Bone health

Osteoporosis risk factors you cannot change:

• Age – quite simply, fracture risk increases with age
• Female gender – osteoporosis is more common in women than in men
• Race – white people are more at risk
• Genetic factors – having a relative with osteoporosis might mean an increased risk but lifestyle choices can determine whether the disease will develop or not
• Previous fracture
• Medications that have a negative effect on bone density – for example, glucocorticoids and adrenocorticotropic hormone, antiepileptic medicines, cancer medications, which use hormones to treat breast and prostate cancer, proton pump inhibitors, selective serotonin reuptake inhibitors and thiazolidinediones
• Certain medical conditions, such as endocrine and hormonal disorders, gastrointestinal diseases, rheumatoid arthritis, chronic kidney disease, certain types of cancer, HIV/AIDS and anorexia nervosa
• Early onset of menopause or absence of menstrual periods in premenopausal women (due to hormone disorders, hysterectomy, anorexia or extreme levels of physical activity) – lack of oestrogen causes higher bone loss
• Having no children – women who never had children tend to have a higher risk

Osteoporosis risk factors you can change:

• Eating disorders – although they are very difficult to live with, it is possible to recover and become healthy again
• Poor nutrition – diet low in calcium, protein, vitamin D and also fruit and vegetables
• High alcohol consumption – a significant risk factor for osteoporosis
• Weight – low body weight or being underweight can contribute to lower bone mineral density
• Sedentary lifestyle – due to a lack of stimulation for the bones
• Smoking – smokers tend to have lower bone density
• Elevated blood homocysteine – high levels are associated with an increased risk – but it can be easily avoided with regular vitamin B12 intake
• Low peak bone density – which would have happened in young adulthood

Protein is vital for healthy bones and studies show that lower-than-optimal protein intake increases your fracture risk. However, higher protein intake doesn’t mean stronger bones – eating more protein than is recommended doesn’t result in increased bone density. It is recommended that we need around 0.8 grams of protein per kilogram of body weight, while children, athletes and people with physically demanding work need a little more.

Older people often tend to have lower protein intake and that can undermine their bone health regardless of other factors. Research indicates that increasing protein intake reduces the risk of fractures in older adults. See more about protein here.

Best plant-based sources: pulses (including soya and products made from it), wholegrains, nuts and seeds.

Calcium plays an important role in maintaining bone health and strength; in fact, around 99 per cent of our calcium is stored in our bones and teeth. The other one per cent is responsible for a range of important functions, such as regulating muscle contraction and heartbeat, blood clotting and functioning of the nervous system.

Recommended daily intakes of calcium vary by country – the UK Government currently suggests that adults over 19 years of age need 700 milligrams per day.

Eating calcium-rich foods is vital for healthy bones at any age – studies of both children and adults confirm that having a calcium intake at or slightly above the recommended intake produces stronger bones and reduces the risk of fracture.  

It’s interesting, however, that countries with traditionally lower calcium intakes have similar or somewhat lower osteoporosis rates compared to countries with higher calcium, especially dairy calcium, intake. That’s not to say that you should neglect your calcium intake – getting enough is very important for good health – but more calcium doesn’t necessarily mean stronger bones.

It is generally accepted that daily calcium intake shouldn’t go above 2,000 milligrams and the UK Government warns that taking more than 1,500 milligrams can lead to stomach pain and diarrhoea.

Taking calcium supplements is not recommended as it doesn’t meaningfully reduce your risk of fractures and may cause health issues. Your body cannot immediately build high doses of calcium into the bones and if you take in too much on a daily basis, your body may store it in the wrong places, such as blood vessel walls, making them harder and limiting their function. This has raised concerns that calcium supplements may increase the risk of cardiovascular disease.

For most people, it’s better to obtain calcium from your diet than from supplements.

Best plant-based sources: kale, collard/spring/mustard greens, broccoli, Chinese leaf, bok choy, cabbage, sesame seeds and tahini (sesame seed paste), almonds, chia seeds, tofu (made with calcium sulphate), tempeh, beans, dried figs, plant-based milks and yoghurts fortified with calcium, fortified vegan breakfast cereal (eg Ready Brek), wholemeal bread, butternut squash and oranges

Magnesium is as important as calcium for bone health – it helps maintain and repair bone, yet it is not mentioned very often as a nutrient necessary for strong bones. Science clearly indicates that low magnesium intakes lead to poorer bone density and a higher risk of fractures.

It’s best to obtain magnesium from a balanced diet rather than supplements as both low and high intakes can harm bones.

