OVERVIEW OF OSTEOPOROSIS

What is Osteoporosis?

Osteoporosis is a disease of bones where bone mineral density is reduced and the amount and variety of proteins in bone is altered. This change in bone structure makes bones brittle and increases the risk of fracture.

Bone is made up of minerals, mainly calcium and phosphate, bound together by strong collagen fibres. 99% of the body’s calcium is stored in bone. Our bones have a thick hard outer shell and softer spongy bone (or trabecular bone) which has a honeycombe-like structure. The most active cells in the bone are osteoblasts and osteoclasts found in the bone marrow which work on bone formation and removal. Osteoblasts constantly work on building the bone and osteoclasts are responsible for the removal of the bone.

The balance between the breakdown of old bone and the formation of new bone changes at different stages of our lives.

It has been discovered that by approximately 22 years of age there is a continuous increase in bone mass e.g. osteoblasts that are making more bone than osteoclasts are able to remove. It is estimated that by the age of 40 our bone mass starts to decrease e.g. the removal of the bone by osteoclasts is higher than regeneration of new bone by osteoblasts.

Reduced bone mass is a part of the aging process but it is usually a lot faster in post-menopausal women due to the hormonal changes and especially to reduction in oestrogen levels.

Osteoporosis is usually diagnosed after a fracture is identified, in hospital, using a DEXA scan. There is, however, no single blood test which will tell your doctor if you have osteoporosis.

Prevalence of osteoporosis.

  • Approximately 3 million people in the UK have osteoporosis.
  • One in two women and one in five men, over the age of 50, will break a bone mainly due to poor bone health.
  • 70,000 people have osteoporotic hip fractures each year

Causes of osteoporosis

Bones are at their thickest and strongest up to your mid 20-s, but from 40 onwards our bones gradually lose their density as a natural part of ageing. Genetics play an important part in the development of osteoporosis along withy other factors such as the menopause, hysterectomy before the age of 45, previous bone fractures, long-term immobility, being underweight, long-term use of corticosteroids, breast cancer treatment, Aromatase inhibitors, an overactive thyroid, rheumatoid arthritis, a decreased function of the testicles (hypogonadism), Crohn’s disease, chronic liver disease or coeliac disease.

The good news is, that despite the above list of un-modifiable factors, there is convincing research evidence that we can improve our bone health by a well-balanced diet and a good exercise regime.

 

NUTRITION AND EXERCISE

Diet and exercise has a role to play in the treatment of Osteoporosis.

The key advice is to have a healthy balanced diet rich in calcium and vitamin D and regular exercise, especially weight bearing exercise. The National Osteoporosis Society recommends jogging, aerobics, tennis, weight-training, dancing and brisk walking.

CALCIUM A

Good dietary sources of calcium include milk and dairy products, fortified soya milk and yoghurts, tofu, fortified breakfast cereals and some green leaf vegetables. If your dietary calcium intake appears to be less than 800mg/day, calcium supplements should be considered.

VITAMIN D

To absorb calcium you need vitamin D. Vitamin D is produced naturally when your skin is exposed to sunlight and can also be obtained from some foods such as oily fish, fortified margarine, liver etc. However, remember that wearing sunscreen higher than Factor 8 reduces vitamin D production from sunlight by 95%.

SUPPLEMENTS

If you don’t get enough vitamin D and calcium, you might have to consider taking supplements. An ideal calcium intake for adults is between 700mg to 1000mg a day. From the age of 1 the recommended level of vitamin D to prevent osteoporosis is 10mcg (400 IU*) per day. Those over 70 years old with proven osteoporosis should take 15mcg (600 IU*) per day. Remember, that your body can only cope with a certain amount of calcium, and if you take too much you may develop kidney stones or other complications. Calcium can also interfere with absorption of some important minerals like iron. Therefore it is important to consult your doctor or dietitian to advise you on the type and amount of supplements to take.

PROTEIN RICH FOODS

Make sure that you consume enough protein-containing foods such as lean meat, fish, dairy or vegetarian alternatives, tofu or pulses, twice a day.

SOYA

Low levels of oestrogen following menopause or ovary removal can increase the risk of osteoporosis. Consuming plant oestrogen may potentially help with calcium absorption. Research shows that populations consuming large amounts of soya, which is a rich source of plant oestrogen, appear to have higher bone densities than those with a lower intake of soya. Soya products also seem to help to reduce the symptoms of menopause, such as hot flushes.

VITAMIN K

Consuming adequate amounts of vitamin K, found in green leaf vegetables, helps form the bone-hardening protein called osteocalcin.

There is also evidence to suggest that the following dietary factors can have an adverse effect on bone health:

  • General malnutrition
  • Excessive vitamin A consumption of over of 1500mcg (5000IU*) daily
  • High sodium intake
  • Low potassium intake
  • Inadequate Calcium : Phosphate ratio
  • Inadequate Zinc, Cupper Manganese and vitamin C intake
  • Alcohol
  • Smoking

 

MEDICATIONS

To increase your bone density your doctor may prescribe to you the following medicines.

  • Calcitonin (eg Miacalcic) – a hormone usually made by the thyroid gland. Its function is to block the action of the cells that break down bone.
  • Bisphosphonates (e.g. alendronate – Fosamax, etidronate – didronel, risedronate – actonel, and zoledronate – Aclast). Their function is to slow down bone loss.
  • Strontium ranelate (eg Protelos) – it stimulates new bone to grow and reduces bone loss.
  • Raloxifene (eg Evista) – this is a synthetic hormone that works similarly to oestrogen in your bones.
  • Parathyroid hormone peptides (parathyroid hormone (eg Preotact) and teriparatide (eg Forsteo) – these help to regulate calcium levels and the activity of cells involved in bone formation.
  • Denosumab (Prolia) – given as an injection every six months, it’s a biological treatment that works by blocking the formation of cells that break down bone.
  • Hormone replacement therapy (HRT) – this relieves symptoms of the menopause by restoring hormones to a pre-menopausal level. HRT has also been shown to reduce osteoporosis, but you probably won’t be prescribed it specifically to treat or prevent the condition.

 

HOW CAN A DIETITIAN HELP?

Diet and exercise has a role to play in the prevention and treatment of osteoporosis.

If you have been diagnosed with Osteoporosis and would like to get dietary and lifestyle advice tailored to your particular needs, please make appointment with our ACE diets specialist Dietitian.

At the first consultation we will make a comprehensive assessment of your current diet and lifestyle. We might also ask you to fill in a 7-day food and activity diary. We will analyse your diary using a nutritional software programme to assess the adequacy of your micro and micro nutrient intake. Based on the assessment the Dietitian can advise you on the most suitable diet, tailored specifically to you, to help improve your bone health. We will advise you on the diet that will maximise the adequate intake of essential nutrients as well as advice regarding the combination of the different foods to ensure the maximum absorption of these nutrients. If necessary we can also advise on the dietary supplements and their use.