A growing body of research proves that vegetables are critical to promoting good health. In fact, vegetables according to research findings are packed with essential vitamins, minerals, fibre, and disease-fighting phyto-chemicals. But recent study released last week indicates that eating plenty of vegetable soup everyday fights cell damage as well as help reduce risk of degenerative disease such as heart disease, diabetes and certain categories of cancers. BEN UKWUOMA and CHUKWUMA MUANYA report.

Love EdikangIkong and all the other vegetable-rich soups? That is, you like to indulge yourself so often with generous helpings of mixed vegetable soups containing pumpkin leaves, water leaf, onions, peppers and seasonings? Or 'pepper soup'(mixture of different species of local pepper, onions, garlic, ginger, curry and seasonings)? Well, go on, eat some more.

Recent studies suggest that eating a combination of vegetables in form of soup, like the ever delicious Edikang ikong or 'pepper can fight cell damage, thus reducing the risk of degenerative diseases.

Indeed, vegetable soup seems like a healthy meal and a new study provides even more compelling evidence that it is. Scientists at Tufts University, Boston, USA, in a study published recently in Journal of Nutrition reports that volunteers eating a type of vegetable soup twice a day had lower amounts of stress-related molecules in their blood after just seven days. The researchers say the beneficial effect was due at least in part to an increase in vitamin C intake.

The volunteers consumed gazpacho, a Mediterranean-style cold soup of uncooked vegetables. It contained generous amounts of tomatoes, which are rich in vitamin C, along with peppers, cucumbers, onions, garlic, oil, and seasonings.

Previous studies have shown that eating three servings of vegetables a day can cut a man's risk of prostate cancer nearly in half.

A vegetable is basically any part of a plant that can be eaten, such as buds, flower buds, leaves and shoots.

A study of Nigerian material of Waterleaf( Talinum triangulare), shows that it is rich in mineral salts such as iron, potassium, calcium, phosphorus, magnesium, manganese, copper and vitamins C, A and B(in large dose), essential amino acids and high ash-content. Clinical trials of the young vegetable shows it nourishes the foetus in mammals, soothe inflammations, alleviates bladder problems, calms stomach troubles and heals scurvy(because of high vitamin C content) and relieve sore throat.

Waterleaf belongs to the plant family Portulacaceace and it is known by different names by the various ethnic tribes in Southern Nigeria where it is found. The Edos call it adodoro, Efik mmong mmong ikong, Igbo nti oke or ofe-bekee, Tiv ashwe, Yoruba gbure, Ilorin gure, and in Yagbaland, Kogi State it is called Adegbere.

Local studies have also shown that fluted pumpkin (Telfaira occidentalis) leaves, popularly called ugu, is efficient in building up or renewal of cells, and tissues as well as anaemia.

Tropical stinging nettle (Urtica dioca) according to local studies has been used as a soothing balm for wobbling joints. Indeed, a recent United Kingdom study shows its efficacy in osteoarthritis. In Nigeria, the Yorubas call it Esisi, and it is Osokporode in Urhobo. It is reportedly rich in mineral salts especially those of iron, phosphorus, magnesaium, calcium, and silicon, which make them diuretic and depurative. They also contain vitamins A, C, and K, formic acid, tannin, and other substances that have not been studied.

Medical experts have also re-affirmed the medicinal potential of cabbage in treatment of warts, tumours, sores, and in weak stomach, liver, or bladder. It has been reported that as well as mineral salts and vitamins(mainly A and C), cabbage contains mucilage and vitamin U( which is yet to be isolated).

Nigerian material of Sweet Basil(Ocinum gratissimum) has shown good result in typhoid fever, diabetes, pile, menstrual disturbances and convulsion. Sweet Basil is known as Effirin in Yoruba, Nchuanwu in Igbo, Da'ddoya or Deidoya in Hausa, Eran in Urhobo, and Nton in Efik. It is said to be replete in vitamins, mineral salts and a bitter principle.

Indeed, vegetables have been shown to contain compounds that are valuable antioxidants and protectants. Chief among these according to a biochemist at College of Medicine University of Lagos(CMUL), Dr Osaretin Ebuehi, are the carotenoids.