Best plant-based sources: dark green leafy vegetables, nuts and seeds, wholegrains (oats, brown rice, wholemeal bread, whole wheat pasta, quinoa), avocados, figs, bananas, apricots, pulses (tofu, baked beans, soya beans, edamame and lentils) and cocoa powder.

Potassium plays an indispensable role in maintaining acid-base balance in the body. It neutralises excess acid, which is produced from some foods during metabolic processes. Calcium can also do this but in order for that to happen, it may be drawn from the bones. A plentiful potassium intake from foods is the best acid-reducing strategy.

As research shows, higher potassium intake may also boost the activity of the bone-building and repairing cells (osteoblasts) and at the same time slow down bone loss by inhibiting the bone-deconstructing cells (osteoclasts). On top of that, healthy potassium intake may enhance calcium absorption in the intestines.

No wonder that higher potassium intake is linked to higher bone density and a reduced risk of fractures in people of all ages! Luckily, wholesome plant-based foods are rich in potassium.

Best plant-based sources: pulses (beans, lentils, soya, chickpeas), potatoes (regular and sweet potatoes), dried fruit (apricots, raisins, dates and figs), honeydew and cantaloupe melon, oranges, bananas, squash (acorn and butternut), avocado, spinach, broccoli and mushrooms

Iron is essential for bones because it is involved in a chain of reactions resulting in the manufacture of bone protein – collagen. It also plays a role in vitamin D metabolism, which is also vital for healthy bones.

Iron deficiency may lead to compromised bone health and osteoporosis but so can very high iron intakes, so it’s important to achieve a healthy balance, preferably through diet rather than supplements.

However, there are many situations in which you may opt for an iron supplement to top up your levels. In those cases, choose a supplement that covers your daily iron needs but doesn’t supply extremely high doses.

Best plant-based sources: wholegrains (wholemeal bread, wholewheat pasta, oats), fortified breakfast cereals, pulses (lentils, beans, tofu, peas, chickpeas), seeds (pumpkin seeds, sesame seeds and tahini, chia seeds), cashews, dried fruit (apricots, prunes and figs), dark green leafy vegetables and herbs.

Boron is essential for vitamin D, calcium and magnesium metabolism and its plentiful intake is associated with better bone health. In addition, boron is needed for the manufacture of sex hormones, which are also vital for strong and healthy bones.

Copper is vital for the formation of bone and cartilage proteins – collagen and elastin. It also stimulates bone repairing cells (osteoblasts) and hinders the activity of bone-degrading cells (osteoclasts). A diet low or lacking in copper leads to an increased risk of fractures and osteoporosis. However, high copper intakes can be harmful too. That’s why it’s best to obtain copper from diet rather than supplements.

Zinc is a part of our bone tissue and is also involved in the synthesis of the bone protein collagen. Moreover, it stimulates bone repair and mineralisation and may slow down bone loss. It’s not surprising that low zinc levels may lead to osteoporosis. In fact, science shows that plentiful zinc intake from foods is linked with as much as a 60 per cent lower risk of osteoporosis.

Best plant-based sources of boron, copper and zinc: pulses (beans, lentils, soya, chickpeas), nuts, seeds and green leafy vegetables.

Boron is also abundant in coffee and dried fruit.

The body requires vitamin D to absorb and retain calcium in the bones. If you lack vitamin D, you can develop calcium deficiency even if your diet provides plenty. The consequences may be serious, resulting in rickets or osteomalacia (softening of the bones).

Vitamin D is either obtained from the diet or made in the skin following exposure to sunlight. However, having fortified foods such as plant milks, cereals and margarines may not be enough and regardless of diet, some people may need to supplement vitamin D from October to April because our skin simply cannot make enough. The recommended daily dose is 10 micrograms or 400 IU (international units).

During warmer months, your skin can probably make sufficient vitamin D when exposed to natural sunlight, unless you spend your days indoors or always protect your skin, in which case you may need a supplement all year long.

It is important to get the balance right between being cautious about exposure to the sun and aware of the need for some exposure. It is recommended to spend at least 15 to 20 minutes a day outside during the warmer months with exposed face and hands (without using sun cream) to give the skin a chance to make enough vitamin D for your daily needs. The skin reacts to daylight even when it’s cloudy, so the weather doesn’t need to be sunny for your skin to do its job.

If you get enough exposure over the summer months, you may store up sufficient vitamin D to see you through the winter. However, even with good sun exposure in summer, many people in the UK (especially those with darker skin, older adults, people with higher body fat and those with limited sun exposure) fall into vitamin D deficiency during winter.

