The hard, outer-shell of bones thins and the holes in cancellous bone get larger. If this level of loss is over that expected for the age, this is called ‘bone loss’ or in medical terms osteopenia (mild loss) or osteoporosis (significant loss). The adjacent picture show the difference between normal bone on the left and thinned bone on the right.
The three most common osteoporotic fractures are the wrist, hip and spine as shown in the x-rays. A crush fracture of the spine can occur suddenly, be very pain full and even cause nerve damage and pain. Also the spine can crumble over time causing deformity and loss of height.
A number of factors affect bone health such as our age, gender (women more at risk after menopause), having a family history of weak bones. In practical term the causes can be split into three categorie
Medical factors include:
- Any chronic illnesses that cause disability and make a person less mobile.
- Spontaneous early menopause in women
- Surgery or radiotherapy to the ovaries r testes (usually part of a medical treatment)
- Diabetes, Asthma and Rheumatoid arthritis, Chronic liver or kidney disease
- Inflammatory bowel diseases, such as Crohn’s disease and ulcerative colitis
- Over active thyroid disease, eating disorders, such as anorexia nervosa
2. Drugs, taken over a long time, which increase the risk of bone loss include:
- Aromatase inhibitors for breast cancer (anastrozole, letrozole and exemestane)
- LHRH agonists such as Goserelin (Zoladex®)
- Chemotherapy which damages ovarian function (in premenopausal women)
- Some chemotherapy agents specifically damage bones (e.g. methotrexate)
- Newer Immunotherapy cancer treatments ( e.g. imatinib, nilotinib and dasatinib)
- Some anti-epileptic drugs, such as phenytoin.
- Proton pump inhibitors for indigestion (omeprazole, lanzoprazole)
3. Lifestyle factors with increase the risk of bone loss
- Lack of physical activity
- Low body weight (BMI<20kg/m2)
- Drinking more than 3.5 units of alcohol / day
- Lack of sun exposure
- Poor diet
How to maintain and improve bone density
Correct underlying contributory medical conditions. In the first instances any underlying medical conditions should be investigated and treated. Most notably the bone health of post menopausal women can be helped by Hormone Replacement Therapy (HRT) for a limited period of time remembering that prolonged use can increase the breast cancer risk. It particularly helps women, without breast cancer, who have been made prematurely post menopausal by surgery or chemotherapy. If a man has a low testosterone level because of cancer treatments, he can be given testosterone replacement treatment to get his levels back to normal. Testosterone replacement is usually regarded as not suitable for men with prostate cancer as it can encourage prostate cancer cells to grow. However evidence is emerging that correcting a low level in men with low risk prostate cancer may be appropriate and improves their quality of life as well as bone density.
Calcium and vitamin D supplements: There is conflicting information about the benefits of calcium supplements, which are commonly taken to support bone health. There is some limited support in the literature particularly if taken along side additional medical or lifestyle interventions [Ryan, Swenson] but other studies show no benefit [Datta, Record]. A recent meta-analysis of 59 RCT concluded very clinical benefit on bone density measurement or risk of fractures [Tai]. Of more concern, another meta-analysis, also published in the BMJ, of 15 RCT reported they are associated with an increase in cardiovascular disease such as angina and heart attacks [Bollard]. On separate issue, another study specifically involving women taking aromatase inhibitors found that high dose Vitamin D with calcium helped reduce joint pains [Prieto-Alhambra]. Apart from this study, the evidence suggests they should only be taken to correct specific calcium or vitamin D deficiency or to support bisphosphonates therapies.
Bisphosphonates: These are drugs that interfere with osteoclast function hence increasing done density and reducing the risk of fractures. They have been shown to help age related osteoporosis and prevent bone loss caused by hormonal therapy and other cancer treatments. They are also used to prevent or treat cancer that has spread to the bone. There are several bisphosphonates used to treat osteoporosis, including alendronic acid, ibandronic acid, risedronate sodium, zoledronic acid. They are generally well-tolerated but are best taken on an empty stomach, sitting up or standing which can be a nuisance. A rare side effect of bisphosphonate treatment is osteonecrosis of the jaw. It happens when healthy bone tissue in the jaw becomes damaged and dies. This can cause loosening of the teeth and problems with the way the gums heal. This very infrequently happens with oral bisphosphonate and very rarely with the doses given for osteoporosis (as opposed to the dose to treat bony metastasis).
If you haven’t been to the dentist for six months before starting these drugs or if you have dentures that don’t fit well, it’s essential that you attend for a check-up for taking them.
