Just Say NO to High Blood Pressure!

It has long been known that compounds known as nitrates have a beneficial effect for the cardiovascular system.  The most common example of this is nitroglycerin, a drug that is used for angina (chest pain due to spasm of blood vessels).  Nitrates are transformed by bacteria in the mouth to nitrites, which are then converted in the blood into nitric oxide (NO).  NO relaxes blood vessels, which can lower blood pressure.

In addition to pharmaceutical nitrates, attention has been focused recently on whole foods sources of nitrates.  Two studies took a look at the effects of beetroot juice on blood pressure.  In 2012, Australian researchers (1) found that consuming beetroot juice significantly lowered systolic blood pressure for up to 6 hours, compared to placebo.  Beets are a good source of nitrates, which the body can convert into NO.

But 500 g of beetroot juice is quite a bit.  Some clever Brits (2) therefore compared drinking liquid beetroot juice to consuming a special beetroot enriched bread.  They found that both were equally effective in lowering blood pressure, and the bread may be more palatable.  Furthermore, in their study, they noticed that the blood pressure lowering benefits persisted for 24 hours.

One caveat to keep in mind is that both of these studies were performed with healthy subjects.  However, eating more vegetables is definitely good for your health anyway, so increasing your beet intake is a good idea if you're trying to lower your blood pressure.  You can also look at other vegetables that are high in nitrates, such as radishes, carrots, and lettuce.  And don't forget the blood pressure lowering benefits of chocolate for dessert!

1.  Coles, L and Clifton, P.  Effect of beetroot juice on lowering blood pressure in free-living, disease-free adults: a randomized, placebo-controlled trial.  Nutr J. 2012; 11: 106.

2.  Hobbs DA, et al. Blood pressure-lowering effects of beetroot juice and novel beetroot-enriched bread products in normotensive male subjects. Br J Nutr. 2012 Dec 14;108(11): 2066-74. Epub 2012 Mar 14.

Chocolate: Health Food or Not?

At this time of year, perhaps you've finished off your Valentine's Day chocolate, only to be looking forward to some chocolate in your Easter basket soon.  Americans definitely need to cut down on sweets:  The high sugar and saturated fat content in most milk chocolate can be a contributor to obesity and metabolic syndrome (a combination of insulin resistance, high blood pressure, and abnormal blood lipid levels).

On the other hand, the evidence for the health benefits of chocolate have been accumulating more and more in recent years.  The perks seem to be related to the flavanol content of the cocoa bean (Theobroma cacao).  The higher the cocoa (cacao) content, the better:  and dark chocolate (55% cacao or higher) is your best bet.  Eating an average of about one ounce per day can really boost cardiovascular and general health, including:

• Decreasing stroke risk by 14% for women (1) or 17% for men (2)
• Decreasing risk of heart failure in older women by 26-32% (3)
• Modestly reducing blood pressure (4-7)
• Decreasing "bad" cholesterol (LDL), and increasing "good" cholesterol (HDL) (8-9)
• Improving cognitive function (10)
• Most surprising of all:  decreasing body mass index (BMI) (11).  In other words, chocolate can lead to weight loss!

Just remember to enjoy your dark chocolate in moderation, as part of an overall nutrient-dense Mediterranean-type diet, including lots of fruits and veggies, nuts, legumes, lean protein, and healthy fats such as extra virgin olive oil.

