Tea is a versatile beverage that you can enjoy either iced or hot. But if you are someone who sips a cup of tea every day, you may be wondering whether drinking tea is interfering with your blood pressure. The answer is that the different compounds of tea can create mixed effects.
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Caffeine and Blood Pressure
Caffeine is a bitter substance found naturally in tea leaves and other plants. The Food and Drug Administration has recommended that healthy adults drink no more than 400 milligrams of caffeine each day. Regular tea can contain 14 to 60 milligrams of caffeine per 8 ounces, notes the U.S. National Library of Medicine. Small traces of caffeine will still be found in tea that is considered caffeine free, just less than their regular counterparts.
Caffeine has many effects on the body, such as stimulating your central nervous system so you feel energetic and awake. It may also increase your blood pressure temporarily, especially one hour after consumption, when it's at peak level in the blood. The reason behind the brief rise in blood pressure is still unclear, and some people may be more sensitive to caffeine effects than others, according to the Mayo Clinic.
If you already deal with high blood pressure, it's best to consult your doctor on whether you should limit or stop drinking caffeinated beverages. It's also important to avoid drinking large amounts of caffeine before participating in activities that naturally raise your blood pressure, such as exercising or physical labor, says Mayo Clinic.
Read more: Caffeine in Green Tea Vs. Black Tea
Tea in its natural form can sometimes present a sweet flavor but does not include added sugar. Depending on the brand, some companies may add sugar in the form of granulated sugar, artificial sweetener or other sugar substitutes.
"Drinking large amounts of sugar-sweetened tea may increase your blood pressure," says SaVanna Shoemaker, RDN, LD, a dietitian/nutritionist in Little Rock, Arkansas. "Ideally, you should have your tea unsweetened or lightly sweetened with honey or a plant-based sweetener like stevia."
The Centers for Disease Control and Prevention recommends that added sugar intake should be less than 10 percent of total daily calories. Added sugars are various sugars or syrups that get added to foods or beverages when they are processed. Examples of added sugars include:
- Brown sugar
- High-fructose corn syrup
- Raw sugar
Too many added sugars in the diet can lead to health problems such as Type 2 diabetes, heart disease and obesity. the CDC points out.
Benefits of Tea
Caffeine is only one compound in tea, but there are many more that have health-boosting properties, according to an October 2019 review in the journal Antioxidants. "Tea contains powerful antioxidants called catechins that can reduce inflammation and reverse cellular damage," adds Shoemaker. "These effects promote healthier blood pressure levels."
Catechins are one of more than 8,000 kinds of polyphenols. Some studies indicate that polyphenols in tea help reduce blood pressure. One study published in JAMA Internal Medicine in January 2012 found that drinking 3 cups of black tea daily for six months resulted in lower systolic and diastolic blood pressure by 2 to 3 millimeters of mercury.
A review of studies published in May 2019 in Nutrients showed similar results, including a reduction of blood pressure even among people who have hypertension.
Beyond promoting healthier blood pressure levels, catechins are also known to have antimicrobial abilities to prevent infections. A study done on catechins, published in July 2018 in BioMed Research International, found that adults who took green tea supplements two times daily for three months had 32 percent fewer incidents of cold or influenza symptoms. They also reported 23 percent fewer illnesses that lasted two days or longer.
Drinking tea with high catechin levels has also been affiliated with the prevention and treatment of various diseases, such as arthritis, cancer, diabetes, cardiovascular disease and neurologic and oral health, say the BioMed Research study authors.
- Antioxidants: "A Comprehensive Insight on the Health Benefits and Phytoconstituents of Camellia sinensis and Recent Approaches for Its Quality Control"
- U.S. Food and Drug Administration: "Spilling the Beans: How Much Caffeine Is Too Much?"
- U.S. National Library of Medicine: "Caffeine"
- Mayo Clinic: "Caffeine: How Does It Affect Blood Pressure?”
- SaVanna Shoemaker, RDN, LD, registered dietitian/nutritionist, Little Rock, Arkansas
- Centers for Disease Control and Prevention: "Know Your Limit for Added Sugars"
- JAMA Internal Medicine: "Effects of Black Tea on Blood Pressure: A Randomized Controlled Trial"
- Nutrients: "Effects and Mechanisms of Tea Regulating Blood Pressure: Evidences and Promises"
- BioMed Research International: "Green Tea Catechins: Their Use in Treating and Preventing Infectious Diseases"