How Often Should We Eat Red Meat?

By Dr Harold Gunatillake
Health writer
FRCS, FACS (US), FIACS (US),
AM (SING), MBBS (Cey)
Does red meat cause heart disease or cancer? This question comes up quite frequently among the health presenters, and the answer is yes, and no. As far as white meat is concerned there is no question, causes no heart disease or cancer.
Red meat is full of saturated fat in the skin, tissues under, and in the flesh (meat). Saturated fat tends to store in the body and cause obesity, and the cholesterol formed from such fats cause thickening of arteries and the risk of heart disease is quite expected. And then, there seems to be an increase in incidence of colorectal cancer among people who eat more than 4 oz. of meat a day.
A recent National Institutes of Health – AARP study of more than a half-million older Americans concluded that people who ate the most red meat and processed meat over a 10-year-period were likely to die sooner than those who ate in smaller amounts. Those who ate about 4 ounces of red meat a day were more likely to die of cancer or heart disease than those who ate the least, about a half-ounce a day. Epidemiologists classified the increased risk as ‘modest’ in the study.
The meat industry in the US does not believe that there is any link between red meat, processed meat and gut cancer. Cancer incidence among vegetarians, results from a European prospective study published in Am J ClinNutr May 2009 reported, “The overall cancer incidence rates of both the vegetarians and the non-vegetarians in this study are low compared with national rates. Within the study, the incidence of all cancers combined was lower among vegetarians than among meat eaters, but the incidence of colorectal cancer was higher in vegetarians than in meat eaters”
According to Indian studies by Doval of Rajiv Gandhi Cancer Institute and Research Centre told IANS: “Though there are hereditary reasons for its occurrence, in India due to poor dietary habits and population becoming older, the number of patients of colorectal cancer is increasing.” Last year, the Rajiv Gandhi Hospital diagnosed about 400 cases of colorectal cancer, of which 50 percent were in the advance stage.
Indian studies do not reveal lower incidence of heart disease or colorectal cancer, though most of the population are vegetarians. Studies on the prevalence of colorectal cancer in Colombo North district in Sri Lanka, reveal that the incidence of colorectal cancer is rising, though most people cannot afford to eat meat products, especially the expensive processed meat products available in the super-markets.
Ceylon Med J 2008 Mar; 53(1). 17-21 studies presented by T. Perera, R. E. Wijesuriya and P. H. Suraweera from the Department of Surgery, Ragama Unit Sri Lanka revealed, “Between 1992 and 1997 the crude annual incidence of colorectal cancer was 1.9 per 100,000, which increased over the years. The current national crude annual incidence is 3.2 per 100,000 in women and 4.9 in men. Median age at presentation was 60 years with similar prevalence of cancer in men and women. In the entire group, 28% of cancers were in those less than 50 years old. Survival at 2 and 5 years was 69% and 52%. The majority of cancer related deaths were within the first 2 years after surgery.”

CONCLUSION:

The burden of colorectal cancer in Sri Lanka is on the rise. Up to a third of cancers occur in those under 50 years, and the majority of cancers are in the rectum or recto-sigmoid region. Flexible sigmoidoscopy offers a useful screening tool.
But many studies have found links between incidence of heart disease and colorectal cancers in the West… Another one that followed more than 72,000 women for 18 years found that those who ate a Western-style diet high in red and processed meats, desserts, refined grains, and French fries had an increased risk of heart disease, cancer, and also death from other causes.
“The association between consumption of red and processed meats and cancer, particularly colorectal cancer, is very consistent,” says Marji McCullough, PhD, a nutritional epidemiologist with the American Cancer Society.
To our observations it is the Western type of diets containing low fibre, including processed meat that may be causing colorectal cancers and heart disease, while in the less developed countries there may be other risk factors for the rise of both heart disease and colorectal cancer.

