Do you ever wonder what causes one person to catch a cold and another to avoid it? Why serious outbreaks of infectious disease leave some individuals untouched? Why some people are affected by allergies while some are not? The answer to these questions lies in the most powerful curing machine in our body: the immune system.
Our immunity is our self-defence system. Just like our nation's defence force keeps us protected from the enemies, our body's immunity does the same for our bodies. It follows then that our immune system needs to be strong enough to keep infectious organisms from entering our body and multiplying, and to re-establish health when disease does gain a foothold.
Our immune system
Our immune system is made up of special cells, proteins, tissues, and organs. It defends us against germs and micro-organisms at all times.
Through a series of steps called the immune response, the immune system attacks organisms and substances that invade our body and cause diseases.
The cells that are part of this defence system are white blood cells, or leucocytes. They come in two basic types, which combine to seek out and destroy the organisms or substances that enter our body.
The two basic types of leucocytes are:
- Phagocytes, cells that chew up invading organisms
- Lymphocytes, cells that allow the body to remember and recognise previous invaders and help to destroy them. These are of two types - First, the B lymphocytes that are the body's military intelligence system, seeking out their targets and sending defences to lock onto them. Second, the T cells that are like soldiers, destroying the invaders that the intelligence system has identified.
We have three types of immunity - innate, adaptive, and passive.
Everyone is born with innate [or natural] immunity, a type of general protection that humans have. Many germs that affect other species don't harm us. Innate immunity includes the external barriers of the body, like the skin and mucous membranes [those that line the nose, throat, and gastrointestinal tract], which are our first line-of-defence in preventing germs from entering our body. If this outer defensive wall is broken [like if you get a cut], the skin attempts to heal the break quickly and special immune cells on the skin attack invading germs.
A second kind of protection is called adaptive [or active] immunity. This type of immunity develops throughout our lives. Adaptive immunity involves the lymphocytes and develops as children and adults are exposed to diseases or immunised against diseases through vaccination.
Passive immunity is "borrowed" from another source and it lasts for a short time. For example, antibodies in a mother's breast milk provide an infant with temporary immunity to diseases that the mother has been exposed to. This can help protect the infant against infection during the early years of childhood.
What affects our immunity?
The immunity of a person can be significantly affected by the lifestyle and diet. There are some well-known ways to improve your self-defence system like:
- Eat well
- Move a lot
- Manage stress.
Let's discuss and know more on how they play a vital role in building our immunity.
Eat well, not big
Several nutrients play a crucial role in maintenance of an optimum immune system. "Proper nutrition not only benefits the immune system, but will also prepare the body for periods of stress, reducing the adverse effects of stress and enhancing recovery from stressful periods. There are two major changes you can make in your diet to help your immune system - enrich your diet with anti-oxidants and make sure you are getting enough nutrients and micronutrients", says Richa Anand, Executive Dietician, Dr L H Hiranandani Hospital.
Anti-oxidants are vitamins and minerals, found in foods and available as supplements, that remove harmful oxidants from the bloodstream. Oxidants, also known as free radicals, are the toxic by-products our bodies make when we turn food into energy. Free radicals are capable of damaging DNA and suppressing the body's immune system which can lead to development of diseases. You cannot prevent these diseases simply by taking anti-oxidants, however your immunity can be strengthened. Studies have shown that eating a diet rich in anti-oxidant-containing foods, such as fruits, vegetables and whole grains; have been linked to a reduced risk of cardiovascular disease.
Nutrients and micronutrients
Marginal nutrient deficiencies in the diet can also weaken the immune system. Marginal nutrient deficiencies are common in both younger and older individuals. The typical Indian diet is often deficient in a variety of nutrients including calcium, iron, vitamin A, and vitamin C. Furthermore, the recommended daily allowance [RDA] for many nutrients might be well below what is needed to optimally protect the immune system.
For this reason, vitamin and mineral supplements are used to protect us against micronutrient deficiencies.
Exercise, even a simple moderate-paced walk, has been proved to boost the immune system. According to a study by David Nieman, exercise physiologist at University of North Carolina, "Women who walk 45 minutes a day are half as likely to catch a flu or cold. What's more, active women in their 70s had immune systems that were as healthy as women in their 30s and twice as healthy as more sedentary seniors."
Perhaps the biggest benefit of exercise is indirectly related to the immune system in that exercise gives you "well-worked" organs, muscle, tissue, and fluids which results in healthier bodies later in life. Many different studies have shown that exercise slows down the body's deterioration. According to the study of Fred Kasch of the Fred Kasch Exercise Physiology Lab at Sand Diego State University, "Aging accounts for about one-third of a body's aerobic decline. Inactivity is responsible for the remaining two-thirds." Jim Graves of the University of Florida Centre for Exercise Sciences says, "Exercise will prevent most age-related-deteriorations till the age of 60 years." After 60, the body does slow down, but exercise can still keep your body fit and active.