Denosumab is a targeted antibody treatment that again impairs osteoclastic activity and is often used if bisphosphonate drugs are not tolerated. Although some doctors chose them from the start because they only require a subcutaneous (under the skin) injection once every six months as an injection just under the skin. If you are taking denosumab, your doctor may advise you to take calcium and vitamin D supplements.
Raloxifene is used to prevent and treat osteoporosis in women who have been through the menopause. The drug shares some of the helpful effects of oestrogen, reducing the breakdown of bone and the risk of fractures. It’s used only for women who can’t take bisphosphonates. Women with breast cancer who are treated with tamoxifen should not take raloxifene. This is because it may interfere with tamoxifen.
Parathyroid hormone (PTH) is a naturally occurring hormone that’s produced by the parathyroid glands, which are attached to the thyroid gland in the front of the neck. PTH stimulates bone formation and helps the body absorb calcium. There’s a synthetic version of PTH which can be injected just under the skin every day for a maximum of 24 months. It’s more likely to be given to people who have broken bones caused by severe osteoporosis but is not given to people with bony metastasis.
The evidence (references): A number of intervention studies have linked regular physical activity with a reduction in the risk of bone mineral loss [Waltman,Mackey]. For example, in a randomised controlled trial (RCT) involving 66 women with breast cancer, a third walked briskly or jogged for 15-30 minutes four days/week and used resistance bands at other times. A third just used resistance bands and tubing and a third were given no exercise instruction. The average decline in Bone Mineral Density (BMD) was significantly less in the aerobic exercise and resistance group (0.7%), was 4% in the resistance training only group and 6% but in those who didn’t exercise. Another study evaluated an exercise programme in 223 post-menopausal women who had completed initial breast cancer treatment and, as well as on-going hormones, were being treated with bone hardening drugs (risedronate, calcium and vitamin D). Participants who were adherent to the exercises programme were 20% less likely than participants on medications alone to lose BMD at the femoral neck.
Types of exercise to help bone health: It’s best to find something you enjoy, especially if it also has a sociable element, so you’ll carry on with it and not get bored. Exercise needs to be done regularly to have the most benefit. When exercising, try to push yourself and add some weights and resistance but do not push yourself too hard at first. At the end of an activity, you should feel warm and slightly out of breath, but not exhausted. With practice, you’ll soon find you’re able to do more. Weight-bearing and resistance exercise is the best to send signals to the cells in the bone to lay down more calcium and harden them but it is important you also exercise your whole body and do different types of exercise either in the same session or alternating:
High-intensity resistance and impact training (HiRIT) has been shown in a recent randomised trial from Australia to improve bone density (and physical strength) in both in the hips and back with no increased risk of fractures.The HiRIT program consisted of resistance exercises such as the deadlift, overhead press, and back squat, performed in five sets of five repetitions. The impact loading exercise was a jumping chin-up with a drop landing. Obviously this, is something to work up to preferably with supervision.
Balance, co-ordination, stretching and flexibility. These can also help the joints, reduce fibrosis in the tissues, stimulate the mind, prevent falls, help people maintain their mobility and independence in later life. Yoga, tai chi, pilates, body balance and qi gong Yoga, tai chi and qi gong are good examples and they can also help relax you and reduce stress.
Aerobic exercises that raises the heart rate for 30 minutes five times a week. The 30 minutes could be made up of three 10-minute periods of activity. This type of aerobic activity strengthens and protects the heart, lungs and metabolism and helps maintain a healthy weight. Weight-bearing aerobic exercises are the best to increase bone density and these include walking, jogging, skipping, climbing stairs, dancing and hiking. Exercises such as swimming and cycling are good for your heart and lungs but are not weight-bearing.
Resistance exercises involve making your muscles work harder than usual, against some form of resistance. They strengthen muscles, bones and joints. They may also improve your balance. The exercises can be done with hand weights, machines or elastic bands.
Anaerobic exercises. These are exercises, which use up more oxygen than you can replace by breathing faster. When you stop anaerobic exercises, you have to breath heavily until you have paid back the oxygen debt in you body. Examples would be fast running, cycling, rowing or swimming. It is good to introduce an element of this in every session but only after reaching a suitable level of fitness and warming up and stretching before hand.
