From the November/December issue of Vegetarian Nutrition and Health
Letter
Red meat and health
Vegetarian diets offer protection against chronic disease in a number of ways. A plant-based menu is higher in fiber, nutrients like folate and vitamin E, and in phytochemicals, including many antioxidants. But what vegetarians don't eat counts, too. Vegetarian diets are typically lower in saturated fat and cholesterol. These kinds of observations have led some experts to suggest that a prudent omnivore diet that includes lean meats can reap the benefits of a vegetarian diet, as long as the omnivore diet is rich in fiber, fruits and vegetables, and avoids more fatty animal foods. Whether or not this is true remains to be seen. Some research challenges this idea--particularly where red meat is concerned.
There is no question that red meat is a concentrated source of many nutrients. Most importantly, it provides protein, iron, and zinc. But since protein is well supplied from a variety of plant foods, and deficiency is rare among vegetarians, the fact that meat supplies this nutrient is of little importance. Furthermore, while vegetarians have adequate protein intake, most Westerners get far too much. High protein, from meat in particular, may adversely affect bone health.
Although red meat is also touted as a good source of well-absorbed iron, vegetarians seem to get plenty of this nutrient, since iron deficiency is not a common problem in the vegetarian population. And high iron intakes have been linked to increased risk for heart disease and possibly to increased risk for cancer.
People who don't eat meat do need to give a bit of extra attention to zinc in their diets. Red meat is one of the better food sources of this nutrient, but vegetarians can get adequate zinc by consuming nuts, seeds, legumes, and dairy foods. The fact is, plant foods can provide the same nutrients that are in red meat and they also provide some unique compounds. Both fiber and phytochemicals, which have numerous health benefits, are abundant in plant foods but are not found in meat. However, establishing that red meat isn't necessary for health and that it lacks a number of health-promoting factors isn't the same as saying that it may be detrimental to your health.
Criticisms of red meat have always focused on the fact that it is high in fat, saturated fat, and cholesterol. While fat content of different cuts of meat varies markedly, there is little doubt that the commonly consumed types are high in total fat--averaging about 50 percent of calories. A 3 -ounce serving of ground beef labeled "lean" provides 18 grams of fat and more than 7 grams of saturated fat. If a person consumes 2,000 calories per day and aims to keep fat intake down to 25 percent of calories, that single small serving of beef provides a third of the day's total fat allowance. Not surprisingly, the Adventist Health Study (see the October VNHL) found that men who consumed beef four or more times per week were twice as likely to die from heart disease as men not consuming beef.1
Red meat has also been linked to increased cancer risk. In a comprehensive review of existing studies, Dr. Sheila Bingham, of the Dunn Nutrition Center in Cambridge, England, concluded that, although there is some inconsistency, studies suggest that red meats and processed meats increase colorectal cancer risk.2 The World Cancer Research Fund (WCRF) summarized the research with this conclusion in their landmark report, Food, Nutrition, and the Prevention of Cancer: "Diets containing substantial amounts of red meat probably increase the risk of colorectal cancer--also, such diets possibly increase the risk of pancreatic, breast, prostate, and renal cancers." In their dietary recommendations for reducing cancer risk, the WCRF advised that red meat, if eaten at all, should be limited to three ounces daily.3 Harvard health expert Walter Willet suggest that, " the optimal amount of red meat to be eaten is zero."4
Several theories have been proposed for the observed relationship between red meat and cancer risk. First, the high iron content of red meat may promote the generation of free radicals, molecules that lead to oxidation of DNA. Oxidized DNA has been linked to cancer. One recent study at Wayne State University in Detroit showed that both beef and pork intake were linked to DNA damage and, therefore, possibly to cancer risk.5 (see Findings in the July/August issue of VNHL).
Another theory focuses on the changes that occur when red meat is cooked, especially at high temperatures under moist conditions. This leads to the production of compounds in meat called heterocyclic amines (HCAs). These are mutagens--compounds that can cause changes in DNA and raise risk for cancer. The way meat is prepared affects production of HCA. Those who eat meat that is fried or well done have a greater risk for cancer than those who eat meat cooked in other ways. Further, certain individuals are "fast metabolizers" of HCAs. They metabolize the compounds more quickly, putting them at greater risk for cancer. One study found that fast metabolizers who consumed well done meat were three times more likely to develop colon cancer than slower metabolizers. The relationship held when the two groups consumed meat that was prepared to the rare or medium stage. And when fast metabolizers consumed meat that was well-done, their cancer risk was six times greater than slow metabolizers who ate rare or medium-cooked beef.6 The rate at which a person metabolizes HCAs is genetically determined. HCAs may also raise risk for heart disease, since there is some evidence that they damage heart muscle cells.
