Chocolade en de botten*
Uit een studie onder duizend vrouwen in de leeftijd van 70 tot 85 blijkt dat zij die iedere dag (veel)
chocolade eten een duidelijk slechtere botdichtheid hebben dan zij die dat zo af en toe maar eens doen. In
chocolade zit behalve veel gezonde bioactieve stoffen ook oxaalzuur dat de opname van calcium afremt en in veel chocolade zitten ook suikers die de calciumuitscheiding bevorderen.
"Chocoholics" may risk brittle bone disease
There's increasing evidence that chocolate is good for the heart, but new research suggests it may not be so great for the bones.
Older women who ate chocolate every day had weaker, thinner bones than their peers, who indulged less frequently, and the difference didn't appear to be due to overall dietary habits, Dr. Jonathan M. Hodgson of the University of Western Australia School of Medicine and Pharmacology, Perth and colleagues found.
"This is the first study to investigate the relation between chocolate intake and bone structural measurements and raises concerns that frequent chocolate consumption may increase the risk of osteoporosis and fracture," Hodgson and his team write in the American Journal of Clinical Nutrition.
Chocolates are rich in flavonoids, which some studies suggest can be good for the bones, the researchers say. However, they add, chocolate also contains oxalate, which blocks the absorption of calcium, and sugar, which can boost calcium excretion.
To investigate chocolate's effect on the bones, the researchers looked at 1,001 women aged 70 to 85 who were participating in a study of calcium supplementation and fracture risk.
Women who were daily chocolate consumers had a 3.1 percent lower bone density, on average, than those who ate chocolate less than once a week, as well as weaker bones in the heel and tibia, or shin bone.
Frequent chocolate eaters ate the same amount of fresh fruit and vegetables as those who ate chocolate less often. They also consumed no more saturated fats, carbohydrates or sugar, and less protein, starch, fiber, and potassium.
Women who ate chocolate every day weighed less and, on average, had lower a body mass index (BMI), the ratio of height to weight, a formula frequently used to determine if an individual is over- or underweight. The chocolate eaters also consumed more calories and had a higher socioeconomic status.
The relationship between heavy chocolate consumption and lower bone density remained even after the researchers took these factors into account. They suggest: "the effect may be associated with a constituent of chocolate rather than an associated lifestyle or dietary factor."
They call for further studies to confirm or disprove the relationship, and conclude that "confirmation could have important implications for the prevention of osteoporosis and fracture."
SOURCE: American Journal of Clinical Nutrition (Februari
2008)
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