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You're already dutifully limiting your sodium and eating a produce-packed diet in an effort to reduce your blood pressure.

Now, it turns out, you can add a square of chocolate to that heart-healthy regimen - guilt-free.

According to a study published in today's issue of the Journal of the American Medical Association, eating a small portion of dark chocolate each day can lower your blood pressure without packing on the pounds. That's good news for the 15 per cent of Canadians who have high blood pressure.

This isn't the first study to demonstrate the benefits of eating chocolate.

In 2005, Italian researchers reported that eating 100 grams of dark chocolate every day for two weeks lowered blood pressure, reduced LDL (bad) cholesterol and improved how the body used insulin (the hormone that clears sugar from the bloodstream) in 20 men and women with high blood pressure.

But the new findings suggest that a reduction in blood pressure can be achieved without eating such a large portion of chocolate each day (100 grams contains 470 calories and 30 grams of fat).

In the new study, 6.3 grams of dark chocolate a day - only 30 calories' worth - was sufficient to lower blood pressure.

Dark chocolate's heart-healthy effects are thought to come from flavonoids, natural compounds in cocoa beans that give dark chocolate its bittersweet taste.

Flavonoids, which exist only in small amounts in milk chocolate and not at all in white chocolate, have been shown to inhibit blood clot formation, help blood vessels widen and relax and slow the oxidation of LDL cholesterol.

In the study, researchers from the University Hospital in Cologne, Germany, gave 44 volunteers aged 55 to 75 either 6.3 grams of dark chocolate or an equivalent 30-calorie portion of white chocolate for 18 weeks.

Participants had prehypertension or hypertension but were otherwise healthy and were not taking blood pressure medications.

Blood pressure is the force generated by your heart as it pushes blood through the arteries. Adults should have a blood pressure of less than 120/80 mmHg (millimetres of mercury). Hypertension is diagnosed at 140/90 mmHg, but one in five Canadians fall into the category in between, called prehypertension (130-139/85-89 mmHg). Unless lifestyle changes are made to bring blood pressure down, 60 per cent of people with prehypertension will develop hypertension within four years.

Participants in the study were instructed to maintain their usual diet and physical activity and abstain from all other cocoa products. After 18 weeks, no one gained weight but only the dark chocolate eaters experienced a decline in blood pressure.

Everyone in the dark chocolate group had lower systolic (the upper number) or diastolic (the bottom number) blood pressure, and four people moved from hypertension to prehypertension. No one in that group, however, achieved optimal blood pressure.

The researchers noted that while the change in blood pressure was small for each study participant, it was noteworthy. In the population at large, such reductions would translate into lower death rates from heart disease and stroke.

It might seem more appealing to eat a bit of chocolate every day than to undergo lifestyle changes, but if you want to reduce your blood pressure more dramatically, you'll need to make additional changes to your diet.

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Lowering blood pressure with DASH

The Dietary Approaches to Stop Hypertension eating plan emphasizes vegetables, fruits, whole grains and other foods

that are heart-healthy and lower in salt/sodium.

Food Group	Daily Servings	Serving Size
Grain products	7-8	1 slice bread
		1/2 cup cooked grain
Vegetables	4-5	1 cup raw leafy vegetable
		1/2 cup cooked vegetable
		3/4 cup vegetable juice
Fruits	4-5	3/4 cup fruit juice
		1 medium fruit
		1/4 cup dried fruit
		1/2 cup fresh/frozen fruit
Low-fat/fat-free dairy	2-3	1 cup milk
		1 cup yogurt
		1.5 ounces low-fat cheese
Meat, poultry, fish	2 or less	3 ounces cooked meat, poultry, fish
Nuts, seeds, beans	4-5 per week	1/3 cup nuts
		2 tablespoons seeds
		1/2 cup cooked legumes
Fats and oils	2-3	1 tablespoon vegetable oil
		1 tablespoon margarine
		2 tablespoons fat-reduced dressing

Daily servings are based on 2000 calories per day.

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Eat some greens with that chocolate

In clinical trials, the Dietary Approaches to Stop Hypertension (DASH) diet achieved a reduction in blood pressure similar to that obtained by drug treatment in individuals with mild hypertension. While enjoying your 30 calories of dark chocolate (for more flavonoids, choose dark chocolate that contains at least 70 per cent cocoa solids), follow this DASH diet advice.

Eat fruit, vegetables, low-fat dairy and legumes, which are low in saturated fat, cholesterol and total fat.

Limit sodium.

Lose excess weight. If you're overweight and have hypertension, losing 10 pounds will lower your blood pressure. The DASH diet was not designed to promote weight loss. If you need to cut calories, replace high-calorie foods with more fruits and vegetables.

Be active. Do 30 minutes of moderately intense physical activity most days of the week.

Eating dark chocolate, or any other dietary modification, should not replace blood pressure medication.

For more information about the DASH diet, visit http://www.nhlbi.nih.gov/health/public/heart/hbp/dash/index.htm