Herbal teas provide a variety of prescription free health benefits

Kathleen Blanchard's picture
Herbal tea
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Scientists from the United States Department of Agriculture recently conducted a review of herbal teas, finding scientific evidence of the health benefits from enjoying a cup of peppermint, chamomile, or hibiscus tea.

Health benefits of herbal tea go beyond relaxation

Diane McKay and Jeffrey Blumberg, with the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University in Boston, Massachusetts, examined the health effects of three popular herbal teas in America. The researchers work in the Antioxidants Research Laboratory In their investigation and review they found green, black, and oolong teas are not the only infused beverages that are healthy.

Chamomile tea

The popular calming tea chamomile lacked any studies in humans suggesting it can aid sleep and relaxation. Instead, researchers found the tea has moderate antimicrobial and antioxidant properties, shown in test tube studies. They also found chamomile tea can prevent platelets that form blood clots from clumping together, noting the anti-platelet effect was significant. In animal feeding studies, the herbal tea was shown to possibly lower cholesterol in addition to being a potent anti-inflammatory.

Peppermint tea review shows antiviral, antimicrobial properties

In the review, the scientists found peppermint tea has an anesthetic and analgesic effect on the central nervous system found in animal studies. They also found evidence that peppermint tea has significant antimicrobial and antiviral activities in test tube studies, strong antioxidant and antitumor actions and potential as an allergy remedy.

The authors found no human studies about the health benefit of peppermint tea, though several have been published pointing to peppermint oil's health benefits.

In a meta analysis published September 24, 2008 in the British Medical Journal, researchers found peppermint oil can ease IBS symptoms. The authors of the investigation concluded simple remedies are often overlooked "with the advent of "newer more expensive drugs. The scientists studied the effects of peppermint oil, antispasmodics and fiber in the treatment of irritable bowel syndrome.

Hibiscus tea lowers blood pressure

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A cup of hibiscus tea that is made from the flower of the plant could keep blood pressure lower. McKay conducted a study that included 65 mildly hypertensive or pre-hypertensive participants, age 30 to 70 (blood pressure greater than 120/80).

Throughout the six week study the volunteers were asked to maintain their normal activity and dietary routine. One group was given a cup of hibiscus tea three times a day and the other an hibiscus flavored placebo tea. At the end of the six weeks, the group given the herbal tea had a 7.2 mm/Hg drop in systolic blood pressure. The placebo group had a 1.3 mm/Hg change.

In a second analysis, those with the highest blood pressure - 129 or greater - had an even more significant response, experiencing blood pressure lowering of 13.2 mm/Hg for the top or systolic reading and 4.2 mm/Hg. In another study, published in the Journal of Human Hypertension, the brew was found to lower blood pressure for type 2 diabetics and was compared to black tea. Other studies compared hibiscus tea to the antihypertensive drugs lisinopril and another to the drug captopril, finding the tea has diuretic properties in addition to the same properties as the medications for converting angiotensin in the kidneys.

The researchers say herbal tea health benefits are not just folklore. The review of data, especially showing the blood pressure lowering effect of hibiscus tea, supports the benefits of daily consumption. The scientists note there is science based evidence that the three widely consumed herbal teas have benefits for health that should be further studied.

Resources:
PubMed: "Effectiveness and tolerability of a standardized extract from Hibiscus sabdariffa in patients with mild to moderate hypertension: a controlled and randomized clinical trial"
Herrera-Arellano A, Flores-Romero S, Chávez-Soto MA, Tortoriello J.

Planta Med 2007; 73(1): 6-12
DOI: 10.1055/s-2006-957065

Journal of Human Hypertension 23, 48-54 (January 2009)
doi:10.1038/jhh.2008.100

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