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Cold, Flu, & Cough Health Center

Myths and Facts About Your Immune System

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Your immune system helps guard your body from germs, viruses, and other threats. What you do every day can help, or hamper, your immune system.

What works and what doesn't? How can you keep your immune system in top shape? Let's separate myth from fact.

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Fact: Lasting stress is bad for you.

Ongoing stress, such as being in a difficult relationship, living with a chronic disease, or being a caregiver, can take its toll on your immune system. Over time, it can make you more vulnerable to illnesses, from colds and flu to chronic diseases such as diabetes and heart disease. Chronic stress seems to age the immune system, studies show, making you more likely to get a cold or the flu, and to develop diabetes and heart disease.

Everyone goes through stress. What matters is how you handle it. Getting better at managing stress can help. Even something as simple as deep breathing can lessen the effects of stress. Or try other relaxation techniques, such as:

Counseling can make a big difference, too.

Myth: Getting a flu shot weakens your immune system and makes you more likely to get the flu.

Totally untrue. Getting a flu vaccine prepares your immune system for the flu.

A flu vaccine teaches your immune system to recognize that virus as a threat. While some people may still get the flu after having a flu shot, they'll probably have a milder form of the illness. That's because antibodies made in response to the vaccine can still provide some protection.

So why do some people swear a flu vaccine gave them the flu? Some may mistake the occasional, short-lived side effects of the vaccine (slight fever, aches) for flu symptoms. And the time of year people are most likely to get the vaccine is when colds and other respiratory illnesses are common. If you get the vaccine and then get sick with an unrelated bug, you may assume, incorrectly, that the vaccine caused the illness.

Fact: What you eat affects your immune system.

While no single food will upgrade your immune system, poor nutrition can have a negative effect on the immune system. What counts is having a balanced diet.

Just about everyone could stand to eat more fruits and vegetables. They're rich in vitamins and minerals that are good for you. If you’re thinking about getting supplements to cover your nutritional needs, check with your doctor or a dietitian. Chances are, you’re getting what you need from food, unless you're on a strict diet, are pregnant, or have certain medical conditions.

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