RBSE Class 10 Science Notes Chapter 1 Food and Human Health

Rajasthan Board RBSE Class 10 Science Notes Chapter 1 Food and Human Health

• Nutrition: The process of obtaining and utilizing food by living beings is called nutrition.
• Nutrients: Various constituents of food which are necessary for metabolic processes are called nutrients. Carbohydrates, proteins, fats, vitamins and minerals  are the nutrients.
• Carbohydrates and fats provide energy to the body: Hence, they are known as energy giving food. Proteins facilitates growth and repair and hence it is called the body-building food. Vitamins and minerals help the body in fighting diseases. So, vitamins and minerals are called protective food.

Balanced and Unbalanced Food: On the basis of presence of different nutrients, food can be divided into two types, which are as follows:

Balanced Food: A food which has all the nutrients in right proportion is called balanced food. A balanced diet is necessary for proper growth and development. Even for grown up adults, a balanced diet is necessary to maintain good health.

• Unbalanced Food: A food which does not have all the nutrients in right proportion is called unbalanced food. Unbalanced food can have many short-term and long-term consequences. Malnutrition, diseases and permanent debility are some of the consequences of taking unbalanced food.

Malnutrition: Lack of some or most of the nutrients in a person’s diet for a long duration is called malnutrition. Malnutrition can result in many diseases.

Vitamin Malnutrition: Vitamins are needed in very small quantities. But lack of a vitamin can cause problems. Following table shows the diseases caused because of deficiency of different vitamins.

Vitamins	Deficiency Disease	Symptoms
Vitamin A	Night blindness	Difficulty in seeing in dim light
Thiamine (B12)	Beriberi	Weak heart beat, weak muscles and nerves

• Mineral Malnutrition: Minerals are required in very small quantities. But lack of minerals can result in many diseases because minerals play important role in many metabolic activities. For example; iron is necessary for red blood cells. Lack of iron results in a disease called anaemia. Following table shows some minerals, their roles and their sources.

Importance of Water:

• Water is needed for every biological function.
• Water helps in proper bowel movement.
• Water helps in proper digestion of food.
• One should drink plenty of water.

Shortage of Drinking Water: The earth has plenty of water but more than 95% of total water on earth is in the form of saline water. Less than 2% of total water on earth is available as drinking water. Due to this, people often have to face shortage of drinking water. We should always keep in mind that water is precious.

Properties of Drinking Water:

• It should be colourless.
• It should be odourless.
• It should be free of any visible impurities.
• It should have right balance of minerals.

Harmful Effects of Contaminated Water:

• Drinking contaminated water can result in many diseases like cholera, diarrhoea, jaundice, etc.
• Dracunculus medinensis or Guinea worm is a nematode which lay its eggs in water. Using this contaminated water causes dracunculiasis or Guinea worm disease or ‘naru’ disease. This disease had once created havoc in Rajasthan. Thanks to untiring efforts by the health workers, this disease has been eradicated from Rajasthan.

Obesity: A condition in which the body accumulates too much fat is called obesity. Obesity can cause many complications. An obese person is likely to suffer from heart disease, hypertension, diabetes and arthritis.

Blood Pressure: The pressure exerted by arteries to the blood flow is called blood pressure. In a healthy person, the blood pressure is 80/120 mm Hg. This figure shows two types of blood pressure, i.e. systolic blood pressure and diastolic blood pressure.

• Systolic Blood Pressure: The pressure during contraction or systole of left ventricle is called systolic blood pressure. Systolic blood pressure is always high, i.e. 120 mm Hg is systolic blood pressure.
• Diastolic Blood Pressure: The pressure during relaxation or diastole of left ventricle is called diastolic blood pressure. Diastolic blood pressure is always on the lower side, i.e. 80 mm Hg is diastolic blood pressure.

Hypertension: When blood pressure is constantly higher than the normal range, it is called hypertension or high blood pressure. Obesity, diabetes and old age can cause hypertension. A fat-rich diet results in high level of cholesterol in blood. Cholesterol blocks the arteries and blocked arteries cause high blood pressure. In the long run, high blood pressure progresses to coronary artery disease which is a type of heart disease.

Taking a balanced diet which is low on fat and high on fibre can help prevent hypertension. A regular regimen of exercise also helps in controlling hypertension.

Hypotension: When blood pressure falls below the normal range, it is called hypotension or low blood pressure. Hypotension results in reduced blood supply to important organs; like heart, brain and kidneys. This may result in permanent damage to these organs and may also result in death.

Addictive Substances: Some substances have such properties that people become addicted to them. These are called addictive substances. These are very harmful to the body.
Some addictive substances are given below:
(i) Gutkha: This is a mixture of betel nut, lime, catechu and some flavouring agents. People often mix tobacco along with it.

(ii) Tobacco: Tobacco is consumed in variety of ways. Some people use tobacco for smoking while some people chew tobacco. Both gutkha and tobacco cause mouth cancer. They can also cause lung cancer.

(iii) Alcohol: Alcohol is highly addictive substance. Ethanol or ethyl alcohol is used in different ratios in different alcoholic beverages.

Some harmful effects of alcohol are as follows:

• Lack of alertness.
• Lack of control on cognitive functions.
• Liver damage in the long run.
• Blindness and even death may happen in case someone consumes spurious liquor.
• Alcohol consumption can put a severe strain on one’s pocket.

(iv) Opium: Opium extract is used for making painkillers and many other medicines. But many people develop opium addiction. This can ruin a person’s life. Some ladies give small dose of opium to their children so that the child can go to sleep. Some people boil the shell of opium and drink the extract. Opium damages the immune system of the body. This results in frequent episodes of sickness and finally results in premature death.

Other Addictive Substances: Apart from above mentioned addictive substance:; people also use marijuana, charas, heroin, LSD, etc. The youth often falls in trap of these substances. This results in mental and physical imbalances. It affects family ties, produces unproductive and unemployed youth which can prove to be disastrous for the society.

Misuse of Medicines:

• There are many medicines which can cause sedation if taken in higher dose. Morphene, diazepam, nitrazepam, buprinorphin, pathadene, codeine, etc. are examples of such medicines. Many medicine sellers often sell these medicines without prescription. Many young people consume these medicines in order to get their daily fix.
• Many children use paint thinner, shoe police, iodine, etc. for intoxication. Many ragpickers, and motor mechanics of very young age can be spotted inhaling the fumes of these substances.
• Punjab, Haryana, Rajasthan and Gujarat are badly affected by opium menace. Young people of the north eastern states have become victims of heroin. This is a dangerous situation and everybody needs to make efforts to root out the scourge of drugs.

Food Adulteration: Many sellers often mix some unwanted substances to food to earn heavy profit. But food adulteration can be harmful for health. Consuming adulterated food can cause cancer, food poisoning and many other diseases.