How to protect yourself against osteoporosis: From your teens to your 40s and older

When you think about your physical wellness, how often does bone health occur to you? Not often, we imagine. 

“Few women think of bone strength or mass until later in life or when they sustain fractures associated with low bone mass,” said Dr Lim Lian Arn, an orthopaedic surgeon at Gleneagles Hospital.

“By that time, however, it is already, in a sense, late in the game,” he said.

This condition of reduced bone mass and quality, leading to increased fracture risk, is what describes osteoporosis.

And it is more common in women.

Over the next two decades, a staggering 319 million people above the age of 50 from the Asia-Pacific are projected to be at high risk of osteoporotic fracture, according to statistics cited by the Asia Pacific Consortium on Osteoporosis, which is launching what it describes as a "world-first, interactive, educational healthcare" resource for physicians to foster best practice osteoporosis care in the region. 

More than 50 per cent of the world's hip fractures are expected to occur in the region by 2050, it said, adding that Singapore currently has one of the highest numbers of hip fractures globally.

According to Dr Chew Chee Kian, an endocrinologist at Tan Tock Seng Hospital (TTSH), incidence rates of hip fractures increased five-fold in Singapore women between the 1960s and 1990s, amid the country's "rapidly ageing population".

Knowing the pattern of bone mass changes across a woman’s lifespan can influence the strategies women use to reduce their risk of osteoporosis, and these have to be put into action earlier, not later.

“Osteoporosis can occur at any stage of a woman’s life, although it is more common in postmenopausal women,” said Dr Chew. To mark World Osteoporosis Day on Oct 20, we look at how bone mass changes in women at every stage of life and what lifestyle habits you can change or adopt for optimum bone health.  

IN ADOLESCENCE AND YOUTH

• Ensure diet is rich in calcium and vitamin D
• Avoid caffeinated drinks
• Engage in high-impact exercise

Optimal adult bone mass is genetically predetermined and for women, this is gained mostly between the ages of 12 and 20, said Dr Chew. “Adolescence represents a window of opportunity to maximise bone gain,” he said.

What to eat: To promote rapid bone accrual, girls between the ages of 10 and 18 should consume 1,000mg of calcium a day, according to the Health Promotion Board (HPB). This can be obtained from dairy products such as milk, yoghurt and cheese, as well as dark green vegetables, soya products and calcium-fortified soya milk, said Dr Chew. 

To promote better absorption of calcium, girls should also ensure adequate vitamin D intake. The HPB’s recommended daily absorption of vitamin D is 2.5mcg for those aged seven and above. 

This can be obtained through adequate sun exposure – Dr Chew recommends being exposed to sunlight for about 10 minutes to 15 minutes daily between 10am to 3pm – or eating foods that are enriched with vitamin D, including oily fish like salmon and sardines, eggs and liver. 

Girls should avoid caffeinated drinks, including colas and energy drinks, because caffeine increases urinary and faecal calcium losses, said TTSH dietitian Clarissa Tai.

What to do: A 2016 report found that more than 80 per cent of girls aged between 11 and 17 were physically inactive, said Dr Lim. “We suspect that since that time, that percentage has not changed significantly and is something we need to keep an eye on.” 

This period is crucial as a 10 per cent increase in peak bone mass in adolescents can reduce the risk of osteoporotic fractures in adults by 50 per cent, said Dr Lim.  

Hence, exercise and activity should be encouraged, in particular high-impact movement, because “the more you stress the bone, the more it responds to that stress by becoming stronger”, said Dr Lim. 

Exercises that stress the bones and strengthen them include running, skipping and trampolining. 

FROM YOUR 20S TO 40S

• Adjust calcium and vitamin D intake accordingly
• Cut down on salty and processed food
• Avoid smoking
• Limit alcoholic drinks to one a day
• Limit caffeinated drinks to three cups a day

Bone mass gain begins to slow down when a woman turns 20 and final peak bone mass is attained at the age of 30. After this, it remains largely stable, doctors told CNA Women. 

During this period, women typically experience lifestyle changes and milestones that may impact the preservation of their bone mass, such as largely sedentary work and the adoption of habits such as alcohol drinking and smoking. 