Cause

If eating red meat and processed meat does increase the risk of cancer among the affluent races, then what is the cause?
That is not clear but there are several areas that researchers are studying, including:
•      Saturated fat in all meats, dairy products, so freely available and consumed among the affluent countries may be linked to cancers of the colon and breast as well as to heart disease.
•     Carcinogens formed during the cooking process of meat. Heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs) are chemicals formed when meat, including beef, pork, fish, muscle and poultry is cooked using high-temperature methods, such as pan frying or grilling directly over an open flame.
The formation of HCAs and PAHs is influenced by the type of meat, the cooking time, the cooking temperature, and the cooking method. Exposure to high levels of HCAs and PAHs can cause cancer in animals; however, whether such exposure causes cancer in humans is unclear.
Currently, no Federal guidelines address consumption levels of HCAs and PAHs formed in meat. Studies have shown that exposure to HCAs and PAHs can cause cancer in animal models. In many experiments, rodents fed a diet supplemented with HCAs developed tumours of the breast, colon, liver, skin, lung, prostate, and other organs. Rodents fed PAHs also developed cancers, including leukaemia and tumours of the gastrointestinal tract and lungs. However, the doses of HCAs and PAHs used in these studies were very high—equivalent to thousands of times the doses that a person would consume in a normal diet.
HCA and PAH formation can be reduced by avoiding direct exposure of meat to an open flame or a hot metal surface, reducing the cooking time, and using a microwave oven to partially cook meat before exposing it to high temperatures.
Ongoing studies are investigating the associations between meat intake, meat cooking methods, and cancer risk.
(Some of this information from the National Cancer Institute facts sheet)
•    Heme iron, the type of iron found in meat may produce chemicals to damage cells leading to cancer. This is a possibility.
Is pork a red meat or a white meat? Pork is considered a red meat as it contains myoglobin (protein) that holds oxygen in the muscles, determines the colour of meat. Fish and chicken have very little myoglobin. Hence pork is considered as red meat.
In Sri Lanka, pork is consumed in large quantities along the coastal regions, and at one stage the pigs served a useful purpose as scavengers like the prawns in the sea. No higher incidence of colorectal cancer or heart disease has been recorded in the respective hospitals in those coastal areas. “People don’t need to give up red meat,” says Christine Rosenbloom, PhD, RD, a nutrition professor at Georgia State University. “They need to make better selections in the type of meat they eat and the portions.”
Government guidelines in MyPyramid suggest 5 to 6 1/2 ounces daily of protein from a variety of sources, including lean meats, nuts, and seafood. So if you’re planning on eating a burger for dinner, it should be a 3-ounce hamburger patty, about the size of a standard McDonald’s burger.

 Pancreatic Cancer

A link between eating processed meat, such as bacon or sausages, and pancreatic cancer has been suggested by researchers in Sweden. The World Cancer Research Fund suggested the link may be down to obesity.
Eating red and processed meat has already been linked to bowel cancer. As a result the UK government recommended in 2011 that people eat no more than 70g a day. Prof Susanna Larsson, who conducted the study at the Karolinska Institute, told the BBC that links to other cancers was “quite controversial”. She added: “It is known that eating meat increases the risk of colorectal cancer, it’s not so much known about other cancers.”
Cancer Research UK said the risk of developing pancreatic cancer in a lifetime was “comparatively small” – one in 77 for men and one in 79 for women.
(Some reference to James Gallagher Health reporter BBC News)

Nutritional benefits

Though the incidence of heart disease and cancers may be high on consuming red meat daily, there are certain benefits of eating red meat. Red meat is high in iron, something many teenage girls and women in their childbearing years are lacking.
The heme iron in red meat is easily absorbed by the body. Red meat also supplies vitamin B12, which helps make DNA and keeps nerve and red blood cells healthy, and zinc, which keeps the immune system working properly. Red meat provides protein, which helps build bones and muscles.
“Calorie for calorie, beef is one of the most nutrient-rich foods,” says Shalene McNeil, PhD, executive director of nutrition research for the National Cattlemen’s Beef Association. “One 3-ounce serving of lean beef contributes only 180 calories, but you get 10 essential nutrients.”
In an island like Sri Lanka, where people do not get to eat sufficient proteins in their food, red meat would become part of the essential daily diet, provided one can afford.

Courtesy Food and Health

   The heme iron in red meat is easily absorbed by the body. Red meat also supplies vitamin B12, which helps make DNA and keeps nerve and red blood cells healthy, and zinc, which keeps the immune system working properly. Red meat provides protein, which helps build bones and muscles.