Best plant-based sources: vegan supplements (not all vitamin D is vegan), fortified plant-based milks, vegetable margarines, bread and breakfast cereals (if labelled suitable for vegans) and vitamin D mushrooms (exposed to sunlight for long enough so vitamin D production is triggered – they are labelled so you know what you’re buying)

Vitamin C has two vital roles in bone health – it is needed by our bone-building and repairing cells (osteoblasts) and it’s also essential for the formation of the bone protein, collagen. Having an ample vitamin C intake is associated with higher bone density and it’s best when this is achieved through diet rather than supplements.

One study found that a higher vitamin C intake from foods was associated with a 33 per cent lower risk of developing osteoporosis. Another study, adding more weight to this, found that a higher intake of vitamin C foods reduced the risk of both hip fracture and osteoporosis by 34 per cent.

Best plant-based sources: strawberries, kiwi, grapefruit, oranges, raspberries, mango, pineapple, blackcurrants, cantaloupe melon, papaya, watercress, tomatoes, peppers (all kinds), kale, spring greens, Brussels sprouts, broccoli, cabbage, mangetout, cauliflower, potatoes and spinach.

Vitamin K is necessary for the formation of one of our bone proteins – osteocalcin. It would be impossible to have healthy and strong bones without vitamin K. As research shows, low levels of vitamin K lead to an increased risk of fractures while higher levels considerably reduce the risk.

In addition, vitamin K supports bone-building processes and suppresses bone breakdown, which may lead to an improved bone density.

Best plant sources include: green leafy vegetables (collard/spring greens, kale, Brussels sprouts and spinach), herbs, leeks, spring onions

Several B group vitamins have been identified as vital for bone health.

Vitamin B12 is particularly important for healthy bones and low levels are associated with a decreased bone density. Vitamin B12, along with vitamin B6 and folic acid, helps control a substance called homocysteine – a by-product of the breakdown of methionine, one of the amino acids that build protein. Under normal circumstances, it is broken down and excreted by the body. However, if you lack vitamin B12, B6 and/or folic acid, homocysteine levels in the body may rise and interfere with the correct linking of collagen fibres in the bone.

Best plant sources include: wholegrains (eg oats, brown rice, wholegrain bread), nuts and seeds, green leafy vegetables, avocado, mushrooms, beans and lentils; vitamin B12 is best taken as a supplement

As food is digested, acids or alkaline molecules are released into the blood. Food metabolism usually creates more acids, such as sulphuric and phosphoric, than alkaline substances, resulting in an overall acid load in the blood. As the body needs to maintain a steady pH of the blood, it rapidly neutralises these acids with calcium or other buffers. There’s a certain level of calcium available in the blood but if that isn’t enough, calcium may be drawn from your body’s main reserve – your bones.

Protein can be both good and bad for the bone – it depends where it comes from and your overall diet. Protein, particularly animal protein, has an acid-forming effect because of its greater content of sulphur-containing amino acids (the building blocks of protein) compared to plant protein. It has been suggested by some that consumption of animal protein sources (meat, eggs, cheese) might increase the risk of bone loss, while plant-based diets may have a protective effect on bone health.

Things are a little more complex, however, because while animal protein requires more calcium to neutralise the resulting acids, higher protein intake also increases calcium absorption in the gut – so if you have good calcium sources in your diet, higher protein intake is not bad for the bones.

While the negative effects of animal protein foods may be countered by a diet rich in calcium and alkali-producing fruits and vegetables, most people who eat meat, eggs and cheese also eat plenty of processed and sugary foods (which also produce acids) and may have a low calcium and wholefood intake – a typical Western diet. So, on balance, their bodies are likely to lose calcium, which puts them at risk of low bone mineral density. On top of that, high sodium (salt) intake, also causes calcium losses. In scientific studies, Western diets are usually associated with poorer bone health.

A vegan diet, rich in plant protein, produces much less acid and more alkalis in the body. It’s not simply about plant protein on its own but about the fact that plant-based foods are usually also sources of alkalising minerals, such as potassium and magnesium – they are an excellent package deal.

It’s important to note that potassium is vital to bone health and the best sources are plant-based foods, such as wholegrains, pulses, nuts, fruit and vegetables. Traditionally, the human diet contained a lot of potassium but processed foods and animal products contain very little and so a Western diet is lacking in this crucial mineral. A healthy plant-based diet can help improve bone health by providing alkalising minerals and a wide spectrum of other nutrients important for healthy bones.

Another aspect of diet is its inflammatory potential – certain foods help to reduce inflammation while others increase it. Modern science indicates that diets rich in pro-inflammatory foods can cause chronic inflammation, which is bad for the bones and may reduce your bone density. It’s because the immune system response to chronic inflammation includes stimulation of the cells that break down bone tissue and hinder bone repair.

