A new study published in the journal Circulation says that red meat is not the cause of heart disease and diabetes.
Lead author of the study, Renata Micha, of the Harvard School of Public Health, said, “Although most dietary guidelines recommend reducing meat consumption, prior individual studies have shown mixed results for relationships between meat consumption and cardiovascular diseases and diabetes.…Most prior studies also did not separately consider the health effects of eating unprocessed red versus processed meats.…Processed meats such as bacon, salami, sausages, hot dogs and processed deli meats may be the most important to avoid.”
She continued: “When we looked at average nutrients in unprocessed red and processed meats eaten in the United States, we found that they contained similar average amounts of saturated fat and cholesterol. In contrast, processed meats contained, on average, 4 times more sodium and 50% more nitrate preservatives….This suggests that differences in salt and preservatives, rather than fats, might explain the higher risk of heart disease and diabetes seen with processed meats, but not with unprocessed red meats.” (http://www.hsph.harvard.edu/news/press-releases/2010-releases/processed-meats-unprocessed-heart-disease-diabetes.html)
So the study fingers salt and nitrites as being the real danger to health. However, I’d like to point out that high blood pressure is associated with high-carb diets and that on a diet with 50 carbs or less per day, you may actually need to supplement with additional salt. The researches ignored the fact that processed meats usually contain a fair amount of sugar. Ham, for example may have up to a teaspoon of sugar per serving. Additionally, processed meats, such as cold cuts and hot dogs, are more likely to be part of a sandwich accompanied by the usual bun, chips or fries, and a soft drink than a steak or a lamb chop. But what about the nitrites?
In most studies, such as this meta-analysis, all the variables are not considered separately. The nitrites in bacon, hot dogs, and ham were probably mentioned because they are perceived to be unhealthful. But are they really? If you love bacon as much as I do, maybe this quiz from Sandy Szwarc will ease your mind about eating it and other cured meats.
Sandy Szwarc, BSN, RN, CCP, of the Junk Food Science blog (http://junkfoodscience.blogspot.com), asks: Which will give you the most ingested nitrites?
467 servings of hotdogs
1 serving of arugula
2 servings of butterhead lettuce
4 servings of celery or beets
The spit in your mouth?
She explains how a small study of rats done at MIT in the 1970s started the nitrites-cause-cancer scare. The National Academy of Sciences reviewed the scientific data in 1981 and found no link between nitrates or nitrites and human cancers, or any evidence that they are carcinogenic. Since then, more than 50 studies and many scientific organizations have investigated a possible link between nitrates and cancer and found no association.
Even more surprising, scientific evidence is building that nitrates are actually good for us. They are produced in our bodies in greater amounts than we eat in food, and nitrate is important for maintaining healthy immune and cardiovascular systems. It is being studied as a treatment for health problems, such as high blood pressure, heart attacks, sickle cell disease, and circulatory problems.
Salivary nitrite accounts for 70 to 97 percent of our total nitrite exposure. Our primary source of nitrite from food is vegetables. Nitrites occur naturally in vegetables and plants as a result of the nitrogen cycle where nitrogen is fixed by bacteria.
To see if people could be getting too many nitrites from vegetables, the Scientific Panel on Contaminants in the Food Chain of the EFSA (European Safety Authority)
http://www.efsa.europa.eu/EFSA/efsa _locale1178620753812_1178712852460.htm compiled the analytical results from 20 member states and Norway on the nitrite levels in produce. The report was published on June 5, 2008 in the EFSA Journal. Here are some of the average levels they found:
Arugula 4,677 ppm (parts per million)
Butterhead lettuce 2,026 ppm
Beets 1,279 ppm
Celery 1,103 ppm
Hot dogs or processed meat 10 ppm
“…so what about those expensive “nitrate-free” hotdogs and cured meats being sold to chemical-anxious consumers? They use “natural’ sources of the very same chemical, such as celery and beet juice and sea salt. A chemical is still the same chemical, regardless of where it comes from.…”—Sandy Szwarc, BSN, RN, CCP
“I eat it (bacon) every day. Last time my blood pressure was checked (last week, when I went for a physical), it was 111 over 64. From eating bacon, eggs, sausage, cheese, hamburgers, chicken with the skin on it, and green vegetables swimming in butter…The dietary science that’s based in evidence, not just passed-down hearsay, says sugar is what’s really toxic, and carbohydrates, including starchy carbohydrates, are what causes the insulin reaction that puts on fat….”—Amy Alkon, AKA The Advice Goddesss, syndicated advice columnist, journalist, and blogger.
“The public perception is that nitrite/nitrate are carcinogens but they are not. Many studies implicating nitrite and nitrate in cancer are based on very weak epidememiological data. If nitrite and nitrate were harmful to us, then we would not be advised to eat green leafy vegetables or swallow our own saliva, which is enriched in nitrate.”—Dr. Nathan Bryan, Ph.D., whose research has unveiled many beneficial effects of nitrite in the treatment and prevention of human disease, the Institute of Molecular Medicine, the University of Texas, Houston.
Footnotes: Bryan NS, Calvert JW, Elrod JW, Duranski MR, Gundewar S, Ji SY, Lefer DJ (2007) Dietary Nitrite Supplementation Protects Against Myocardial Ischemia-Reperfusion Injury. Proc Natl Acad Sci USA. Nov 27;104(48):19144-9.
Elrod JW, Calvert JW, Gundewar S, Bryan NS, Lefer DJ (2008) Nitric Oxide Promotes Distant Organ Protection: Evidence for an Endocrine Role of Nitric Oxide. Proc Natl Acad Sci USA. Aug 12;105(32):11430-35.
Bryan NS, Fernandez BO, Garcia-Saura MF, Bauer SM, Milsom AB, Rassaf T, Maloney R, Bharti A, Rodriguez J, Feelisch M (2005) Nitrite is a signaling molecule and regulator of gene expression in mammalian tissues. Nature Chemical Biology. Oct (1); 290-297.
(C) 2010, Judy Barnes Baker