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Dubai: With Ramadan here, the change in eating patterns can mean that you devote more attention than normal to nutrition, ensuring that you are partaking of the optimum benefits of the food you eat.

When it comes to fruits and vegetables, much of the nutritional debate is focused on how we should eat them. For instance, in vegetables there are many types that can be cooked in their skins and some which have to be peeled before cooking.

In fruits too, many varieties need to be peeled, while other kinds can be eaten with their skins on.

According to nutritional experts, vegetables and fruits have their densest concentration of vitamins and beneficial compounds in the skin or close to the skin and by skinning them, we lose many of the benefits.

Making this issue more contentious is the fact that modern-day farming necessitates the use of pesticides to grow our food.

The recent ban imposed by the Ministry of Climate Change and Environment on food imports from five neighbouring countries over fears of high levels of pesticide residue in them puts the focus back on how pesticides affect the nutritional quality of fresh fruits and vegetables.

Safe supply in UAE

Jehaina Hassan Al Ali, principal food studies and surveys officer with the Applied Nutrition Unit of the Food Safety Department at Dubai Municipality, puts into perspective the issue of pesticide residues.

First of all, she says that for consumers in the UAE there is no need to worry about this as the government takes every precaution to ensure that food meets the standards of safety.

“Don’t worry about pesticides if you are in the UAE as we have a very safe supply of food. At times we get contaminated food and the authorities here take it out of the market quickly,” said Al Ali and the ban is a case in point.

Regarding the use of pesticides, she said, “it is important to know that fertilisers and pesticides have a big role to play in ensuring food sufficiency.

"While fertilisers are important to replenish soil, pesticides help the plants stay protected from insects that would destroy them. Uses of pesticides and fertilisers have safe and standardised recommendations and the residues of these pesticides are analysed periodically at the point of import.”

High residues of pesticides, she said, indicate poor farming practices. When used in the recommended way, fertilisers and pesticides pose no risk to consumers.

Fertilisers and pesticides

Though it wouldn’t cause acute poisoning, when eaten in large quantities over several years, these residues may cause harm to the human body, she pointed out.

As a nutritionist, Al Ali believes most people don’t eat enough fruits and vegetables. “That’s where I would start first,” she said.

Dr Juliot Vinolia, clinical dietician and consultant nutritionist at Medeor 24/7 Hospital, explained: “Fertilisers are added to the soil to increase productivity by sustaining the elements of soil like water and bacteria that support growth.

“They can be made from biologically degradable natural resources like cow dung and composite or otherwise synthetically made with salts and minerals to nourish the soil. Long-term use of synthetic materials not only denatures the soil’s natural balance but also makes it unfit for agriculture.”

How plants guard our health

Plants have an internal defence mechanism to deal with infestations.

“To counter any such attack, plants produce their own antibodies. When infested by bugs and microbes, as a defence mechanism, plants produce certain compounds called phenolic phytonutrients — for instance, flavones and anthocyanin,” explained Juliot Vinolia, dietitian.

“These nutrients serve as an insect repellant and also inhibit bacterial growth. These phytonutrients function as antioxidants in our body and fight diseases like cancer and heart disease. However, excess use of fertilisers and pesticides shuts down the defence mechanisms of plants, resulting in fruits and vegetables with poor quality antioxidants, thereby reducing nutrition value,” she said.

It is also true that pesticide impact is, naturally, different with fruits and vegetables that can be peeled before consumption and those that are preferably eaten with their skin on, in order to optimise fibre consumption. Usually increasing the number of servings of fruit and vegetables can definitely give you more nutrition, say experts.

Nadine Aoun, clinical dietician, Medcare Hospital, said: “Eating fruits and vegetables helps reduce the risk of many diseases including heart diseases, high blood pressure and some cancers.

“They are rich in vitamins and minerals that help you feel healthy and energised. Fruits are a quick, natural snack. The right amount of fruits to be taken depends on several factors like age, gender and physical activity. So choosing how many servings of fruits to take is based on one’s daily needs, since there is no one-size-fits all.”

How to get rid of pesticide residue?

If you want a fully pesticide-free fruit or vegetable, buy organic.

Smart tip:

Choose fruits and vegetables from their native lands. For a fruit or vegetable to be grown in a non-native land, it usually requires fertiliser and pesticide support.

For instance, India and the Philippines are known for their banana cultivation.

Rinsing techniques

Simple rinsing is not enough to rid many fruits of pesticide residue as rinsing alone does not wash away all residue.

