Nitrates/Nitrites in Foods and Their Effects

Hydroponics—Farming without soil, which uses less water

Nitrates in Plants

Several factors influence the accumulation of nitrates in plants, which include:

• Lack of sunlight or water, variety, maturity
• High levels of fertilizers
• Excessive use of nitrogen fertilizers should be avoided so as to reduce nitrate buildup in soil and vegetables.^[5] 
• Nitrate levels in the soil, and 
• Quality of irrigation water

Nitrate is nontoxic below maximum residue levels (MRLs), but if it reaches above this level, it "could" (see more details later) be dangerous due to its reduction in nitrites, which can react with amines and amides to produce “N-nitroso” compounds responsible for gastric cancer.^[5,6] High levels of nitrates in children stomach are also responsible for methemoglobinemia (blue baby syndrome).^[7,8]

The Healthy Route to Nitrite Processing

Certain vegetables contain nitrates, which break down into nitrites when eaten. Nitrites are necessary and life-enhancing, providing the nitric oxide we need to keep our blood vessels dilated, and minimize risk of high blood pressure. 

Studies have shown that nitrites packaged in vegetables can improve oxygen efficiency and delivery by dilating blood vessels, resulting in:^[1]

• lowered blood pressure
• improved breathing for those with Chronic Obstructive Pulmonary Disease (COPD)
• decreased age-related cognitive decline
• increased blood flow in those with Peripheral Artery Disease.

The Unhealthy Route to Nitrite Processing

If nitrites are so beneficial, how can they be so harmful when consumed in meat? The answer is not in the nitrites themselves, but in how they can be converted, under certain circumstances, into nitrosamines—recognized as one of the most potent carcinogens in the world.^[1]

Research is now clarifying that nitrosamines are formed when nitrites are consumed in the absence of plants (vs. meat), because phytonutrients found in plants can block nitrosamine formation. Because meat contains none of these plant phytonutrients, when nitrites are added to meat as preservatives and colorings, nitrosamines form in processed meat.

Summary

Because phytonutrients found in plants can block nitrosamine formation, it's safer to consume plants with nitrates/nitrites than meats with added nitrates/nitrites.  However, in order to maximize the health benefits from eating vegetables, measures should be also taken to reduce the nitrate and nitrite exposures.^[9] For example, 

• Vegetables must be stored and processed properly to prevent bacterial contamination and hence reduction of nitrate to nitrite.^[10]
• Consume vegetables with high phytonutrients contents vs. low phytonutrients contents.
• Avoid processed meat because nitrites and nitrates are added to processed meat to help them maintain that nice pink color:^[2-4]
• The problem is, in the presence of heat—especially high heat—nitrites can combine with amines in processed meat to form nitrosamines, and these are carcinogenic.

References

1. Effects of agriculture production systems on nitrate and nitrite accumulation on baby-leaf salads
2. EWG Releases Dirty Dozen Guide to Food Additives (Dr. Mercola)
3. Total N-nitroso compounds and their precursors in hot dogs and in the gastrointestinal tract and feces of rats and mice: possible etiologic agents for colon cancer.
4. No risk from nitrates in vegetables, says EFSA
5. Santamaria P. Nitrate in vegetables: toxicity, content, intake and EC regulation (review) J. Sci. Food Agric. 2006;86:10–17.
6. Savino F, Maccario S, Guidi C, Castagno E, Farinasso D, Cresi F, et al. Methemoglobinemia caused by the ingestion of courgette soup given in order to resolve constipation in two formula-fed infants. Ann. Nutr. Metab. 2006;50:368–371.
7. Greer FR, Shannon M. Infant methemoglobinemia: the role of dietary nitrate in food and water. American Academy of Pediatrics Committee on Nutrition, American Academy of Pediatrics Committee on Environmental Health, 2005. Pediatrics. 2005;116:784–786.
8. Chan TYK. Vegetable-borne nitrate and nitrite and the risk of methaemoglobinaemia. Toxicol. Lett. 2011;200:107–108.
9. Correia M, Barroso A, Barroso MF, Soares D, Oliveira MBPP, Delerue-Matos C. Contribution of different vegetable types to exogenous nitrate and nitrite exposure. Food Chem. 2010;120:960–966.
10. Leszczyńska T, Filipiak-Florkiewicz A, Cieślik E, Sikora E, Pisulewski PM. Effects of some processing methods on nitrate and nitrite changes in cruciferous vegetables. J. Food Compos. Anal. 2009;22:315–321.

