Moalem describes on page 67 how vitamin D, which we get from sunlight, has shown evidence of inhibiting the growth of cancerous cells. This implies that increased exposure to sunlight can possibly reduce the risk of cancer. In fact, there is recent evidence that shows that vitamin D can help reduce the risk for breast cancer.
This relates to Big Idea 4, that biological systems interact, and these systems have complex properties. If it is true that vitamin D reduces the risk for cancer, then areas where sunlight is more prevalent should have less people affected by cancer.
Research the prevalence of cancer in certain parts of the world and explain if your findings support or goes against the idea that vitamin D lowers the risk of cancer. If your finding goes against this idea, research other factors that explains why certain parts of the world are more susceptible to cancer than others.
(Aaron Chai, achai@students.d125.org)
The theory that vitamin D can inhibit cancer cell growth is a great new find considering UV rays from the sun is such a prevalent cause of skin cancers. However, according to the article "Ovarian Cancer Rates Lower in Sunny Areas" from MSNBC news, women who live in places that are exposed to more sunshine are much less likely to develop ovarian cancer. Also, a recent study within this same article confirms that "adults who take 400 IU of vitamin D each day were half as likely as people who took no vitamin D supplements to develop pancreatic cancer."(MSNBC) Dr. Cedric F. Garland of the University of San Diego led a team in the study of 175 countries' ovarian cancer rates compared with the latitude, UV radiation exposure, and level of ozone layer (which affects UV strength). They found that "ovarian cancer rates were highest in higher-latitude regions in both hemispheres. In addition, greater UV exposure and lower ozone levels were both linked to lower ovarian cancer rates."(MSNBC) Although UV radiation can potentially cause cancer, spending time in the sun each day and taking vitamin D supplements proved to diminish chances of developing cancer. According to Moalem, "when it comes to prostate cancer in black men, the risk is considerably lower in Florida." (Moalem 67) This suggests that vitamin D has played a role in lowering risks in development in cancer. Even African Americans, with their dark skin making it even more difficult to absorb vitamin D, have seen lower rates of developing prostate cancer in that sunny state. There is ever mounting evidence today that vitamin D plays a role in preventing the development of cancer.
ReplyDelete(Vivian To vivto4@student.d125.org)
The prevalence of cancer throughout the world shows that many of the first world countries such as the United States (300.2 people per 100k), Denmark (326.1 people per 100k), and Australia (314.1 people per 100k) have the highest rates of cancer within the population. This is contrary to much of Africa, in which many countries have rates below 150 people per 100k with cancer. This seems to go against the claim that people who are able to obtain higher amounts of Vitamin D are at lower risks of cancer. This is mainly because many of the top 20 countries (http://www.wcrf.org/cancer_statistics/cancer_frequency.php) are countries regarded to be upper tier countries. This would mean that many of them, even if unable to obtain Vitamin D through sunlight naturally, can get Vitamin D through supplements and within their diets. On the other hand, the impoverished countries of Africa, many of whose citizens cannot afford to obtain Vitamin D through meals, have some of the lowest rates of cancer (http://visual.ly/cancers-global-footprint?view=true). Compounding with this is that the rate of intake of Vitamin D is lower in people with darker skin colors. Also compounding the fact that many women who are Muslim also wear head coverings and/or robes, it is actually a surprise that many of these lower tier countries have low cancer rates. Another reason why cancer may be so much more prevalent in the upper tier countries is that the citizens of such countries tend to live longer, and cancer becomes more common the older one becomes. The life expectancy in the upper tier countries is much higher than the expectancy in the lower tiered countries, which is also why there is a higher rate of cancer within the more advanced countries; cause there are more people reaching the age where they become highly vulnerable.
ReplyDeleteOMG vivian WHYYY????
Deletenow I gotta do a follow up cry.
I'M SO SORRY RAY!!!! But yours has some great stuff in it :)
DeleteThis comment has been removed by the author.
DeleteAfter visiting the Cancer Research UK website, I was able to find evidence that supported the theory that "vitamin D inhibits the growth of cancerous cells in the prostate and in other areas" (Moalem 67). In Western Africa, a region that receives plenty of sunlight, prostate cancer accounted for about 7% of all cancers diagnosed. In Western Europe, an area that receives less sunlight (and less vitamin D), prostate cancer accounted for 16% of all cancers diagnosed. It appears as though areas that receive more sunlight(and vitamin D) typically have low rates of prostate cancer when compared to areas with lower levels of sunlight.
ReplyDeleteThis relationship between levels of sunlight (vitamin D) and prostate cancer also seems to exist in other forms of cancer. The four regions that have the highest incidence of cancer per 100,000 people are regions that are typically associated with lower sunlight levels (Australia, North America, Western and Northern Europe), while the seven regions with the lowest cancer incidence were all from Africa. While there statistics show a correlation between Vitamin D and cancer rates, they do not show causation, as there are many other factors that can cause cancer in populations. Cancers are often linked to behavioral choices such as poor nutrition and smoking. Therefore, it is no surprise that first-world countries often have the most cancers diagnosed each year, as people in these countries have enough money to make behavioral decisions that put them at an increased risk for cancer.
These ideas relate to Big Idea #4, that biological systems interact, and these systems have complex properties. The genetic diversity of humans can explain why some cancers are more prevalent among certain populations, as genetic mutations can leave a population at a greater risk for developing certain types of cancers. Furthermore, various environmental conditions such as diet, air quality, and climate can influence the frequencies of certain cancers. This relates to the ideas of epigenetics and gene expression, as various external stimuli are shown to have an effect in genetic expression and mutation.