1. Larsson SC, Virtmo J, Wolk A. Chocolate consumption and risk of stroke in women. J Am Coll Cardiol. 2011;58:1828-1829.
2. Larsson SC, Virtamo J, Wolk A. Chocolate consumption and risk of stroke: a prospective cohort of men and meta-analysis. Neurology. 2012;79:1223-1229.
3. Mostofsky E, Levitan EB, Wolk A, Mittleman MA. Chocolate intake and incidence of heart failure: a population-based prospective study of middle-aged and elderly women. Circ Heart Fail. 2010;3:612-616.
4. Ried K, Sullivan TR, Fakler P, Franks OR, Stocks NP. Effect of cocoa on blood pressure. Cochrane Database Syst Rev. 2012;8:CD008893.
5. Buijsse B, Weikert C, Drogan D, Bergmann M, Boeing H. Chocolate consumption in relation to blood pressure and risk of cardiovascular disease in German adults. Eur Heart J. 2010;31:1616-1623.
6. Taubert D, Roesen R, Lehmann C, Jung N, Schömig E. Effects of low habitual cocoa intake on blood pressure and bioactive nitric oxide: a randomized controlled trial. JAMA. 2007;298:49-60.
7. Buijsse B, Feskens EJ, Kok FJ, Kromhout D. Cocoa intake, blood pressure, and cardiovascular mortality: the Zutphen Elderly Study. Arch Intern Med. 2006;166:411-417.
8. Jia L, Liu X, Bai YY, et al. Short-term effect of cocoa product consumption on lipid profile: a meta-analysis of randomized controlled trials. Am J Clin Nutr. 2010;92:218-225.
9. Mursu J, Voutilainen S, Nurmi T, et al. Dark chocolate consumption increases HDL cholesterol concentration and chocolate fatty acids may inhibit lipid peroxidation in healthy humans. Free Radic Biol Med. 2004;37:1351-1359.
10. Desideri G, Kwik-Uribe C, Grassi D, et al. Benefits in cognitive function, blood pressure, and insulin resistance through cocoa flavanol consumption in elderly subjects with mild cognitive impairment: the Cocoa, Cognition, and Aging (CoCoA) study. Hypertension. 2012;60:794-801.
11. Golomb BA, Koperski S, White HL. Association between more frequent chocolate consumption and lower body mass index. Arch Intern Med. 2012;172:519-521.

Seeds of Heart Health for the New Year

You've probably heard my mantra for a healthy diet (borrowed from author Michael Pollan):  "Eat food.  Not too much.  Mostly plants."  To expand on this, we can look to the Mediterranean diet -- that style of eating that is based on whole grains, vegetables, nuts, legumes (beans), and smaller amounts of animal-based protein.  This simple approach works well for maintaining a healthy body weight, and preventing chronic diseases such as cardiovascular disease.

A review (1) in the journal Clinical Lipidology (yes, you read that right; "lipidology" means the study of cholesterol and other fats) looks at dietary factors most associated with lowering cholesterol.

"The foods with the most evidence for cholesterol reduction are nuts, legumes, whole cereals rich in soluble fiber, and cocoa and its main commercial product, chocolate."

OK -- this sounds a lot like the Mediterranean diet.  What the author goes on to point out, though, is that all of these foods are actually seeds.  Obvious once someone points it out, isn't it?  Yet with as many years as I've taught patients and students about nutrition, this struck me as a beautifully concise revelation.  Even whole grains like oats are seeds.  And chocolate?  Yes, please!

Seeds contain fiber, healthy fats, and disease-busting phytonutrients.  Think of them as plant foods bursting with concentrated potential.

1.  Ros E.  How Important Is Dietary Management in Hypercholesterolemia?  Clin Lipidology. 2012;7(5):489-492.

More Good News for Chocolate

Ah, how times change.  Just a few years ago, chocolate was undoubtedly in the junk food category, yet a flurry of recent research has confirmed its benefits to cardiovascular health.  The latest is a study from Sweden published last month (1) that showed that higher chocolate consumption cut men's stroke risk by 17%.  And it didn't need to be much -- just an average of about 2 ounces per week, compared to non-consumers.  The key seems to be the flavonoids in cocoa:  compounds that have antioxidant activity, and improve endothelial function (the inner lining of large blood vessels).

Prior research showed cardiovascular benefits from dark chocolate, which have a higher cocoa content (55-90%) than milk chocolate (30%).  So for maximal benefit, reach for the dark chocolate.  This also avoids the high amounts of sugar and saturated fat in milk chocolate, which can contribute to obesity and metabolic syndrome.

It might take time to get used to the less sweet taste of dark chocolate, but with small amounts (1/2 - 1 ounce per day), your palate will adjust.  My advice?  Become a chocolate snob.  Buy good quality dark chocolate, and really focus in and enjoy that little tidbit, rather than cramming down a whole bar of cheap milk chocolate.


1.  Chocolate consumption and risk of stroke:  A prospective cohort of men and meta-analysis.  Neurology. 2012;79:1223-1229. Published online August 29, 2012.