Finally, toxic compounds, called nitroso compounds, are produced in the colon when red meat is consumed. These mutation-causing compounds increase dramatically in proportion to increased red meat consumption. One theory is that the unabsorbed iron from meat is responsible for this effect.7
Although most of the concern has focused on the relationship of red meat to cancer and heart disease risk, it may affect risk for other diseases as well. Red meat may promote the growth of certain bacteria that produce a toxic metabolite, a spasmogen that weakens the wall of the colon and favors the development of diverticuli.8 Additionally, meat protein may increase risk of kidney stones.9
Finally, a very speculative but interesting theory about red meat, and about meat in general, has been put forth by Dr. Steven Provonsha of the Department of Preventive Medicine at Kaiser Permanente. He suggests that consumption of flesh food, because it is body tissue, activates a hormonal response like that seen in injury, illness, or starvation. That is, the body mistakenly thinks that it is starving and, as a result, defense or survival mechanisms are triggered. While these defense mechanisms are crucial to survival during starvation, under normal conditions these hormonal changes could increase risk of diseases like hypertension, diabetes, and heart disease in response to repeated flesh consumption over a prolonged period of time.
Although more research is needed in all of these areas, it is clear that at least part of the benefit of vegetarian diets is due to avoidance of foods like red meat. But it is certainly not the whole story. What vegetarians do eat probably matters just as much. The key to a healthful vegetarian menu lies in eating a wide variety of whole plant foods including whole grains, plenty of legumes, and generous amounts of fruits and vegetables.
1. VNHL
2. Cancer Lett 114: 25-34, 1997
3. Food, Nutrition and the Prevention of Cancer: a global perspective
4. Willet's quote
5. J Am Diet Assoc 98: 524, 1998
6. Cancer Epidemiol, Biomarkers & Prev 3: 675-682, 1994
7. Carcinogenesis 17: 515-523, 1996.
8. Gut 26: 541-543, 1986.
9. N Engl J Med 328: 333-838, 1993.
10. Personal communication
Meat is often touted as a super source of nutrients such as protein, iron, and zinc. But are you in danger of deficiency if you don't eat meat? Not if you consume a well-balanced vegetarian diet.
Protein: A single serving of meat provides roughly 25 grams of protein or about one-half the RDA. This means that the average meat eater gets far more protein than he or she needs, and is at greater risk for problems like osteoporosis and possibly kidney disease. Vegetarians, on the other hand, have adequate but not excessive intakes of protein. A cup of beans provides about 15 grams of protein, and a half cup of grains or vegetables provides about 3 grams. This means that meeting protein needs on a vegetarian diet--with or without animal products like dairy and eggs--is a breeze, provided you eat a variety of plant foods. Make sure you meet calorie needs as well, since protein needs increase when calorie intake is too low. As we've pointed out before, there is no need to eat special combinations of foods to meet protein needs.
Iron: While meat is indeed very rich in iron, research shows that high intake of heme iron (the kind found in meat) and high iron stores (which are typical of men who eat meat) may increase risk for heart disease and cancer. It makes more sense to get iron from plant foods. Plant foods are abundant in non-heme iron, and vegetarian diets are typically higher in iron than diets that contain meat. The iron in vegetarian diets is absorbed less well, so make sure you maximize absorption by eating a source of vitamin C with every meal. And avoid calcium supplements with meals, since high doses of calcium interfere with absorption. Among the best sources of iron are whole grains (enriched grains are a super source as well and can be a good choice for children especially), legumes, dried fruits, tomato juice, and potatoes (with their skins).
Zinc: Vegetarian diets tend to be adequate in zinc, but absorption of this nutrient is not as efficient from plant foods as from animal foods, so vegetarians must give some extra attention to it. Do identify several good sources of zinc that you enjoy and that you can include in your diet frequently. Some good sources include bran flakes and other bran cereals, peas, sea vegetables, legumes (especially adzuki beans, chickpeas, and tempeh), nuts and seeds (especially peanuts, Brazil nuts, and tahini), milk, yogurt, and cheese. Watch for a feature article on zinc in VNHL in 1999.
The bottom line: Given the risks associated with red meat and the fact that it doesn't have any unique nutritional value, meat doesn't seem to offer anything that justifies its consumption.
