SciShow debunks several common misconceptions about cancer. The first myth is that sharks don't get cancer, which is not true. While sharks do have a lower incidence of cancer, it's not due to their cartilage, and taking shark cartilage supplements has no proven benefits in preventing or treating cancer.
Another myth is that cancer patients should avoid eating sugar, as cancer cells feed on sugar. However, the body converts all calories into glucose, so restricting sugar intake won't affect tumor growth.
The show also discusses the misconception that taking antioxidant supplements can prevent cancer. While antioxidants are important, there's limited evidence that taking supplements has any benefit in preventing cancer, and some studies suggest that antioxidant supplements may even accelerate cancer progression.
Additionally, the show addresses concerns about biopsies spreading cancer, but notes that the risk is small and that doctors use techniques to minimize the spread of tumor cells.
The show also tackles two misconceptions about the current state of cancer: that cancer is a modern disease, and that cancer rates are increasing. While it's true that modern life exposes us to more carcinogens, cancer has been around for thousands of years and is not unique to modern society. Additionally, while the total number of cancer cases and deaths is increasing, this is largely due to the fact that people are living longer, and death rates from cancer are actually declining in many countries.
Here are the key facts from the text:
1. Studies in the 1970s suggested that sharks don't get cancer, but this has been misinterpreted and sharks do get cancer.
2. Shark cartilage has been found to contain chemicals that can prevent blood vessel formation, which could help prevent tumors from growing.
3. However, there is no evidence that taking shark cartilage supplements can cure or prevent cancer in humans.
4. Cancer cells use a different process to make energy than healthy cells, which requires more glucose.
5. German scientist Otto Warburg discovered in 1924 that cancer cells prefer to use a process that requires more glucose, even in the presence of oxygen.
6. However, restricting sugar intake does not seem to have any effect on cancer cells' access to glucose.
7. Antioxidants are important for neutralizing reactive oxygen species that can damage cells and lead to cancer.
8. However, taking antioxidant supplements has not been shown to lower the risk of cancer, and may even speed up the progression of cancer in some cases.
9. Biopsies can dislodge tumor cells, but the risk of these cells spreading and causing more tumors is low, and the benefits of biopsies outweigh the risks.
10. Cancer is not a modern disease, and has been found in 3,000-year-old human remains and even in dinosaurs.
11. The global burden of cancer is shifting from developed to developing nations, with rates decreasing in higher-income countries and increasing in lower-income countries.
12. Death rates from cancer in the United States are declining, but the total number of cancer cases and deaths is increasing due to an aging population.
13. The risk of cancer increases with age, and as people live longer, they are more likely to develop cancer.
14. Researchers have found sharks in the wild with tumors.
15. Some chemicals in cartilage can prevent blood vessels from forming, a process called angiogenesis.