Many women will also experience pregnancy in this period. The mum’s calcium is transferred to the foetus for bone development mostly in the second and third trimesters of pregnancy, said Dr Chew. Calcium is also excreted in breast milk during lactation. 

“High calcium demand, coupled with hormonal changes during pregnancy and lactation, make women susceptible to bone loss and subsequent osteoporosis later in life.

“After delivery and cessation of lactation, bone loss reverses and recovery occurs,” Dr Chew added.

What to eat: Continue to consume foods rich in calcium during this time, with the recommended intake being 800mg a day. If you’re pregnant or lactating, the recommended intake for calcium is 1,000mg daily. 

The recommended daily intake for vitamin D also increases due to this, to 10mcg. At this stage, you may also take calcium and vitamin D supplements but only if you’re unable to obtain the adequate amounts from your diet and sun exposure. 

Protein is also essential for good muscle function and health, which helps strengthen the bone. Tai said adults below the age of 50 should consume 0.8g/kg of body weight per day. Be careful about consuming too much protein because this may cause calcium loss, Dr Chew warned. 

During this period, cut down on salty foods as much as possible as salt can inhibit calcium absorption. Tai recommends limiting it to less than 2,000mg of sodium a day, or less than one teaspoon of salt a day. 

To achieve this, start by comparing food labels and purchasing products with lower salt content. You can also reduce your intake of broths or soups and flavour foods with spices or pepper when cooking. 

A diet high in refined sugars and processed food has also been associated with lower bone mineral density, said Tai. Opt for unsweetened or reduced sugar drinks, only consuming sugar-free sweets and replacing canned or dried fruit with fresh fruit. 

Women should also limit alcoholic drinks to one a day as these can reduce bone formation and calcium absorption. Similarly, coffee, tea and soft drinks should be limited to three cups a day because the caffeine from these can cause calcium loss. 

What to do: Compared to physical inactivity, regular weight-bearing exercises (or workouts that keep you on your feet, with your bones supporting your weight) have been shown to increase bone gain, said Dr Chew. At a minimum, women in this age group should commit to simple exercises like brisk walking, jogging and skipping. 

Avoid smoking, doctors say, as it causes bone loss and reduces the production of oestrogen, which helps regulate bone turnover and maintain a healthy bone mass. 

IN YOUR 50S AND ABOVE

• Consume more calcium, complemented by adequate sunlight
• Consume more protein
• Ensure diet includes sources of magnesium and vitamin K
• Do exercises that promote balance

With the onset of menopause around the age of 50, bone loss accelerates due to a marked decrease in oestrogen levels, said Dr Chew. 

By 10 years after menopause, at around 60 years, oestrogen-related bone loss slows down and age-related bone loss predominates, he said. The rate of loss of bone mass continues at that accelerated pace until the end of life, doctors said. 

What to eat: Women older than 50 may begin consuming 1,200mg of calcium per day. This can come from a variety of foods including low-fat milk, fish with edible bones like sardines and mackerel, baked beans and beancurd.

As vitamin D is needed for better calcium absorption, women in this age group should continue to ensure adequate sun exposure, around 30 minutes daily, said Tai. 

Some groups of individuals, including the frail elderly as well as those who wear more veiled clothing or have a deeper skin tone may have minimal exposure to sunlight and may benefit from taking vitamin D supplements. This should not exceed 100mcg per day, said Tai, as excessive intake can lead to symptoms like diarrhoea, nausea, joint pain and headaches.

During this period, women may begin to consume more protein, around 1.2g/kg body weight per day. However, you should consult your doctor first as these recommendations may need to be adjusted if you have certain medical conditions, such as chronic kidney disease. 

Minerals such as magnesium and vitamin K may play important roles in bone health, said the dietitian. Low magnesium levels have been associated with increased fractures and lower bone mineral density, while vitamin K is required in the formation of bone proteins. 

A diet high in vitamin K is associated with a lower risk of fracture and enhances bone mineral density in older people, she said. Consuming green leafy vegetables, nuts and seeds, wholegrains and yoghurt all help to ensure that one is getting adequate amounts of these nutrients, she added. 

What to do: For older women, Dr Chew recommends exercises that strengthen the core and promote balance as these prevent falls. Such exercises include tai chi, qigong and yoga.