Can Tea Be Thy Medicine?

I have always been told to not throw out the leaves, so here I wonder how can the whole plant be used, and what are the health benefits to drinking raspberry leaf tea?

Raspberry leaf is known by the botanical name Rubus idaeus. The leaves have delicate hairs that make up its silver lining. It is easy to brew, and can be bought in a disposable tea bag, or by loose dried leaves. Red raspberry leaf tea has a plethora of vitamins such as vitamin A, vitamin C, vitamin E, some B vitamins, and minerals such as calcium, magnesium, and potassium. Each of these vitamins and minerals have their own protective effect.

Vitamins C and vitamin E are known as antioxidants which prevent oxidative stress and improve cellular processes. Reactive oxygen species (ROS), or free radicals, are generated by our bodies endogenous pathways, and are detrimental when in excess to our body’s natural antioxidant pathways. ROS alter lipids, proteins, DNA, and trigger a number of human diseases (Lobo, Patil, Phatak, & Chandra, 2010). External consumption of antioxidants, such as vitamin C found in plants, can prevent oxidative stress, as they act as a reducing agent that neutralizes reactive oxygen species. Raspberry leaves are also found to have high concentrations of phenolic compounds such as chlorogenic acid, caffeic acid, p-coumaric acid, p-hydroxybenzoic acid/vanillinic acid, and ellagic acid (Ferlemi & Lamari, 2016). Phenolic compounds also act as antioxidants in the body.

The most abundant group in raspberry leaves are flavonoids, containing flavonols such as quercetin, quercetin-3-O-rutinoside, quercetin-3-O-galactoside, quercetin-3-O-glucoside, quercetin-3-O-glucuronide, kaempferol-3-O-glucoside, as well as the flavoinoid group flavon-3-ol, epicatechin gallate methyl gallate. Flavonoids are known to improve metabolic syndrome risk factors, give colour to fruits and vegetables, act as antioxidants, anti-inflammatroy, antimutagenic, anticarcinogenic and benefit the immune system (Panche, Diwan, & Chandra, 2016).

During a cross-sectional multivariable analyses with 2734 healthy twins, the data suggested that higher intake of flavonoids, including flavan-3-ols and flavanols were associated with lower fat mass, independent from the shared genetic and commonly shared environmental factors that influenced each twin (Jennings, Macgregor, Spector, & Cassidy, 2017). These findings were not significantly changed after the introduction of additional fiber, fruit, and vegetable intake. However, the report states that there was no association with total tea intake and fat mass, but there was a lower BMI in those participants who had tea versus the nonconsumers.

Flavon-3-ols such as those found in raspberry leaves were tested in pure form on diet-induced obese mice and a control group. It was found that the herb supplement reversed the obesity in rats, as the hormone activity levels of fatty acid synthase and acetyl-CoA carboxylase-1 mRNA, two enzymes that are required for endogenous fatty acid synthesis, were decreased (Wolfram, et al., 2005). This indicated that using herb supplements with flavon-3-ols may be an important option for the prevention and treatment of obesity. A similar, less invasive, study was performed on humans, and found that there may be an inverse relationship between tea consumption and body fat, especially for habitual tea drinkers (Wu, et al., 2003).

The benefits of raspberry leaf tea consumption do not stop at weight management and antioxidant. It is used as well as a symptomatic relief of minor spasm associated with menstrual periods, treatment of inflammation in mouth or throat, relief of mild diarrhea, used against chronic skin conditions, and for the treatment of conjunctivitis (Ferlemi & Lamari, 2016). This may be due to its minor antimicrobial potency. Raspberry leaf tea was tested against eight bacterial strains: Escherichia coli, Salmonella typhi, Streptococcus aureus, Proteus mirabilis, Micrococcus luteus, Citrobacter, Bacillus subtilis and Pseudomonas aeruginosa (Muhammad, Mansoor, & Rahman, 2011). The leaves demonstrated a minimum dose level inhibition. The stem and root of the plant were stronger inhibitors, and the fruit was less potent.

So please! Do not toss your raspberry leaves!

References:

Ferlemi, A.-V., & Lamari, F. (2016). Berry Leaves: An Alternative Source of Bioactive Natural Products of Nutritional and Medicinal Value. Antioxidants, 5(2), 17. doi: 10.3390/antiox5020017

Jennings, A., Macgregor, A., Spector, T., & Cassidy, A. (2017). Higher dietary flavonoid intakes are associated with lower objectively measured body composition in women: evidence from discordant monozygotic twins. The American Journal of Clinical Nutrition, 105(3), 626–634. doi: 10.3945/ajcn.116.144394

Lobo, V., Patil, A., Phatak, A., & Chandra, N. (2010). Free radicals, antioxidants and functional foods: Impact on human health. Pharmacognosy Reviews, 4(8), 118. doi: 10.4103/0973-7847.70902

Muhammad, R., Mansoor, A., & Rahman, N. (2011). Antimicrobial screening of fruit, leaves, root and stem of Rubus fruticosus. Journal of Medicinal Plants Research, 5(24). Retrieved from http://www.academicjournals.org/app/webroot/article/article1381913021_Riaz et al.pdf

Panche, A. N., Diwan, A. D., & Chandra, S. R. (2016). Flavonoids: an overview. Journal of Nutritional Science, 5. doi: 10.1017/jns.2016.41

Wolfram, S., Raederstorff, D., Wang, Y., Teixeira, S. R., Elste, V., & Weber, P. (2005). TEAVIGO (Epigallocatechin Gallate) Supplementation Prevents Obesity in Rodents by Reducing Adipose Tissue Mass. Annals of Nutrition and Metabolism, 49(1), 54–63. doi: 10.1159/000084178

Wu, C.-H., Lu, F.-H., Chang, C.-S., Chang, T.-C., Wang, R.-H., & Chang, C.-J. (2003). Relationship among Habitual Tea Consumption, Percent Body Fat, and Body Fat Distribution. Obesity Research, 11(9), 1088–1095. doi: 10.1038/oby.2003.149