Joan Ransley

One in every nine women will develop breast cancer at some stage during their lives.  A quarter develops breast cancer before the menopause when it can run a more aggressive course leading to infertility and early death.  It is hardly surprising that breast cancer is the disease women fear most.  But can it be prevented?

Pre-menopausal breast cancers are dependant on oestrogen.  This is why they show such a dramatic response to oestrogen blockers such as the drug Tamoxifen.   Women who produce a lot of oestrogen in their life cycle – obese woman and those who start their periods early and end them late are more at risk.

A recent study published in the International Journal of Epidemiology by researchers at the University of Leeds showed that eating a high fibre diet halves the risk of developing breast cancer in pre – menopausal women. But the amount consumed to have this preventative effect was 30g of fibre a day.   To put that into perspective, the average fibre intake among women in the UK is just 12g.

One reason why a high fibre diet has a protective effect is because eating foods derived from plants can reduce the amount of oestrogen and other hormones linked to breast cancer, circulating in the body.

All plant foods contain some dietary fibre but those that contain substantial amounts include wholegrain bread, brown rice, pasta, oats, beans, peas, lentils, grains, seeds and fruit and vegetables.

There are two main types of fibre which have different effects on the body.  The soluble fibres found in pulses and oats slow the absorption of fat and sugar from the small intestine, while the insoluble fibres such wheat bran accelerate the passage of faeces through the colon which can reduce the recycling of oestrogen in the body.

The Leeds University study showed that both cereal and total fibre was protective against breast cancer. So the message is – eat a variety of high fibre foods to benefit from this effect.

So how is it possible to change a typical low fibre diet eaten by most women in the UK to the sort of high fibre diet sufficient to prevent breast cancer?

The simple answer is to substitute foods low in fibre with those high in fibre and you should aim for about 10g of fibre per meal. If you eat less at meals you can make up with high fibre snacks like dried fruit and nuts.

Starting with breakfast – eat a breakfast cereal that has high fibre content. Those made from whole grains such as wheat and oats are best. Food labels displayed on the side of cereal packets show the amount of fibre per portion. Weet-a-bix and Shredded Wheat contain about 5g per average portion. Allbran contains a hefty – 10g. Muesli made from oats, organic fruit and seeds will get you about 4g, but adding a chopped banana and a delicious fruit smoothie brings the total up to 8g.

At lunchtime – substituting wholemeal bread for white bread in your sandwich will add another 3g of fibre to your daily score. A 40g snack of mixed nuts and dried fruit and a Sharon fruit provide 4g and add only an extra 300 kcals of energy to your diet.

Eating the recommended five pieces of fruit and vegetables a day will go a long way towards helping you to attain a high fibre diet.  Typically a banana, apple, two Satsuma, a portion of broccoli and chick peas will provide 10g fibre.

Evening meals that include vegetables, pulses and whole grains will provide the final opportunity to add fibre to your diet. There are now so many great ingredients to experiment with.  For example. Waitrose have just launched a new range – Simply Wholesome – which includes some crunchy, nutty and delicious products. Try the brown basmati, red Carmague and wild rice mix – a portion of which will add about 2g to your meal.

But is it possible to eat too much fibre?

Food containing wheat bran also contains phytates which inhibit the absorption of essential minerals like calcium, iron, zinc and copper. Theoretically this could lead to a deficiency of these essential minerals. However there is no evidence of any serious deficiencies in people on a high fibre diet but it would seem prudent to limit the intake in elderly people who may not be eating very much and in children who are still growing. The Department of Health recommends adults should eat 18g per day.

Eating a high fibre diet goes along with healthy eating advice as these foods contain a lot of other nutrients that are good for our health. So to make a start on upping the fibre in your diet here is a delicious sweet potato, ginger and ground nut stew that contains a hefty 9g fibre.

Sweet potato, ginger and groundnut stew

Serves 4

• 2 tbsp olive oil
• 1 large onion, chopped
• 2 cloves of garlic, chopped
• 20g fresh ginger, peeled and finely grated
• half long red chilli, deseeded and finely chopped
• 600g sweet potato, chopped into small cubes
• 300g white cabbage, chopped
• 1 dsp paprika
• 400g can of plum tomatoes
• 200ml pineapple juice
• 100g good quality smooth peanut butter
• Sea salt and pepper

Sweat the onion in the oil until soft. Add the garlic, ginger and chilli. Cook for two minutes. Add the sweet potato and chopped cabbage. Stir in the paprika and add the tomatoes and pineapple juice. Cover the pan and cook gently for about 20 minutes or until the vegetables are soft. Stir in the peanut butter and season to taste.

To add a finishing touch – mix together a tablespoon of grated carrot, a few slices of ripe banana, a sprinkling of chopped coriander and a squeeze of lime juice – scatter over the finished dish. Serve with rice or crispy, roast parsnips to add a further 3g of fibre to your meal.