Should we eat meat?
For those of you who watched the SBS documentary on the safety of eating meat, by Michael Mosely, you still might be wondering what the conclusion is.
Here’s a summary of the BBC report:
http://www.bbc.com/news/health-28797106
How safe is eating meat?
Michael Mosley embarked on a four week trial, eating 130g of meat a day to research the effects on his body.
Statistics have previously supported the idea that the threat to health comes not from eating white meat, like chicken, but from red and processed meat…so only red meat and processed meats were researched in this study.
Despite the negative headlines, on average Brits still eat about 70g of red and processed meat a day, with a quarter of men eating almost twice as much.
Moseley visited numerous experts, finding out what they themselves eat and presenting their views.
Most agreed that there are lots of good things in red meat. Beef, whole or minced, is a great source of protein and essential nutrients, like iron and vitamin B12, which are vital for health. Other sources of red meat are lamb and pork.
Red and processed meats tend to be high in saturated fat. Red meat looks darker than white meat like poultry because of higher levels of haemoglobin and myoglobin, the iron and oxygen-binding proteins you find in blood and muscle.
Saturated fat
The saturated fat content of red meat has now shown not to be the villain. Contrary to previous belief, it is not showing up as a contributing factor to heart disease and cancer. We need saturated fat in our diet as protection for the cells. Butter is an example of an excellent saturated fat. It not only protects the cells but also provides the fat saturated vitamins A,D, E and K.
If fat is not the problem, are there any other problems with eating red meat?
A study on the L-carnitine in red meat showed that too much of this amino acid could be a problem.
“There’s long been a perception—not necessarily backed by strong evidence—that eating steak, hamburger, lamb, and other red meat ups the risk of heart disease. The saturated fat and cholesterol they deliver have been cited as key culprits. A team from a half dozen U.S. medical centers says the offending ingredient is L-carnitine, a compound that is abundant in red meat.
According to this work, published online in the journal Nature Medicine, eating red meat delivers L-carnitine to bacteria that live in the human gut. These bacteria digest L-carnitine and turn it into a compound called trimethylamine-N-oxide (TMAO). In studies in mice, TMAO has been shown to cause atherosclerosis, the disease process that leads to cholesterol-clogged arteries. We know that clogged coronary arteries can lead to heart attacks.” http://www.health.harvard.edu/blog/new-study-links-l-carnitine-in-red-meat-to-heart-disease-201304176083
So this could be a reason to limit red meat intake, to a suggested twice a week.
Processed meat
Processed meat on the other hand is a different proposition to unprocessed red meat. Processed meat includes bacon, sausages, hot dogs, salami and ham.
Mosely reports, “Eating lots more processed meat certainly had a bad effect on my body. After a month of bacon sandwiches and burgers I had piled on the weight…”
But even worse, studies show that the nitrites used in the manufacturing of processed meats may be a contributor to cancer.
“Higher consumption of processed meats like hot dogs, pepperoni, and bacon is associated with increased risk of colon cancer. The thing is, HCAs aren’t the only compound in these types of processed meats potentially linked to cancer; the preservatives are as well.
Nitrites and nitrates are added to meats to preserve color and prevent spoilage. Unfortunately, these compounds can be converted to nitrosamines, which are also known causes of cancer in animals (though again, the link in people is unclear). Hot dogs, bacon and the like may also be preserved by methods involving smoke or salt, which also increases the exposure to potentially carcinogenic chemicals.”
http://www.cancer.org/cancer/news/expertvoices/post/2011/03/31/hot-dog!-headlines-can-be-deceiving.aspx
Conclusions
The researchers found that eating moderate amounts of red meat had no effect on mortality. The lowest overall mortality rates were in those eating up to 80g a day. Scientists agree that too much processed meat, such as bacon, ham and salami, is not good for health
The researchers concluded that “a low – but not a zero – consumption of unprocessed red meat might be beneficial for health. This is understandable as meat is an important source of nutrients, such as protein, iron, zinc, several B-vitamins as well as vitamin A and essential fatty acids.”
The Epic study, like almost every other study that has been done, found that eating processed meat, such as bacon, ham or salami, had a negative effect on health. Anything over 40g a day and deaths from heart disease and cancer began to climb.
Professor Sir David Speigelhalter of Cambridge University says another way of looking at this is, if the studies are right, that you would expect someone who eats a bacon sandwich every day to live, on average, two years less than someone who does not.