Starting young
Reproduced from Issue 135 of Arthritis Today
Young children should eat good food and do plenty of exercise if they’re to avoid developing osteoporosis when they’re older. But it’s now known that keeping bones healthy starts even earlier – in the womb. New arc research which looks at how these factors interact should lead to some sensible guidance for new mothers - and mums to be.
Left to right: Dr Zoe Cole, Natalie Brooks, Holly Carpenter, Lynda Carpenter and Corinne Brooks (front).
Osteoporosis is the last thing on the minds of the two four-year-old girls (pictured right). But their mothers are all too aware that their children’s diet and exercise patterns will play a major part in the health of their children in later years.
The amount of bone grown during childhood and adolescence is an important contributor to keeping bones strong and warding off the brittle bone disease of osteoporosis.
While eating healthily and being active during toddling years is essential, keeping bones healthy starts even earlier – in the womb in fact. Corinne Brooks and Lynda Carpenter, the mothers of two little girls Natalie and Holly are more mindful of this than most, for during the past few years they have been part of the Southampton Women’s Survey, helping to provide evidence that a mother’s lifestyle during pregnancy plays just as big a part in their offspring’s future bone health as what happens to the baby after birth. They come back regularly to have their children’s bone density measured and their diets scrutinised.
Corinne and Lynda are among a group of 12,500 women and their children taking part in the survey, which started recruiting in 1998. What makes it unique is that it recruited the women before they became mothers, following them through pregnancy, and one of the additional studies attached to the main survey is now charting the progress of their children’s bones from birth to the age of seven.
Dr Zoë Cole, a specialist registrar in rheumatology at Southampton General Hospital, has now been awarded a three-year £164,135 clinical research fellowship from the Arthritis Research Campaign to continue the research, and specifically to find out how the two factors – poor growth of the foetus in the womb, and diet and exercise during a child’s early life – interact.
“I will be trying to find out as much as I can about the crucial time of bone development, and how this relates to later life disease,” explained Dr Cole. “How much is due to what happens in utero – in the womb – and how much is due to diet and activity levels?”
The effects of diets and lifestyles
The Southampton Women’s Survey has already provided much evidence about the effects of diets and lifestyles on people’s health and well-being in conditions as diverse as lung function, allergies, pre-menstrual syndrome and depression, as well as osteoporosis.
As part of the osteoporosis study, women have provided information about their food intake, activity levels, had their height and weight measured, blood tests and scans taken of the thickness and strength of their bones, and asked about their education and social class, whether or not they smoked. When they became pregnant they had further interviews and scans of their unborn babies at nine and 35 weeks. The women also had heel scans that show their bone changes during pregnancy. The babies’ fathers also had a bone scan, to provide information about the role of the father in determining babies’ bone structure.
Within a few weeks of birth several hundred babies had a bone density scan (DXA) to measure their bones, to provide an idea of how the babies’ skeleton grew during pregnancy. This was compared with the lifestyle information from the parents to identify key factors that can affect babies’ bone growth before birth.
Professor Cyrus Cooper from the University of Southampton (and a major arc grant holder), who is leading the osteoporosis study, has produced some fascinating research findings about the role of Vitamin D during pregnancy and its effects on babies’ bones.
In a study published in The Lancet in 2006, a study of 198 mothers indicated that the children of those mothers who lacked Vitamin D during pregnancy, had weaker bones at the age of nine. Vitamin D is necessary for the body to absorb calcium, which itself plays a key role in the formation of healthy bones. It is found in sunlight, and also in oily fish or fish body oil supplements.
Those women who took supplements or were exposed to more sunlight, which helps the body grow its own Vitamin D, had children with high bone density. Women who gave birth in spring, and were therefore exposed to less sunlight during winter months, had babies with lower bone density. It was the vitamin deficiency of the mother, rather than that of the child in early life, which affected the child’s bone strength in later life.
A new clinical trial into vitamin D and pregnancy
Professor Cooper is now setting up a clinical trial that may provide unequivocal evidence that supplementation of Vitamin D-deficient pregnant women could lead to stronger bones in their babies in later life.
Meanwhile Zoë Cole is about to invite up to 400 mothers back to the clinic with their children, now aged seven. The women will fill in daily food diaries on behalf of their offspring, and both mothers and children will have an activity monitor to measure their heart rate and muscle contractions to measure how active they are in a week. The youngsters will also have full body DXA scan and a CT scan of either the leg or arm to measure the health and strength of their bones.
“We can find out exactly how fit these kids are.”
“It’s an acknowledged problem that there is a concern that only mothers who are interested in nutrition and healthy lifestyles will come along, so it won’t be representative, but we think the women on the survey are pretty representative of Southampton, and that Southampton is quite representative of the country,” says Dr Cole. “It can be very difficult for mums to correctly estimate how much activity their children do. That’s where the heart monitor comes in; so we can find out exactly how fit these kids are.”
Corinne Brooks and Lynda Carpenter, both typical working mothers, provide healthy diets for their youngsters. Natalie eats no junk food and loves oily fish, and is also very active. The little girl has done gymnastics since she could walk, swims regularly and goes to the park every day. As an occasional treat she and her brother Wilfred, aged two, have ice-cream. But then they usually get a sugar rush and “go nuts” says their mum Corinne Brooks.
“I think taking part in the survey has made me more aware about healthy living, although during pregnancy I wanted to do everything right anyway,” adds Corinne. “Having to complete your child’s food diary does make you more aware of what they are eating. I have this ideal in my head of what the children should eat which I can’t always stick to if I’m busy. I suspect I gild the lily a little sometimes!”
Holly Carpenter is lucky in that her father works for a fruit and vegetable company so fresh produce is in regular supply, and the little girl will happily eat broccoli, Brussel sprouts, cabbage and cauliflower and adores pasta. She also has plenty of fresh meat, pasta and yoghurt. And like most four-year-olds she also likes chocolate – in moderation, of course.
While there are no guarantees, Corinne and Lynda are both doing all they can to ensure that their daughters will grow up with healthy bodies – and strong bones.
Natalie Brooks’ food diary:
Eats home-cooked food, no junk or fast-food.
No fizzy drinks apart from sparkling water. Has water with her meal.
Occasionally drinks pure fruit juice, not squash.
Full fat milk on cereal.
Eats sweets and chocolate “in moderation”.
Occasionally has low-fat crisps.
Eats burgers - home-made only.
Eats plenty of red meat and oily fish.
Favourite meal: salmon fishcakes.