Ebuehi explained: "There are over 600 carotenoids in plants and in some animals (pink salmon is pink because of the the carotenoid 'astaxanthin' it contains). Only some - mainly beta-carotene- are precursors to vitamin A production by the body. The carotenoids not destined to be converted to vitamin A and unconverted beta-carotene are present in our tissues in very small amounts. The main carotenoids in human tissues eating a western diet are beta-carotene, alpha-carotene, lycopene, lutein, zeaxanthin, and beta-cryptoxanthin.

Lycopene has the greatest antioxidant properties, beta-carotene and cryptoxanthin has the next greatest activity, then lutein and zeaxanthin."

He continued: "One very useful measure of the protective antioxidant potential of a vegetable or fruit is to measure its ability to absorb damaging oxygen radicals. These free radicals are implicated in ageing, especially memory loss and loss of co-ordination, and degenerative diseases. This does not measure the activity of specific protective phytochemicals that may use other biochemical pathways to inhibit tumours or protect blood vessel walls, for example. It does give us a way to measure one element of the relative health 'usefulness' of a vegetable, without having to understand which natural plant chemical, or combination of chemicals acting together, are responsible for the effect.

"From the measurements of various vegetables so far, scientists estimate that a single serving of fresh or freshly cooked vegetables has, on average, 300 to 400 'ORAC(Oxygen Radical Absorbance Capacity) units'. But some specific vegetables-such as garlic and kale-have particularly high antioxidant levels. A single garlic clove, which weighs around 5 grams, has around 100 ORAC units. But even a small - 30 gram (about 1 ounce) - serving of carrots, much lower on the ORAC scale, just about matches a clove of garlic for oxygen radical absorbance capacity.

"Beyond anti oxidant activity, it is suspected that some carotenoids, such as lutein (found in dark green leafy vegetables), can act as an immuno-stimulant, perhaps influencing immune cells at the gene level. Lutein, in particular, is believed to be able to increase the density of the macular pigment in the eye and maybe reduce the risk of 'age related macular degeneration'. A good reason for parents to eat their greens, too."

A nutritionist at Nigerian Institute of Medical Research(NIMR), Lagos, Dr Rosemary Anyanwu, told The Guardian that Vegetables help retain stronger bones.

She said: "Vegetables and fruits have been shown to decrease the amount of calcium excreted in the urine. Vegetables and fruit as an 'alkaline buffer' neutralising acids produced when fish and meat are digested. These acids would otherwise tend to increase the amount of calcium lost in the urine -sufficient fruit and vegetables consumption neutralises this effect.

"Vegetables are important to get enough vitamins for health. They are particularly important as a source of vitamin A, vitamin C, and folate (folic acid, folacin). These three are the 'biggies', but most vegetables are a 'good' source of thiamine (B1), potatoes and green leafy vegetables are rated a 'good' source of riboflavin (B2), and potatoes, broccoli, cauliflower and tomatoes are a 'good' source of pantothenic acid (B5). Pyridoxine (B6) is important in brain function, immune system function, and as a precursor to several important hormones. All the brassicas are rated a 'good' source, as are potatoes, spinach, peas, carrots, watercress, and onions.

"Many vegetables contain small but useful amounts of vitamin E. Vegetables are generally very good sources of most minerals (with the exception of iron). Tubers and roots as an energy source aside, it is the protective phyto-chemicals and the vital vitamin C, vitamin A, and folic acid content that make vegetables essential to human well-being. Vegetables are generally a good source of calcium, and green beans, in particular are a good source. There are differences between green bean varieties - the variety 'Hystle' has nearly double the amount of calcium as the variety 'Labrador'. It is likely that scientists will work to breed enhanced mineral and vitamin content in the future."

Many studies have shown that vitamin C is a potent antioxidant that counters damage to human cells and tissues caused by highly reactive molecules called free radicals. But this study indicates that "the protective effect of vegetables may extend beyond their antioxidant capacity," says lead investigator Antonio Martin.

The results, he says, point to other important functions of vitamin C at the molecular level. These functions include a major role in preventing the formation of compounds involved in abnormal inflammation and a biochemical process called oxidative stress, both of which can alter cells in ways that set the stage for chronic diseases.

People probably do not have to consume vegetables in the form of a soup to get the benefits seen in the study, Martin and his colleagues note in the November Journal of Nutrition. They do not rule out, however, that additional nutrients in the particular mix of vegetables used in the gazpacho may provide a synergistic effect.

