Osteoporosis: Causes, therapy and prevention
Osteoporosis is a fairly common progressive condition in which bones become thinner, weaker and fragile, and are more likely to break because their mineral density is reduced. There are often no warning signs or symptoms until a minor fall or a sudden impact causes a fracture of the bone. It affects both men and women and although it is most commonly seen among the elderly, it can affect young individuals as well. Women are at a higher risk of developing osteoporosis compared to men because of the hormonal changes that occur in the menopause, which directly affect bone density. Losing bone density is a normal part of the ageing process that is initiated approximately when we get 35 years old; however, under certain conditions loss of bone density can lead to osteoporosis.
At risk groups for developing osteoporosis include:
- Women in the first few years after menopause. This is due to the decrease in estrogen levels that reduces the body’s ability to absorb calcium.
- Women who have had their ovaries removed.
- Individuals with inflammatory conditions, such as rheumatoid arthritis, Crohn's disease and chronic obstructive pulmonary disorder (COPD); or with conditions that affect the hormone-producing glands, such as hyperthyroidism or hyperparathyroidism.
- Individuals with a family history of osteoporosis, and particularly with a history of hip fracture.
- Individuals who have been taking medications that affect bone strength or hormone levels for more than three months, including glucocorticoids and medications used to treat breast or prostate cancers.
- Individuals with malabsorption problems.
- Individuals who smoke, drink heavily, or do not exercise regularly.
- Individuals with a BMI of 19kg/m2 or less and those with eating disorders including anorexia and bulimia.
Osteoporosis is often diagnosed after weakened bones have led to a fracture. If you are at risk of developing osteoporosis, your doctor may refer you for a bone mineral density scan, known as a dual energy X-ray absorptiometry (DEXA, or DXA) scan. Normal X-rays are also a useful way of identifying fractures.
Prevention: "How can I safeguard my bones?"
It is very important to strengthen your bones in your first 30 years to minimize age-related bone loss. There are 4 steps that you can take to achieve this:
- Follow a healthy balanced diet that provides daily at least 5 portions of fruit and vegetables and plenty of vitamins and minerals that are needed for bone health including calcium, phosphorus, zinc, vitamin D and vitamin K. It is also essential to ensure adequate intake of protein-containing foods.
- Daily weight-bearing exercise such as weight training, walking, hiking, jogging or dancing, to help strengthen lower bones.
- Avoid smoking as it leads to increased bone loss and increases the risk of osteoporosis.
- Keep your alcohol intake within daily guidelines. Research shows that drinking a lot of alcohol increases the risk of osteoporosis. However, there is some evidence that having a moderate amount of alcohol may be protective. Stay within the guidelines of 2 units of alcohol for women and 3 units of alcohol a day for men, with at least three alcohol free days each week. Each unit equals to 25ml single small shot of spirit (ABV 40%).
How much calcium do I need?
An ideal calcium intake for adults ranges between 700-1000mg per day. You can find calcium in dairy products or plant based milks and yogurts fortified with calcium, beans and lentils, nuts and seeds, dark leafy vegetables such as spinach and kale, amaranth, edamame and tofu. If you find it hard to get this amount from diet alone, you should consider taking a daily supplement providing 400-600mg of calcium. Prefer combining your calcium supplements with those that provide 5-10mcg of vitamin D, in order to enhance calcium absorption.
"How much vitamin D do I need?"
Most of your vitamin D should be made in your body from exposure to sunlight. You can achieve this by leaving your face and forearms uncovered in the sun for about 20 minutes a day between the hours of 10am and 3pm, between April and October. You may also consume foods rich in vitamin D including oily fish, liver, eggs, powdered milk, and fortified margarines, fruit juices and breakfast plant milks and cereals. If you do not meet your vitamin D requirements, vitamin D3 supplements derived from cod liver oil, or vitamin D2 supplements derived from algae oil (for vegetarians & vegans) that provide 10mcg of vitamin D can be useful. Cod liver oil should not be taken by pregnant women as it also contains high levels of vitamin A which can be harmful to the unborn child. If you take a fish liver oil supplement you should not take another source of vitamin D such as multivitamin on the same day.
Vitamin D supplementation is most often required for:
- Children aged six months to five years (7.0-8.5mcg/day) unless they are having at least 500ml of fortified infant formula milk.
- Pregnant and breastfeeding women and people of 65 years (10mcg/day).
- People diagnosed with osteoporosis (prescribed by your doctor).
- Gandy, J. (2014). Manual of dietetic practice. (5th ed.). London: Wiley-Blackwell.
- The British Dietetic Association - Osteoporosis