THE DETAILS: Researchers assigned 65 participants who were aged 30 to 70 to drink about three cups of hibiscus tea a day, or a placebo drink every day, for six weeks. The strength of the brewed tea they drank was comparable to the amount you'd get from brewing blended hibiscus tea bought at a health food store. After the six-week period, those who drank the hibiscus tea showed a 7.2-point drop in their systolic blood pressure (the top number, which shows the force of blood in the arteries as the heart beats), compared to a 1.3 drop in the control group. The authors conclude that hibiscus tea could be a dietary change recommended for people with prehypertension (a reading between 120/80 and 139/89 mmHg, according to the National Institutes of Health) or mild hypertension (140 to 150/90 to 95 mmHg). This isn't the first study touting the benefits of hibiscus tea in dealing with high blood pressure. But this new research does suggest that people who are at risk of developing high blood pressure, not just those who already have it, can lower their numbers back into the safe range by regularly sipping the tea.
WHAT IT MEANS: In 90 to 95 percent of cases, scientists don't know what causes high blood pressure. Race, heredity, family history, and aging can all play a role, as can risk factors like being overweight or obese, living a sedentary life, getting too much salt in the diet, stress, using tobacco and/or alcohol, and eating too little potassium in the diet, as well as certain chronic conditions like diabetes, kidney disease, insomnia, and high cholesterol. Some researchers believe even too little vitamin D can lead to high blood pressure, although that has not been proven.
If left untreated, high blood pressure can damage vascular walls, force your heart to work harder, and prevent adequate oxygen from reaching your organs. It also increases your risk of suffering a stroke, aneurysm, blood clot, or heart attack. And new research is also finding a strong link between high blood pressure and dementia. So it's in everyone's best interest to treat the problem and bring BP readings down to healthier levels. If you are already on blood pressure–lowering drugs, talk to your doctor about incorporating beneficial foods and herbs into your routine to safely lower your blood pressure reading and live a healthier life.
Here are some other ways you can use teas and foods to help keep your blood pressure in check:
• Take these foods off the shopping list. Canned and processed foods should be the first things to toss off the menu, according to James A. Duke, PhD, author of The Green Pharmacy Guide to Healing Foods: Proven Natural Remedies to Treat and Prevent More Than 80 Common Health Concerns (Rodale, 2009). They are laden with sodium, which can draw water into your bloodstream, leading to increased blood pressure. Eating a healthy diet can be affordable and easy if you follow our healthy-eating tips.
Also experiment with using less salt and cooking flavorful meals with popular herb combinations. And while you're at it, cut out plastics as much as possible, and never heat things in plastic. British researchers recently linked higher levels of the plastic chemical BPA, or bisphenol A, to an increased risk of cardiovascular disease. BPA is found in some No. 7 plastics (check for the number stamped onto the plastic container), particularly water bottles and some plastic utensils, on carbonless paper receipts, and in the lining of most metal food and soda cans.
• Try tea. In addition to the new research, several studies out of Iran and Mexico have also found hibiscus tea to significantly lower blood pressure. In his upcoming book, The New Healing Herbs: The Essential Guide to More Than 125 of Nature's Most Potent Herbal Remedies (Rodale, 2010), herbalist Michael Castleman suggests making the tea using 1 to 3 teaspoons of chopped or powdered hibiscus flowers per cup of boiling water; steep the flowers for two to five minutes before straining then drinking. Drink up to three cups a day. You can also easily find prepared hibiscus teas at health food stores. The good news is that no significant side effects have been shown.
Green tea has also been shown to provide benefits, despite its caffeine content. Green tea naturally contains compounds commonly used in synthetic form in blood pressure drugs, including diuretics and ACE inhibitors.
• Pick this produce. Celery, broccoli, carrots, tomatoes, and bananas all work in different ways to help bring your blood pressure down. Choose organic versions whenever possible—pesticide residues can tie up your liver's regular detoxifying duties.
• Eat like Dracula's stalking you. Folklore suggests garlic wards off vampires, but even if you're not worried about a Twilight-type encounter, it's still a good idea to incorporate this powerful herb into your diet, particularly if you live with hypertension. Raw and slightly cooked onions can also be used as potent blood pressure–lowering tools—try working one or two onions into your meals each day.
• Stock up on spinach. Spinach and other bitter greens like beet greens, dandelion, spinach, endive, and horseradish can spark the production of nitric oxide, a molecule that helps relax blood vessels. Try tossing the greens into a salad, or lightly sauté them with onions and garlic.
• Find the right fish. Some fish, such as wild-caught Alaskan salmon, mackerel, and sardines, are low in contaminants and high in heart-healthy omega-3 fatty acids and boast relatively healthy populations in the wild. For a guide to picking the best fish for you and the environment, refer to Environmental Defense Fund's Seafood Selector. Also of note, fish often are rich in coenzyme Q10 (CoQ10). Both preliminary and double-blind trials have found that CoQ10 supplementation can lead to a significant decrease in blood pressure; most research has used 100 milligrams of CoQ10 for at least 10 weeks. Of course, always talk to your doctor and pharmacist before starting a new supplement.