Diet and cancer

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Food factors are recognized to have a significant effect on cancer risk, with different dietary elements increasing and reducing risk. Diet and obesity may be linked to 30-35% of cancer deaths, while physical activity appears to be associated with a 7% risk of cancer. One review in 2011 suggested that total caloric intake affects the incidence of cancer and developmental possibilities.

While many dietary recommendations have been proposed to reduce the risk of cancer, some have significant supporting scientific evidence. Obesity and drinking alcohol confirmed the cause of cancer. Lowering a sweetened drink with sugar is recommended as a measure to overcome obesity. Low diet fruits and vegetables and high red meat have been involved but not confirmed, and the effect may be small for a well-nourished person who maintains a healthy weight.

Some foods are linked to certain cancers. Studies have linked eating red or processed meat to an increased risk of breast cancer, colon cancer, prostate cancer, and pancreatic cancer, which may be partly explained by the presence of carcinogens in foods cooked at high temperatures. Aflatoxin B1, a food that often contaminates, causes liver cancer, but drinking coffee is associated with reduced risk. Chewing betel seeds causes oral cancer. Pickled vegetables are directly linked to an increased risk of some cancers. Differences in dietary practices can partly explain the differences in cancer incidence in different countries. For example, stomach cancer is more prevalent in Japan because a diet high in salt and colon cancer is more common in the United States. The immigrant community tends to develop the risk of their new state, often within a generation, showing a substantial link between diet and cancer.

Dietary recommendations for cancer prevention usually include weight management and eating "especially vegetables, fruits, grains and fish, and reduced intake of red meat, animal fat, and refined sugar."

Video Diet and cancer

Jenis diet

Diet ketat

A number of diet and diet-based regimens claimed to be useful against cancer. Popular types of "anti-cancer" diets include Breuss diet, Gerson therapy, Budwig protocol and macrobiotic diet. None of these diets are found to be effective, and some are known to be harmful.

Diet pattern

Nutritional epidemics use multivariate statistics, such as major component analysis and factor analysis, to measure how dietary patterns affect cancer risk. (The most widely studied diet is the Mediterranean diet.) Based on their dietary scores, epidemiologists group people into quartiles. To estimate the effect of dietary behavior on cancer risk, they measured the relationship between quantitative and cancer prevalence distribution (in case-control studies) and cancer incidence (in a longitudinal study). They usually include other variables in their statistical model to explain other differences between people with and without cancer (confounders). For breast cancer, there is a trend that is replicated for women with a more "wise or healthy" diet, which is higher in fruits and vegetables, to have a lower cancer risk. "Diet drinkers" is also associated with a higher risk of breast cancer, while associations are inconsistent between more westernized diets and an increased risk of breast cancer. Pickled foods are associated with cancer.

Maps Diet and cancer

Food components

Alcohol

Alcohol is associated with an increased risk of some cancers. 3.6% of all cancer cases and 3.5% of cancer deaths worldwide caused by drinking alcohol. Breast cancer in women is associated with alcohol intake. Alcohol also increases the risk of cancer of the mouth, esophagus, pharynx and larynx, colorectal cancer, liver, stomach and ovarian cancer. The International Agency for Research on Cancer (International Center of Recherche de le Cancer) of the World Health Organization has classified alcohol as a Group 1 carcinogen. Evaluation states, "There is sufficient evidence for carcinogenicity of alcoholic beverages in humans.... Alcoholic drinks are carcinogenic to humans (Group 1)."

Processed and red meat

On October 26, 2015, the International Agency for Research on Cancer The World Health Organization reports that eating processed meats (eg, bacon, ham, hot dog, sausage) or red meat is associated with several types of cancer.

Fiber, fruit and vegetables

Evidence on the influence of dietary fiber on colon cancer risk is mixed with some types of evidence that show benefits and others do not. Eating fruits and vegetables, while it has benefits, is less useful in reducing cancer than ever thought.

A 2014 study found fruit but not vegetables that were protected against upper gastrointestinal cancer. While fruits, vegetables and fiber are protected against colorectal cancer and fibers that are protected from liver cancer.

