Lunch Meat, Hot Dogs, and Cancer

Do you eat lunch meat, hot dogs, bacon, sausages or other packaged or cured meats? If so, all of these products contain added nitrates and nitrites which preserve the meats and fix color, add flavor, and prevent the fats from going bad.

Nitrates and nitrites have become hot topics in recent years because of reports of cancer in animals. You may have noticed grocery store packaged meats with labels touting, “No added Nitrates!” Try googling“nitrate” or “nitrite” and see the long list of articles belittling these compounds. So, what’s the bottom line on nitrates, nitrites, and cancer?

1) What are Nitrates and Nitrites?
Nitrates and nitrites in food are converted in the body to many different compounds, both good and bad. While in the mouth, esophagus, and stomach, nitrates are converted to nitrites, which can be further converted to a group of compounds called ‘nitrosoamines’ – the compounds implicated as carcinogens.

Prior to the 1970s, case reports of illness and death in infants due to nitrites in drinking water, and accounts of the environmental pollution caused by nitrogen oxide compounds led to the initial animal studies showing higher cancer rates with exposure to nitrates and nitrites. In fact, in the 1970s, nitrates and nitrites were nearly banned in meat processing.

2) Where are nitrates and nitrites found?
The World Health Organization estimates average daily dietary intakes for nitrates and nitrites. While 15% of our nitrate intake is from water, the rest comes from foods, mostly vegetables like spinach, beets, celery, lettuce, and other dark green leafy vegetables plus cured meats.

3) What does the research say about cancer in humans?
Nitrosamines have been linked to cancer since the early 1980s when nitrosamines from chewing and smoking tobacco were shown to be strongly associated with oral cancers. Studies also showed higher rates of esophageal, stomach, and colorectal cancers in Chinese and Western societies. Additional support was provided with animal studies showing that diets high in nitrates but lacking antioxidants such as vitamin C and vitamin E resulted in higher gastrointestinal cancer rates.

So, eat your vegetables and avoid process foods folks!
But wait. New research findings have thrown this advice for a tailspin. We now know that nitric oxide, a derivative of nitrate and nitrite, plays a critical role in heart health. So critical, in fact, that we treat heart attacks with a drug that converts to nitric oxide. Some scientists even speculate that the more nitric oxide the better.

In what is likely the best study of its kind on nitrosamines and their association with cancer, the European Prospective Investigation into Cancer and Nutrition (EPIC-Norfolk) Study evaluated over 23,000 participants’ dietary nitrosamines, nitrites and their impact on cancer rates for an average of over 11 years. EPIC showed no significant associations in cancer risk, regardless of the intake of nitrosamines.

Many other recent studies show the same results. If there is an effect of nitrosamines on cancer rates, they are at worst very, very weak. So, while the “gossip” about dietary nitrates, nitrates, nitrosamines and cancer will likely continue, you can sit back and enjoy some salami and cheese.

August 2015. This post was authored by Kevin Conley, University of Illinois at Chicago medical student and Susan Buchanan, MD, MPH, Director of the Great Lakes Center for Children’s Environmental Health – Region 5 Pediatric Environmental Health Specialty Unit (PEHSU).