Safety issues whilst exercising. Exercise is very safe, especially if you join a supervised exercise programme. If you get chest pain or extreme shortness of breath after starting you need to consult you GP. Remember to warm up and warm down with aerobic exercises and stretching. If you have severe osteoporosis already it may be better to avoid high impact exercises until your bones start healing such as jogging, skipping, racquet sports like tennis, some types of dancing. Instead start with low impact exercises such walking (either outside or on a treadmill machine), climbing stairs, using a cross trainer.
2. Nutrition and bone health
Dietary calcium: A daily intake of 700mg of calcium is recommended for adults. If you have osteoporosis, your doctor may advise you to take more (1,000 to 1,200mg a day). To get enough calcium daily it is advisable to eat foods that are rich in calcium, such as:
- dairy products (contain the highest amounts of calcium)
- tinned oily fish where you eat the bones, sardines are particularly high in calcium.
- leafy green vegetables, for example broccoli and curly kale
- soya beans, tofu, kidney beans and baked beans
- dried fruit, for example figs, apricots and raisins
If you have a dairy-free diet, make sure you eat non-dairy foods that contain calcium. You may also choose to take products with added calcium. These include some types of fortified non-dairy milk. Always shake the carton well before use to ensure calcium is mixed throughout the drink. Some foods and drinks upset the calcium balance in the body. These include caffeine, red meat, salt, and fizzy drinks that contain phosphates, such as cola. Avoid having large amounts of these.
Vitamin D; This essential viatminhelps your body absorb calcium, so it’s important to get enough of it to maintain healthy bones and muscles. Lower levels of vitamin D have also been linked to other medical conditions including fertility, dementia, heart disease and arthritis [Nair]. In addition, vitamin D has anti-cancer property by thought to be due to calcitriol’s effect on cellular proliferation, differentiation and apoptosis [Chiang KC]. The vitamin D receptor is highly expressed in epithelial cells known to be at risk of carcinogenesis, such as the breast, skin and prostate. Higher vitamin D levels are associated with lower colorectal, breast and prostate cancer mortality [Schwartz, Zgaga, Ng, Mondul, Pilz]. Despite this, a direct causational link has not been established nor has any benefit of correcting vitamin D levels with supplementation. Sunlight exposure, independent of vitamin D levels, may also have other benefits including reduced rates of depression and lower incidence of prostate cancer due to modulation of the immune system and the circadian rhythm [van der Rhee, Luscome]. Nevertheless, until further research has been performed it is advisable to maintain a good level of vitamin D.
Strategies to enhance Vitamin D levels (more)
Sunlight: As we mainly get Vitamin D from the effects of sunlight on our skin many studies have reported a high incidence for vitamin D deficiency in the UK, particularly by the end of the winter and especially amoung individuals who:
- Cover their skin when outside
- Have dark skin, from African, African-Caribbean and South Asian backgrounds
- Do not spend regular time out of doors – e.g. housebound or in care homes
The most significant way to increase Vitamin D levels is get gentle regular sun exposure. Vitamin D has a half-life of 6 weeks so by mid winter unless other precautions are made most of use will have some degree of Vitamin D deficiency. Investing in a winter holiday in the sun, budget allowing, is one sensible approach. Only 10-15 minutes of exposure to outdoor sun is necessary to start the production of vitamin D but precautions need to be taken to avoid burning while sunbathing as this not only will this create thin, sun-damaged skin, premature aging and an increased risk of skin cancers. Also try to expose areas of the skin that gets the least sun such as the tummy and avoiding the face, hands and upper chest. Take particular care to put total barrier sun block on areas which have received radiotherapy. Some chemotherapy agents can sensitise the skin and make burning more likely so take particular care.
Modulating the carcinogenic effects of the sun: As well as the measures, above, particularly avoiding sun burn, try to reduce exposure to other carcinogens particularly smoking which enhances the harmful effects of sun. Stay away from carcinogenic foods and other carcinogens (read more) and try to eat extra polyphenol rich foods which ensure your antioxidant enzymes are in good working order. After use a good quality after sun preferably with extra olive oil added which is known to enhance DNA repair.
Tanning beds: The benefits of tanning beds are unlikely to counterbalance the risks. Some authors advise use over the winter months to keep up the vitamin D levels. However, in a recent study The Lancet Oncology commented that sun beds pose as big a risk as tobacco and asbestos. It reported a new analysis of about 20 studies, which concluded the risk of skin cancer jumps by 75% when people start using tanning beds before the age of 30. In addition, researchers from the International Agency for Research on Cancer (IARC), the “cancer arm” of the World Health Organization, found that all types of ultraviolet radiation (UVA, UVB, and UVC) caused worrying mutations in studies and have classed them as Group 1 carcinogens and therefore now issued a warning that people younger than 18 years should avoid tanning beds and older people use them with caution.
