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Food made from leaves and grasses may contain pathogens

28/2017, 10.07.2017

BfR supplies hygiene tips on handling lettuce, herbs, teas, smoothies and other plant based foods

More and more people in Germany consume food products made from leaves and grasses, and these products may contain pathogens. As a result, the German German Federal Institute for Risk Assessment (BfR) is now publishing a detailed opinion on bacterial contamination of leaf and grass products that can cause disease in humans. "Most people view lettuce, leafy vegetables, herbs, teas and green smoothies as healthy foods", says BfR President Professor Dr. Dr. Andreas Hensel. "Which makes it more important to point out that good hygiene practices are also necessary with these foods. Regardless of this, a balanced diet containing plenty of fruit and vegetables is indeed the best nutritional strategy." The products assessed by the BfR include fresh leaf vegetables such as lettuce and herbs, dried leaf and grass products as well as dietary supplements, dried herbs and tea leaves as well as green smoothies.

To BfR Opinion

Virtually the entire population of Germany frequently consumes lettuce and fresh herbs. Tea is drunk more often by women than men, and tea consumption increases with age. Bacterial pathogens that can occur in grass and leaf products include Salmonella, Campylobacter, Yersinia, Listeria and EHEC.

Only very few cases of bacterial foodborne infection have been documented to date in Germany as a result of the consumption of grass or leaf products. Nevertheless, the BfR is issuing the following general recommendations to protect consumers and minimise risks:

  • Fresh leaf products should be washed thoroughly before eating raw and should be used as soon as possible. Fresh leaf products that have been chopped into small pieces should be stored at a maximum temperature of 7 °C where possible until eaten and should be used as soon as possible.
  • Freshly prepared green smoothies should be stored at a maximum temperature of 7 °C where possible and consumed on the same day they were prepared. Strong acidification of smoothies – achieved by using citrus fruit or adding lemon juice, for example – slow down or completely prevent the growth of bacteria.
  • Herbal teas should be prepared using boiling water. Pregnant women and persons whose immune system is compromised as a result of their advanced age, underlying medical conditions or medication should refrain from eating pre-cut and packaged lettuce as a precaution and instead prepare their own salads using fresh and thoroughly washed ingredients shortly before they intend to eat them. These people should consult their doctor before consuming nutritional supplements made from dried leaf and grass products.

About the BfR

The German German Federal Institute for Risk Assessment (BfR) is a scientifically independent institution within the portfolio of the Federal Ministry of Food and Agriculture (BMEL) in Germany. It advises the Federal Government and Federal Laender on questions of food, chemical and product safety. The BfR conducts its own research on topics that are closely linked to its assessment tasks.

This text version is a translation of the original German text which is the only legally binding version.



Date Title Size
BfR Opinion No. 013/2017
Grass and leaf products for consumption may be contaminated with human pathogen bacteria 64.1 KB


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