Eastern European countries, would be likely to show some acute symptoms at least on some eating occasions. The highest theoretical exposure estimates in the opinion were actually 75-fold greater than the threshold for acute symptoms.

So would this provide a free kick?

Poppy seed bakery ware (Photo: Wikimedia)

Poppy seed bakery ware (Photo: Wikimedia)

Well, this depends on the food preparation methods. The opium alkaloid content of poppy seeds and poppy seed containing foods can be reduced by several methods of pre-treatment and processing. Food processing may decrease the alkaloid content by up to about 90 %. The most effective methods include washing, soaking and heat treatments, as well as grinding and combinations of these treatments.

Still, acute effects might be seen after a single large portion of some traditional food dishes containing raw, unwashed and unground poppy seeds in high amounts according to the EFSA opinion.

So be warned.

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Aspartame (almost) cleared

The aspartame molecule

The aspartame molecule (Illustration: Wikimedia)

The artificial sweetener aspartame has been associated with some controversy from its initial approval for use in dry food in 1974 by the Food and Drug Administration in the USA. Aspartame has since been deemed safe for human consumption by over 100 regulatory agencies in their respective countries. Although there were some clear irregularities in the initial submission by G.D. Searle, this was not considered detrimental to its approval.

Because of the initial controversy, the safety of aspartame has been studied extensively since its discovery with research that includes animal studies, clinical and epidemiological research, and post-market surveillance. Aspartame is now one of the most rigorously tested food ingredients to date. Comprehensive peer-review studies, as well as independent scrutiny by governmental regulatory bodies, have analysed the published research and deemed aspartame safe for consumption at current levels. This has not silenced the critics.

The ultimate review?

In May, 2011, the European Food Safety Authority (EFSA) was asked by the European Commission to bring forward a full re-evaluation of the safety of aspartame, previously planned for completion by 2020. On January 8, 2013, EFSA released a draft opinion for comment. As part of the evaluation process, EFSA commissioned an external review of the available literature on aspartame. This review was published on 1 March, 2013 and provides an overview of current knowledge regarding the metabolism and toxicity of aspartame. From a database containing 5,023 references the review team identified 1,366 documents of direct or indirect relevance to the risk assessment of aspartame. After scrutiny of those documents, 358 were carried forward for detailed examination.

Review and consultations on aspartame (Photo: ALDEADLE)

Aspartame under review (Photo: ALDEADLE)

The review team noted that aspartame after ingestion is immediately split into three constituents already in the gastrointestinal system and these are consequently absorbed individually. Two of the three components (aspartate and methanol) are cleared rapidly from the body and the only component remaining in the circulation system is phenylalanine. Aspartame itself is normally not absorbed.

The effective potential toxicity of aspartame is therefore only related to the phenylalanine component.

The team reported that:

  • No significant acute or subchronic toxicity had been observed in animal models or in humans even at the highest doses of aspartame which could reasonably be administered, and early concerns that aspartame might cause neurotoxicity in neonates and infants could not be substantiated.
  • There was no evidence to indicate that aspartame is genotoxic. Reported marginally positive results occurred only sporadically and did not indicate any particular cause for concern.
  • Available chronic toxicity studies did not indicate any overt carcinogenic effect in experimental animals due to aspartame, but all the conventional studies were limited in various ways.
  • One epidemiological study addressing possible reproductive effects in humans found an increased risk of preterm delivery in women who frequently consumed either carbonated or (to a lesser extent) non-carbonated diet drinks but did not address aspartame directly and was subject to a number of confounding factors.

The review concluded that there was no consistent evidence that aspartame has adverse effects, either in healthy individuals or in potentially susceptible groups, under normal conditions of use although phenylketonurics do need to regulate their intake of aspartame for health reasons. They are supported in doing this by clear labelling of aspartame-containing products. The review team left some question marks in relation to chronic and reproductive toxicity and supported further research to conclusively exclude any such effects.

Current state of the art

EFSA’s draft opinion now states that aspartame and its metabolites “pose no toxicity concern for consumers at current levels of exposure. The current Acceptable Daily Intake (ADI) is considered to be safe for the general population and consumer exposure to aspartame is below this ADI”. The final opinion is expected to be delivered in May 2013.

If this will be the end of the controversy over the use of aspartame as a food additive is still doubtful. The remaining uncertainty over chronic and reproductive toxicity, although slight, might need to be conclusively resolved to silence all critics. Further unnecessary controversy has been ignited by the dairy industry request to sweeten flavoured milk for children with aspartame without declaring it on the label.