1. Soak vegetables in 90/10 parts water to vinegar proportion for 20 minutes, stirring the bowl occasionally and then wash produce in cold running tap water, gently scrubbing the surface for solid residues.

2. Soak in 10 per cent saline solution and then rinse well in running cold tap water.

Water serves as a great solvent for these chemicals.

3. You can use the commercially available vegetable and fruit rinses. Many of them contain potassium permang-anate that removes dyes used to make fruits more bright and colourful.

4. Sodium-based rinses (such as baking soda powder rubs, etc) wash away pesticide residue by altering the pH balance, which dissolves these chemicals and cleans the surface of the fruit’s skin.

Leafy greens

It is best to wash leafy greens gently in cold running tap water. Cook by sauteing to retain nutrients. Boiling for longer periods depletes its vitamin content.

What lies beneath

All fruits are rich sources of antioxidants such as vitamins A, C, the B complex, soluble fibre, minerals like potassium and other phytonutrients. “Nutrient content of [most] fruits is closer towards their skin. Peeling off the skin is equivalent to removing three-fourths of the nutrients and soluble fibre in them.

Peeling some fruits does, to some extent, eliminate pesticide residue, particularly in fruits that have less water content and a thick cover.

Pesticides penetrate fruits that have more water content and a thin outer layer. Also, the volume of pesticide residue depends on the degree of pesticide exposure.

Ignorance of farmers regarding correct pesticide dosage leads to produce being more exposed to quantities of chemicals.

How can nutrition be optimised by eating fruits?

Choose different-coloured fruits and vegetables in your diet, so you can meet your daily requirements of micronutrients. Include three variety of fruits a day.

1. High fibre content in apple, pear, banana and pineapple, etc

2. Water-laden fruits have more vitamin C such as oranges, melons, kiwi and berries.

3. Dried fruits like apricots, raisins, prunes, figs and dates for iron, potassium, magnesium and fibre.

How many servings a day?

According to the USDA’s recommendation, it is recommended for adults to include 2-4 servings of fruits and 3-5 servings of vegetables on a daily basis.

Pesticides and their harmful impact

Field research conducted by the Environmental Working Group (EWG) found that certain fruits and vegetables had the highest traces of pesticides. These are pesticide-laden due to their vulnerability to bacterial and insect infestation. “Some of these fruits have endocrine disruption pesticides sprayed on them,” Vinolia said.

According to the US National Institute of Environmental Health sciences, Endocrine disruptor pesticides are a group of pesticides that pose great risk to human health. They are…

Diethylstilbestrol (the synthetic estrogen DES)

Dioxin and dioxin-like compounds

Polychlorinated biphenyls (PCBs)

DDT

Organophosphates

These pesticides cause the following harm:

Suppress the function of endocrine glands leading to diseases like diabetes.

Induce cancer of breast and colon.

Trigger autoimmune disorders.

Affect brain development of foetus.

Hormonal imbalance — PCOS and male infertility due to poor testosterone levels

Suppress intellectual function of growing children.

Affect nervous system of children causing hyperactive disorders.

Parkinson’s disease. Overwork the kidneys.

What lies beneath

All fruits are rich sources of antioxidants such as vitamins A, C, the B complex, soluble fibre, minerals like potassium and other phytonutrients. “Nutrient content of [most] fruits is closer towards their skin. Peeling off the skin is equivalent to removing three-fourths of the nutrients and soluble fibre in them.

Peeling some fruits does, to some extent, eliminate pesticide residue, particularly in fruits that have less water content and a thick cover.

Pesticides penetrate fruits that have more water content and a thin outer layer. Also, the volume of pesticide residue depends on the degree of pesticide exposure.

Ignorance of farmers regarding correct pesticide dosage leads to produce being more exposed to quantities of chemicals.

Fruits eaten without peel and how to obtain optimum nutrition

Removing certain fruit peels is equivalent to removing a third of a fruit's nutrient content and soluble fibre. However, peeling some fruits does, to some extent eliminate pesticide residue. Here are fruits that are eaten without peels.

Bananas

What's in it? Good source of Vitamin B6, Vitamin c, manganese, potassium, dietary fiber, biotin, copper.

What's it good for? Helps overcome depression due to high levels of tryptophan which the body converts to serotonin, the mood-elevating brain neurotransmitter. Its Vitamin B6 content helps you sleep well, while magnesium helps to relax the muscles, and its potassium content is essential for heart health, especially blood pressure control.