Esophageal Cancer Risk and Alcohol Flush Reaction

In this article, we will discuss the link between esophageal cancer and alcohol flush reaction:

• Alcohol flush reaction
• is redness or flushing in the face or neck after consuming alcohol.
• Esophagus cancer^[17]
• Esophagus is the muscular tube that connects the throat and stomach.
• Cancer can form in the tissues that line the esophagus.

Higher Esophageal Cancer Risk If You Flush Easily

One Japanese study has found that: you're at higher esophageal cancer risk if you flush easily with drinking. The study found that about 1/3 of Japanese, Korean, and Chinese are "aldehyde dehydrogenase" deficient which make them flush easily with drinking and people who flush easily have 6-10 times higher risk of getting esophageal cancer than individuals who don't flush easily.

Alcohol Flush Reaction

Alcohol is metabolized by several enzymes. It is first broken down into acetaldehyde, a harmful substance that is then converted to harmless acetic acid (or vinegar). When high levels of acetaldehyde occur in the blood, the following “hangover” symptoms occur:

• Facial flushing
• Light headedness
• Palpitations
• Nausea

These symptoms are indicative of a disease known as the Alcohol flush reaction, also known as “Asian Flush” or “Oriental Flushing Syndrome”.^[16]

Enzyme and Gene

Aldehyde dehydrogenase (ALDH2) plays a crucial role in maintaining low blood levels of acetaldehyde during alcohol oxidation. Unfortunately, there is a mutant form of aldehyde dehydrogenase, termed ALDH2*2,

A gene is a locus (or region) of DNA that encodes a functional RNA or protein product, Genes can acquire mutations in their sequence, leading to different variants, known as alleles, in the population. These alleles encode slightly different versions of a protein, which cause different phenotype traits.

ALDH2 gene contains instructions for producing aldehyde dehydrogenase. A variant called ALDH2*2 in this gene results in an inactive enzyme. For individuals with the mutant allele:

• Homozygous individuals (with mutant alleles present on both homologous chromosomes)
• have almost no ALDH2 activity
• Heterozygous individuals
• have reduced activity.

Esophageal cancer

Esophageal cancer ^[6] is one of the common malignancies, with an increasing incidence and a high mortality in both developed and developing countries. Esophageal cancer exists in two main forms with distinct etiological and pathological characteristics:

• Esophageal squamous cell carcinoma (ESCC)
• Adenocarcinoma.

Whereas adenocarcinoma is more prevalent in the USA and some other Western countries, ESCC is the predominant type in the other parts of the world, especially in Asia, accounting for >90% of esophageal cancer worldwide.

How to Lower Your Risk

Most of esophageal cancer patients are over 60 and more common in men. If you're at higher risk, pay attention to the following advice:

