Pineapple said
The following is the text version of popular science:
(i)
Out of the Lantern Festival, the year is really over. Just as the so-called "three pounds of fat every festive season", many small partners said that the biggest harvest of the New Year is the happy meat, and they have set up fat reduction goals.
It is worth emphasizing that obesity is not only a physical thing, but also brings various health problems, including cancer.
Being overweight and obese is a very clear risk of cancer and one of the broadest spectrum of carcinogenic risks; at least a dozen cancers have been associated, including breast, kidney, liver, pancreatic, stomach, and more. Colorectal cancer is currently soaring among young people under the age of 45, and increasing obesity is considered one of the most important factors.
Obesity in Europe and the United States appeared earlier and more seriously, so they did a lot of research around the relationship between obesity and health.
Their data show that many overweight or obese people have significantly increased the incidence of tumors compared with the average person. For example, the probability of liver cancer is 200% (twice), the probability of kidney cancer is 200%, the probability of esophageal cancer is 200%, the probability of stomach cancer is 200%, the probability of pancreatic cancer is 150%, the probability of colorectal cancer is 130%, and so on.
China is similar.
According to the latest research, 10% of men and 13% of women in China's liver cancer are caused by being overweight.
The more developed the city, the higher the proportion of cancer caused by obesity. For example, among women in Beijing, 25% of breast cancer, 19% of kidney cancer, and 11% of thyroid cancer are related to being overweight.
(ii)
So the question is, why does obesity increase cancer risk?
The answer is not simple, and after many years of research, scientists have proposed several potential biological mechanisms.
One of the most widely accepted theories is the "chronic inflammation theory." Obese people are prone to a variety of chronic inflammations.
Inflammation itself is a normal physiological phenomenon and is a necessary process for tissue repair after injury. Injured cells attract immune cells by releasing chemical signals such as cytokines. After the immune cells come, on the one hand, they clean up the broken cells, and on the other hand, stimulate the cell division and growth to fill the gap.
Normally, once the tissue is repaired, the inflammatory process is over. But sometimes, when there is no tissue injury, inflammation is always present, which is chronic inflammation. There are many possibilities behind it, sometimes from persistent bacterial viral infections, sometimes immune cells attacking normal tissues, and sometimes systemic imbalances caused by obesity.
Many studies have shown that chronic inflammation significantly increases the risk of cancer. On the one hand, in this process, the tissue is repeatedly destroyed, and at the same time, the cells are constantly stimulated to divide and grow, which greatly increases the probability of DNA mutation. On the other hand, some immune cells can also directly stimulate the growth of cancer cells.
People with chronic enteritis are more likely to get colorectal cancer;
People with chronic hepatitis are more likely to get liver cancer;
People with chronic gastritis are more likely to get stomach cancer;
Wait a minute......
In addition, obesity causes cancer for other reasons.
Take excessive amounts of estrogen, for example.
Adipose tissue can produce estrogen, so the estrogen content in obese people is relatively high. This has the potential to increase the risk of gynecological tumors such as breast and ovarian cancer.
Another example is excessive insulin and related growth factors.
Obesity can lead to the weakening of insulin's ability to control blood sugar, with the emergence of so-called "insulin resistance". In order to maintain normal blood sugar levels, the body's self-regulation mechanisms can cause the body to secrete several or even more than a dozen times the amount of insulin and related hormones, including "growth promoting factor (IGF-1)". Many cancer cells have insulin receptors on their surfaces, which, if combined with insulin or growth-promoting factors, may stimulate cancer cell growth.
In addition to the above reasons, adipose tissue also directly affects the secretion and balance of many other hormones, such as leptin, adiponectin, etc., and these hormones and other cell growth are inextricably linked, and long-term imbalances can affect tumorigenesis.
Pictured: Obesity in China is becoming increasingly prominent
(iii)
Obesity not only increases the risk of cancer, but also affects the effectiveness of cancer treatment.
Obesity may affect quality of life after treatment.
In women, being overweight increases the risk of developing lymphedema in people who have recovered from breast cancer. For men, being overweight increases the risk of incontinence after prostate cancer surgery.
Obesity may increase the risk of tumor recurrence.
Large clinical studies have shown that for stage 2 or 3 rectal cancer, overweight patients, especially male patients, have a higher risk of local recurrence after surgery.
Obesity may increase the risk of dying from cancer.
In patients with multiple myeloma, the risk of death in a group of severely obese groups increased by 50% relative to normal weight!
All in all, overweight and obesity are clear broad-spectrum cancer risk factors and one of the important factors influencing the effectiveness of cancer treatment. Since the higher the risk of getting fat, we must control the intake of high-calorie foods, at least not continuous weight gain.
In addition to eating less, what else can you do?
Move it!
I've written before that exercise is a clear broad-spectrum anti-cancer measure that significantly reduces the risk of more than a dozen cancers, is more useful than any health supplement, and is more useful than any anti-cancer food. (1.44 million people big data: exercise really prevents cancer!) ）
How big is your "harvest" for the New Year?
bibliography:
1. Body Fatness and Cancer--Viewpoint of theIARC Working Group. New England Journal of Medicine 2016; 375(8):794-798.
2. Excess body weight and the risk of primaryliver cancer: an updated meta-analysis of prospective studies. European Journalof Cancer 2012; 48(14):2137-2145.
3. Body mass index, waist circumference,diabetes, and risk of liver cancer for U.S. adults. Cancer Research 2016;76(20):6076-6083.
4. Long-term effect of aspirin on cancer riskin carriers of hereditary colorectal cancer: an analysis from the CAPP2randomised controlled trial. Lancet. 2011 Dec 17; 378(9809): 2081–2087.
5. The role of inflammation and liver cancer. Advances in Experimental Medicine and Biology 2014; 816:401-435.
6. The increased risk of cancer andcancer-related mortality. Physiological Reviews 2015; 95(3):727-748.
7. Prospective study of body size throughoutthe life-course and the incidence of endometrial cancer among premenopausal andpostmenopausal women. International Journal of Cancer 2015; 137(3):625-37.
8. Overweight, obesity, and mortality fromcancer in a prospectively studied cohort of U.S. adults. New England Journal ofMedicine 2003; 348(17):1625-1638.
9. Impact of obesity on cancer survivorshipand the potential relevance of race and ethnicity. Journal of the NationalCancer Institute 2013; 105(18):1344-1354.
10. Cancer-related lymphedema risk factors,diagnosis, treatment, and impact: a review. Journal of Clinical Oncology 2012;30(30):3726-3733.
11. Role of abdominal obesity for functionaloutcomes and complications in men treated with radical prostatectomy forprostate cancer: results of the Multicenter Italian Report on RadicalProstatectomy (MIRROR) study. Scandinavian Journal of Urology 2014;48(2):138-145.
12. Impact of body mass index on outcomes andtreatment-related toxicity in patients with stage II and III rectal cancer:findings from Intergroup Trial 0114. Journal of Clinical Oncology 2004; 22(4):648-657.
13. Body size and multiple myeloma mortality: apooled analysis of 20 prospective studies. British Journal of Haematology 2014;166(5):667-676.
14. Report on nutrition and chronic diseases among Chinese residents (2015)
_________
Previous article