By Oge Okafor
Nutritionists, dieticians and health experts have always encouraged us to include in our diets fruits and vegetables because of their nutritional value. In fact, they advise us to eat five to nine portions (servings) of fruits and vegetables daily. Some even recommend that you fill half your plate with colourful fruits and vegetables at every meal.
The amount of vegetables one needs to eat depends on age, sex and level of physical activity
As easy as it may sound, the truth is that these recommendations, as hard as we try, can be difficult to keep up with. There are many reasons why it’s difficult to meet these recommendations as some people (children) don’t like vegetables; others do not known their nutritional value and also maybe due to economic recession.
But even if you do try to eat vegetables, do you know that your diet is probably still not as healthy as it could be? And that’s all down to the way many of us cook our veggies – which can ruin the health benefits that are otherwise contained in our favourite super foods, says Tracy Lesht, a nutritionist as reported by Daily mail.
So, if you boil your vegetables, stop at once. Cooking them in this way could be eradicating up to 50 per cent of their nutrients, according to the nutritionist.
She said certain vegetables, namely those containing water-soluble vitamins should never be boiled if you can avoid it. These include cabbage, spinach, kale, broccoli, beans, and peas. The reason is that water-soluble vitamins dissolve in water, so, if you boil vegetables containing these vitamins, you won’t derive much health benefit from them.
Also supporting this claim, Prof Ignatius Onimawo, Professor of Nutritional Biochemistry at Ambrose Alli University, Ekpoma says boiling destroys heat labile (sensitive) vitamins. In addition, water-soluble vitamins leach into the boiling water, which in most cases is thrown away.
According to Wikipedia, in everyday usage, a vegetable is any part of a plant that is consumed by humans as food as part of a savory meal. It normally excludes other food derived from plants such as fruits, nuts and cereal grains, but includes seeds such as pulses.
Vegetables can be eaten either raw or cooked and play an important role in human nutrition, being mostly low in fat and carbohydrates, but high in vitamins, minerals and fibre. Many nutritionists encourage people to consume plenty of fruit and vegetables, five or more portions a day often being recommended.
Vegetables play an important role in human nutrition. Most are low in fat and calories but are bulky and filling. They supply dietary fibre and are important sources of essential vitamins, minerals and trace elements. Particularly important are the antioxidant vitamins A, C, and E. When vegetables are included in the diet, there is a reduction in the incidence of cancer, stroke, cardiovascular disease, and other chronic ailments.
Research has shown that compared with individuals who eat less than three servings of fruits and vegetables each day, those that eat more than five servings have an approximately twenty percent lower risk of developing coronary heart disease or stroke.
The nutritional content of vegetables varies considerably as some contain useful amounts of protein, though generally they contain little fat and varying proportions of vitamins such as vitamin A, vitamin K, and vitamin B6; provitamins; dietary minerals and carbohydrates. Vegetables contain a great variety of other phytochemicals (bioactive non-nutrient plant compounds), some of which have been claimed to have antioxidant, antibacterial, antifungal, antiviral, and anticarcinogenic properties.
However, vegetables often also contain toxins and antinutrients, which interfere with the absorption of nutrients. These toxins are natural defenses, used to ward off insects, predators and fungi that might attack the plant. Some beans contain phytohaemagglutinin, and cassava roots contain cyanogenic glycoside, as do bamboo shoots. Adequate cooking can deactivate these toxins. Green potatoes contain glycoalkaloids and should be avoided.
But this isn’t to say you should just stop eating these nutrient-packed foods altogether.
Lesht suggests an alternative to boiling them ferociously – and the trick is to never cook them for too long.
She says, “Minimize the cooking time and use small amounts of water with low heat to absorb the maximum amount of nutrients.”
The advice is backed by NHS Choices, which has blogged about the issue on its website.
It says “By cooking foods, especially boiling them, we lose some of these vitamins.
The best way to keep as many of the water-soluble vitamins as possible is to steam or grill foods, rather than boil them or to use the cooking water in soups or stews rather than pouring it away.”
Reassuringly though, Lesht advises vegetable lovers not to get too hung up on cooking technique.
She said: “At the end of the day, your food needs to be palatable to you. It’s more important to consume fruits and vegetables cooked and prepared the way you enjoy them than it is to be overly concerned with their bioavailability and nutrient loss due to cooking. In the grand scheme of things, eating a vegetable and only absorbing 50 per cent of its nutrients is still better than not eating the vegetable at all.”