Another important component that helps our immune system is relaxation, which includes sleep, low stress, and a good attitude. When we sleep, our bodies recharge themselves: thus repairing tissues, healing, and fuelling cells and organs. Sleep may be the single most important thing we can do to help our immune system. Ever wondered why you catch a cold when you feel "tired and rundown"? That's why.
Indirectly, when we worry about family, jobs, friends or school, we often lose sleep and cannot relax. This means taking valuable recharge time away from our immune system. On a more technical level, recent studies have shown that stressful arguments change the level of hormones that promote or reduce immune system functions.
Finally, feeling good about things also makes a difference. Although there have long been reports of laughter helping people through illness and the like, they were often dismissed as "testimonials". However, science today is discovering why a healthy mental attitude bolsters the immune system. Studies have shown that components of the immune system can respond to chemical secretions by the central nervous system. White blood cells, for example, become less active in fighting infection when exposed to a neuro chemical released in response to stress. David Spiegel of the University of California, San Francisco, led a study showing that women with advanced breast cancer survived nearly twice as long if they participated in a weekly support group.
One of the best ways to lower your immune system and make yourself sick is stress. Similarly, negative emotions like worry and anger will also lower your immune system. So as you might expect, one good way to boost your immune system, as well as to improve the general quality of your life, is to eliminate these negative emotions.
Studies confirm that students during exam time have an increased risk of infections due to the stress-induced effect on immunity. Studies have shown that children affected with chronic asthma improve considerably when away from their parents. This indicates how psychological stress at homes within the family members even at very young age affects immunity.
However, a small amount of stress also has positive effects on the body. Immune system is boosted during short bouts of stress. The "fight or flight" response prompts the immune system to ready itself for infections resulting from the upcoming damage to the body. However, sustained and chronic stress levels ultimately suppress immunity", says Dr Akash Rajpal, Dr L H Hiranandani Hospital.
Vaccination and immunity
Our bodies are designed to protect us from diseases. When you are exposed to an illness, your immune system actually learns from the experience. The next time your body is exposed to the same illness, your immune system often recognises the culprit and sets out to destroy it.
Vaccines expose you to a very small, safe amount of the diseases-causing agent. This mild exposure triggers the production of antibodies against it. If you are exposed to the full-blown disease later in life, you will either not be infected at all or will have a less serious infection. This is a natural way to deal with infectious diseases.
- The viruses and bacteria that cause disease are killed or weakened and then used to make vaccines. They do not actually cause the disease.
- Vaccines make the body think it is being invaded by a specific disease, and the body reacts by producing antibodies.
So, what is the secret of a healthier and longer life? It is the desire and will to eat better, exercise, and relax. This trio can give your immune system a head start in keeping ill health at bay.
With inputs from Dr Akash Rajpal, Dr Bijal Shrivastava, Consultant Paediatrician and Richa Anand, Executive Dietician, Dr L H Hiranandani Hospital.
Rheumatoid Arthritis [RA] is a common type of arthritis triggered by the immune system. It is a chronic disease that causes pain, stiffness, swelling, and limitation in the motion and function of multiple joints. Though joints are the principal body parts affected by RA, inflammation can develop in other organs as well.
The stiffness seen in active RA is typically worst in the morning and may last anywhere from 1-2 hours to the entire day. This long period of morning stiffness is an important diagnostic clue, as not many other arthritic diseases behave this way. While RA can affect any joint, small joints in the hands and feet tend be involved more frequently than others. This produces a pattern of joint disease that is a characteristic of RA.
The disease usually strikes between the ages of 25 and 50 and attacks more women than men. The cause of RA is still unknown.
Recent research indicates that people with RA, particularly those whose disease is not well controlled, may have a higher risk for heart disease and stroke. Talk with your physician about your own risk and ways that you can minimise it.
There is no vaccination, diet or exercise useful to prevent RA. Avoiding being overweight does not prevent RA, but in RA patients with knee and hip arthritis, overweight condition is detrimental.
By Dr Milind Ghare who is the only American Board Certified Rheumatologist in India. He was Consultant Rheumatologist at VA Medical Center, New York, USA and National University Hospital, Singapore. Currently he is Consultant Rheumatologist at L H Hiranandani Hospital, Mumbai.
Did you know?
