Q. My family has a history of bowel cancer. Should I be eating more fibre?

The question in full:

Q. As my family has a history of bowel cancer, should I be eating more fibre? Does the way I cook food affect its fibre content?

A. Yes eating more fibre is definitely one of the best things you can do to prevent bowel cancer in the future. Your aim is to keep your bowel operating smoothly and prevent constipation. The fibre takes up water, which keeps the stool soft and easy to pass but also dilutes down any possible carcinogens.

Fibre from grains appears the most beneficial for preventing bowel cancer so swap to wholemeal or rye breads and wholegrain cereals or oats. Or you could sprinkle some bran cereal eg All-Bran, Sultana Bran or unprocessed wheat bran or psyllium over your usual cereal. I find mixing a tablespoon of bran or psyllium into my morning muesli the easiest way to 'disguise' it!

You can also boost your fibre by eating more legumes (baked beans, lentils) and vegetables such as cabbage, broccoli, spinach, carrots and peas.

Other things to prevent bowel cancer:

• minimise alcohol, particularly beer
• avoid eating charred meat or chicken or char-grilled vegetables, as the burnt or charred bits create compounds that can initiate cancer
• quit smoking if you smoke
• maintain a healthy weight
• eat plenty of vegetables and salads.

Re fibre and cooking

Fibre tends to remain present whether your vegetables and fruit are raw or cooked which is good news. But to maximise your fibre intake, leave the skin on and don't overboil vegetables – they should still be firm and crunchy, not soggy.

Don't have fruit juice – it can be a trap. It's healthy but has had most of its fibre removed during juicing (unless you have a juicer that returns to pulp after juicing). It's better to drink water and eat a whole piece of fresh fruit with its full quota of fibre.