Which types of fat have been linked to cancer?

The type of fat you eat is important for your overall health and particularly the health of your heart. But there is no proof that any particular type of fat – saturated, polyunsaturated or monounsaturated – is any better or worse at preventing cancer.

However, people who eat a relatively low-fat diet with lots of fruit and vegetables, wholegrain starchy foods and pulses tend to have lower rates of cancer than those with a high-fat diet. But it appears that this is because of the benefits of eating a healthy balanced diet with lots of fruit and veg and wholegrain foods, rather than the lack of fat in their diet.

It’s still a good idea to cut-down on fatty foods because these can lead to weight gain, and being overweight or obese can increase the chance of getting some types of cancer. And it’s particularly important to cut-down the amount of saturated fat in our diets because this can help lower cholesterol levels, and reduce the risk of heart disease.

Will eating broccoli and cabbage stop me getting cancer?

There is some evidence that vegetables in the Brassica family (broccoli, cabbage, cauliflower, Brussels sprouts) and the Allium family (onions, garlic) are good at stopping cancer developing. But this kind of research is ongoing, so it’s too early to say whether by eating cabbage every day you’ll reduce your chance of getting cancer.

We do know that eating five or more portions of fruit and vegetables a day might help lower the risk of some types of cancers. It’s also good to eat a wide variety of different types of fruit and veg, so we get a mixture of vitamins and minerals.

Vegetables from the Brassica family are good sources of vitamin C and folate (the natural form of folic acid). So even if these foods aren't cancer busting, give them a chance. You may have been put off overcooked cabbage as a child, but it tastes like a different vegetable if it’s lightly steamed and still crunchy.

Should I take supplements to prevent cancer?

There's been a lot of interest in the anti-cancer properties of certain vitamins and minerals, such as vitamin C, vitamin E, folic acid and selenium. But the evidence is mixed and we can’t be sure that taking a vitamin supplement or eating foods rich in a particular vitamin or mineral will prevent cancer. It’s important to avoid taking beta-carotene supplements if you smoke, because high doses might increase the risk of smokers developing cancer.

It’s the same story with the other naturally-occurring compounds in food, such as lycopene in tomatoes, polyphenols in tea, and flavanoids in fruit and veg and red wine. We don’t have proof that these ‘bioactive’ compounds have anti-cancer properties when they’re extracted and made into tablets or powders.

What we do know is that eating lots of fruit and vegetables might protect us against some cancers, because they give us a combination of vitamins, minerals and other bioactive compounds in a natural way.

Do blueberries prevent cancer?

Blueberries have, like lots of other foods such as green tea, avocados, broccoli, garlic, carrots, grapes, cabbage, raspberries, red wine and oranges, often been referred to as a ‘super food’. This is because they’re rich in antioxidants or other food components that scientists have found can reduce, in laboratory conditions, the growth of cancer cells. But there’s a big leap between what works in a test tube and what works in our bodies, and it’s far too early to say that eating a handful of foods from this list is enough to keep cancer at bay.

Most of these so-called ‘super foods’ are fruits or vegetables, and we know that eating plenty fruit and vegetables might help prevent some cancers. But it’s thought that this protective affect is due to a combination of all the different components in the fruit and veg rather than any one particular component in the food. So try to choose a variety of fruit and veg and don’t forget frozen, canned, dried or juiced.

What should someone with Type 2 diabetes eat?

People with Type 2 diabetes should follow general healthy eating advice. This means eating a balanced diet that is:

• low in fat (particularly saturated fat)
• low in sugar
• low in salt
• high in fruit and vegetables (at least five portions a day)
• high in starchy carbohydrate foods, such as bread, chapatti, rice, pasta and yams

However, people with diabetes should avoid drinking large amounts of fruit juice because the fruit sugar (fructose) can cause problems with blood sugar control.

Generally, your mother should restrict the amount of sugary food (such as sweets or cakes) that she eats because the body absorbs the sugars from these foods too quickly and this could interfere with her blood sugar control. It's better to eat carbohydrates in a form that releases sugars more slowly, for example, wholemeal bread.