Mango

What's in it? Vitamin C, Vitamin A, folate, Vitamin B6, potassium, Vitamin K

What's it good for? Prevents colon cancer and breast cancer, and leukemia with its antioxidant compounts, and also improves eye health and digestion

Papaya

What's in it? Rich in antioxidants: carotenes, flavonoids, Vitamin C

What's it good for? Its Vitamin B content is a good source of fibre and magnesium; it helps in cardiovascular health, protects against colon cancer and reduces inflammation due to richness of antioxidants

Pineapple

What's in it? Potassium, calcium, phosphorous, manganese, rich in fibre and Vitamin C

What's it good for? Good for healthy immune system due to Vitamin C, eye health, aids in digestion and has anti-inflammatory benefits 

Longan

What's in it? Vitamin C, iron, phosphorus, magnesium, potassium and Vitamin A

What's it good for? Improves wound healing, helps reduce the risk of developing certain types of cancer, improves blood circulation and increases iron assimilation in human body, which prevents occurrence of anaemia 

Rambutan

What's in it? Vitamin C, calcium, phosphorus, iron

What's it good for? Increases energy and prevents bloatedness, protects the body from getting damaged from free radicals, has good fiber content to keep you full for a long time.

Melons

What's in it? Vitamin C, A, potassium, Vitamin B, Vitamin K, magnesium and fibre

What's it good for? Helps in preventing cancer due to their high content of carotenoids, helps in smooth and easy bowel movement, contains Vitamin B which account for most of your body’s energy production, good for the skin

Citrus fruits
Oranges, lemons, grapefruit, tangerines

What's in it? Vitamin C, fibre, calcium, potassium, folate, Vitamin A

What's it good for? Rich in flavonoids which have anticancer properties, helps keep your immune system strong; fights off disease, infection and colds much easier.

Fruits eaten with skin or unpeeled: Potential for pesticide residue

This category includes peaches, plums, grapes, apples, tomatilloes, strawberries, all kinds of berries and guava, among others. Nutritionist Nadine Aoun says: “Many vitamins and nutrients are found in the skin as well as in the flesh.”

Apples

A large red apple when eaten with skin contains about:

5gm of fibre, 13mg of calcium, 239mg of potassium and 10mg of vitamin C.

Remove the skin, and it still contains about 3gm of fibre, 11mg of calcium, 194mg of potassium, plenty of vitamin C and other nutrients.

Chikoos (Sapodilla/sapota)

Nearly 50 per cent of the nutritive components are present nearer the peel.

Grapes

Purple grapes are rich in anthocyanins while white /green grapes are composed more of tannins, especially, catechin. These antioxidant compounds are concentrated densely in the skin and seeds.

Guava

The skin of guava has antimicrobial properties against bacterial strains of Staphylococcus aureus and MRSA strains, which are highly antibiotic resistant bacteria. The phenolic compounds in the skin namely Gallic acid and Ferulic acid help fight infections by breaking the cell wall of these bacteria.

Banana

The peel contains lutein essential for eyesight. Tryptophan, an amino acid, is highly concentrated in the peel — and it helps to control mood swings.

Although the peel has a bitter taste and a ropey consistency, an overripe banana (brown or black) peel becomes thinner, sweeter and easier to chew. You can also juice the peel (ripe or overripe) with the rest of the banana. Or boil the peel to make it softer, or throw it in the frying pan to crispen.

How to maximise nutrient density in vegetables

Some examples of how nutrient loss takes place when vegetables are peeled:

Sweet potato

With skin: 100-gram serving contains 2gm of protein, 3gm of fibre, and 20mg of vitamin C.

Without skin: Boiling, which leaches some nutrients, still boasts 1.4gm of protein, 2.5gm of fibre, 13mg of vitamin C.

Potatoes

With skin: 100gm of potato packs seven times more calcium and 17 times more iron than the same amount of potato flesh.

Without skin: You lose nearly 90 per cent of iron content and half of its fibre.

Pumpkin

Studies have shown that pumpkin skin contains lutein, xanthin, and carotenes — pigments that have potential antimicrobial effect against yeast infections.

Onion

Like apple skin and mango skin, onion’s outer skin contains quercetin. Although this skin is not directly edible, you can draw out some of those nutrients by adding it to stock.

Carrots

90 per cent of the carotene is present nearer the outermost layer of carrots. Scrapping only the brown muddy areas and washing it well in cold water helps retain the Vitamin A. Thin-layer scraping without losing the dark orange colour is also preferable.

Cucumbers

Cucumber peels contain 40 per cent of the fibre, carotenes, Vitamin A and K, zeaxanthin, and lutein. Cucumber peel is a good source of dietary fibre that helps reduce constipation and offers some protection against colon cancers by eliminating toxic compounds from the gut.