Dietary sources of vitamin D: Small amount of vitamin D can be found naturally in foods and others such as breakfast cereals, breads and soy products have had fortified vitamin D. The Tesco’s supermarket have introduce a mushroom which has had its vitamin D levels enhanced by sun exposure and sun dried mushrooms (Porcini) are available in select delicatessens but are more expensive. Other natural food sources include:
- Oily fish such as marcel, sardines and anchovies
- Grass fed meat and liver
- Free range chicken or game egg yolks.
The recommended daily Amount (RDA) of vitamin D for adults is around (600-800 iu /day) but more is necessary if there is a history of deficiency or bowel malabsorption. Government websites advise taking over the counter Vitamin D supplements, unless you are able to get a winter, holiday, particularly during autumn and winter when sunlight levels are low. People who have a higher risk of vitamin D deficiency are advised to consider taking a vitamin D supplement all year round and at a higher does of 1000 ui. It is extremely unlikey to get Vitamin D toxicity, with diet and sun and reports with supplements have usually been caused by megadoses of vitamin D supplements such as over 50,000 iu a day for several months. To be on the safe side do not exceed 3000iu / day. Unless you have a known vitamin E deficiency ensure the supplement you buy, over the counter, does not contain added vitamin E, which is common place in brands seen in many supermarkets, health food stores and high street pharmacies.
Other dietary influences on bone density
Plant proteins; Osteoporosis is lower amoung Asian women and vegetarian populations thought to be a consequence of higher plants and lower meat consumption [Fujii, Thorpe]. The European Prospective Investigation into Cancer and Nutrition (EPIC) study has been following the dietary habits of 48,830 people over several years and concluded that high consumptions of animal protein is harms bones, whereas higher vegetable protein is beneficial to bone health [Weikert]. The benefits of plant proteins, and particularly soy intake, were further confirmed in a number of other studies [McTiernan, Fujii, Merill, McTiernan, Marini]. Genistein found in soya products was specifically was investigated in a double-blind placebo RCT involving 389 post-menopausal women for 24-months. After 36-months, bone mineral density increases were greater with the soy extract group for both femoral neck and lumbar spine compared to placebo. On a safety perspective, genistein did not significantly change mammographic breast density or endometrial thickness, and BRCA1 and BRCA2 expression was preserved despite ongoing potential concerns [Marini].
Polyphenol rich foods: The bone health benefits of fruit, vegetables, pulses and grains do not just relate to their proteins but the levels of phytochemicals, particularly polyphenols [Fujii; Thorpe, Hardcastle]. There are several ways polyphenols could influence bone density. One laboratory study found that osteoclast number and bone reabsorption activity were increased in bone when the animal was exposed to increased oxidative stress [Garrett]. Other studies showed that pre-exposure with berries rich in antioxidant polyphenols reduced markers of oxidative stress, increased glutathione activity and down regulated osteoclatic activity [Rendina]. A further mechanism was highlighted which found that regular consumption of polyphenol rich foods inhibited osteoclast formation by decreasing RANKL activation of osteoclasts. In addition, they reduced insulin like growth factor-1 and stimulated expression of NF-κB, reducing chronic inflammatory responses Trzeciakiewicz A, Droke.
In terms of which polyphenols have the best benefit, the isoflavones and flavanoids are particularly beneficial but these have the advantage of additional plant protein within the same food sources such as soya products [Droke, McTiernan, Hardcastle, Fujii, Merill, McTiernan, Marini]. Green tea, as well as having antioxidant properties, reduces inflammation had been shown to inhibit inappropriate osteoclatogenesisi [Shen Chwan-Li et al]. Curcumin appears to be particularly potent in protecting BMD in ovariectomised animals at doses, which could be easily achieved in humans albeit with some supplementation [Ki, Wright].
In summary, many authors state that emphasis on polyphenol rich foods or supplements would be a good dietary strategy to lessen the effects of disease, treatment or age-related bone loss and more emphasis should be given to advice when considering bone health [Sacco, Hubert]. In this web site, we have highlighted recipes, which increase polyphenol and plant protein intake but unless concerted daily efforts are made a polyphenol rich supplement such as pomi-t may be necessary maintain suitable the levels.