If she is prone to low blood sugar (hypoglycaemia), she may sometimes need to eat foods to increase her blood sugar quickly. If possible, it's better to eat something that will increase her blood sugar gradually, such as a slice of toast. Her GP or nurse practitioner can advise her on how to be prepared for hypoglycaemia and how to manage it.

The Food Standards Agency and Diabetes UK (formerly the British Diabetic Association) don't recommend specially labelled 'diabetic' products. These foods aren't necessarily healthier or more suitable for people with diabetes than other foods. And they tend to be more expensive than other products.

Above all, it's important for your mother to maintain a healthy weight, especially as she gets older.

Will eating lots of processed food give me cancer?

There is some evidence that people who eat lots of processed meat (such as bacon, ham, sausages and salami) might have a greater chance of developing bowel cancer (which affects the colon and rectum).

Processed foods can form part of a healthy balanced diet but remember to check the label and choose those that are lower in fat, saturated fat, salt and sugar.

In general, people who have a healthy balanced diet, with fruit and vegetables, wholegrain starchy foods and some fish, are less likely to get certain types of cancer. For more information on eating a healthy balanced diet, see the eatwell plate.

What foods can I eat to stop me getting cancer?

There are reports in the press nearly every day that claim that different foods may prevent cancer, but there isn’t enough evidence at the moment to support this. The best thing you can do is eat a healthy balanced diet with plenty of fruit and vegetables, plenty of starchy foods, some protein-rich foods such as meat, fish, eggs and beans, and some dairy foods. Try to cut down the amount of red and processed meat you eat, if you eat a lot, and also cut down on fatty, sugary and salty foods. And remember it’s important not to drink too much alcohol.

Getting more active and maintaining a healthy weight will help to reduce your risk of developing some cancers and heart disease.

For more information on eating a healthy balanced diet, see the eatwell plate.

Can foods improve medical conditions?

We often read in newspapers or on the Internet about how certain foods or diets can improve particular medical conditions.

There has been some research into the health benefits of individual foods, but in general we need to eat a variety of food types to make sure we're getting the range of nutrients our bodies need.

Most people should eat a balanced diet, which means one that is rich in starchy foods (such as bread, pasta and rice) and we should choose wholegrain varieties where possible. We should also be eating:

• lots of fruit and vegetables (at least five portions a day)
• moderate amounts of meat, fish or alternatives (such as eggs, beans and lentils)
• moderate amounts of milk and dairy foods
• small amounts of fatty foods or sugary foods or drinks

If you are experiencing health problems, consult your GP and always seek professional advice before making major changes to your diet. Avoid cutting out certain food groups or eating large amounts of any foods because this could have a negative effect on your health.

A lot of information is available about food, but you should try to make sure that any advice you take comes from a reliable source.

If you have a specific medical condition and want personalised advice, contact a State Registered Dietitian through your local hospital or GP surgery.

You can also find a dietitian on the Dietitians Unlimited website.

Will cod liver oil protect me from osteoarthritis?

For osteoarthritis, prevention is key. The best thing you can do is maintain a healthy weight by eating a varied and balanced diet and keeping physically active. The aim should be to eat a diet that is rich in starchy foods, such as wholegrain rice and bread, and moderate amounts of meat and dairy products, with at least five portions of a variety of fruit and vegetables every day.

It is also important to eat two portions of fish a week. One of these should be oily fish, such as salmon, mackerel or sardines. This may help people who suffer from rheumatoid arthritis because the fats found in oily fish may have an anti-inflammatory effect.

When someone has osteoarthritis, the smooth cartilage that takes the strain in a normal joint becomes rough, brittle and weak. To make up for this, the bone beneath thickens and spreads out, forming knobbly outgrowths. This causes stiffness and pain.

This form of arthritis is most common in older people and is very rare in people under the age of 40. Women are more likely to suffer from it than men, and people who are overweight or obese are more at risk from the disease, especially in their knees. Joints that have suffered injury are also more susceptible to osteoarthritis.

There has been research into the use of fish oil supplements in treating various forms of arthritis, although the focus is generally on rheumatoid arthritis as opposed to osteoarthritis. Rheumatoid arthritis is caused by the body's immune system attacking the joints and causing inflammation.

