Acute care for strokes developed at the University of Helsinki and the Hospital District of Helsinki and Uusimaa has improved patients’ chances of full recovery or at least functional independence.

Every year, just under 15,000 Finns suffer a stroke, or the occlusion of a cerebral blood vessel, of whom less than 20% die within a year. Up to the 1990s, no effective treatment was available for acute strokes. Survival often meant severe disability.

Markku Kaste, professor of neurology at the University of Helsinki, and his research group initiated research in the 1990s focused on developing thrombolytic therapy for strokes at Helsinki University Hospital. The efficacy of the therapy is based on the fastest possible dissolution of a cerebral blood vessel blockage in order to limit the injury caused by the lack of oxygen in the brain.

Kaste planned international multicentre studies to investigate the safety and efficacy of thrombolytic therapy. Although the initial results were not encouraging, Kaste and his colleagues, Professors Perttu Lindsberg and Turgut Tatlisumak, saw the potential in the novel form of treatment, carrying on with its deployment before gaining official approval.

Research findings: Thrombolytic therapy prevents disabilities caused by a stroke.

International studies indicated that thrombolytic therapy completed in time and in the correct way improved patients’ chances of full recovery or at least functional independence.

Under the direction of Professor Lindsberg, a model known as the Helsinki Stroke Model was established as a clinical pathway for stroke patients, to this day recognised as the fastest pathway in the world. It takes approximately 18 minutes from the arrival of the patient at the hospital to the initiation of thrombolytic treatment.  

Indeed, key to its success is diagnosing the condition and initiating the treatment as quickly as possible. Previously, stroke patients were not among the patients most in need of urgent care, as they could not be helped during the acute phase. With determination, researchers started transforming old practices, and even the layout of the emergency department in Meilahti was redesigned to facilitate treatment.

Training was needed for both clinical specialists as well as emergency services call handlers and emergency care staff. Another result of collaboration was a campaign targeted at the public to disseminate information on stroke symptoms and the need to immediately call the emergency number at the onset of characteristic symptoms. Still ongoing is research cooperation focused on further reducing the delay preceding hospital care with a group headed by Docent Markku Kuisma, who is in charge of prehospital emergency care.

A study published in 2018 also confirmed that speed has not replaced quality: the diagnostics of stroke patients and their access to thrombolytic treatment are top level at Meilahti.

Research impact: Finland has the quickest path to effective treatment for stroke patients.

The model employed at Meilahti was quickly introduced in other Finnish university hospitals and central hospitals, for which a nationwide teleconsultation service has been provided for years: the HUS Telestroke service.  

Stroke-related research continues to receive a strong emphasis on the medical campus of the University of Helsinki, providing a good channel for introducing new kinds of treatment methods. Indeed, a new kind of method known as thrombectomy, or the mechanical extraction of a blood clot inside the blood vessel, has been widely deployed. This method can be used when the clot is in a large brain vessel, which often makes even immediate thrombolytic treatment ineffective.

Finnish stroke patients have an excellent chance of reaching the best possible care in time and completely recovering from this serious condition. The Helsinki University Hospital is also an internationally recognised pioneer and benchmark in the emergency care of strokes.   

Further information on the research:

Further information on stroke therapies in the Hospital District of Helsinki and Uusimaa

Professor Perttu Lindsberg's research group Stroke and Cerebrovascular Disease

Current Care Guidelines for strokes (for patients, in Finnish only)

A study carried out at the University of Helsinki revealed that both Finnish and imported honey occasionally contains Clostridium botulinum bacteria, which are hazardous to infants and have been linked with sudden infant death syndrome. The outcome of the finding was the addition of a warning to honey jar labels.

Botulism is a serious disease caused by botulinum toxin, a neurotoxin secreted by Clostridium botulinum bacteria. Left untreated, it may result in death.

Infant botulism is one of the manifestations of botulism, occurring in children under one year of age. Spores of Clostridium botulinum found in the environment are considered harmless to healthy adults, but in the intestinal tract of infants the spores may germinate into an active bacterial flora that produces botulin. Infant botulism has also been established as a cause in certain cases of sudden infant death syndrome, with honey being the only food associated with infant botulism cases.

In her doctoral dissertation completed in 2006, Mari Nevas, a researcher of food hygiene at the Faculty of Veterinary Medicine, University of Helsinki, investigated whether spores of Clostridium botulinum bacteria can be found in Finnish honey. The study was instigated by cases of infant botulism that occurred in Norway and Denmark involving honey being fed to babies.

For her dissertation, Nevas collected almost 2,000 samples from dozens of Finnish bee farms under a follow-up study, in addition to which she collected honey samples from the Nordic countries, analysing the number of Clostridium botulinum spores they contained. The study was funded by the Ministry of Agriculture and Forestry.

Research findings: Honey contains spores of Clostridium botulinum bacteria, but their numbers can be influenced.

Honey produced in Finland was found to contain spores of Clostridium botulinum. The numbers were low, but due to the uneven distribution of the spores found in the honey, the risk of infant botulism caused by honey cannot be ignored. However, spore numbers can be influenced through the honey production process.

Clostridium botulinum bacteria are common, for example, in soil, at the bottom of waterways and in the intestinal tract of fish. Dust containing spores is carried by honey producers and their equipment to honey spinning facilities, potentially ending up in the honey. Indeed, it was production hygiene that turned out to be a significant factor in the contamination of spun honey.