Probiotics bacteria have been shown to reduce gut inflammatory markers and there is a known link between chronic gut inflammation and bone health. In number of laboratory studies, just 4-6 weeks of probiotics significant increased biochemical markers of bone and calcium metabolism and increased bone density in animals with establish osteoporosis or prevented its development following removal of the ovaries or testes [Chiang, Yacon, Ohlsson]. Many authors or suggesting benefits in humans, which may well be the case, although it would be advantageous to confirm this with randomised trials [Reid]. It taking a probiotic it is also worth noting that they are not all the same (see about probiotics)
Vitamin K2 (Menaquinon ): Phylloquinone (vitamin K1) is essential for the formation of several clotting factors and is the target for warfarin. It is exclusively synthesized in green plants and severe deficiency will cause bleeding disorders. More recently its relevance for bone health has emerged particularly with a variant called menaquinones (vitamin K2), which is formed by bacterial fermentation foods (see below). Although more confirmatory research is needed, it appears that vitamin K2 helps harden the bones as it is required for the Gamma carboxylation of osteocalcin, a bone matrix protein which is made in osteoblasts to form bone. Numerous studies have reported that elderly people with hip fractures have a lower level of Vitamin K2 than the general age related population [Hodges]. An animal study showed that a vitamin K2 rich diet prevent ovariectomy-induced bone loss [Yamaguchi].
Quite remarkably, Vitamin K2 has the opposite effect on arterial calcification. It inhibits the formation of calcified plaques in coronary and systemic arteries which is likely to explain the cardioprotective links reported in population based studies [Shanahan, Jie K, Beulens, Geleijnse, Kurnatowska, Shea]
How to increase dietary vitamin K2 levels: The most notably source of vitamin K2 is a fermented soya dish call natto, popular in Japan. It is very high in Vitamin K2 containing >1000 μg /100g) the next nearest food being cheese (60 μg/100g) or curd at 24 μg/100g. Studies from Japan have shown that consumption of natto, up to three times a week significantly increased serum Vitamin K2 levels as well as gamma carboxylated osteocalcin, a marker of fracture risk [Tsukamoto]. There is one main draw back to natto, to a western pallet it tastes awful although some say, with perseverance it can become an acquired taste. Alternative dietary sources are listed below but dietary supplements can ensure adequate intake, although they don’t have the added benefit of the probiotic bacteria which natto also contains. In summary dietary sources of vitamin k2 include:
- Other fermented products – Miso soup, Serrano ham, tempura
Other trace minerals
It is not just calcium and proteins, which make up healthy bones, other minerals have a role too, albeit to a lesser extent [Eaton-Evans]. For example, on the basis of experimental and epidemiological studies low magnesium has harmful effects on the bones [Catiglioni]. Magnesium deficiency contributes to osteoporosis directly by acting on crystal formation and on bone cells and indirectly by impacting on the secretion and the activity of parathyroid hormone and by promoting low grade inflammation. Other trace minerals such as zinc, manganese and copper may be important in maintaining bone quality through their role as metallo-enzymes in the synthesis of collagen and other proteins that form the structure of bone [Gür]. Animal experiments inducing deficiencies in these trace minerals cause bone loss [Saltman] but fortunately, we know from micronutrient tests in humans that these deficiencies are rare. Nevertheless it would be important pay attention to foods containing these essential minerals including:
- Fish such as Halibut and other white sea fish
- Almonds and cashews
- Other nuts
- Whole potatoes
Zinc (more about dietary zinc):
- Oysters, crab, lobster, clams and shrimp,
- Cashew nuts sesame seeds,
- Parsley, spinach,
- Quinoa and lentils
- Crimini and shiitake mushrooms
- Dark chocolate
- Whole grains and beans,
- Nuts and sunflower seeds
- Whole potatoes and leafy dark green vegetables
- Dark Chocolate
- Black pepper
- Organ meats (kidneys, liver)
Other lifestyle factors
Smoking – There list of health risks for smoking just gets longer and longer. Loss of bone density is just one of them. If you smoke – see tips to quit.
Alcohol: Greater bone density was found in men consuming seven or more alcoholic beverages weekly than in non-drinkers, highlighting the potential benefits of low to moderate alcohol consumption. On the other hand, men with high alcohol intake had a worse BMD.
Weight optimisaion: In 2007 a US study, reported that heavier people had better bone density. The same authors, in another study, also reported that among breast cancer survivors, smoking and being underweight (BMI less than 19) were associated with lower BMD. If you are underweight (Body Mass Index <20 kg/m2), it would be worth bulking up with a combination of carbohydrates, proteins and weight baring exercises.