1. Don't eat foods that are burning hot. Wait until it cools down a little bit.^[5]
2. Stop smoking.^{[4, 9]}
• Cigarette smoking and heavy drinking are the two major causes of esophageal cancer, especially when combined.
3. If you have Gastroesophageal reflux disease (GERD), treat it immediately. The acid burns the tissue and makes it rough and scarred, which is where the cancer begins to grow.^[12]
• Place a tall book (of the same thickness) underneath both posts of your bed frame on the side of your headboard. This will keep your bed at a slight angle so that the acid will go down instead of up into your esophagus.
• Avoid red sauces like tomato sauce, garlic, and things with caffeine like peppermint tea or chocolate.
• Do not wear control top underwear, because it is very tight and squeezes the acid up into your esophagus.
4. Avoid swallowing lye or other caustic substances.
5. Avoid dietary substance such as nitrosamine. High temperatures, as in frying, can enhance the formation ofnitrosamines.
6. Don't overweight.
• Obesity increases the risk of adenocarcinoma fourfold.
• When you gain weight, the stomach gets pulled down from the extra weight and the kink that is usually between the esophagus and the stomach gets pulled out. This results in that connective area getting very thick, which can lead to Esophageal Cancer.^[12]
7. Avoid alcohol^[19]
• There is strong evidence that alcohol causes cancer of the liver, colon, rectum, esophagus, larynx, pharynx and female breast.
8. If you have been infected with the Helicobacter pylori bacterim, treat it immediately.^[9]
9. Reducing radiation exposure to the chest.^[9]
10. Avoid red sauces like tomato sauce, garlic, and things with caffeine like peppermint tea or chocolate.
11. Take a vitamin E supplement
• High blood levels of alpha-tocopherol, a form of vitamin E, may lower the risk of developing cancer of the stomach and esophagus, according to new research from China.
12. NSAIDs
• Risk appears to be less in patients using aspirin or related drugs (NSAIDs).^{[2, 6]} 
• However, be warned that aspirin is a blood thinner and overdosing can cause excessive bleeding (see [10] for more side effects). 
13. Consuming more cruciferous foods
• According to the National Cancer Institute, diets high in cruciferous (cabbage, broccoli^[11], cauliflower) and green and yellow vegetables and fruits are associated with a decreased risk of esophageal cancer^[2] 
14. Moderate coffee consumption
• Moderate coffee consumption is associated with a decreased risk too^{.[2, 7]} 
15. Zinc
• Zinc supplements can significantly inhibit the proliferation of esophageal cancer cells, according to a study co-authored by a University of Texas at Arlington researcher.^[21]
• Zinc can protect us against esophageal cancer.^{[3, 8]}

References

1. 日本研究发现：喝酒易脸红易罹食道癌
2. http://en.wikipedia.org/wiki/Esophageal_cancer
3. "Younger you" by Eric R. Braverman, M.D.
4. Factors associated with carcinoma of the oesophagus at Mulago Hospital, Uganda.
5. An Epidemiological Study of Precursor Lesions of Esophageal Cancer among Young Persons in a High-Risk Population in Huixian, China
6. Expression of macrophage migration inhibitory factor in esophageal squamous cell carcinoma and effects of bile acids and NSAIDs
7. Coffee and tea intake and risk of oral, pharyngeal and esophageal cancer
8. Zinc Deficiency Linked to Increased Risk of Less-Common Form of Esophageal Cancer
9. American Medical Association Complete Guide to Prevention and Wellness
10. Pros and Cons of Aspirin
11. Boosting Broccoli's Anti-Cancer Effect
12. Dr Oz: What Causes Heartburn?
13. ERCC1 Levels Strongly Associated with Survival in Esophageal Cancer
14. Digestive System
15. Red face after drinking suggests high blood pressure
16. Thomasson HR, Edenberg HJ, Crabb DW; et al. (April 1991). "Alcohol and aldehyde dehydrogenase genotypes and alcoholism in Chinese men". American Journal of Human Genetics 48 (4): 677–81.
17. The top 10 deadliest cancers -- and why there is no cure
• 1. Lung Cancer 2. Colon Cancer 3. Breast Cancer 4. Pancreatic Cancer 5. Prostate 6. Leukemia 7. Non-Hodgkin lymphoma 8. Liver Cancer 9. Ovarian Cancer 10. Esophageal cancer
18. Spitting up in babies: What's normal, what's not
• Normally, a muscle (lower esophageal sphincter) between the esophagus and the stomach keeps stomach contents where they belong. Until this muscle has time to mature, spitting up might be an issue — especially if your baby is relatively full.
19. Alcohol's cancer risks outweigh any health benefits, study shows
20. This is your brain on alcohol
• Even moderate drinking is associated w/ shrinkage in areas of the brain involved in cognition and learning
21. Zinc can halt the growth of cancer cells, study says
22. Alcohol, ‘Asian glow’ mutation may contribute to Alzheimer’s disease, study finds