You will be surprised to know the effect of these on immunity:
- Listening to music can boost your immunity, but it has to be the music you love. "This brings us to the fundamentals of music therapy which is nowadays abundantly used to reduce stress and thereby increase immunity and quality of health", says Dr Nehha Rajpal, MBBS, who practices music therapy and is a professional singer. There are many institutes and hospitals that use music therapy to supplement treatment of diseases like diabetes mellitus, hypertension, recovery from an episode of stroke, comatose patients. "Music also plays a beneficial role in pregnancy. Studies have revealed that appropriate Garbh Sanskar and music therapy during pregnancy enables a stress-free environment for the expecting mother, and enhanced milestones for the newborn", adds Nehha.
- Noise hurts more than your ears. Any unwanted and intrusive sound can trigger muscle tension, speed heartbeat, constrict blood vessels and cause digestive upsets. Chronic exposure to noise can lead to even longer-lasting changes in blood pressure, cholesterol levels and immune function.
- Your immune system likes it when you spend time with friends. "We have phenomenal data showing the value of nurturing, social support and camaraderie," says neurologist Barry Bittman, MD, CEO of the Mind-Body Wellness Center in Meadville, PA. In one such study, researchers exposed people to a cold virus and then monitored how many contacts those people had with friends, family, co-workers and members of church and community groups. The more social contacts the people had - and the more diverse the contacts - the less likely they were to catch cold.
- Touch is important too. Giving or getting hugs or other forms of touch can boost the activity of the natural killer cells that seek out and destroy cancer cells or cells that have been invaded by viruses.
- The immune system takes many of its cues from our thoughts and feelings, so try to keep your outlook upbeat. Mayo Clinic researchers have found that people who were optimists in their youth tended to live 12 years longer than pessimists. A study by Anna L. Marsland, Ph.D., R.N., a psychologist at the University of Pittsburgh Medical Centre, found that people who were negative, moody, nervous and easily stressed had a weaker immune response to hepatitis vaccination than their more positive peers. Negativity is a personality trait that's difficult to change, but if wearing rose-colored glasses can improve your immunity, why not try a pair?
- Laugh out loud: While painful emotions like anger and grief can impair health, laughter does the opposite. A real belly laugh increases infection-fighting antibodies and boosts natural killer-cell activity
- Brain power: Certain kinds of thinking may boost immunity. University of California, Berkeley, neuroscientist Marian Diamond, Ph.D., found that playing bridge stimulated women's immune systems. Her research is the first to show a connection between the immune system and the part of the brain that handles planning, memory, initiative, judgment and abstract thinking. Says Diamond: "Any mental activity that uses one or a combination of these intellectual functions might benefit immune activity."
- Meditation: Meditation has become increasingly popular today. It provides a simple way to relax, relieve stress, boost your immune system, and create wellbeing and happiness in your life. The method of meditation you choose is not important as achieving the desired result — a quiet mind, which promotes inner peace and relaxation. There are many different types of meditation, and you should choose whatever you enjoy and feel is best for you.
Damages due to dental diseases are usually not reversible. Hence it is prudent to treat them early and at best prevent them. Prevention includes brushing twice daily with correct brushing techniques, flossing, proper rinsing after every meal, eating healthy food, and regular dental check-ups. Regular treatments reduce the occurrence of dental diseases.
Dental fillings – Tooth decay, wear or trauma cause structural damage to tooth. They can be restored with filling materials like silver amalgam, gold, tooth coloured composite resins or porcelain.
Orthodontics – Dental brace wires are used to straighten and correct misaligned teeth. They are best done in growing children and teenagers. But they can be comfortably performed on adults.
Root canal treatment – This involves removal of infected pulp tissue within the root chamber of the tooth. The cleaned chamber and canal are then filled with inert filling. Such a restored tooth is brittle and needs a crown to prevent fracture.
Teeth whitening – Teeth discolouration occurs due to age, eating habits, smoking and tobacco intake, drug intake and trauma. In-office bleaching or home-use bleaching kits allow substantial change of colour and brightness. Over-the-counter kits are not effective due to their very low concentration and poor control of application. Regular touch-ups and discontinuation of causative agents is essential for optimum results.
Kid's [Paediatric] dentistry – Infants and children are not immune to dental diseases. Though milk teeth are replaced by permanent teeth, they are needed for good health during child's growth and development. Due to wrong eating habits, tooth decay has become the common problem of children today. Hence, it is of utmost importance to maintain teeth in their best health. Clean the teeth as soon as they erupt with a soft washcloth or brush. Initiate good and regular eating habits.
By Dr Sharat Shetty, Consulting Prosthodontist, Dr L H Hiranandani Hospital
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