Having
too little calcium in the diet increases women's risk of a hormone condition
that can cause bone fractures and kidney stones, scientists suggest.
Primary
hyperparathyroidism (PHPT) affects around one in 800 people during their
lifetime and is most common in post-menopausal women. Writing in the British
Medical Journal, the team suggest increasing calcium intake cuts the risk of
the disease. Adults need around 700mg of calcium a day. Milk and other dairy
foods, nuts and fish such as sardines and pilchards (where the bones are eaten)
are some dietary sources of calcium. Taking too much could cause stomach pains
and diarrhoea.
PHPT
is caused by overactive parathyroid glands secreting too much parathyroid
hormone. As well as bone and kidney problems, there have also been suggestions
it is linked to an increased risk of high blood pressure, heart attack and
stroke.
The
importance of calcium
Calcium is a mineral that helps build strong
bones and teeth, regulates muscle contraction and makes sure the blood is
clotting normally. Milk and dairy products have long been held as an important
source of calcium. Other sources of calcium include fish, dried fruit, sesame
seeds, almonds, soya and dark green leafy vegetables. Vitamin D is also
important because it helps the body absorb and retain calcium in the bones,
making them strong
Benefits v s risks
The US team from Brigham and Women's Hospital
looked at 58,300 women who were taking part in a much broader ongoing piece of
research called the Nurses' Health Study. All were aged between 39 and 66 in
1986, when the study began, and had no history of PHPT. The women have completed food questionnaires
to record how frequently they ate particular foods or supplements - including
calcium - every four years, with the latest being completed in 2008. Over that
22 year period, 277 cases of PHPT were confirmed. The researchers divided all
the women into five groups, depending on the calcium intake. They accounted for
factors such as age, body mass and ethnicity. It was found those with the
highest intake of dietary calcium had a 44% reduced risk of developing PHPT
compared with the group with the lowest.
Writing
in the journal, the team led by Dr Julie Paik, said: "Increased calcium
intake, including both dietary and supplemental calcium, is independently
associated with a reduced risk of developing primary hyperparathyroidism in
women." James Norman, of the Norman Parathyroid Centre in
Florida, added that daily calcium supplements in "modest doses" were
likely to provide "more benefits than risks". But experts in the UK
say people should be able to get the calcium they need from their diets.
BBC News
No comments:
Post a Comment