October 13,
2005
20th
October is World Osteoporosis Day, and the theme for this year is
Strong Bones for Healthy Living, with special focus on the
beneficial role of exercise in the prevention of osteoporosis. In
support of the event, the Asian Food Information Centre provides
some insights on osteoporosis trends in the region, and tips for
prevention.
What is
Osteoporosis?
Osteoporosis is
a degenerative, skeletal disease that is characterised
by more brittle bones and increased frequency of fractures, especially of hip,
vertebrae and wrist. Osteoporosis can strike adults from the age of about 30,
but is more common in those aged 60+.
Isn’t
osteoporosis a problem of the western world ?
Based on current
trends, the World Osteoporosis Foundation project that more than 50% of all
osteoporotic hip fractures will occur in Asia by the year 2050.
Why is
osteoporosis on the increase ?
Undoubtedly,
increased life expectancy is contributing to the rise because bone density
declines with age, and without active steps to slow this process more and more
individuals’ will be faced with fragile bones in old age.
Plus, many
Asian diets are low in calcium, an essential mineral for maximising bone
density.
Also,
the
trend towards increasingly sedentary lifestyles with little or no weight-bearing
activities such as walking, manual work, carrying goods and effects is a major
contributing factor.
How Important
is Exercise for Strong Bones?
Both weight
bearing and resistance exercises are essential for building and maintaining bone
health. Exercise has also been demonstrated
to help by improving balance and muscle strength, which reduces the risk of
falls- the most common cause of an osteoporotic fracture.
Weight-bearing
exercises, in which the bones and muscles work against gravity increases bone
density. Any exercise in which feet and legs are bearing body weight, such as
walking, jogging, stair climbing, dancing, or lifting weights will improve bone
density; swimming and bicycling are not weight-bearing and so although highly
beneficial for health in other ways will not help towards the prevention of
osteoporosis.
Resistance
exercises that use muscle strength will improve muscle mass and also strengthen
bone. Activities such as weight lifting, not only improve bone density, they
also improve the strength of the muscles attached to bone providing additional
protection against fracture.
How Important
is Nutrition for Strong Bones?
Maintaining a
diet that includes adequate amounts of calcium and vitamin D is also essential
for reducing the risk of developing osteoporosis.
The Best
Dietary Calcium Sources ?
Dairy foods
such as milk, yoghurt, cheese are all excellent sources
of calcium.
Green beans,
bok choy, broccoli, Chinese cabbage flower leaves, Chinese mustard greens,
Chinese spinach, kale, spinach, sweet potatoes are also good sources of
calcium.
Soy milk and
bean
curds made with
calcium salts are all rich in calcium and other nutrients
in soy-based foods might also offer additional protection against osteoporosis.
There are also
an increasing number of calcium fortified foods available in the market, such as
orange juice and breakfast cereals and these can make a valuable contribution
to dietary calcium intake.
What about
lactose intolerance ?
Many Asian
adults are lactose intolerant, as a result of a lack of the digestive enzyme
lactase in the gut. This can lead to digestive problems, such as bloating, gas,
cramps and diarrhoea, and those who have experienced these symptoms tend to
avoid dairy products as a result.
Researchers
from Purdue University in the US, published a review of osteoporosis and lactose
intolerance in 2001 in the Journal of the American College
of Nutrition. The review found that individuals with lactose intolerance have
lower bone density. However, the review also recommended, that the majority of
those who are lactose intolerance could consume
some calcium-rich dairy products, by following some or all of these tips -
Ø
Lactose in yogurt (especially live culture yoghurt) is digested better than
lactose in milk, and yogurt has been found to be well tolerated by many with
lactose maldigesters.
Ø
Consuming small amounts of lactose-containing foods as part of a mixed meal is
better tolerated than eating dairy foods on their own.
Ø
Hard cheeses, chocolate and higher fat milks, and ice cream are usually better
tolerated than other dairy foods.
Ø
Commercially available lactose digestive aids can aid in the digestion of dairy
products.
The Best
Dietary Sources
of Vitamin D?
Vitamin D can
be synthesised in the skin through direct exposure to sunlight. The amount of
vitamin D produced in the skin varies depending on total exposure to UV light.
Time of day, intensity of skin pigmentation, the use of sunscreen will all have
a direct impact on how much vitamin D the body is able to produce internally,
and for many including some vitamin D-rich foods in the diet is a prudent
precaution.
For those who
have little or no direct exposure to sunlight such as those who are housebound,
or who cover most of their face and body for religious or cosmetic reasons,
dietary sources of vitamin D are especially crucial.
The best
dietary sources of vitamin D are vitamin D-fortified dairy products, egg yolks,
oily fish and liver. Fortified milks, fortified margarine, butter, cereals,
beef, liver, and oils are also rich in vitamin D.
What about
Supplements?
For those who
are unable to meet all their calcium and/or vitamin
D needs through diet alone, it may be advisable to consider a dietary
supplement. Calcium supplements and low doses of vitamin D have been shown to
reduce the risk of hip fracture in elderly women.
In Conclusion
Bone mass peaks
in early adulthood, and then starts to decline slowly throughout later life.
Maximising the density of bone mass in early adulthood, and then slowing the
demineralisation process in later life is key to the prevention of osteoporosis
in later life.
A diet which
includes
some calcium and vitamin
D rich foods every day. Along with regular weight bearing exercise are the most
effective methods available for prevention of osteoporosis.
END
Additional
Information –
Ø
China: From
1988 to 1992, the incidence of hip fractures in Beijing increased by 34% in
women and 33% in men.
Ø
Hong Kong: In
1996, the acute hospital care cost of hip fracture per year amounted to US$17
million. The incidence of hip fracture has increased by 200% in the last 3
decades. The prevalence of vertebral fracture was 17% in men and 30% in women.
Ø
India: Expert
groups estimate the number of osteoporosis patients is currently at
approximately 26 million (2003 figures) with the numbers projected to increase
to 36 million by 2013.
Ø
Japan: New hip
fractures increased a dramatic 1.7-fold in the 10 years from 1987 to 1997 in
Japan. The prevalence of osteoporosis in the Japanese female population aged
50-79 years has been estimated to be about 35% at the spine and 9.5% at the hip.
Ø
Korea: The
occurrence of hip fractures increased about 4-fold over 10 years (1991-2001).
The number of hip fractures after 75 years of age was 4.3 per 1000 women and
2.97 per thousand in men.
Ø
Singapore:
Compared to the 1960's, hip fractures in women have gone up 5 times in women and
1.5 times in men.
Links to
additional information –
