- High blood pressure , or hypertension, increases the risk of heart disease and stroke, both of which are leading causes of deathTrusted Source in the United States.
- Nutrition advice on how to lower blood pressure often includes using herbs and spices rather than salt to flavor meals. However, experts know little about the health benefits of herbs and spices.
- A recent randomized controlled trial suggests that a diet rich in herbs and spices may reduce blood pressure in people at risk of cardiovascular disease.
According to the Centers for Disease Control and Prevention (CDC), nearly halfTrusted Source of adults in the U.S. have hypertension blood pressure.
Untreated hypertension increasesTrusted Source the risk of cardiovascular disease, such as heart attack, stroke, heart failure, kidney disease, vision loss, and damage to blood vessels.
Dietary guidance on reducing blood pressure includes reducing salt intake. The Dietary Guidelines for Americans recommend using herbs and spices instead of salt to flavor food.
Experts know less about the health effects of herbs and spices than they do about those of salt. However, some studies have shown that herbs and spices can reduce lipemiaTrusted Source — the excess of lipids in the blood — hyperglycemiaTrusted Source, and oxidative stress.
The Source of blood pressure report
To dig a little deeper, researchers at Pennsylvania State University recently conducted a randomized controlled trial investigating the effect of longer-term consumption of herbs and spices on risk factors for cardiovascular disease.
They found that a higher level of herbs and spices in food reduced 24-hour blood pressure readings.
Prof. Penny Kris-Etherton, one of the lead authors of the study, told Medical News Today, “Indeed, the blood pressure-lowering effects of herbs and spices in an average Western diet were surprising to me.”
“We [already know] about the effects of many lifestyle factors, especially dietary factors, that can increase blood pressure — such as sodium, alcohol, and caffeine — and others that can decrease blood pressure, such as potassium, magnesium, and calcium, […] weight loss, physical activity, and some vitamins, including folate and vitamin D when intake is low, but the blood pressure-lowering effects of herbs and spices are new!”
“In terms of herbs and spices,” she continued, “there hasn’t been a clinical trial showing benefits on blood pressure lowering until our study.”
Three test diets
A total of 71 participants aged 30–75 years joined the study. All participants had one or more risk factors for cardiovascular disease and had overweight or obesity.
After the participants fasted for 12 hours, the researchers made baseline assessments. These included height, weight, waist circumference, a fasting blood sample, and vascular testing.
Vascular testing included central and peripheral pressure and arterial stiffness measurements. The participants also wore a blood pressure monitor for 24 hours.
The researchers then randomly assigned the participants to one of three groups. Each group would eat one of three diets: a low spice diet, a moderately spiced diet, or a high spice diet. These diets included a daily intake of 0.5 grams (g), 3.3 g, and 6.6 g of herbs and spices, respectively.
The aim was to incorporate herbs and spices into a diet that was representative of the average U.S. diet. The additional herbs and spices included cinnamon, turmeric, and oregano.
The participants followed their respective diets for 4 weeks, with a 2-week break in between. At the end of each diet period, the participants returned for follow-up assessments. A total of 63 individuals completed the study.
Improvement in blood pressure
The study showed that the high spice diet tended to improve 24-hour readings. To compared with the medium and low spice diets.
The researchers did not observe any effect of the diets on low-density lipoprotein cholesterol. Clinic-measured blood pressure, markers of glycemia, vascular function, or oxidative stress.
However, they say that 24-hour blood pressure readings are a stronger predictorTrusted Source of cardiovascular death than clinic blood pressure measurement.
The authors believe that the study might have been too short for vascular remodeling to occur. Which might explain why they did not see any effect on arterial stiffness.
They also note that the dosages of herbs and spices might not be adequate to overturn the metabolic effects of an unhealthy background diet. Therefore, they cannot recommend increasing intake of herbs and spices alone in the context of a poor quality diet to lower the risk of cardiovascular disease.
Moreover, because each day of the menu included different amounts of the 24 herbs and spices, exposure was not consistent. As herbs and spices do not stay in the system for very long. The food consumed during the days closest to testing may have influenced the results more strongly.