Chocolate linked to low blood pressure

[Al-khiyal]

Eating dark chocolate may be almost as effective at lowering blood pressure as taking the most common anti-hypertensive drugs, a review of studies has found. Tea, on the other hand, appears to be ineffective.

The article says a diet rich in fruits and vegetables is healthy partly because plants contain chemical substances called polyphenols that help control blood pressure. From more than 3,000 papers, researchers picked the largest randomized and controlled prospective studies and used statistical techniques to combine the data. It appears in the April 9 issue of The Archives of Internal Medicine.

Four of the five studies on chocolate found it reduced blood pressure

Chocolate linked to low blood pressure

[Al-khiyal]

Abstract

Background Epidemiological evidence suggests blood pressure–lowering effects of cocoa and tea. We undertook a meta-analysis of randomized controlled trials to determine changes in systolic and diastolic blood pressure due to the intake of cocoa products or black and green tea.

Methods MEDLINE, EMBASE, SCOPUS, Science Citation Index, and the Cochrane Controlled Trials Register were searched from 1966 until October 2006 for studies in parallel group or crossover design involving 10 or more adults in whom blood pressure was assessed before and after receiving cocoa products or black or green tea for at least 7 days.

Results Five randomized controlled studies of cocoa administration involving a total of 173 subjects with a median duration of 2 weeks were included. After the cocoa diets, the pooled mean systolic and diastolic blood pressure were –4.7 mm Hg (95% confidence interval [CI], –7.6 to –1.8 mm Hg; P = .002) and –2.8 mm Hg (95% CI, –4.8 to –0.8 mm Hg; P = .006) lower, respectively, compared with the cocoa-free controls. Five studies of tea consumption involving a total of 343 subjects with a median duration of 4 weeks were selected. The tea intake had no significant effects on blood pressure. The estimated pooled changes were 0.4 mm Hg (95% CI, –1.3 to 2.2 mm Hg; P = .63) in systolic and –0.6 mm Hg (95% CI, –1.5 to 0.4 mm Hg; P = .38) in diastolic blood pressure compared with controls.

Conclusion Current randomized dietary studies indicate that consumption of foods rich in cocoa may reduce blood pressure, while tea intake appears to have no effect.

Author Affiliations: Department of Pharmacology, University Hospital of Cologne, Cologne, Germany.

Effect of cocoa and tea intake on blood pressure: A Meta-analysis

[Bent_Bladi]

... chocolate may lower your blood pressure... bas it contains 22% fat. So it'll lower the blood pressure but higher your cholesterol

[Cheba_Mami]

July 3, 2007: A mouthful of dark chocolate each day could reduce blood pressure, cutting the risk of stroke, research suggests.

Forty-four people with raised blood pressure were put into two groups. One ate six grams of dark chocolate daily, the other the same amount of white.

The first group saw blood pressure fall slightly, but the others saw no change, researchers wrote in the Journal of American Medicine (JAMA).

The British Heart Foundation warned chocolate was a "treat not treatment".

The suggestion that cocoa has health benefits is not new, and previous research had also suggested it could bring down blood pressure.

This has been attributed to the chemical plant substances known as flavanols which it contains.

However it had been thought that large quantities were needed to achieve the desired effect, and that the benefits would then be offset by the consequences of consuming the high levels of fat and sugar associated with cocoa products.

But researchers at the University Hospital of Cologne say they have now shown that benefits can be achieved with a small amount - 30 calories worth of chocolate.

They looked at 44 people aged between 56 to 73 with either upper-range prehypertension (blood pressure between 130/85 and 139/89) or stage 1 hypertension (between 140/90 and 160/100).

None of those eating dark chocolate registered changes in body weight, or their levels of glucose and lipids.

But their systolic blood pressure - the upper reading which measures the force of blood as the heart beats - fell by 2.9mm, and their diastolic blood pressure - the lower figure taken as the heart relaxes - by 1.9mm.

The researchers noted that the reduction was small, but stressed that the effects were clinically noteworthy. A 3mm reduction in blood pressure could "reduce the relative risk of stroke mortality by 8%, of coronary artery disease by 5%, and of all cause mortality by 4%", they wrote.

They also stressed that asking people to consume a couple of chunks of chocolate a day was far easier than encouraging "complex behavioural changes" to help them reduce their blood pressure.

The British Heart Foundation's nutritionist Sara Stanner said it was "important to remember that chocolate is also high in fat and calories so over-indulgence is not good for your heart.

"Fruits and vegetables provide a range of polyphenols, as well as important vitamins and minerals. Eating five or more portions of fruit and vegetables a day is therefore the best way to protect your heart - and you don't need to worry about over-indulging."

BBC NEWS | Health | Chocolate 'lowers' blood pressure