Taking folic acid supplements for more than three years can reduce your risk of stroke by almost 30 per cent according to research from the Children’s Memorial Research Centre in Chicago.

Bananas must be the ultimate healthy snack, packaged in their own smart yellow wrapper and packed with essential vitamins, minerals and fibre. They also contain far more carbohydrates than most fruits, but are lower on the glycemic index than most tropical fruits. Made even lower by eating them with a handful of nuts or seeds.

Bananas pack lots of dietary fibre, with 100g – roughly one small fruit – providing 14% of your daily dose. Epidemiological research in the US has shown that eating plenty of high-fibre foods can, in the long term, lower the risk of cardiovascular and coronary heart disease by up to 12%. Eating fibre-rich foods also keeps your bowel movements regular, preventing constipation and reducing the risk of developing colon diseases such as diverticulitis and cancer.

Bananas are high in potassium, with that one small fruit providing 10% of your daily recommended allowance. Diets rich in potassium can help to lower blood pressure, which slashes your risk of having a stroke. 100g of banana also provide nearly 30% of your daily needs of vitamin B6, which plays an important role in manufacturing antibodies in the immune system, aiding protein metabolism and red blood cell formation and helping the central nervous system to function normally. Finally, bananas are also effective antacids, and contain substances that can inhibit Helicobacter pylori, a bacterium which has been identified as a major cause of stomach ulcers.

Finally, according to a recent review in Biotechnology Progress, researchers have found that bananas are the most promising edible vaccine against hepatitis B, which is carried by about five per cent of the world’s population.

Water is absolutely essential for every function of the body. It is necessary for digestion, absorption, circulation and excretion. We might be able to survive without food for five weeks but we can’t live more than 5 days without water. We’re all made up of more than 70% water and we need every drop to help transport nutrients and waste products in and out of the cells, carry waste out of the body, and maintain body temperature.

Most of us do not drink enough water. We should all be drinking six to eight glasses a day. Try hot water and a slice of lemon before breakfast: it’s wonderfully refreshing and excellent for the liver. Herbal teas do count towards your liquid intake but other drinks don’t.

But do you know exactly what is in the water that you drink?

It is estimated that as many as 60,000 different chemicals now contaminate our water supply. In addition to man-made oestrogens (e.g. xenoestrogens and oestrogens from the contraceptive pill and HRT), a 2004 report found traces of Prozac and seven other drugs in the UK water supply. The standard purification techniques used by most water companies remove the bugs from the water but do not remove all the dissolved chemicals. In attempts to clean the water, other chemicals are often added including chlorine and aluminium. Not only may these chemicals be toxic in their own right, but chlorine may react with organic waste to form compounds which can increase the risk of cancer of the colon, rectum and bladder.

The recognition that there is a possibility that much of our tap water is contaminated has seen a boom in bottled water sales. Trouble is the next bottle of water you drink may be nothing more than tap water that has passed through a filter.

Tap water is not ideal but if you filter it, that helps. Filtered tap water is the cheapest and easiest way to ensure the water you are drinking is relatively clean. Water filter jugs are readily available. Use the filtered water for cooking as well as for hot and cold drinks. Bear in mind that filters can become breeding grounds for bacteria so replace the filter every month and clean the jug at least once a week. A good quality filter should eliminate or greatly reduce the levels of heavy metals such as lead, cadmium and chlorine and remove any adverse tastes, colours and smells in the water.

If you want to go to the next level you can buy plumbed in filters for use in your kitchen sink or you can go for a system which is fitted to your mains water system at home. Alternatively buy water bottled in glass rather than plastic as plastic bottled water can increase the amount of toxins from the bottle into the water.

Bottled water now outsells cola in the UK (which can only be a good thing) and is very convenient when you are on the go. There are concerns about toxins leaking into the water from plastic bottles. To avoid this risk buy water in glass bottles or only buy bottled water that has a best before date. Besides the health implications, plastic bottles contribute to the half a million tonnes of plastic we throw away each year.

Be careful of using filtered tap water rule if your house was built before 1970 which may have lead pipes. Tap water that flows through lead pipes can pick up lead particles, which can then be ingested. Children are particularly vulnerable to lead poisoning and there may be a link between early lead exposure and learning difficulties. If you are concerned that your home has lead pipes use only the cold water as the hot water is more likely to contain chemicals, like lead and asbestos. Let the cold water tap run for a few minutes until it is as cold as it can get to flush out the pipes. The longer it sits in the pipes the higher the level of pollutants. You should also call your water supplier as they may be able to test the water.

There is a difference between mineral and spring bottled water.

Spring Water is normally taken from one or more underground sources and has undergone a range of treatments, such as filtration and blending.

Natural mineral water is bottled in its natural underground state and is untreated. It has to come from an officially registered source, conform to purity standards and carry details of its source and mineral analysis on the bottle.

Naturally sparkling water is natural water from its underground source with enough natural carbon dioxide naturally occurring to make it bubbly.

Sparkling (carbonated) water –will have had carbon dioxide added during bottling just as ordinary fizzy drinks do.

Some waters, if they don’t say mineral or spring, can just be tap water filtered.

Watch out for the flavoured spring waters as they sound wonderfully natural, but often contain sugar or artificial sweeteners and other ‘nasties.

So the best form of water, in my opinion, is to drink still mineral water from glass bottles.