Preventing osteoporosis is not always possible, but everyone has the ability to reduce fracture risk and minimise the effects. Here are some guidelines for healthy bones.
Don't cut out alcohol completely
Recent US research found although moderate alcohol consumption is beneficial for bones, bone mineral density is lower in men who drink more than two standard drinks each day. Similar results have been found in women, too.
Too much alcohol interferes with bone growth and the replacement of bone tissue. During adolescence, alcohol consumption can reduce peak bone mass, producing weaker bones in adulthood. In adults, alcohol consumption inhibits the function of osteoblasts and interferes with vitamin D production, which all disrupt calcium balance. Excess alcohol also plays havoc with hormone production by reducing testosterone levels in men and oestrogen levels in women, both of which increase osteoporosis risk. If you don't drink, there's no need to start now, but if you do, enjoy it in moderation.
Don't cut out dairy
As our biggest source of calcium, dairy products (or calcium-fortified soy alternatives) are important for bone health: 99% of your body's calcium is stored in bones and teeth. The remaining 1% can be found circulating in your body, where it plays a role in heart health, muscle and nerve contraction, and blood clotting.
If we don't get enough calcium, circulating levels of calcium are maintained at the expense of our bones. Optimising calcium intake early in life can reduce the likelihood of pre-pubertal bone fractures and increase peak bone mass in adults by 5-10%, which has the potential to reduce fracture risk by more than 50% in the later years.
A lifetime of dieting can lead to an inadequate intake of important bone nutrients, which increases the risk of developing osteoporosis. And maintaining a low body weight reduces the load placed on bones – a cause for concern because bones respond to mechanical stress such as body weight by stimulating formation of osteoblasts, improving bone strength.
Carrying excess weight is a separate danger, as having a BMI above 30 can increase the risk of becoming immobile, developing osteoarthritis, and falling. A healthy body weight achieved through a healthy, balanced diet, is best for bone health.
Don't be afraid to weight train
Weight-training not only results in stronger muscles and a slimmer appearance, it also builds bone strength. When exercising, bone responds by getting stronger, resulting in increased bone mineral density in adolescents, maintained bone density in young adults, and slower bone loss in older adults.
According to US research, exercising regularly may not reverse advanced bone loss, but it can reduce the risk of developing osteoporosis by 59%. Performing at least 30 minutes of weight-bearing exercise, such as brisk walking or running on most days of the week, as well as two to three weekly weight-training sessions, will help maintain strong bones. And keep up non-impact exercises such as tai chi and yoga as they improve balance, posture and functional movements, which can help to decrease the risk of falls and broken bones.
Do limit salt intake
Salt (sodium chloride) intake directly affects the amount of calcium our bodies excrete in urine. And the more salt we eat, the more calcium we excrete. Luckily for us, our body has the ability to compensate by increasing calcium absorption in the small intestine. But there's a danger here if you're not getting enough calcium – then, the amount of calcium your body absorbs will be less than needed to offset salt's effects, so your body will take the calcium it needs from your bones instead.
So, for strong healthy bones and to reduce your risk of heart disease and stroke, limit salt intake.
Do add milk to your coffee
Caffeine produces a small increase in urinary calcium excretion and a very small decrease in calcium absorption. If your calcium intake is less than 750mg per day, a daily caffeine intake equivalent to about three cups of brewed coffee is enough to promote bone loss.
But research shows this can be negated with a diet containing adequate calcium, as the body can balance out caffeine's effects by reducing calcium excretion later in the day. To help ensure adequate calcium intake, try drinking your coffee with milk and limit caffeine consumption to no more than 300mg per day (equivalent to six teas, three instant/plunger coffees, or one to two regular espressos).
Do stop smoking
Despite the majority of New Zealanders being non-smokers, nearly one-quarter are still risking their bone health by lighting up. In fact, smokers have been found to have significantly lower bone mass than non-smokers. It's thought the cadmium in cigarettes lowers bone density.
Do choose calcium-fortified
Even though dairy is our main source of calcium, most of us don't get as much as we need. Drinking milk with extra calcium is a good way to boost your calcium intake – two glasses of calcium-fortified cow's milk will give you the same calcium as three glasses of regular milk.
Don't stay inside all day
UV rays on your skin are the best source of vitamin D – a fat-soluble vitamin which increases absorption of calcium and phosphorus in the gut, maintains calcium levels in the blood, and helps strengthen the skeleton. In general, exposing 15% of your body to the sun for about 10 minutes a day in summer, and about 20-30 minutes in winter will help to ensure you reach your daily vitamin D requirements and reduce osteoporosis risk.
Do eat protein
Some studies have shown that increasing protein intake can sometimes increase urinary calcium excretion, potentially resulting in weaker bones. But these studies have generally been conducted with pure protein rather than dietary sources such as milk, which contain other bone-friendly components such as phosphorus.
n longer-term studies, the negative effect of protein on bone is not seen, which suggests it simply may take a while for the body to adjust its response to a change in protein intake. According to 2007 research, high protein intakes were found to be associated with higher bone mass, as long as calcium intakes were above 600mg each day.
Studies in the elderly have also linked low protein intake to increased bone loss.
For healthy bones, make sure you include protein in your diet, along with sufficient calcium.