Increasingly, people are turning to holistic diets that are as unrefined and unprocessed as possible. As part of this move towards natural food, people are tending to eat more raw food. With some foods – fruit, for example – this ensures maximum nutrient content, but in other cases, raw foods are indigestible or contain toxicants. For these reasons and others, cooked foods remain an important part of the diet.
Advocates consider raw foods to be superior to cooked foods, not just because they retain the nutrients and enzymes that are normally destroyed by heat, but also because they believe that raw foods contain ‘living’ properties that are vital to good health. They may adopt a diet that consists almost entirely of raw foods. Whereas some foods may safely be consumed in their raw state, others must be cooked thoroughly in order to eliminate harmful bacteria and to help make nutrients more available.
A raw food diet generally focuses on fruit, vegetables, nuts, seeds, grains and pulses. A wide range of appetizing, nutrient-rich meals can be prepared using these foods. Salads, soups, dips and fruit salads, for example, are all ways of enjoying raw foods.
Advocates believe that raw foods possess living properties that have the power to make a person feel more alive and energetic because they can detoxify and rejuvenate the body. They contain health-promoting sub-stances, including enzymes, vitamins, essential fats and fibre. These substances would be progressively broken down during the normal cooking process.
Raw food diets concentrate on fruit, vegetables, nuts, seeds, grains and pulses, with approximately 75 per cent of the diet being eaten raw. Some extreme raw diets cut out pulses, rice, pasta and potatoes, as these foods cannot be eaten unless they are cooked. Dairy products may also be excluded because they have been processed in some way. Such extreme diets can lack protein, iron and calcium, and should never be undertaken without professional advice from a nutritionist.
Because a raw food diet is high in insoluble fibre, it is a good cure for constipation. It is also high in soluble fibre, which is associated with a reduced risk of heart disease. A high consumption of fruit and vegetables is believed to help the body to fight infection and to protect against some forms of cancer this is thought to be due to their phytonutrient content. However, an excessive intake of raw food can lead to irritable bowel syndrome in some people.
While it is certainly a good idea to include raw fruit and vegetables as part of a healthy diet, it would not be wise to eat all foods in their raw form. Cooking is necessary to make some foods safe to eat. It can also increase the availability of some nutrients and, in other cases, it makes foods more digestible.
In traditional Chinese nutrition, cold, raw foods are believed to be inappropriate for people who live in a cold climate, or who suffer with ‘cold’ conditions of the body.
Some foods, such as eggs, should always be cooked thoroughly to avoid the possibility of food poisoning from salmonella – a bacterium that lives in chickens. If the animal’s reproductive tract is infected, eggs can become infected before the shell forms. A small number of eggs become infected from faecal contamination, which can penetrate the shell if it is damaged. Dishes such as custards, mousses, meringues and mayonnaise include raw or lightly cooked eggs and should therefore be avoided by the elderly, the very young,and anyone who has a weakened immune system (such as cancer or AIDS patients).
All raw meat can harbour parasites and bacteria that can lead to food poisoning and in the most severe cases even death. And although raw fish is nutritious, there is a risk of parasite infection. Adequate cooking kills the dangerous organisms in these foods. Thorough cooking is also needed to make some fruit and vegetables, such as broad beans and rhubarb, safe for human consumption.
Although cooking destroys heat-sensitive nutrients, it is possible to minimize these losses by choosing a suitable cooking method and avoiding overcooking. Methods such as steaming and steam-frying can reduce the loss of nutrients. Light cooking, such as steaming, can increase the availability of betacarotene (an important antioxidant that helps protect the body from disease. Some starchy foods, such as potatoes, benefit from boiling because it quickly breaks down the starch granules. The disadvantage of boiling is that it causes nutrients to leach into the cooking water. However, if the water is retained and used to make soups or sauces, the nutrients can still be taken in. Keeping foods warm after they have been cooked – by keeping them on a low heat – increases vitamin losses and so should be avoided.