Possible Haematological Abnormalities Induced by Herbal Tea Consumption: A Review

Nowadays, a vast majority of herbal products used in traditional medicine are consumed in the form of tea due to their aromas, favourable tastes, and health-boosting effects arising from the antioxidant activity of the phenolic content. Even though people are advised to include these herbal teas in their daily diet as health promoters, the articles in the literature often present conflicting findings on the relationship between herbal tea consumption and haematological parameters. In this review, we recompiled the limited research on the possible relationship between herbal tea consumption and haematological alterations. We suggest that the contributions of active ingredients in the herbal tea products may affect haematological parameters such as the degree of iron absorption, serum ferritin concentration, thrombocyte level, aggregation rate, and lymphocyte mediated immunity. Populations, especially pregnant women and patients under the risk of haematological diseases, should consume these products under the control of physicians or other healthcare professionals. Furthermore, online marketing of these products or via TV commercials should be restricted due to the increasing misusage and related haematological alterations.