The ham sandwich, a staple lunch item, is facing renewed scrutiny due to concerns over processed meats and their link to cancer. However, nutritionist Angela Dowden argues that the humble ham sandwich is a "secret nutritional powerhouse" that can be enjoyed as part of a varied diet, provided certain factors are considered.
Concerns about processed red meats like bacon, ham, and sausages stem from the World Health Organization's classification of them as carcinogens. These concerns are linked to preservatives called nitrites, which give cured meats their characteristic pink color. Nitrites can react with compounds in meat to form nitrosamines in the stomach, chemicals associated with digestive cancers. A 2019 study indicated that consuming even one rasher of bacon or slice of ham daily increases the risk of bowel cancer by 20 percent.
Despite these warnings, Dowden asserts that not all processed red meat carries the same risk, and the ham sandwich has been unfairly vilified. Most packaged ham is a good source of protein, offering approximately 8g of protein for less than 50 calories per two average slices. This protein content is higher than an equivalent serving of cheddar cheese and slightly more than one egg, with significantly less saturated fat than cheese. Ham also provides essential vitamin B12 and thiamin, vital for energy conversion. When served on wholemeal bread, a ham sandwich can contribute approximately 7g of fiber, a quarter of the recommended daily intake, which is known to prevent bowel cancer.
The critical difference between ham and other processed meats like bacon lies in preparation and the formation of harmful compounds. High heat, such as that used in frying bacon until crisp, can promote the formation of nitrosamines. Furthermore, frying, grilling, or barbecuing any meat can create other potentially cancer-causing chemicals like heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs). Ham, often boiled or steam-cooked at gentler temperatures (around 70-80°C) and consumed cold, experiences less intense heat, resulting in fewer pre-formed nitrosamines.
The natural composition of pork also plays a role. Pork contains less haem iron than beef, and haem iron can fuel the chemical reactions that create nitrosamines during curing and cooking. This suggests ham may have a lower potential for nitrosamine formation compared to cured beef products. The addition of ascorbate, a form of vitamin C, to brines used in curing ham and bacon also helps mitigate this risk by intercepting nitrites before they can form nitrosamines. Modern food safety regulations have further contributed by enforcing lower nitrite limits since the 1970s and 80s.
To further reduce potential nitrosamine formation, pairing a ham sandwich with foods rich in vitamin C, such as orange juice, red peppers, or a side salad, can be beneficial. These foods help neutralize nitrites in the stomach.
Dowden acknowledges two potential drawbacks of ham: its salt content and the presence of phosphates in some products. A two-slice serving of ham contains about 10 percent of the daily recommended salt limit, though this is comparable to or less than some non-red meat sandwich options. Phosphates, used as moisture retainers, are a concern for individuals with kidney disease and potentially for long-term health in healthy individuals. However, phosphate-free varieties are readily available and often cost the same. For context, regular consumption of diet sodas can introduce higher phosphate levels due to the presence of phosphoric acid.
For those seeking to minimize nitrite intake further, nitrite-free ham options, such as Parma ham or Serrano ham, are available, and many supermarkets now offer nitrite-free versions of standard deli hams. Dowden suggests that while eating a ham sandwich daily may not be ideal, consuming it a couple of times a week, especially on wholemeal bread with a generous portion of salad, is a healthy choice.