A new study published in the Journal of the American Medical Association
shows a doubling of the risk of colon cancer for people who are heavy consumers
of red
meat. More specifically, it shows that the risk doubles compared to
those who consume smaller quantities of red meat. But how does this compare
to people who
consume no red meat at all?
This is conjecture, but I'm willing to bet that heavy consumers of red
meat probably have quadruple the risk (or more) of colon cancer compared
to vegetarians or
people who consume no red meat. By the way, you don't have to be a
vegetarian to boycott red meat. You can still be a consumer of other sources
of animal
protein (fish, seafood, etc.) while avoiding red meat.
There are plenty of health reasons to avoid eating red meat, and a higher
risk of colon cancer is just one of them. The saturated animal fat found
in red meat products
contributes to heart disease and atherosclerosis. In addition, red
meat can contain contaminants such as heavy metals, pesticides and undesirable
environmental
pollutants that tend to collect in the fat tissues of cows, which are
absorbed into your body when you eat cow fat. And you can't eat red meat
without getting some
animal fat.
Then, of course, there's what I call the vibration of red meat, which
concerns the homeopathy of the meat, or the environment in which the cow
was raised. Was it a
natural environment? Did the cow have access to open fields, sunlight
and clean water? Or was this a cow raised as part of a slaughterhouse operation,
produced for
the sole purpose of generating profits? If you eat cows' meat that
has undergone that kind of experience, you are consuming a product that
is tainted with the
negative experience of the animal from which it came.
There are a lot of negative effects associated with the consumption
of red meat, and this is why more and more people are now giving up red
meat and moving to
healthier foods like fish, free-range chicken, or better yet, plant-based
proteins like spirulina or soy products like soy milk and tofu. This is
where you'll get your best
protective effect and disease prevention, and you will be helping protect
the environment at the same time. After all, it's far less stressful on
the environment to
produce food as plants than as animals.
It takes 10 acres to produce the same amount of red meat protein as
it does to produce one acre of soy beans. And producing spirulina yields
a tenfold increase
over the production of soybeans. So think about it: one acre of farmland
used to produce spirulina can produce 100 times as much protein as beef
and red meat.
That will be very important to realize as our world population grows
and it becomes increasingly difficult to produce the protein required by
the population.
How to make the transition away from red meat
These are all reasons to avoid an animal-based diet and pursue a plant-based
diet. Many people reading this are already following a plant-based diet,
but some of
you who might be considering making the change probably aren't sure
exactly how to do it.
Perhaps you want to merely reduce your consumption of red meat but
not give it up completely yet, which is fine, since that's the way all
of us ex-meat-eaters got
into plant-based diets to begin with. Few people ate more meat than
I did because I grew up in an environment where we had all the red meat
we wanted at no
charge (my grandfather was a cattle rancher). We had a freezer full
of red meat at all times, and we could have as much hamburger, steak or
other cuts of meat as
we wanted. I consumed large quantities of red meat for nearly 30 years.
I found the transition away from red meat to be difficult at first.
I started consuming less of it and eating other meat alternatives, and
pretty soon I began to view red
meat in a different way, because if you eat less of it, you eventually
start to lose your appetite for it. And within less than a year, any time
I would see red meat at the
grocery store, it would gross me out. I look at it and I realize what
it is: a chunk of flesh sliced off the carcass of a living creature that
has been ground up and stuffed
into a box. Usually there's some blood running around in the container
as well. Every time I would look at that I would get grossed out and think
to myself, "Gee, is
this really what I want to eat for the rest of my life? This sliced
up chunk of a dead cow?" And the answer was, "No." So it didn't take very
long before I didn't want
any red meat, and now I can't imagine eating it.
That's one way to get rid of red meat in your diet, but there are many
other ways and I encourage you to experiment and see how you'd like to
approach it. But the
bottom line on red meat is that there is an increasing body of evidence
supporting the notion that you can prevent cancer by pursuing a plant-based
diet. If you want
to be healthy, it's time to join the vegetarians. Maybe even join the
vegans, if you have the courage.
Endometriosis caused by eating red meat and avoiding fresh vegetables, says research; infertility may result
Think about limiting or eliminating your consumption of red meat and
instead nourish your body with the phytonutrients, phytochemicals, vitamins,
minerals and even
the living energy of plants. That's how you'll be the healthiest you
can be.
Jun 16, 2005
People who eat a diet high in red and processed meat increase their risk of bowel cancer by as much as a third, new research shows.
Past studies have highlighted a possible link between eating large amounts of red meat and a greater risk of bowel cancer.