Fats are involved in this inflammation and it is thought that those found in fish can affect the process and help reduce inflammation. Some studies testing this theory on people with rheumatoid arthritis have shown benefits, while other studies have shown no benefit at all. Research is continuing.

Some research suggests that having more than an average of 1.5mg per day of vitamin A over many years may affect our bones and make them more likely to fracture when we're older. This is in addition to the risk of osteoporosis that older people, particularly women, face.

Fish liver oil supplements (as well as many multivitamins) are high in vitamin A. So if you take supplements containing vitamin A, make sure you don't have more than a total of 1.5mg per day from your food and supplements. If you eat liver or liver products such as pâtè every week, you should avoid taking any supplements that contain vitamin A, because liver is very rich in vitamin A.

Women who have been through the menopause and older men, who are more at risk of osteoporosis, should avoid eating liver or liver products more than once a week, or eat only small portions of liver. People at risk of osteoporosis who eat liver or liver products such as pâtè every week, should also avoid taking supplements containing vitamin A, and this includes fish liver oils.

So if you want to take a fish supplement, you might want to choose to take fish oil supplements rather than cod liver oil or other fish liver oil supplements.

How can I find an accredited nutritionist or dietitian?

There are a number of ways you can find a qualified professional to advise you about your diet. You could consult either a dietitian or a nutritionist, depending on the kind of advice you want.

Registered dietitians (RDs) are experts in diet and nutrition, so they can provide advice on all aspects of eating and diet, including special diets for medical conditions. The title 'dietitian' is protected by the Health Professionals Council (HPC). This means that someone can't call themselves a dietitian unless they are suitably qualified and registered with the HPC. Registered dietitians are regulated by the Government. The professional association for dietitians is the British Dietetic Association.

You can contact a registered dietitian through your local hospital or GP surgery. You can also search online for a dietitian at Dietitians Unlimited, which is run by the Freelance Dietitians Group of the British Dietetic Association. The HPC publishes its register online, so you can check on its website to see if a dietitian is registered.

Nutritionists are qualified to provide information about food and healthy eating, but not about special therapeutic diets. The Nutrition Society has a register of nutritionists (R Nutr), associate nutritionists (A Nutr) and public health nutritionists (R PH Nutr). The purpose of this register is to provide a list of nutritionists who have received an approved level of training.

A list of registered nutritionists can be found on the Nutrition Society website.

Does what I eat affect the health of my bones?

Diet is very important for keeping our bones healthy, and so is doing enough physical activity. Weight-bearing exercise is particularly important for keeping our bones strong, for example, walking, climbing stairs, running and playing football.

Bones are complicated living organs that are constantly changing and repairing. Most people know that bones need calcium. Milk and milk products are the best source of calcium. Soya beans, tofu and fish where you eat the bones (such as sardines, whitebait and pilchards) are other good sources. But we also need vitamin D for the calcium to be absorbed into the bones to make them strong.

We get most of our vitamin D from the action of sunlight on our skin. So it's important to spend some time outdoors (taking care not to get sunburnt). We get the rest of our vitamin D from food. It's found in oily fish such as salmon, mackerel and sardines, and in eggs, some breakfast cereals and margarines.

Some research suggests that having more than an average of 1.5mg per day of vitamin A over many years may affect our bones and make them more likely to fracture when we're older. If you eat liver (which is a very rich source of vitamin A) or liver products such as pâtè every week, you are likely to be having, on average, 1.5mg of vitamin A per day.

If you aren't getting enough vitamin D, you might be more at risk of the harmful effects of too much vitamin A. People who may be particularly short of vitamin D include women of Asian origin, if you always cover up all your skin when you're outside and older people who rarely get outdoors, or people who eat no meat or oily fish. So if you're short of vitamin D it might be a good idea to boost the amount you're getting. You might want to think about taking a 10 microgram supplement of vitamin D each day.

There are also many other nutrients that are thought to be important for healthy bones. Lots of these are found in fruit and vegetables.

So, to keep your bones healthy, the best advice is to get active outdoors and eat a balanced diet, including at least five portions of a variety of fruit and vegetables every day, a moderate amount of milk and dairy products, and at least two portions of fish (one of which should be oily fish) every week.