Arbor Clinical Nutrition Update #152: Chocolate and health

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Just thought I'd share this with you... :-)

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ARBOR CLINICAL NUTRITION UPDATES ©

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This week we review some recent research concerning the health aspects of

chocolate. For those with children (or nephews and nieces), this might be

an appropriate topic to prepare you for the upcoming Easter holiday !

 

We would be very pleased if you were to share this publication with health

professional friends and colleagues. Subscribing instructions for them are

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Kind regards,

 

Editorial team,

Arbor Clinical Nutrition Updates

http://arborcom.com

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NUTRITION RESEARCH REVIEW

 

 

Study 1: Cocoa, oxidation and inflammation

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Chocolate and cocoa drink decrease LDL oxidation susceptibility but do not

affect markers of inflammation, according to a new study from Texas.

 

Subjects: 25 healthy subjects.

 

Method: Cross-over non-blinded study in which subjects were given cocoa in

the form of chocolate and cocoa drink daily for 6 weeks. Measures of

oxidative stress, (e.g. LDL oxidation kinetics and urinary isoprostanes)

and markers of inflammation (e.g. whole-blood cytokines, interleukins TNF

and C-reactive protein) were assessed before, at after a 6 week washout

period after conclusion of cocoa supplementation.

 

Results: There was a significant decrease in LDL oxidisability during the

cocoa supplementation phase. - see Table. There was however no change in

measures of inflammation.

 

Table: Conjugated diene formation lag time

with cocoa supplementation

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Pre-supplementation 91.3 min (18.0)

Supplementation 101.0 min (20.7)

Washout 96.4 min (7.5)

 

p<0.05

 

Reference: J Nutr 2002 Dec;132(12):3663-7

 

Study 2: Cocoa is like a mild aspirin

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Cocoa has a similar but lesser effect on platelet activation and function

than does aspirin, according to a recent American research.

 

Subjects: 16 healthy adults.

 

Method: Cross-over design. Subjects consumed aspirin (81 mg), cocoa (as a

drink), or a combination of aspirin and cocoa. Platelet function was

assessed by a variety of tests (e.g. epinephrine-induction) at 2 and 6

hours after consumption.

 

Results: Cocoa (given alone or with aspirin) increased the plasma level of

the cocoa-derived flavonoid epicatechin.

 

Both aspirin and cocoa inhibited platelet function. Aspirin tended to do so

at both 2 and 6 hours, whereas cocoa on its own more at 6 hours. There was

some evidence of an additive effect of combining the two.

 

Reference: Thromb Res 2002 May 15;106(4-5):191-7

 

 

Study 3: Cocoa and chocolate reduce oxidation

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Cocoa powder and dark chocolate reduce lipid oxidation susceptibility and

increase total antioxidant capacity without adversely affecting

prostaglandin levels. These are conclusions from another American study.

 

Subjects: 23 healthy subjects.

 

Method: Randomised, 2 limb cross-over study. Subjects were placed on either

an average American diet (controlled for content of fibre, caffeine, and

theobromine) or the same diet supplemented with cocoa powder (22 gm/day)

and dark chocolate (16 gm/day), then switched to the other diet.

 

Results: There was a 4% increase in total serum oxidation capacity (p=0.04)

and an 8% increase in LDL oxidation lag time (p=0.01) on the

cocoa-chocolate diet, compared with the normal diet. These two parameters

were positively correlated (r = 0.32, p =0.03).

 

Although HDL was significantly higher on the cocoa-chocolate diet (4%

greater p = 0.02), there was no significant difference in HDL:LDL ratios.

There were no differences between diets in relation to 24 hour urinary

prostaglandin excretion (thromboxane B2 and 6-keto-prostaglandin F-1-alpha.)

 

Reference: Am J Clin Nutr 2001 Nov;74(5):596-602

 

 

COMMENTS

For many years chocolate has been looked on as an indulgence, for which

some people (more often women than men) have cravings, which has been

described as at times bordering on addiction (refs.1,2,3).

 

Chocolate has been something of a `guilty pleasure', and has been held

responsible for ill effects as varied as elevation of lipids, disturbance

of diabetic control, dental caries, migraine, heartburn and renal stones

(refs.4-7).

 

However, in recent years there has been quite a reassessment of the health

impact of chocolate. For one thing, it has become apparent that its effect

on lipid profile is less than one might assume from looking at its

saturated fat content. This may be because much of the saturated fat is in

the form of stearic acid. The more common view is now that chocolate can

happily be eaten in moderation, including by those specifically wanting to

follow a `heart friendly' diet (refs.8,9,10).

 

Evidence has also suggested that small amounts of chocolate can be eaten by

diabetics without any significant adverse impact on their glucose control

(ref.11).

 

But the biggest change in thinking has been the realisation that chocolate

may have positive health benefits related to the content of antioxidant and

platelet inhibiting compounds in cocoa (particularly polyphenol flavonoids

such as epicatechin) (ref.12).

 

The polyphenol content of cocoa foods varies, being more in dark than light

chocolate for example (ref. 10).

 

Since these cocoa flavonoids are platelet inhibitors, it is possible that

they may also not only have anti-coagulation but also anti-inflammatory

effects. Indeed, some have even postulated that, although there is little

concrete evidence so far to prove it, chocolate and other cocoa consumption

 

may help prevent cancer (ref.13).

 

Polyphenols are also found in tea and red wine (refs.13,14), and in some

respects the change in attitude towards chocolate reflects that towards

these latter foods over the decade or two.

 

These three new studies are consistent with the more recent thinking about

chocolate. As research data accumulates, we get some sense of the degree of

antioxidant and anti-inflammatory effects and how they compare, for

example, to those of red wine.

 

At this stage, chocolate appears to be a mild antioxidant, and any

anti-inflammatory effect may be milder still. Since chocolate does have

other components that have potential adverse effects when eaten to excess

(e.g. saturated fat and sugar) it seems prudent that we do not talk about

it as some kind of `health food'. At the same time, the evidence so far

accumulated can certainly help to take away any guilt from the undoubted

enjoyment of eating chocolate in moderation !

 

 

References:

1. J Am Diet Assoc 1999 Oct;99(10):1249-56

2. Appetite 1993 Dec;21(3):233-46

3. Appetite 1991 Dec;17(3):199-212

4. Community Dent Oral Epidemiol 1983 Dec;11(6):337-41

4. Am J Dig Dis 1975 Aug;20(8):703-7

5. Cephalalgia 1991 May;11(2):93-5

6. Am J Gastroenterol 1988 Jun;83(6):633-6

7. Horm Metab Res 1994 Aug;26(8):383-6

8. Am J Clin Nutr 1994 Dec;60(6 Suppl):1014S-1016S

9. Am J Clin Nutr 1994 Dec;60(6 Suppl):1037S-1042S

10. J Am Diet Assoc 2003 Feb;103(2):215-23

11. Eur J Pediatr 1993 Aug;152(8):635-9

12. J Am Coll Nutr 2001 Oct;20(5 Suppl):436S-439S; discussion 440S-442S

13. Exp Biol Med (Maywood) 2001 Nov;226(10):891-7

14. J Nutr 2000 Aug;130(8S Suppl):2120S-6S

 

 

 

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