Lingonberry (Vaccinium vitis-idaea) may not be a fruit that you have heard of however in Scandinavian countries including Finland, Norway, Sweden and Denmark it is very popular.
What makes this berry special is that it is a major source of the antioxidant quercetin and quercetin related compounds (e.g. quercetin glycosides).
The lingonberry is related to cranberries (Vaccinium oxycoccus) and bilberries (Vaccinium myrtillus). Both Cranberries and bilberries are closely related to the blueberries and black currants (Ribes nigrum). 
A clinical trial was published in the European Journal of Clinical Nutrition to determine if blood levels of quercetin would increase if berries were eaten daily.
Quercetin is a polyphenol present in many of these plants reported to have many health benefits that we have discussed before – click here.
Click here to see more clinical trials with berries.
Here are the study details:
Design: Randomized parallel dietary intervention.
Berries: The subjects in the berry group were given 2 kg each of deep-frozen black currants, lingonberries and bilberries. The berries were packed in 100 g portions in plastic bags. The subjects were instructed to take one bag out of the freezer each day and eat one portion of berries per day.
Blood sampling: Blood samples were taken 2 weeks prior to the study, at baseline and at weeks 2, 4 and 8. Blood serum concentrations of quercetin were analyzed.
Here are the main results
– The Berry Group consumed an average of 12.3 mg of quercetin daily during the 8 week study.
– Blood levels of quercetin with berry consumption was 32–51% higher compared with the control group
Read the results of a clinical trial with onion extract for lowering cholesterol.
– The increase in serum quercetin was similar to or higher than what was previously reported in 12 men consuming 375 ml of black tea or 750 ml of red wine for 4 days, but less than half of what was found when the subjects consumed 50 g of fried onions.
– Based on the results of this study no conclusions can be made about which of the berries contributed most to the increase in serum quercetin concentrations.
Here are what the authors of the study had to say
Increased intake of berries can be recommended because, in addition to quercetin, they are rich sources of many other potentially beneficial compounds as well, and are low in fat and energy. Anthocyanins, for instance, are present in berries in high concentrations and are potent antioxidants in vitro. However, their bioavailability appears to be quite low and they are excreted very rapidly. Therefore compounds such as quercetin and phenolic acids, together with vitamin C, could play a more important role in the possible health effects of berries.
and
In conclusion, the results of this study indicate that berries are a good source of bioavailable quercetin, and that in the Finnish population the mean fasting serum quercetin concentration is about 20 µg/l.
Take away message
In general, berries are an important source of quercetin in the Finnish diet. Quercetin has been shown to have many health promoting properties. One example is that Quercetin can regulate allergy symptoms, stimulate the immune system, stabilize mast cells, reduce uric acid in patients with gout and more.
Reference:
Consumption of black currants, lingonberries and bilberries increases serum quercetin concentrations. European Journal of Clinical Nutrition. 2003; Volume 57 (Issue 1): Pages 37-42.
His research on plant medicine has led to more than 45 publications and abstracts.This research has been presented at international meetings in the USA, France, Turkey, Peru, Israel, Austria, and Italy.
Categories: Antioxidant, Clinical Trials, Food
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