The latest research, published in the Journal of the National Cancer Institute, used data from a long-running study of the diets of more than half a million people across Europe.
The European Prospective Investigation into Cancer and Nutrition (EPIC) found that the risk of developing bowel cancer for people who regularly ate more than two portions of red and processed meat a day was a third (35%) higher than for those who ate less than one portion a week.
The study also found that the risk of developing the disease increased for those people who had a low-fibre diet.
Poultry was not found to influence the risk of bowel cancer, but the researchers did find that people who ate more fish faced less chance of developing the disease.
The risk of bowel cancer dropped by nearly a third (30%) for people who ate one portion or more of fish every other day - compared to those who ate fish less than once a week.
The research was funded by the Medical Research Council (MRC), Cancer Research UK and the International Agency for Research on Cancer.
Professor Sheila Bingham, a principal investigator of the study from the MRC Dunn Human Nutrition Unit in Cambridge, said: "People have suspected for some time that high levels of red and processed meat increase risk of bowel cancer, but this is one of the largest studies worldwide and the first from Europe of this type to show a strong relationship.
"The overall picture is very consistent for red and processed meat and fibre across all the European populations studied."
EPIC coordinator Dr Elio Riboli, of the World Health Organisation International Agency for Research into Cancer, added: "This study of so many different populations and diets has provided an accurate picture of how different kinds of familiar foods in our diet relate to the incidence of bowel cancer.
"Other risk factors for the disease include obesity and lack of physical activity.
"Smoking and excess alcohol may also play a role. These factors were all taken into account in the analysis."
Professor Tim Key, deputy director of Cancer Research UK's epidemiology unit, said the study strengthened evidence that bowel cancer risk could be cut by increasing fibre in the diet and reducing consumption of red and processed meat.
"Around 35,000 cases of bowel cancer are diagnosed each year in the UK.
"We estimate that more than two-thirds of colorectal cancer cases - 25,000 cases in the UK - could be avoided by changes in lifestyle in Western countries," he added.
The Meat and Livestock Commission (MLC) said that people in Britain ate well below the 160g-per-day consumption levels that were used to class high intake in the study.
They said that the amount of red and processed meat eaten by the average Briton was only 93g a day.
Mike Attenborough, MLC technical director, said: "Once again this points towards the need for moderation and balance in what we eat.
"Meat is typically eaten with vegetables and sources of fibre such as potatoes, all of which are considered by scientists to have a protective effect against bowel cancer.
"Lean red meat is recognised as an important part of a healthy, balanced diet, and research shows it is a valuable source of protein, iron, zinc and other essential nutrients."
Source: AAP
The same article was also reported by - and adjusted according their
implications with their local meat industry:
http://news.webindia123.com/news/showdetails.asp?id=88940&cat=Health
http://www.irishhealth.com/?level=4&id=7689
http://www.turkishweekly.net/news.php?id=12789
http://edition.cnn.com/2005/HEALTH/06/15/meat.cancer/
Red meat could be good for you
A leading nutritionist has provoked controversy by suggesting people who do not eat red meat are risking their health.
The suggestion has been dismissed as flying the face of scientific evidence by vegan and vegetarian groups.
Professor Robert Pickard, director general of the British Nutrition Foundation, said a vegetarian diet was not natural for mankind.
Addressing a seminar of nutritionists at Stratford-upon-Avon, Professor
Pickard said: "Man is an omnivore.
Anyone thinking of restricting their diet by becoming a vegetarian is potentially taking risks with their health
Professor Robert Pickard, British Nutrition Foundation
"Anyone thinking of restricting their diet by becoming a vegetarian is potentially taking risks with their health."
Professor Pickard said the gut contained a kilogram of bacteria to help digest the wide variety of food present in an omnivorous diet.
He said there was evidence that leaving the bacteria idle as a result of a restricted diet can make it easier for disease to take hold.
"Evolutionary science tells us that man emerged from an insect-eating group of mammals whose adaptability was greatly accelerated by the adoption of an omnivorous diet.
"Man's teeth, jaws and gut have evolved to deal with a mixture of meat and vegetables."
Third way diet
Professor Pickard said that this `third way' diet provided primitive man with a high-energy food intake making him a more effective species.
This gave him more time to think and stay ahead of competitor species.
"Meat should now play a central part in any person's diet.
A meat-free diet is commonly chosen by top class athletes precisely because it improves one's health
Catherine Grainger, Vegan Society
"It provides iron for the blood, vitamin D for the bones, and proteins and fatty acids for growth.