Flavonoid

Flavonoids (especially flavonoids such as catechins) are "the most common group of polyphenol compounds in human food and are found everywhere in plants." While some studies have suggested flavonoids may have a role in cancer prevention, others have convinced or suggested they may be harmful.

Mushroom

According to Cancer Research UK, "there is currently no evidence that any type of fungus or mushroom extract can prevent or cure cancer", although research on several species continues.

Bioactive nutrients

According to the American Cancer Society, although laboratory studies have shown a possible link between soy and cancer, there has been no conclusive evidence of the effects of soy anti-cancer in humans.

Laboratory experiments have found that turmeric may have anti-cancer effects. Although trials are in progress, large doses need to be taken for any effect. It is not known what effect turmeric is positive for humans with cancer.

Although green tea has been promoted for its anti-cancer effects, the research in it has produced mixed results; it is not known whether it helps people prevent or treat cancer. A review of all the studies published by the Food and Drug Administration in 2011 concluded that it is very unlikely that green tea prevents all types of cancer in humans.

Resveratrol has demonstrated anti-cancer activity in laboratory experiments, but in 2009, there was no evidence of an effect on cancer in humans.

Vitamin D supplements have been widely marketed on the internet and elsewhere to be claimed as anti-cancer. There is however sufficient evidence to recommend that vitamin D be prescribed for people with cancer, although there is some evidence that hypovitaminosis D may be associated with poor outcomes for some cancers. A systematic review of 2014 by Cochrane Collaboration found, "there is no strong evidence that vitamin D supplementation decreases or increases the incidence of cancer in women living in an elderly majority community."

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Action mechanism

Methionine metabolism

Although many cellular mechanisms are involved in food intake, many studies over the last few decades show defects in the metabolic pathway metabolism as the cause of carcinogenesis. For example, lack of a major dietary source of methyl donor, methionine and choline, leads to the formation of liver cancer in rodents. Methionine is an essential amino acid that must be provided by food intake from protein or methyl donor (choline and betaine found in beef, eggs and some vegetables). Methionine assimilates are altered in S-adenosyl methionine (SAM), which is the main metabolite for the synthesis of polyamine, eg spermidine, and cysteine ​​formation (see picture on right). The products of methionine splitting are also recycled to methionine with the conversion of homocysteine ​​remethyls and methylthioadenosine (MTA) (see picture on right). Vitamin B ₆ , B ₁₂ , folic acid and choline are important cofactors for this reaction. SAM is a substrate for methylation reactions catalyzed by DNA, RNA and protein methyltransferasease.

The products of this reaction are DNA, RNA or protein and methylated S-adenosylhomocysteine ​​(SAH). SAH has a negative feedback on its own production as a methyltransferase enzyme inhibitor. Therefore, SAM: the ratio of SAH directly regulate methylation mobile, while the levels of vitamin B ₆ , B ₁₂ , folic acid and choline regulate indirectly the state of methylation through metabolic cycle methionine. Overview cancer that almost everywhere is a maladapsi methionine metabolic pathways in response to genetic or environmental conditions that result in reduced methylation SAM and/or SAM. Is that a deficiency in an enzyme such as methylthioadenosine phosphorylase, dependence methionine cancer cells, high levels of synthesis of polyamine in cancer, or induction of cancer through diet is taken from a donor of methyl extrinsic or improved in inhibitor methylation, tumor formation is strongly correlated with decreased levels of SAM in mice, rats and humans.

According to a 2012 review, the effects of methionine restriction on cancer have not been studied directly in humans and "there is still not enough knowledge to provide reliable nutritional advice".

Signaling path

Several oncogenic signal pathways have been involved in the process of cancer cell invasion and metastasis. Among these signaling pathways, Wnt signaling and Hedgehog signaling pathways are involved in embryonic development, in stem cell biology of cancer (CSCs) and in the acquisition of epithelial transition to mesenchymal (EMT).

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See also

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References

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External links

• "Diet, eat healthy and cancer". info.cancerresearchuk.org . Cancer Research UK.
• "EPIC (European Candidate Investigation into Cancer and Nutrition) Study". epic.iarc.fr . International Agency for Research on Cancer: World Health Organization.

Source of the article : Wikipedia