References:
1) Bryan, Nathan S., Dominik D. Alexander, James R. Coughlin, Andrew L. Milkowski, and Paolo Boffetta. “Ingested Nitrate and Nitrite and Stomach Cancer Risk: An Updated Review.” Food and Chemical Toxicology 50.10 (2012): 3646-665. Web.
2) Catsburg, Chelsea E., Manuela Gago-Dominguez, Jian-Min Yuan, J. Esteban Castelao, Victoria K. Cortessis, Malcolm C. Pike, and Mariana C. Stern. “Dietary Sources of N-nitroso Compounds and Bladder Cancer Risk: Findings from the Los Angeles Bladder Cancer Study.” International Journal of Cancer Int. J. Cancer 134.1 (2013): 125-35. Web.
3) Kim, Eunjung, Desire Coelho, and François Blachier. “Review of the Association between Meat Consumption and Risk of Colorectal Cancer.” Nutrition Research 33.12 (2013): 983-94. Pubmed. Web.
4) Loh, Y. H., P. Jakszyn, R. N. Luben, A. A. Mulligan, P. N. Mitrou, and K.-T. Khaw. “N-nitroso Compounds and Cancer Incidence: The European Prospective Investigation into Cancer and Nutrition (EPIC)-Norfolk Study.” American Journal of Clinical Nutrition 93.5 (2011): 1053-061. Web.
5) Lundberg, J. O., and E. Weitzberg. “Biology of Nitrogen Oxides in the Gastrointestinal Tract.” Gut 62.4 (2012): 616-29. Pubmed. Web.
6) Sindelar, Jeffrey J., and Andrew L. Milkowski. “Human Safety Controversies Surrounding Nitrate and Nitrite in the Diet.” Nitric Oxide 26.4 (2012): 259-66. Pubmed. Web.
7) U.S. EPA, Agency for Toxic Substances and Disease Registry, and TEACH Database. “Nitrates and Nitrites.” Nitrates and Nitrites (2007): n. pag. Env. Web.
8) Zhu, Yun, Peizhon Wang, and John R. Mclaughlin. “Dietary N-nitroso Compounds and Risk of Colorectal Cancer: A Case-control Study in Newfoundland and Labrador and Ontario, Canada.” British Journal of Nutrition 111 (2014): 1109-117. Pubmed. Web.

Summertime – and the Breathing is Easy — cough, wheeze, pant…

If you, your child, or your patients have asthma, you may have noticed that symptoms get worse on hot, humid days. Unfortunately, ozone and particles in the air – the main components of air pollution — may be to blame. People who suffer from wheezing, coughing, or shortness of breath on hot days should consider staying in air conditioned environments when air pollution levels are high.

How can you find out what the air pollution levels are in your community?

Look up your Air Quality Index
The Air Quality Index (AQI) was developed by the US Environmental Protection Agency (EPA) to report daily air quality. It describes how clean the air is and what health effects might be a concern. Monitors across the country record levels of pollution and convert the results into a score which is reported to the public. Many areas also attempt to forecast upcoming AQI so you can plan your outdoor activities to avoid exposure.

What Does the AQI Measure?
The AQI is calculated for each of the 5 major air pollutants regulated by the EPA in the Clean Air Act. These pollutants are ozone, particulate matter, carbon monoxide, sulfur dioxide, and nitrogen dioxide. Ozone and particulate matter are the most common pollutants that cause elevated AQIs. Large cities are required to report their values, and most public health agencies in smaller communities also report the AQI as one of their public health services.

What Does the AQI Number Mean?
The AQI is reported both as a number and a color. Green and yellow levels are acceptable, and various red shades mean the value is unhealthy. In general, values less than 100 are acceptable, although people with particular sensitivities to certain pollutants may experience symptoms. Levels 101-150 are described as “unhealthy for sensitive groups.” These groups include children, older adults, or people with lung diseases such as asthma and emphysema. Values from 151-200 mean that even healthy people may start to have symptoms; 201-300 triggers a health alert stating that more serious health risks may occur, and greater than 300 will trigger an air quality emergency.

Why Does it Matter?
Local air quality affects how you breathe. This is especially true for those who suffer from lung conditions such as asthma or are in high risk groups such as children or older adults. Research has shown that higher AQI levels correlate with increased ER visits for asthma.

How can I find out my community’s AQI?

You can find the AQI in multiple places:
Internet: Multiple agencies have developed websites that report the AQI. www.airnow.gov has AQI information for over 300 cities across the US.
Email: There is a free service called Enviroflash which will alert you via email about the air quality in your area. Their website is www.enviroflash.com
Local Media: Television, radio and newspapers often include AQI information as part of their weather forecasts or weather sections.

What Do I Do With This Information?
If you suffer from lung disease or are in a high risk group you can look up the Air Quality Index and take preventive measures if the levels are elevated. The most important measures are reducing the amount of time and intensity of outdoor activities when AQI levels are elevated. By looking at the AQI you can tailor your outdoor activities in order to prevent breathing problems before they occur.

August 2015. This post was written by Christopher George, MD, MPH, University of Illinois at Chicago Residency in Occupational and Environmental Medicine, and Susan Buchanan, MD, MPH, Director of the Great Lakes Center for Children’s Environmental Health – Region 5 Pediatric Environmental Health Specialty Unit (PEHSU).

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