-Drew Kyser (akyser4@students.d125.org)
REVISED RESPONSE:
ReplyDeleteWhile I agree with Vivian’s idea that there is a correlation between Vitamin D intake and the prevalence of certain cancers within a population, I believe that there are other factors that can explain this phenomenon. Countries with greater UV exposure (like many of those in Africa), typically have less food ability than many of the first world countries that receive less sunlight. Therefore, there is a much lower rate of obesity within these countries than in first world countries. There is a significant amount of evidence stating that obesity can increase the risk of developing certain cancers. A Science Daily article reported that obesity can “provide a favorable environment to promote cancer growth” in the prostate (2012). The connection between obesity and cancer is supported by Ray’s post, as he states that the United States, Australia, and Denmark have the highest cancer rates within a population. Obesity statistics found on nationmaster.com state that these countries have the #1, #6, and #22 highest obesity rates respectively.
After visiting the Cancer Research UK website, I was able to find evidence that supported the theory that "vitamin D inhibits the growth of cancerous cells in the prostate and in other areas" (Moalem 67). In Western Africa, a region that receives plenty of sunlight, prostate cancer accounted for about 7% of all cancers diagnosed. In Western Europe, an area that receives less sunlight (and less vitamin D), prostate cancer accounted for 16% of all cancers diagnosed. It appears as though areas that receive more sunlight(and vitamin D) typically have low rates of prostate cancer when compared to areas with lower levels of sunlight.
This relationship between levels of sunlight (vitamin D) and prostate cancer also seems to exist in other forms of cancer. The four regions that have the highest incidence of cancer per 100,000 people are regions that are typically associated with lower sunlight levels (Australia, North America, Western and Northern Europe), while the seven regions with the lowest cancer incidence were all from Africa. While there statistics show a correlation between Vitamin D and cancer rates, they do not show causation, as there are many other factors that can cause cancer in populations. Cancers are often linked to behavioral choices such as poor nutrition and smoking. Therefore, it is no surprise that first-world countries often have the most cancers diagnosed each year, as people in these countries have enough money to make behavioral decisions that put them at an increased risk for cancer.
These ideas relate to Big Idea #4, that biological systems interact, and these systems have complex properties. The genetic diversity of humans can explain why some cancers are more prevalent among certain populations, as genetic mutations can leave a population at a greater risk for developing certain types of cancers. Furthermore, various environmental conditions such as diet, air quality, and climate can influence the frequencies of certain cancers. This relates to the ideas of epigenetics and gene expression, as various external stimuli are shown to have an effect in genetic expression and mutation.
The theory that vitamin D can inhibit cancer cell growth is a great new find considering UV rays from the sun is such a prevalent cause of skin cancers. However, according to the article "Ovarian Cancer Rates Lower in Sunny Areas" from NBC news, women who live in places that are exposed to more sunshine are much less likely to develop ovarian cancer. Also, a recent study within this same article confirms that "adults who take 400 IU of vitamin D each day were half as likely as people who took no vitamin D supplements to develop pancreatic cancer."(NBC) Dr. Cedric F. Garland of the University of San Diego led a team in the study of 175 countries' ovarian cancer rates compared with the latitude, UV radiation exposure, and level of ozone layer (which affects UV strength). They found that "ovarian cancer rates were highest in higher-latitude regions in both hemispheres. In addition, greater UV exposure and lower ozone levels were both linked to lower ovarian cancer rates."(NBC) Although UV radiation can potentially cause cancer, spending time in the sun each day and taking vitamin D supplements proved to diminish chances of developing cancer. According to Moalem, "when it comes to prostate cancer in black men, the risk is considerably lower in Florida." (Moalem 67) This suggests that vitamin D has played a role in lowering risks in development in cancer. Even African Americans, with their dark skin making it even more difficult to absorb vitamin D, have seen lower rates of developing prostate cancer in that sunny state. There is ever mounting evidence today that vitamin D plays a role in preventing the development of cancer.
DeleteThis concept of cancer development in specific areas of the world is related to Big Idea 4, Biological systems interact, and these systems and their interactions possess complex properties. High levels of vitamin D are able to help prevent cancer -causing mutations, so the person’s risk for the disease is much lower. According to the article, “The Role of Vitamin D in Cancer Prevention” from the American Journal of Public Health, “Vitamin D and its metabolites reduce the incidence of many types of cancer by inhibiting tumor angiogenesis, stimulating mutual adherence of cells, and enhancing intercellular communication through gap junctions, thereby strengthening the inhibition of proliferation that results from tight physical contact with adjacent cells within a tissue (contact inhibition).” Vitamin D actively improves cell- to -cell communication and prevents the development of tumors within each cell to allow the organism to live and function properly with low risks of cancer. So environments that see more sunlight allow people to absorb higher levels of vitamin D.
Around the world various environmental factors play a role in cancer prevalence, and sunlight. According to data from the World Cancer Research Fund International Denmark, a nation that spends the majority of the each year (October-March) in long nights and a rainy season, has the highest rate of cancer development in the world at 326.1 cases per 100,000. However, South Africa, with its constant sunlight, has the lowest cancer rates at 202.0 cases per 100,000. This information is clear evidence that supports the idea that vitamin D plays a role in cancer prevention.
(Vivian To vivto4@student.d125.org)