Red meat, coffee, butter – do we have to give them up?
As studies suggest some meats can raise the risk of diabetes and buttery foods are bad for the heart, experts reveal what we should cut out.
With so much conflicting evidence on what constitutes a healthy diet, it is easy to be baffled about what we should be eating – and what we should give up entirely.
Last month, a large study led by scientists at the University of Cambridge involving almost two million adults revealed that eating just two slices of ham a day, or the equivalent amount of other processed meats, could raise the risk of type 2 diabetes by 15 per cent. Eating 100g of red meat a day was associated with a 10 per cent higher risk.
Meanwhile, a trial by the University of Oxford last week found that regularly eating buttery foods such as pastries and cakes could take a major toll on heart health.
Should we just stop eating these foods altogether? And what else might be off the menu? We asked leading nutrition experts for their verdict.
RED MEAT
Too much red meat was listed by the International Agency for Research on Cancer as a probable cause of bowel cancer, with chemicals naturally present in meat shown to damage bowel cells.
Cooking methods that involve extreme heat, such as barbecuing, grilling or frying, can generate more damaging chemicals such as heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs), which are also linked to bowel cancer.
“Red meat intake is also linked to heart disease and stroke,” says the registered nutritionist Eli Brecher.
That said, red meat is a great source of the best and most easily absorbed form of iron, called haem iron – vital to the process of carrying oxygen around the body to supply energy. It is also an important provider of vitamin B12, crucial for healthy blood and nerve function.
Verdict: You don’t have to give up, but do limit how much you eat Aim for at least two meat-free days a week.
“It’s a useful source of iron and B12, but we should definitely not exceed government guidelines of no more than 70g of red meat a day, or 490g a week – equivalent to one third of an 8oz steak or five tablespoons of beef mince,” Brecher says.
Dr Linia Patel, a state registered dietitian who is also a research scientist at the University of Milan, adds: “It’s best to stew or slow-cook red meat instead of barbecuing or frying it, to avoid exposure to high temperatures.”
PROCESSED MEAT
As tasty as it might be, the meat in a bacon sandwich, a hot dog or pepperoni pizza has been categorised as a group 1 carcinogen – in the same group as smoking and alcohol – by the IARC.
A 2020 study by Cancer Research UK scientists involving 474,996 adults found that those eating 79g of processed meat, the equivalent of three slices of ham a day, had a 32 per cent increased risk of bowel cancer compared with people eating less than 11g daily.
The chemicals added to meat during processing, such as nitrates and nitrites (used to keep it fresh for longer), have been shown to damage cells in the bowel. The Lancet Diabetes & Endocrinology research follows a study published last year in Mayo Clinic Proceedings, which found that too much salt, present in high amounts in processed meats, also raises the risk of type 2 diabetes.
Verdict: Best avoided Patel says that switching to plant-based processed-meat alternatives such as vegan “bacon” is not a good thing either. “We just don’t have enough data on them yet,” she says. “I would keep intake of any processed foods to a minimum.”
WHITE BREAD
“Wholemeal, wholegrain and seedy breads contain more fibre than white and better support a healthy gut and stable energy levels,” Brecher says.
“They are also higher in nutrients that come from the bran and the germ of the grain, which gets stripped in the white, refined version.”
But white bread does have some virtues. Researchers comparing how processed white bread and artisanal wholegrain sourdough affected 20 healthy participants for a study in Cell Metabolism found there were “no clinically significant differences” on any of the measurements, including levels of the essential minerals, markers for inflammation and health of the gut microbiome.
About half of participants in that study also had a better blood sugar response to processed white bread than the wholegrain sourdough, suggesting stark individual responses.
Verdict: Eat a few slices of white bread a week if you enjoy it, but prioritise wholegrain for added fibre, Brecher says.
COFFEE
Coffee contains variable amounts of caffeine (depending on how you make it or where you buy it), high intakes of which can cause anxiety and poor sleep.
A study presented to the American College of Cardiology Asia conference last month warned that drinking 400mg of caffeine – the amount in about four regular-sized cups of coffee – a day could increase the risk of heart disease in healthy people.
“Regular caffeine consumption could disturb the parasympathetic system, leading to elevated blood pressure and heart rates,” said Nency Kagathara, a researcher at Zydus Medical College and Hospital, Dahod, India, and lead author of the paper.
There is, however, evidence on the health benefits of coffee. It contains hundreds of antioxidants and beneficial plant components that are good for your health.
Researchers reporting in the European Journal of Preventive Cardiology found that drinking two to three daily cups of coffee resulted in a lower risk of cardiovascular disease, and this year, a study of 1,719 bowel cancer patients in the International Journal of Cancer found that those who drank at least two cups of coffee a day were less likely to see the disease return. Two years ago, researchers from Australia found that drinking between two and three cups of coffee a day increased longevity and lowered the risk of heart disease.
