Pears are full of fibre, with 100g – roughly half of one large pear – providing 3.g, which is a generous 17% of your daily recommended amount. Fibre-rich diets have been shown to lower the risk of diverticulitis, an inflammation of the intestine that is extremely common as we get older, and epidemiological studies have identified an inverse correlation between vegetable, fruit and whole-grain intake, plant-food intake and the risk of rectal cancer. The soluble fibre, pectin, found particularly in the peel also helps to reduce ‘bad’ LDL cholesterol and can lower the risk of dying from heart disease by around a third.

Pears are also an excellent source of copper, with 0.082mg/100g – that’s nearly 7% of your daily intake from just half a pear. Copper is an essential mineral which has an antioxidant effect in the body. It helps to produce red and white blood cells, triggers the release of iron to form haemoglobin, is important for the immune system and plays an important role in the operation of many enzymes.

 

One of particular interest is superoxide dismutase (SOD): this neutralises the superoxide radicals which are a by-product of metabolism and can damage cell membranes, but deficiencies in copper levels mean that SOD cannot work efficiently. Research has shown a link between high blood levels of SOD and protective effects of death from cancer, while scientists also think that low levels of copper could be a contributory factor in the development of colon cancer. Copper also needs zinc to function in the SOD enzyme, and pears provide 0.1mg/100g – 3% of your daily needs.

 

Antioxidant vitamin C is also abundant in pears. Just 100g of pear provides 4.2mg, which is 10% of your daily recommended intake, helping to boost your immune system and keep your bones, teeth and collagen healthy.

 

Pears have a low glycaemic index which helps to keep blood sugar and therefore insulin levels stable. Low GI diets can ward off weight gain and, in the long-term, conditions such as type 2 diabetes and the metabolic syndrome. Interestingly, a study which examined the effect on weight loss of adding fruit into the diet, found that women who ate three pears or apples a day had a ‘significant’ weight loss at the end of the three-month trial.

 

 

Sweet potatoes are one of the oldest vegetables known to be consumed by humans and research dates this vegetable back to prehistoric times.

The sweet potato is native to Central America and was bought to Europe by Christopher Columbus in 1492.  By the 16^th century they were introduced to the Philippines, Africa, India and also to the US. 

Sweet potatoes belong to the Convolvulaceae or morning glory plant family and are different from yams, which they are often confused, which is a root vegetable belonging to the Dioscoreae family.

There are about 400 different varieties of sweet potato and the skin and flesh can vary in colour with some white, yellow, orange, deep purple and pink varieties.  The most common being the yellow-orange variety which is slightly longer than an ordinary potato and tapered at the ends.

Sweet potatoes are packed full of nutrients with excellent sources of beta-carotene, vitamin C, manganese, vitamin B6, potassium and iron. They are also a good source of dietary fibre. The orange colour is due to the beta-carotene content which gives the sweet potato valuable anti-oxidant properties.  The body can produce vitamin A from beta-carotene and it is though that the beta-carotene from sweet potatoes is more easily used by the body than that from dark, leafy vegetables.

The purple sweet potato has been found to have the high antioxidant activity of all the sweet potatoes and in one study the antioxidant activity (anthocyanins coming from the purple colour) was over three times higher than that of blueberries.

Try to buy organic sweet potatoes so that if you are just having them as a steamed vegetable, you do not have to peel because as with most fruit and vegetables most of the goodness is in the skin and with sweet potatoes the antioxidant activity is three times higher in the skin than in the flesh.

 

The humble tomato has been at the centre of a whirlwind of scientific activity for several years, mainly because of its high lycopene content. Lycopene, a carotenoid compound which is found in relatively few foods, gives tomatoes their deep red colour and is a potent antioxidant which can protect cells and DNA from free-radical damage. Significantly, cooked tomato products are even higher in lycopene than the raw fruit – 100g of canned tomato paste, for example, contains an astonishing 28,764mcg, which is more than any other food tested so far.

The latest research shows that the higher the levels of lycopene in the bloodstream the lower is the risk of cardiovascular disease and cancer, including rectal, pancreatic and ovarian. In one study eating lycopene-rich foods such as tomatoes was found to reduce the risk of developing prostate cancer by up to 50 per cent, while another study showed that low levels of lycopene increased the risk of developing colorectal adenomas (a precursor for most colorectal cancers) by 230%.

 

Raw tomatoes are also a good source of lutein, which is important for eye health.  100g of tomatoes, which is about one small tomato, provides:

 

• 7.5% of our daily requirement for folate, which reduces the risk of coronary heart disease by lowering blood levels of homocysteine. (NB it also protects a developing foetus from neural tube defects such as spina bifida)

• 7% for fibre.  Diets high in fibre can prevent heart disease, as well as constipation and colon diseases such as diverticulitis and cancer

• 7% for potassium which lowers blood pressure, reducing the risk of strokes in the long term

• 32% for vitamin C a powerful antioxidant which prevents oxidation of ‘bad’ LDL cholesterol – a process that enables LDL to stick to artery walls, where it can eventually cause blockages, resulting in strokes, angina and heart attacks. 

 

Diabetics and people with insulin resistance could benefit from eating tomatoes. They are high in chromium which is important for regulating blood sugar levels – people with type 2 diabetes, for example, have lower blood levels of chromium than those without the condition.