Facilities where hands can be washed and dedicated indoor footwear are used significantly decrease the probability of spore occurrence in spun honey. According to another observation, sufficient lighting in production facilities enhances their cleanliness and reduces the amount of dust and, thus, the number of spores.

The study demonstrated that the number of Clostridium botulinum spores in honey can be reduced. As spores are common in the environment, entirely spore-free honey cannot evidently be produced.

Research impact: Warning label added to honey jars

The authority responsible for monitoring food safety in Finland, at the time the Finnish Food Safety Authority Evira, published the first research findings in 2000. In 2001, it made a decision on the mandatory labelling for honey jars, according to which honey is not recommended for children under one year of age.

At first, honey producers demanded the labelling be voluntary, only later collectively getting behind the decision. They saw the warning as a guarantee of the safety of Finnish honey: it is an act of responsibility to include a warning on the jars, even if the risk of infant botulism is supposedly low. After all, the seriousness of the disease makes the risk significant. In Finnish culture, feeding honey to babies has not traditionally been widespread, but in certain cultures babies are soothed, for example, by dipping their pacifiers in honey.

Today, the Clostridium botulinum research group of the Faculty of Veterinary Medicine is an extensive and international group funded by, among others, the European Research Council and the Academy of Finland. The group is headed by Professor Miia Lindström. The group is focused on food safety risks caused by Clostridium botulinum and is investigating the mechanisms and epigenetics of botulin production.

Further information on the research:

Clostridium botulinum in honey production with respect to infant botulism

Mari Nevas’s research, projects and other activities

Finnish Beekeepers’ Association

Foetal development is affected by the diet of the mother. A study carried out at the University of Helsinki shed new light on glycyrrhizin, a substance found in liquorice, and brought about a change in Finnish health recommendations.

Even though the maternal diet during pregnancy has a significant impact on the health of the foetus and the child after birth, many effects remain unknown. In previous experiments conducted with animals at the University of Edinburgh, it was demonstrated that glycyrrhizin, a natural sweetening agent found in liquorice, inhibits the barrier mechanism of the placenta which prevents cortisol, a maternal stress hormone, from entering the foetus. In other words, the mother’s diet can increase the adverse effects of maternal stress on the development of the foetus.

Under the direction of Academy Professor Katri Räikkönen, the Developmental Psychology Research Group at the University of Helsinki carried out the world’s first cohort study focused on glycyrrhizin.

The researchers monitored more than 1,000 mothers who gave birth in 1998. At the maternity ward, the mothers recorded their liquorice consumption during pregnancy, while their children were examined at the age of 8 and 12 in psychological and medical examinations.

Research findings: glycyrrhizin is harmful to the foetus

Studies published between 2009 and 2017 confirmed that glycyrrhizin, a natural ingredient of liquorice, can harm the development of the foetus. In humans, the substance also disturbs the functioning of a placental barrier enzyme that usually protects the developing foetus from the mother’s high stress hormone levels.

Cortisol, a stress hormone, is necessary for foetal development, but in large quantities it hinders the foetal development of children’s organs, particularly the brain.

In the follow-up study conducted by Räikkönen’s research group, the children of mothers who had consumed liquorice products containing large amounts of glycyrrhizin were found to be less successful in cognitive tests, in addition to which they had a tendency for inattentiveness and ADHD symptoms. The children were more sensitive to stressful situations, and the onset of puberty among girls occurred slightly earlier than normal.

The amount of glycyrrhizin varies greatly by liquorice product. A small packet of sweets may contain a lot of the substance, while in a larger bag of sweets the amount may be only moderate. Thus, even limited consumption of liquorice may result in abundant glycyrrhizin consumption.

In Räikkönen’s study, high consumption denoted 500 mg of glycyrrhizin per week, which comprises only roughly 100 g of pure liquorice.

What the researchers found noteworthy was that mothers eat liquorice regardless of their level of education and income. This differs from tobacco and alcohol consumption.

Research impact: national recommendations updated

In early 2016, the National Nutrition Council of Finland made a change to its dietary recommendations for pregnant women. The amendment was based on convincing evidence gained in experimental animal models and the research findings of Räikkönen’s group.

Foodstuffs which contain glycyrrhizin, namely liquorice and salty liquorice, should no longer be consumed at all during pregnancy to ensure the safety of the foetus. Previously, the recommendation was only to avoid these products during pregnancy if the mother was suffering from hypertension, as the blood pressure-increasing effect of liquorice has been known for a long time.

Liquorice is not the only foodstuff that contains glycyrrhizin. Academy Professor Katri Räikkönen and her colleagues have compiled a list of approximately 600 products containing the substance, and now the research group is seeking funding for its SafePreg smart phone application. Expectant mothers and their families can use the application to find out which products contain glycyrrhizin even if it is not stated in the product description.

A communication channel for the food industry is also being planned, through which mothers and families could be provided with information on a healthy and safe diet during pregnancy. New products containing glycyrrhizin regularly arrive on the market, making the dissemination of up-to-date information important.

Further information on the research:

Original studies: American Journal of Epidemiology (2017)Psychoneuroendocrinology (2010)American Journal of Epidemiology (2009)

Katri Räikkönen’s research, projects and other activities

‘Eating together – food recommendations for families with children’ by the National Institute for Health and Welfare