Very often different theories and studies cause strife in scientific circles, but sometimes even the most unbelievable of them ultimately prove true. See these 7 most controversial theories that were eventually proven true:
1. Air pollution causes lung cancer
Since 1939, many scientists have argued that cancer is mainly caused by various factors such as air pollution. It took 21 years to confirm this theory.
2. Bacteria cause ulcers
In 1982, doctors Robin Warren and Barry Marshall from Australia associated the bacteria «Helicobacter pylori» with the ulcer, but the medical community argued that the cause of the condition was stress in combination with specific food choices. However, in mid 1990s, the American Institute of Health confirmed their theory.
3. The aspirin reduces the risk of heart attack
In 1950, Lawrence Craven from California published his first research which showed that the effect of aspirin prevents the blood clots that cause heart disease. About 40 years later, the prescription of one aspirin a day to patients with heart disease was adopted.
4. X-rays are harmful
A study of 1911 linked the X-rays to leukemia and other cancers, but the widespread use of the rays that age and mistrust of the medical community did not allow confirmation of this theory. Eventually, in 1956, the American Academy of Sciences issued a report condemning the widespread use of X-rays.
5. Manganese is harmful for the brain
Exposure to high levels of manganese can lead to a condition that is similar to Parkinson’s disease. This condition may lead to mental disorders, tremors, lethargy, and even death.
6. Myopia is a sign of intelligence
According to researchers of Queen Mary Hospital and the University of Hong Kong, the genes associated with myopia survive because they are related to intelligence. So the theory that intelligence and myopia may be connected with each other has a genetic basis.
7. Sunny days make men more violent
According to researchers of Ben-Gurion University in Israel, the crime is two to three times more frequent during the summer in both hemispheres. The main “suspect” appears to be serotonin.