"Its role has emerged as a result of million of years of evolution. It is also highly likely that red meat contains many other beneficial nutrients that we do not yet fully understand."
Ian Tokelove, a spokesman for the Food Commission, set up to provide information on healthy diets to the consumer, refused to back Professor Pickard.
He said: "Meat does have a role to play in the diet, but it has been shown not to be essential.
"The body is adaptable and vegetarians actually have a healthy diet."
Vegetarian response
The Vegetarian Society said comments such as those made by Professor Pickard made many vegetarians worry about their diet - unjustifiably.
Sam Calvert, head of public affairs, said: "There is not cause for concern. There are three million vegetarians in the UK, and it can clearly be seen that vegetarianism is not have a detrimental effect on their health - in fact research shows that it has a positive effect."
Ms Calvert quoted a study published in the British Medical Journal in 1994 which showed vegetarians were 20% less likely than meat eaters to die before the age of 65 - and 40% less likely to die prematurely from cancer.
Catherine Grainger, of the Vegan Society, said Professor Pickard's comments contradicted advice from the World Health Organization, and the UK and US governments, who all recommend reducing consumption of foods high in saturated fats and cholesterol in favour high fibre, plant-based foods
"Professor Pickard's suggestion that meat should play a central part in any person's diet is outrageous given the wealth of scientific evidence showing that vegetarians and vegans are healthier than meat-eaters."
"Not only does a meat-free diet easily provide all the nutrients necessary
for good health - including iron, protein, calcium, fatty acids and vitamin
D - it is also commonly chosen by top class athletes and health care professionals
precisely because it improves one's health."
Iron and protein: red meat substitutes
The information in this fact sheet is provided by naturopath Janella Purcell from the Today Show on Channel Nine.
Overview
There is a place for red meat in our diets if we choose, but it isn't essential. Animal meat is high in saturated fats, which can lead to heart disease and obesity. We certainly need protein and iron, but animal meat isn't the only, or the best, source of protein and iron. Furthermore, if you are eating meat, then it's wise to buy it organically grown, as that way you can be sure your meat is chemical and antibiotic free.
So what can the 21st-century person eat to meet the recommended daily allowance of protein and iron? Protein is needed for growth and development. It's also used for energy and to manufacture hormones, antibodies, enzymes and tissues. It helps keep the acidity in our bodies in check by maintaining a proper acid/alkaline balance.
Amino acids are the building blocks of proteins. Complete proteins contain all of the essential amino acids. These are eggs, milk, cheese, poultry, meat and fish. Incomplete proteins contain only some of the essential amino acids. These are grains, legumes and green leafy vegetables. If you combine, for example, beans with brown rice, nuts, seeds or corn, you have a complete protein. All soy products are complete proteins, as is yoghurt.
The average vegetarian/aquatarian (seafood eater) diet easily fulfils the daily protein recommendations of the World Health Organisation (WHO). Animal proteins come with the problems of saturated fats, which have been linked to heart disease and cancer. Plant proteins, however, are linked to dietary fibre. It is important to include foods high in Vitamin C, as this will increase iron absorption up to 30 percent.
Foods to include:
Molasses
Mochi (pounded sweet rice)
Leafy greens
Legumes such as lentils, kidney and soybeans
Sesame seeds
Sea vegies
Almonds
Tofu dried peaches
Fish
Whole grains
Pumpkin
Raisins
Watercress
Beetroot
Coconut milk
Chestnuts
Cherries
Chinese red dates
Mulberries
Kelp
Raspberries
Walnuts
Broccoli
Nuts and seeds
It's important to include adequate protein, plus B and C vitamins for iron absorption. The average vegetarian diet supplies twice the minimum daily requirements of iron. It also supplies the body with three times the daily requirement of vitamin C. Studies of the iron content in food show that vegetables, fruit and nuts are much higher in iron content than beef.
Food per 100g
Amaranth 16mg
Dried bean curd (yuba) 11mg
Soybeans 8.4mg
Almonds 7.4mg
Sesame seeds 7.1mg
Lentils and pulses, ranging from 6.9mg
Seaweed 6.3mg
Dried peaches 6mg
Beef 2-3mg
The Australian recommended daily allowances are:
Woman 19-54 years: 12-16mg/day
Men 19+: 7mg/day; aged 54+: 5-7mg/day
Pregnant women: 22 36mg/day
Children aged one to 11: 6-8mg/day; aged 12-18: 10-13mg/day