Living Bones

We tend to think of the skeleton as a fixed frame, as hard and lifeless as the bones in a museum. But living bone is anything but. It is a busy, ever-changing tissue, with its own blood supply and nerves, constantly being broken down and rebuilt. Over roughly ten years, much of the adult skeleton is renewed. That means it is never too early, or too late, to start building stronger bones.

A silent condition

Osteoporosis means "porous bone". Bones gradually lose their density and strength until they break more easily, sometimes from a simple fall or even a cough. It is often called a silent condition, because for many people the first sign is a broken bone.

It is far more common than many realise. More than 3.5 million people in the UK are living with osteoporosis, and half of women and a fifth of men over 50 will break a bone because of it.¹ Broken hips, wrists and spines can have a lasting impact on independence. Yet much of this is preventable.

How bone renews itself

Two teams of cells are constantly at work in our bones. Osteoclasts break down old, worn bone, and osteoblasts lay down new bone in its place. Bone is made of a flexible framework of collagen protein, hardened with minerals, mainly calcium and phosphorus, much like reinforced concrete. The protein gives bone its slight bend, so it doesn't shatter; the minerals give it hardness.

In childhood and early adulthood, building outpaces breaking down. We reach our peak bone mass by around the age of 30. After that, we slowly lose a little each year, and the loss speeds up for women in the years around menopause, when falling oestrogen frees the bone-clearing cells to work faster. Women can lose up to a fifth of their bone density in the five to seven years after menopause.¹ The stronger your bones at their peak, and the slower the loss afterwards, the better protected you are. (See The Second Spring.)

More than calcium

Calcium is vital, but bone needs a whole team of nutrients working together.

Calcium, from food first

Good sources include dairy foods if you tolerate them, sardines and tinned salmon with their soft bones, calcium-set tofu, tahini, almonds, figs, and leafy greens such as kale, broccoli and pak choi. The calcium in kale is absorbed at least as well as the calcium in milk.² Spinach, though rich in calcium, holds on to most of it with oxalates, so it isn't a good source. Calcium from food is the safest choice: some studies have raised questions about whether high-dose calcium supplements may affect heart health.³ (See Food as Medicine.)

Vitamin D

Without vitamin D, we can absorb only a small fraction of the calcium we eat. Our skin makes vitamin D in sunlight, but in the UK, the sun is too weak to make it from around October to March. For this reason, the UK government advises everyone to consider a daily vitamin D supplement of 10 micrograms in autumn and winter.⁴ (See Living by the Sun.)

Vitamin K2

Vitamin K2 helps to direct calcium into the bones, rather than into arteries and soft tissues. It activates a protein called osteocalcin, which binds calcium into bone. In a three-year trial of women after menopause, vitamin K2 slowed the loss of bone density and strength.⁵ The richest source is natto, a fermented soybean dish eaten in Japan; smaller amounts are found in hard cheeses, egg yolks and other fermented foods.

Magnesium

Around 60% of the body's magnesium is stored in the bones. It's needed to activate vitamin D and to form healthy bone crystals. Find it in leafy greens, pumpkin seeds, almonds, beans and whole grains.

Protein

It was once feared that protein weakened bones. We now know the opposite is true: protein makes up around half the volume of bone, and a review of studies found that higher protein intakes are linked with healthier bone density, especially when calcium intake is good.⁶ Protein also protects muscle, which keeps us steady on our feet.

The supporting cast

Vitamin C is needed to make collagen. Zinc, boron and silica also play a part in building bone, and potassium-rich fruit and vegetables are linked with stronger bones.⁷

It is never too early, or too late, to build stronger bones.

What drains the bones

• Too much salt increases the amount of calcium lost in urine.
• Fizzy cola drinks. In a large American study, women who drank cola every day had lower bone density in the hip, a link that wasn't seen with other fizzy drinks.⁹
• Heavy drinking and smoking both speed up bone loss.
• Long-term stress. The stress hormone cortisol slows bone building. (See The Cortisol Clock.)
• Very low-calorie diets and under-eating, especially alongside heavy exercise. (See The Natural Edge.)

Absorption matters

Even the best bone-building diet won't help if the nutrients aren't absorbed. Stomach acid is needed to absorb calcium and magnesium, and bile is needed for vitamins D and K. An inflamed gut can absorb less of everything. Looking after digestion is one of the quiet foundations of strong bones. (Read more in You Are What You Absorb.)

Bones love a challenge

Bone responds to the forces placed on it. When muscles pull on bones, and when bones take an impact, they strengthen themselves. Astronauts can lose bone rapidly in space because, without gravity, their bones simply aren't asked to work.

For a long time, women with low bone density were told to avoid heavy lifting. Then, in an Australian trial called LIFTMOR, women with low bone mass after menopause did short, supervised sessions of heavy weight training and jumping, twice a week for eight months. Their bone density in the spine and hip improved, while it fell in the group doing gentle exercise, and the training was safe.¹⁰

• Strength training. Lifting weights, resistance bands or bodyweight exercises at least twice a week.
• Impact. Brisk walking, stair climbing, dancing, skipping or small jumps, if your joints and bones allow.
• Balance. Exercise programmes, including those with balance training such as tai chi, reduce falls in older adults by about a quarter.¹¹ Fewer falls mean fewer broken bones.

Swimming and cycling are wonderful for the heart, but put little load on the bones, so combine them with strength and impact work. (See Born to Move.)

Herbs for the bones

Herbal tradition offers several mineral-rich plants, often taken as long, strong infusions. They have been relied on for generations, though few have attracted the funding for large modern trials:

• Nettle, rich in calcium, magnesium, iron and silica.
• Oatstraw, a gentle, nourishing tonic for the nerves and bones.
• Horsetail, one of the richest plant sources of silica, but it's not suitable for long-term use, in pregnancy or for people with kidney problems.
• Red clover, whose isoflavones reduced bone loss in women after menopause in a small trial.¹²

Nettle and horsetail are drying herbs, and red clover has gentle oestrogen-like effects. The right choice depends on your constitution and health history (see The Architecture of Balance), so it's best to seek a practitioner's guidance rather than self-prescribe.

At Rootwise, we see strong bones as the result of a whole life well lived: good food that is well absorbed, plenty of movement, balanced hormones and a calmer stress response. If you'd like to know more about your own bone health, the NHS offers bone density (DEXA) scans for people at higher risk, and a qualified practitioner can help you build a plan to protect your bones. No single food or supplement builds strong bones on its own; it's steady nourishment, good absorption, movement and rest, tended together over the years, that makes the difference. (See Vital Force.)