A typical Western diet based on refined carbohydrates (white flour, sugar, snacks), meat, dairy rich in saturated fats, fried foods, sugary drinks and processed foods is very pro-inflammatory, while a healthy vegan diet based on fruit and vegetables, pulses, wholegrains, nuts and seeds and unsaturated fats is anti-inflammatory.

Phytate is a natural compound present in many plant-based foods, such as nuts, seeds, wholegrains and pulses. It’s a powerful antioxidant but it also binds to minerals, such as iron, calcium and zinc and reduces their absorption. Nevertheless, there’s no need to panic – if you have a varied diet, it’s not an issue and you can also reduce the amount of phytate in foods by soaking, sprouting or fermenting them.

And there’s a plot twist! Science has discovered one great health benefit of phytate – it may protect your bones from age-related deterioration. The fact that phytates bind to crystal surfaces is a disadvantage when it comes to mineral absorption but it’s also an advantage because they bind to your bone minerals and prevent their dissolution. Scientific studies found that women who had more phytate in their diet had better bone health than those who had very little. Another study found that people whose diets supplied the most phytate had a significantly lower risk of fracture.

That’s not to say you should purposefully eat more phytate-rich foods – a vegan diet provides plenty – it simply means another advantage of a vegan diet.

Soya contains natural substances called isoflavones (also found in some other plant foods), which can act as very mild oestrogens in the body. Nevertheless, the oestrogen-like effect of isoflavones is much less powerful than that of actual oestrogens (hundreds to a thousand times weaker).

Isoflavones bind to the same receptors in the body as oestrogens and this is why isoflavones have a balancing effect when the levels of oestrogens are very low, such as during the menopause, and can help ease menopause symptoms.

Scientific studies show that soya isoflavones reduce menopause-related bone loss by decreasing bone resorption (breakdown) and stimulating bone formation and repair. In addition, they are also antioxidants and, as such, help protect bone cells from free-radical damage, which may increase their longevity.

Regular soya consumption reduces the risk of fractures in menopausal and postmenopausal women – and it may be even more efficient than taking isoflavone supplements because soya foods contain a whole range of bone-vital nutrients, including vitamin K, calcium, iron, magnesium and zinc.

Studies show that regular fruit and vegetable consumption leads to healthier bones. This is probably thanks to the many vitamins, minerals, antioxidants and other bioactive compounds fruit and vegetables supply and their alkalising effect, which supports bone metabolism.

A Swedish study found that people who don’t eat any fruit or vegetables on a daily basis have an 88 per cent higher risk of hip fracture compared to people who get their five-a-day.

In a large study of older adults, eating only one serving of fruit or vegetables daily was associated with a 39 per cent higher risk of fracture compared to people who ate three to five servings.

Some studies suggest that vegetables may be more bone-protective than fruit but others suggest the opposite so having a varied diet with at least five servings of fruit and veggies may be a good health insurance policy.

High salt (sodium) intake increases calcium losses through urine and may lead to bone loss, particularly in postmenopausal women. It has been associated with osteoporosis and compromised bone architecture. Ideally, you should consume less than six grams of salt daily (six grams is about one teaspoon) – not just for your bone health but also for a healthy heart.

While some studies suggest that caffeine has a negative effect on the bones, interferes with calcium absorption and vitamin D metabolism, others found no connection. On the other hand, some studies show that moderate caffeine intake is linked to a lower risk of osteoporosis.

It seems that low to moderate caffeine intake is either not linked to bone health or may be beneficial, while high intakes – four or more cups of coffee daily – may increase the risk of fractures – so moderation is key.

When it comes to bone health, low alcohol consumption of one to two drinks per day may be mildly beneficial but from three drinks up, the risk of fractures and osteoporosis steeply rises. Science is clear on the issue – heavy drinking is bad for the bones, can lead to osteoporosis and causes a range of other issues too.

Soft drinks increase the risk of fractures and are associated with lower bone density.

Sugar-sweetened drinks contain large amounts of sugar or glucose syrup, which increase acid production in the body and support inflammation – both of these processes are linked to poorer bone health. However, artificially sweetened beverages have also been linked to a higher fracture risk.

Many soft drinks, such as cola, contain acids that provide the characteristic tart or tangy taste but high phosphoric acid content may negatively affect calcium metabolism and its long-term consumption may undermine bone density. What’s more, if your phosphorus intake is high and calcium intake is low, it may lead to an increased rate of bone loss.

It’s also worth pointing out that these drinks tend to replace other beverages or snacks and therefore lead to an overall lower-quality diet.