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Vaccines cause herd immunity. If the majority of people in a community have been vaccinated against a disease, an unvaccinated person is less likely to get the disease since others are less likely to become sick from it and spread the disease.
According to the American College of Allergy, Asthma & Immunology, more than 50 million Americans have some kind of food allergy. Food allergies affect between 4 and 6% of children, and 4% of adults, according to the CDC. The most common food allergies include shellfish, peanuts, walnuts, fish, eggs, milk, and soy.
After 5 years of being diagnosed with rheumatoid arthritis, one every three patients will no longer be able to work.
The average older adult in the United States takes five prescription drugs per day. Half of these drugs contain a sedative. Alcohol should therefore be avoided by most senior citizens because of the dangerous interactions between alcohol and sedatives.
Tobacco depletes the body of vitamins A, C, and E, which can result in any of the following: dry hair, dry skin, dry eyes, poor growth, night blindness, abscesses, insomnia, fatigue, reproductive system problems, sinusitis, pneumonia, frequent respiratory problems, skin disorders, weight loss, rickets, osteomalacia, nervousness, muscle spasms, leg cramps, extremity numbness, bone malformations, decayed teeth, difficulty in walking, irritability, restlessness, profuse sweating, increased uric acid (gout), joint damage, damaged red blood cells, destruction of nerves, infertility, miscarriage, and many types of cancer.
![Over nearly 30 years, humans removed many polar bears for a variety of reasons, from a population in](https://biology-forums.com/gallery/47/medium_33_22_09_11_9_39_28_18111448.jpeg)
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