SARAH DI LORENZO: Are processed deli meats like ham, bacon and salami harming your health?

Deli meats such as ham, salami, bacon and sliced sandwich meats sit in what you could call an awkward place nutritionally.

They are a convenient, tasty protein but research links them with higher long-term health risks.

Processed meat is the umbrella term used in research and by the World Health Organisation. This term includes meat that has been salted, cured, smoked, or processed to enhance flavour and/or shelf life.

Processed meats such as ham, bacon, salami, chorizo, frankfurts, hot dogs, some sausages and most pre-sliced sandwich meats are meat products which often contain added salt, nitrites or nitrates and other additives and flavours.

There are some positives of these meats — to start with they can be a source of protein with about 15–25g per 100g in many sliced meats.

This will support the benefits of protein including muscle maintenance, satiety, hormones, immunity, tissue repair and blood sugar.

For micronutrient intake, red meat-based cuts can provide iron, zinc and B vitamins and especially B12.

These are all important for energy production, red blood cell formation and immune function. There is also the convenience of being shelf-stable.

Curing, salting and smoking were originally developed to prevent meat being spoiled by bacteria and dangerous pathogens like Clostridium botulinum. Nitrites are still used for this safety function today.

Deli meats can be a convenient option to include protein in the diet and a much better choice than options like pastries, pies, sausage rolls and takeaway.

There is a downside to cured and deli meats though. The concern is not about the occasional ham sandwich or your Christmas lunch, rather it is about years and years of consuming deli meats, which increases cancer risk.

The International Agency for Research on Cancer classifies processed meat as Group 1 carcinogenic to humans, based on convincing evidence that regular intake increases bowel cancer risk.

Studies also link higher processed meat intake with increased risk of heart disease, stroke as well as type 2 diabetes.

The most likely cause is a combination of sodium, saturated fat, preservatives and advanced glycation/oxidation products. Many ham, salami and deli meats are very high in salt.

This excessive sodium intake is strongly associated with hypertension and cardiovascular disease. Jerky and biltong fall into the category of processed meats.

Like the other processed meats they contain iron, zinc, protein and B12, but they can be high in sodium and some can contain added sugar, flavours and possibly nitrates. Again they are best as an occasional snack. If you choose to consume these look for shorter ingredient lists.

Overall, the guidelines are to limit processed meats in both how often you consume them and your portion size. Aim to eat every now and then and keep to less than 50g per day. The definition of occasional use would be a couple of times per month.

The goal would be to focus on good quality protein such as chicken, fish, eggs, legumes, tofu, tempeh, nuts and dairy as your everyday proteins.

Another tip is to look for nitrite-free or “no added nitrite” products. Choose lean minimally processed meats such as roast beef or roasted turkey or chicken breast over the heavily smoked, flavoured or ultra-processed meats.

Sticking to your portion size is also important — focus on a healthy balanced plate that includes whole grains, legumes, vegetables and fruit as they support gut health.

Limit charring and high-heat cooking as this can add another layer of carcinogens (heterocyclic amines, PAHs), especially on bacon and sausages.

Cured and deli meats are not actually “toxic” foods, but the weight of evidence shows that regular consumption over a long term is associated with higher risks of bowel cancer, cardiovascular disease and type 2 diabetes, particularly when nitrite-preserved, high in salt and when eaten daily. Other factors are also what you are eating deli meats which needs to be considered

These meats can fit very occasionally into an otherwise plant-rich, whole-food pattern, but they definitely are not a staple protein.

The safest, evidence-based approach is to minimise processed meats and focus your diet on including unprocessed protein sources.