Verdict: Keep drinking it – but in moderation The European Food Safety Authority advises no more than 400mg of caffeine a day, and the NHS advises pregnant women to limit their intake to 200mg because excessive amounts are linked to miscarriages. To be safe, stick to no more than four regular-sized cups a day.
BUTTER
Saturated dairy fats, such as those found in butter, have a reputation for raising cholesterol, which can in turn fur up arteries – both risk factors for cardiovascular disease and dementia.
In July, butter was dealt a further blow when a team that included researchers from the University of Reading published a report in Nature Medicine suggesting that switching to plant-based unsaturated fats, such as olive oil, improves the fat composition of the blood, and that this switch could be linked to a reduced risk of developing cardiovascular disease and type 2 diabetes.
The recent Oxford University trial put a group of volunteers on a calorie-controlled diet high in saturated fat for 24 days, and while they didn’t gain weight, they saw their cholesterol rise by 10 per cent on average. There was also a 20 per cent rise in the fat in their liver, increasing the risk of type 2 diabetes and heart disease.
However, it’s not all bad news for butter. It’s one of few foods to provide vitamin K2, which is mainly found in animal and fermented foods, and is important for bone and heart health. And butter is still preferable to ultra-processed margarine, which may be lower in saturated fat but is high in man-made trans fats, which have an even worse effect on cholesterol levels, and heart and brain health.
Verdict: Enjoy sparingly “A 5g, or teaspoon portion, of butter, no more than twice a day, is enough according to the British Dietetic Association,” Patel says.
EGGS
Many people still have a hang-up about eggs and cholesterol. It’s the dietary cholesterol – about 200mg in a large egg yolk – that’s considered to let them down.
Yet time and again, researchers have shown that consuming cholesterol in eggs does not lead to a dramatic rise in levels of the substance in the blood. In fact, researchers in the European Journal of Nutrition found that eating two eggs a day for 12 weeks did not raise low-density lipoprotein – “bad” cholesterol – when accompanied by weight loss, and last year, a study in Nutrients reported that healthy people who ate five or more eggs a week had a lower risk of developing type 2 diabetes.
Egg yolks are a rich source of lutein and zeaxanthin, both important for eye health. They also contain heart-healthy nutrients including amino acids, omega-3 fatty acids, choline, vitamins D and B12, while the whites are rich in protein and low in fat.
Verdict: Keep eating them. “The NHS sets no upper limit for egg consumption, and for most healthy people, eating one to three eggs a day, including those added as an ingredient to food, is fine,” Patel says.
If you are at high risk of heart disease and have been advised by doctors to consume less than 300mg dietary cholesterol daily you will probably need to limit intake to three eggs a week.
ALCOHOL
We all love to believe that a moderate alcohol intake – a daily glass of wine or beer – is good for us, but scientific consensus is shifting increasingly towards abstinence, or at the very least cutting down to below the weekly 14 units considered by the NHS to be the upper limit for healthy consumption.
Last year, a review in Jama Network Open of the drinking habits of nearly five million people found that even low intakes of alcohol did not protect against early death from any cause. And in 2022, researchers looked at the alcohol consumption of 370,000 participants in the UK Biobank database and found that even low intakes were associated with an increased risk of cardiovascular issues, including hypertension and coronary artery disease.
What about red wine, hailed in the early 2000s for its antioxidant effect? It does contain polyphenol compounds such as resveratrol, which has antioxidant and anti-inflammatory properties, and some early research found links between red wine intake and fewer heart attacks, even suggesting that a daily glass of red was good for cardiovascular health.
But in recent years, red wine’s health halo has slipped. This year, researchers from the University of Leicester said that clinical evidence supporting the value of resveratrol as a health supplement is inconclusive.
Even if resveratrol does help to reduce inflammation, the amounts found in red wine are negligible. A study in Advances in Nutrition suggests we would need to drink up to 500 litres of red wine a day to get enough resveratrol to boost health.
“Just one glass of wine a day increases the risk of high blood pressure and heart problems and, as with any other form of alcohol, high intakes are associated with an increased risk of cancer,” Brecher says. “Get your polyphenols from blueberries, flax seed, pecan nuts and good quality dark chocolate with at least 70 per cent cocoa instead.”
Verdict: Cut down Remember, the 14 weekly units is not a target but an upper intake, which, if exceeded, comes with health risks. A 250ml glass of red contains three units, so drinking one a day will exceed the upper intake by seven units.
“The message now is the less alcohol you drink, the better,” Patel says. “At least try to have some alcohol-free days each week for your liver to be given a chance to regenerate.”
The Times
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