We’re a meat-eating nation, but just how much is too much? Paula Goodyer has the answer.
It feels like we’re caught in a tug ‘o war over red meat. On one side are the meat-loving people from planet Paleo, while on the other are headlines claiming meat causes cancer.
As the nation fires up the barbie for summer’s festival of scorched meat and snags, it’s a good time to ask: should we eat more — or less — meat? We investigate both sides of the story to give you the full picture.
The good news…
Key iron source
Besides being a great source of protein, zinc and B vitamins, meat is also an easily absorbed source of iron, which helps prevent anaemia.
In Australia, around 15 per cent of women and eight per cent of pre-schoolers have anaemia, according to the World Health Organization (WHO). Symptoms of anaemia include being constantly tired, lethargic and lacking in concentration. So, eating more red meat is a good way to meet your daily iron requirements.
A protein fix
Meat is one of the best sources of protein. This is not only beneficial for building muscles, but it is also very important for keeping you feeling full, so you’re less likely to overeat between meals.
People who avoid meat often do so out of concern that the fat content will make them gain weight, when, in fact, the protein in meat helps with satiety.
The not-so-good news…
The heat’s on cold meats
Research links diets high in meat, especially processed meats, such as bacon, salami and sausages, to an increased risk of disease.
In 2015, the World Health Organization declared processed meats as Class 1 carcinogens. This means there is strong evidence these meats cause cancer. Researchers say that if we follow the Australian Dietary Guidelines for modest amounts of meat (see Three ways to keep meat on the menu, below), we could avoid five million deaths worldwide each year by 2050.
Risk of bowel cancer
The evidence against eating too much red meat is strongest for bowel cancer, Australia’s second largest cancer killer. “One in six cases of bowel cancer in Australia has been attributed to eating too much red meat and processed meat,” says dietitian Kathy Chapman, Director of Cancer Programs at Cancer Council NSW.
So, why do big serves of meat increase our risk of bowel cancer?
The high amounts of iron may cause damage to our cells and encourage tumour growth.
Harmful chemicals are created when meat is cooked, especially burnt or charred.
Preservatives in processed meat, called nitrates and nitrites, could be the culprits.
“We also need to ask if a high meat intake increases cancer risk because it leaves less room for protective foods like vegetables, legumes and fruit,” says Chapman.
Link with diabetes
A large US study found that people who ate less red meat and more dietary fibre had a reduced risk of developing type 2 diabetes.
“It’s an association; we can’t say that eating less meat is the sole reason for a reduced risk of type 2 diabetes,” says Dr Alan Barclay, an Accredited Practising Dietitian and author of Reversing Diabetes.
Processed meat, over other meat, shows the strongest link for increasing your diabetes risk.
“The nitrate preservatives used in processed meat have been linked to insulin resistance, which increases the risk of type 2 diabetes,” Dr Barclay explains.
“Processed meats like bacon and sausages are often fried at high temperatures, which can produce harmful substances like heterocyclic amines (HCAs), so that might also play a role.“
“The best advice is to stick with the Australian Dietary Guidelines which recommend that you have processed meat no more than once a week,” says Dr Barclay.
A heart stopper
Then there’s heart disease. “The fat found in and around meat, and especially processed meat, is linked to a higher risk of heart disease, but it’s an association, which isn’t the same as saying it’s a cause,” adds cardiologist Professor Paul Nestel of the Baker IDI Heart & Diabetes Institute. “It may be the salt and nitrates that are the problem,” he says.
By contrast, unprocessed meat such as a lean steak is less problematic. “Most researchers agree that having lean meat in moderation — say three times a week — is safe,” Prof Nestel says.
The Cancer Council recommends eating red meat no more than three or four times a week. On the other days, choose fish, poultry or legumes.
The final say…
So, if too much meat can set us up for health problems, should we all go vegetarian?
More of us are making the switch, with the number of Australians eating a vegetarian or almost vegetarian diet growing steadily.
Compared with meat-eaters, vegetarians tend to eat less saturated fat and more fibre, potassium, magnesium and plant chemicals, according to Harvard Medical School. As a result, they often have healthier levels of cholesterol and blood pressure, and a lower body mass index (BMI), all of which are linked to a reduced risk of chronic disease.
“Studies of Seventh Day Adventist groups, who are vegetarian, also show a slightly lower risk of bowel cancer,” adds Chapman. “But the evidence isn’t strong enough to recommend that everyone should eat a vegetarian diet.”
The bottom line is you can get many of the health benefits of a vegetarian diet without avoiding meat entirely. Instead of making meat the focus, prepare meals with an emphasis on plant-based foods and only include small amounts of unprocessed meat.
The Paleo picture
Paleo fans believe that a diet based on what our ancient ancestors ate is good for our health.
However, the meat that hunter-gatherers ate wasn’t from domestic animals that spend their days lazily grazing in lush, green pastures.
Instead, they ate the meat of animals that ran around in the wild and had a different fat profile, with less saturated fat and more healthy omega-3 fats.
Three ways to keep meat on the menu
1. Be portion-wise
Stick to small portions of lean red meat (eg. beef, lamb or pork). Ideally, a (raw) serving should be no more than the size of your palm, with a maximum of 455g cooked (600–700g raw weight) meat per week, according to the Australian Dietary Guidelines. That’s about 65g cooked (or 100g raw) if you’re eating meat every day, or 130g (cooked) every second day. See the pictorial guide below.
2. Go easy on processed meats
If ham, bacon and sausage are staples, think again. In Australia, the Dietary Guidelines say we should only eat these foods ‘sometimes’ and in small amounts — a 50g serve is the recommendation. The World Cancer Research Fund takes a much stronger stand — avoid processed meat altogether is its advice.
3. Cook it slow and low
Cooking your meat at very high temperatures, or in direct contact with a flame or hot surface, such as on a searing hot barbecue or frying pan, produces harmful chemicals. These include polycyclic aromatic hydrocarbons (PHAs) and heterocyclic aromatic amines (HCAs).
Although studies show these chemicals can cause cancer in animals, it’s hard to determine what the effect of cooked meats is on humans. But some studies have found that high intakes of well-done, barbecued or fried meat is associated with an increased risk of developing bowel, prostate and pancreatic cancers.
Cooking meat over very high heat also produces other harmful chemicals called Advanced Glycation End Products (AGEs). These have been linked to diseases such as type 2 diabetes and Alzheimer’s.
So, avoid burning your meat, and cook it slowly. Poaching and steaming are the healthiest methods. And if you are cooking on a barbecue, then use a marinade with acidic ingredients like lemon juice or vinegar with your meat, poultry and fish, which will reduce the level of HCAs, PHAs and AGEs.
Size it right
Use this guide to see what a healthy portion of meat looks like (100g raw).