Lifestyle Factors

Alongside nutrition and exercise, several lifestyle factors significantly influence bone density and fracture risk. The good news is that these are largely within your control.

Smoking

Smoking is one of the most harmful lifestyle factors for bone health. Research shows that:

• Smokers have significantly lower bone density than non-smokers of the same age and sex
• Smoking reduces blood supply to bones, impairing bone cell function
• It lowers oestrogen levels in women, accelerating bone loss
• Smokers have approximately double the hip fracture risk of non-smokers
• Smoking also increases fall risk by affecting balance and coordination

The good news is that quitting smoking reduces fracture risk over time, though the damage already done to bone density cannot be fully reversed.

If you would like support to quit smoking, the HSE's free service Quit.ie offers online tools, a quitline, and text support.

Alcohol

Heavy alcohol consumption is a significant and independent risk factor for osteoporosis:

• Alcohol interferes directly with bone formation by suppressing osteoblast (bone-building cell) activity
• It reduces calcium absorption and increases urinary calcium loss
• Heavy drinkers are at significantly higher risk of falls and fractures
• Alcohol can also interfere with Vitamin D metabolism

The Irish low-risk drinking guidelines recommend:

One standard drink in Ireland contains approximately 10g of alcohol — roughly half a pint of beer, a small glass of wine, or a pub measure of spirits.

For bone health, moderate alcohol consumption (within the above limits) has a less clear impact, but exceeding 14 units/week significantly increases fracture risk. If you are already at high risk of osteoporosis, limiting alcohol consumption is advisable.

Body Weight

Being underweight is a significant risk factor for osteoporosis and fractures:

• A BMI below 18.5 is associated with significantly lower bone density
• Low body weight means less mechanical loading on the skeleton (less stimulus for bone formation)
• Underweight individuals often have lower oestrogen, testosterone, and other hormones that support bone health
• Calorie restriction and disordered eating (anorexia nervosa in particular) are strongly associated with severe, early-onset osteoporosis

Maintaining a healthy body weight is important — but being very overweight also increases fracture risk through increased falls risk, so the goal is a healthy BMI (18.5–25 ideally), achieved through balanced eating and regular activity.

Medications That Affect Bone Health

Several commonly prescribed medications can reduce bone density with long-term use. It is important to know about these — but never stop a prescribed medication without speaking to your GP. In most cases, the condition being treated poses a greater risk than the effect on bones, and bone protection strategies can be put in place.