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The hard working bee

Bee collecting pollen and nectar (Photo: Wikimedia

Bee collecting pollen and nectar (Photo: Wikimedia

Bees are hard at work collecting pollen and nectar to feed themselves and their off-spring. When foraging for food they use the sun for direction, initially using a somewhat irregular path away from the hive to find a suitable source up to 10 km away. The bee will then fly a straight line back to the hive and perform a dancing act to indicate the shortest way to the source for other bees. Many bees will then fly a straight path to the source the original bee found and will repeat the process themselves.

The foraging bees regurgitate nectar and pass it to worker bees in the hive. In order to conserve space and preserve their food, bees transform the nectar into honey by evaporating most of the water from it. Nectar is as much as 70 percent water, while honey is only about 20 percent water. Bees get rid of the extra water by swallowing and regurgitating the nectar over and over. They also fan their wings over the filled cells of the honeycomb. This process retains lots of sugar and the plant’s aromatic oils while adding enzymes from the bees’ mouths.

Honey as human food

Honey is ancient food (Photo: Hillary Stein)

Honey – an ancient food (Photo: Hillary Stein)

Humans have been harvesting honey for more than 6,000 years for our own use. Historically, people have used it to sweeten food and make fermented beverages like mead. Today it is also used in industrial food processing of baked products, confectionary, candy, marmalades, jams, spreads, breakfast cereals, beverages, milk products and many preserved products.

Honey’s high sugar content, flavour and antimicrobial properties make it a useful ingredient. It is also considered to carry health properties.

So far so good making this a good news story. But of course there has to be a negative side to the story as well otherwise it wouldn’t be covered on this food safety blog. And now we come to my own challenge spelling the name of the chemical substance group that can be present in honey and pose a threat to public health. With the dictionary in one hand and typing with the other I want you to be aware of pyrrolizidine alkaloids.

Pyrrolizidine alkaloids are a group of naturally occurring substances that are produced by plants as a defense mechanism against predator attacks.

Pyrrolizidine alkaloids in honey

There are more than 600 different pyrrolizidine alkaloids identified in over 6,000 plants. About half of them are toxic to humans and other animals, mainly damaging the liver or in some cases even causing liver cancer. In an opinion published in 2011, the European Food Safety Authority nominated some pyrrolizidine alkaloids as genotoxic carcinogens. It has been estimated that three percent of the world’s flowering plants contain pyrrolizidine alkaloids, mostly members of the daisy, forget-me-not or borage families as well as the legume family. And unfortunately the pyrrolizidine alkaloids can find their way into honey.

Ragwort a source of pyrrolizidine alkaloids (Photo: Wikimedia)

Ragwort a source of pyrrolizidine alkaloids (Photo: Wikimedia)

Plants that commonly contribute to pyrrolizidine alkaloid contamination of honey include Echium, Senecio and Borago species whose pollen might be used for honey production by the bees. In Australia, the toxins may get into the honey when bees forage on the flowers of Paterson’s Curse, also known as Salvation Jane. Raw honeys from certain countries in Central and South America, Cuba and Uruguay in particular, and Australia and New Zealand show higher levels of pyrrolizidine alkaloids compared to raw honeys from some European and Asian countries.

For most people who eat small amounts of honey, the levels of pyrrolizidine alkaloids would be well below the tolerable daily intake and not a cause for concern. However, chronic effects cannot be excluded and are often difficult to associate with a particular food source. It is thus recommended that anyone who daily eats more than two tablespoons of honey should be careful in not selecting an exclusive product source.

Most honeys are mixed before retail to reduce the levels of pyrrolizidine alkaloids and this reduces potential risks.

Other sources of pyrrolizidine alkaloids

In addition to honey, there are other potentially more important sources of dietary exposure to pyrrolizidine alkaloids. The majority of reports of acute outbreaks of pyrrolizidine alkaloid poisoning have largely been limited to third world countries. Generally, these have been outbreaks where hundreds, and sometimes thousands, have been poisoned from eating staple foods made from cereal crops contaminated with seeds from pyrrolizidine alkaloid-containing weeds. For example, people were taken ill in Pakistan, India and Afghanistan after eating wheat contaminated with seeds from Heliotropium or Crotalaria species. In Jamaica, cases of poisoning have occurred through so-called bush teas containing Crotalaria and parts of the ragwort plant.

More recently, along with an increasing reliance on unconventional medicine and the use of herbal supplements, notably borage leaf, comfrey and coltsfoot, there has been a rise in the number of poisonings seen in industrialised countries. Also Borage oil and Echium oil marketed as dietary supplements, and salad crops contaminated with ragwort or common groundsel could present a risk to the consumer.

Take care

It is believed that the real extent of human poisoning by pyrrolizidine alkaloids has been underreported since the cause of chronic diseases are difficult to establish. So watch your honey consumption and stay away from suspect dietary supplements.

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