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.

Good Bacteria = Smaller Waistline?

Research in the area of normal flora -- the "good," or beneficial bacteria that live in our gut -- has been exploding in recent years.  It has been known for a long time that supplementing with probiotics (those friendly bacteria like Lactobacillus and Bifidus) can help with conditions ranging from eczema to allergies to irritable bowel syndrome.  But the list of benefits of proper microbial balance keeps growing -- and it seems like the more we know, the more we realize how much we don't know yet.

Recently, Chinese researchers (1) found a connection between the microbes in our gut and the problem of obesity.  Mice that were bred to be resistant to obesity, in spite of a high-fat diet, rapidly gained weight when injected with a bacteria from the human gut called Enterobacter cloacae.  They hypothesize that a harmful substance produced by these bacteria, called endotoxin, contributes to insulin resistance.  Insulin resistance is a major contributor to overeating and obesity, and the hallmark of type 2 diabetes.  Think of insulin as a key to open the door to your cells so they can take in blood sugar for energy; insulin resistance is where the lock on the cell doors gets worn and rusty, making it more difficult for insulin to do its job.  Insulin levels rise, which contributes to widespread inflammation in the cardiovascular system, and promotes fat storage.

In the same article, the researchers report a case study of a man who lost 66 pounds in 9 weeks by switching to a diet that promoted good bacteria growth in the intestinal tract.  The harmful Enterobacter was reduced to undetectable levels.

Now before you pop an acidophilus supplement or grab a Yoplait, expecting miraculous weight loss, we need to look a little more closely at the diet supplied to this test subject.  It was very high in fiber, to feed the good bacteria in the gut, and also included traditional Chinese fermented foods that might seem challenging to our palates.  Fermented foods are beginning to look more important than probiotic supplements, simply because of sheer numbers:  supplements might have anywhere from 1 billion to 20 billion bacteria per serving, which sounds like a lot, until you realize that there are about 100 trillion bacteria in your gut!  Traditional fermented foods have much higher levels of good bacteria than supplements.  We're not talking about most commercial yogurts, which are crammed with sugar and have questionable amounts of active bacterial cultures; we're talking about plain yogurt, kefir, miso, traditional sauerkraut, and kimchi, to name a few.

We've barely scratched the surface on research into our normal flora -- not just in the gastrointestinal tract, but also on the skin, respiratory tract, and genitourinary tract.  It makes sense that they would have such a huge influence on our health:  there are ten times as many bacterial cells as human cells in our bodies!  We are really more of an ecosystem rather than a single organism.  Perhaps in the future there will be much less emphasis on therapeutic nutrition, except as it applies to how it influences our flora.

1.  An opportunistic pathogen isolated from the gut of an obese human causes obesity in germfree mice.  The ISME Journal advance online publication 13 December 2012; doi: 10.1038/ismej.2012.153