On the Menu: Getting to the bones of the story
Reduce your risk of osteoporosis by including plenty of calcium and vitamin D in your diet
Make sure your diet is full of calcium-rich foods. Photograph: Thinkstock
Bone is a living tissue. Bone cells are constantly breaking down and constantly being replaced. Many different nutrients are needed to build new and healthy bone cells and we get these from the food we eat.
It’s rather like a bank account, where you make “deposits” of nutrients for new healthy cells and “withdrawals” of bone cells that need replacing. As we get older, more bone is naturally lost than is replaced. There is a natural decline in bone strength.
People with osteoporosis lose more bone at a faster rate than is normal. Osteoporosis causes bones to become fragile. Therefore, they break easily. Even a minor bump or fall can cause a fracture.
The disease affects both men and women. It is more commonly seen in older people but osteoporosis can affect all age groups, even the young.
It is estimated that someone in the EU has a hip fracture as a result of osteoporosis every 30 seconds. The most common bones to fracture are the hip, spine and wrist. However, it can affect any bone in the skeleton.
There are many reasons for an increased risk of developing osteoporosis. nFamily history: 80 per cent of bone is determined by genetics. If a parent or grandparent had osteoporosis or any of the above symptoms, then you may be at a higher risk yourself. nAge: Bone loss increases in later life. It’s estimated that about half of
all people over the age of 75 will have osteoporosis. As we get older, our bones become more fragile and are more likely to break.
nGender: After the menopause, women experience acceleration in bone loss. The female hormone oestrogen has a protective effect on bones. At the menopause (normally around the age of 50), the ovaries almost stop producing this hormone, reducing protection for our bones.
nEating disorders: People who have a history of eating disorders may have missed out on vital nutrients to nourish their bones at a vital stage of development.
nGastrointestinal disorders: Disorders such as coeliac, Crohn’s, ulcerative colitis or primary biliary cirrhosis increase the risk.
nRheumatoid arthritis: The disease itself and steroid treatments can increase the risk.
nEndocrine disorders: High levels of prolactin, cortisol or thyroid and parathyroid hormone problems, diabetes, Turner’s syndrome, Klinefelter’s syndrome, etc can increase the risk.
nSome medications: For example, corticosteroids and some anticonvulsants, can also increase the risk.
Osteoporosis is the most common bone disease in the world, but it is preventable and treatable in the majority of people. Changing what you eat and becoming more active can help reduce your risk of osteoporosis.
The dietary guidelines are similar to those recommended for everyone, so you don’t need to eat any special or expensive foods, but you may identify some improvements or changes to your nutrition plan.
Calcium is required for healthy blood vessels to contract and dilate; muscle function; nerve transmission; and hormonal secretion. Less than 1 per cent of our total body calcium is needed to support these crucial functions. The remaining 99 per cent of the body’s calcium is stored in the bones and teeth where it supports their structure and function. Calcium’s most notable role is in helping to reduce the risk of osteoporosis.
You can get enough calcium by eating a variety of foods, including the following:
nMilk, yoghurt, and cheese contain calcium that is easily absorbed and utilised.
nFish with soft bones that you eat, such as tinned sardines and salmon.
nGreen vegetables such as spinach and kale provide some calcium,
but some plant sources contain oxalic acid and phytic acid, which interfere with absorption.
nCalcium is added to some breakfast cereals, fruit juices, soya and rice drinks, and tofu.
nMost grains (found in breads, pastas
and unfortified cereals), while not rich in calcium, add to our calcium intake because we eat these foods frequently
Vitamin D is a fat-soluble vitamin that is found in certain foods. It is both a nutrient and a hormone our bodies can make through the action of the sunlight on our skin. That’s why it is sometimes referred to as the “sunshine vitamin”.
However, as Ireland is so far north, in the months between November and March there is an insufficiency of both the quality and quantity of sunlight necessary to produce adequate vitamin D by the body.
Even on sunny days in the winter, the sun’s rays are not the right type for the production of vitamin D. Moreover, with most people working indoors and using sunscreen when outside, vitamin D from sunlight exposure has decreased.
Darker skinned people living in Ireland are particularly at risk as they require more than 10 times more sunlight to produce enough vitamin D.
Older people who don’t get sufficient skin exposure to the sun along with a poor dietary intake, those who cover themselves for religious or cultural reasons, those with malabsorption conditions and those with kidney disease, are particularly at risk of vitamin D deficiency.
Certain medications may interfere with the body’s conversion of vitamin D. Therefore, older people and those who are confined indoors may also benefit from a vitamin D supplement.
AbsorptionThe body needs vitamin D to absorb calcium. Without it, we can absorb no more than 15 per cent of the calcium we consume. When this happens, the body must take calcium from its stores in the skeleton, which can weaken the existing bone and prevent the formation of strong, new bone, potentially resulting in osteoporosis.
Recent research has also looked at vitamin D’s role in a variety of diseases other than bone health. Many studies have highlighted an association between having a low vitamin D status and cardiovascular diseases, diabetes, some cancers, cognitive decline, depression and autoimmune diseases. These studies suggest that the role of vitamin D far exceeds its previous remit of good bone health.
Very few foods are naturally good sources of vitamin D. Oily fish including salmon and mackerel are the best sources. Egg contains a small amount naturally. The rest are fortified foods. Vitamin D is added to some milks and to some brands of other dairy products, orange juice, soya milk and fortified cereals. Check the food label to see if vitamin D has been added to a particular product. Consider a blood test to determine your levels and a supplement if dietary intake is poor.
Paula Mee is a dietitian and member of the INDI. She works in Medfit Proactive Healthcare. See medfit.ie; Tweet @paula_mee