They fed the volunteers the prepared soup, they explain, because "it's a simple way to ingest generous amounts of vegetables." Gazpacho is a popular food in Spain, Martin's native country.

His team recruited 12 volunteers, half men and half women. All were in their early 20s and none had a major health problem. The participants maintained their usual lifestyles and ate as they normally would, except for the bonus soup. None of them took vitamins and minerals or medications before or during the study.

Before the volunteers began the twice-daily soup regimen, the researchers collected blood samples from them and measured concentrations of vitamin C as well as several compounds that indicate inflammation and oxidative stress.

The gazpacho was prepared in a home-style blender, then vacuum packed in individual portions. The volunteers consumed a total of 17 ounces of the soup every day for 14 days. The researchers collected blood samples again on the 7th and 14th days of the study.

The results showed that as of the 7th day, the amount of vitamin C in the volunteers' blood increased by 26 percent for the men and 25 percent for the women. The concentrations remained elevated during the final week of the study.

The researchers also measured blood concentrations of several molecules that the body secretes in response to stress. High readings for these molecules can indicate increased vulnerability to various illnesses because stress molecules, such as various hormone-like prostaglandins, induce inflammation and oxidative stress. Inflammation normally aids the repair of injured tissue as part of the body's infection-fighting defences, but when a person's internal regulatory mechanisms are faulty, systemic low-grade inflammation can cause progressive damage.

After a week of consuming the soup consistently, the volunteers had a significant decrease in blood concentrations of prostaglandin E2, which is produced during inflammation and influences immune responses.

The young men and women also had lowered their amounts of two other stress markers: a particular isoprostane molecule that increases with age and in chronic diseases, and a molecule called monocyte chemotactic protein-1, which has been found in high concentrations in artery-clogging plaques that pave the way to heart disease.

The blood concentrations of these three compounds dropped inversely in proportion to the increase of vitamin C concentrations in the volunteers' blood. This clear inverse correlation, the researchers say, suggests that the vitamin C gave strong protection against the damaging effects of inflammation and oxidative stress.

Moreover, the volunteers had decreased amounts of uric acid in their blood. A build up of uric acid causes the joint inflammation called gout. Research suggests that high amounts of uric acid may also contribute to the development of vascular dysfunction and heart disease by impairing some cells that line blood vessels. In this study, uric acid concentrations were 18 percent lower in the male volunteers and 8 percent lower in the women on the 7th day of the soup experiment than on the first day.

Current dietary recommendations say that everyone should eat at least five portions of fruits and vegetables a day to reduce the risk of major illness, including cancer and heart disease. The results of this study, Martin says, "strongly suggest that increasing vegetable consumption could improve human health."

Martin says he and his colleagues designed this and some earlier studies to examine the effects of ingesting vitamin C through diet rather than in the form of vitamin supplements. While vitamin C is a critical nutrient in a number of biological processes, the human body can't produce it naturally and must acquire it from dietary sources.

A year ago, Martin's team did a study that found similar benefits from regular consumption of orange juice. Blood concentrations of vitamin C rose significantly among a group of volunteers who drank two glasses or orange juice every day for 2 weeks. Citrus fruits are the chief source of vitamin C in Western diets, Martin points out, but tomato-based products are also an important source.

Martin says "hundreds of studies" have demonstrated that vitamin C is an important nutrient for human health, "although we do not know the exact mechanisms behind these healthy effects." Analysing the effects of vitamin C in the bloodstream, he says, is a stand-in for studying various functions of vitamin C in human tissues.

"Vitamin C is one of the most amazing nutrients in the human diet," Martin says. Among other things, it's important in the production of collagen proteins, which form bone and cartilage in vertebrates. It's also a cofactor in the production of several signal transmitters in the brain.

Brain tissue, Martin notes, contains the highest concentrations of vitamin C in the body. In a study 2 years ago, he and his colleagues found that increased concentrations of vitamin C in cells of human brain tissue improved the function of lysosomes, which are cell parts containing enzymes that break down and eliminate waste products. Scientists now know that the function of lysosomes decreases as people age, Martin points out.

While the present study examined the effects of increased vitamin C intake in healthy young people, Martin says he's convinced that the results would hold in other populations, including the elderly.