Dark Chocolate, but Not White, Can Improve Cholesterol and Blood Sugar, Experts Find
If you're eating chocolate for the health
benefits -- and aren't we all? -- you must pick wisely, new research
suggests.
"Eat dark chocolate,
not white chocolate," says researcher Mee Young Hong, PhD, associate
professor of exercise and nutritional sciences at San Diego State
University. She compared dark and white chocolate, looking at health
effects, such as improving cholesterol.
Dark chocolate was the clear winner, she says. She is due to
present the findings at the Experimental Biology 2012 meeting in San
Diego.
Chocolate and Health Benefits: Study Details
Hong compared white chocolate, which has no cocoa solids, to
regular dark chocolate containing 70% cocoa. The cocoa solids contain
healthy compounds called flavonols. These have antioxidant and
anti-inflammatory properties.
She also tested dark chocolate containing 70% cocoa that had been
overheated or ''bloomed." ("You know when you leave chocolate in the
[hot] car?" she asks. That's ''bloomed" -- melted and then maybe
hardened again.)
She wanted to see if the melting would rob the dark chocolate of the health effects.
Hong's team assigned 31 men and women to eat about 1.7 ounces (a
standard-size chocolate bar is about 1.5 ounces) of dark, white, or
''bloomed" dark chocolate every day for 15 days. Before and after the
study, Hong's team measured blood pressure, blood sugar, and cholesterol.
Compared to those who ate white chocolate, those eating either dark chocolate had:
- Lower blood sugar levels
- Improved LDL or ''bad" cholesterol
- Improved HDL or "good" cholesterol
She didn't find differences in blood pressure between the white chocolate eaters and the dark chocolate eaters.
As for why the dark chocolate may help blood sugar levels, Hong
says its antioxidants may help the body use its insulin more efficiently
to control blood sugar. This, in turn, helps to lower blood sugar
levels naturally.
Compared to people who ate white chocolate, those who ate dark
lowered their bad cholesterol by about 20%, Hong tells WebMD. Dark
chocolate eaters increased their good cholesterol by 20%, compared to
white chocolate eaters.
The white chocolate, but not the dark, made the skin blood flow slow down -- not a desirable quality. Skin blood flow is a way to measure how the blood vessels are functioning.
The study did not have industry funding.
Chocolate for Health: Perspectives
Some of the findings echo that of other research, says Joe
Vinson, PhD, a professor of chemistry at the University of Scranton and a
long-time researcher on antioxidants in foods. He reviewed the
findings.
"The fact that white chocolate (containing fat and sugar) makes
the skin blood flow slow down is newsworthy," he says. The message to
stay healthy, he says, is: "Don't eat fat and sugar without
antioxidants."
The finding about bloomed chocolate is reassuring if you're
wondering whether to eat old chocolate, Vinson says. He says it may look
bad but that it still has active antioxidants.
Other studies have found lowering of blood pressure with dark
chocolate, says Eric Ding, PhD, a nutritional epidemiologist and
instructor of medicine at Harvard Medical School. He reviewed the
findings.
The fact that Hong did not, he says, could simply be because of the small size of the study.
"The LDL decrease and the HDL increase are consistent with previous research," Ding tells WebMD.
The blood sugar finding is newer, he says.
Hong reminds chocolate lovers that moderation is key.
These findings were presented at a medical conference. They
should be considered preliminary as they have not yet undergone the
"peer review" process, in which outside experts scrutinize the data
prior to publication in a medical journal.