Red meat has been a part of diets worldwide since early man. It is an excellent source of protein, vitamins (such as B vitamins) and minerals (such as iron and zinc).
However, red meat has long been associated with increasing the risk of heart disease, cancer and early death. What may not be so well known is the link between red meat consumption and type 2 diabetes.
A paper published in the Lancet in September 2024 highlighted this link to type 2 diabetes using data from the Americas, the Mediterranean, Europe, south-east Asia and the Western Pacific (20 countries included).
This recent study, with nearly 2 million participants, found that high consumption of unprocessed red meat, such as beef, lamb and pork, and processed meat, such as bacon, salami and chorizo, increased the incidence of type 2 diabetes.
The researchers also highlighted a link between the consumption of poultry and the incidence of type 2 diabetes, but the link was weaker and varied across the populations.
Type 2 diabetes is a serious public health issue affecting 462 million people globally. It occurs when our bodies don’t make enough insulin or can’t use insulin well.
Insulin is a hormone produced by the pancreas, a small leaf-shaped gland that sits behind the stomach and just in front of the spine. Insulin helps blood glucose enter cells, which stops levels from rising in the blood.
In type 2 diabetes, due to our body not having enough insulin or inability to use the insulin (also referred to as “insulin resistance” or “impaired insulin sensitivity”), blood glucose reaches high levels, causing symptoms such as extreme thirst, increased need to pass urine and feelings of tiredness. Long-term health issues include nerve damage, foot problems and heart disease.
The underlying mechanisms linking red meat intake with type 2 diabetes are unclear. Mechanisms could relate to the function of the pancreas, insulin sensitivity or a combination of the two.
Red meat has high levels of saturated fat and is low in polyunsaturated fats, which could disrupt insulin sensitivity.
Research has also shown that a high protein intake from animal sources (compared to vegetarian sources) can increase the risk of type 2 diabetes, possibly due to the high levels of branched-chain amino acids (BCAA) in animal protein.
BCAA include the amino acids leucine, isoleucine and valine. In a small study, short-term BCAA infusions increased insulin resistance in humans. Similar findings were shown in larger human studies.
High levels of plasma BCAA can have various origins. These connections between red meat, BCAA, insulin resistance and type 2 diabetes are worth exploring further.
Another potential mechanism involves gut microbiota, the collection of microbes in our gut.
Our microbiota metabolises choline (a water-soluble essential nutrient) and L-carnitine (an amino acid found naturally in food), both of which are abundant in red meat, producing trimethylamine. Increased trimethylamine has been associated with a higher risk of developing type 2 diabetes.
How we cook meat may also add to this conundrum. Cooking meat at high temperatures, such as grilling and barbecuing, can produce harmful compounds called “advanced glycation end products”.
These compounds can damage cells due to oxidative stress (caused by unstable atoms called free radicals), lead to inflammation (which can be damaging if it occurs in healthy tissues or lasts too long) and insulin resistance.
Red meat is a great source of iron. But some studies have shown long-term iron intake or iron overload, particularly haem iron (iron from animal-based sources), may increase the risk of type 2 diabetes.
According to a World Health Organization report, in the last 50 years, global consumption of all types of meat has increased. In some wealthy countries, such as the UK, red meat consumption appears to be stable or declining. Although there is a lot of variation in meat consumption between and within countries.
In the UK, people are advised to consume no more than 70g (cooked weight) of red meat per day and to avoid eating processed meat. A similar recommendation is given across many countries.
With the winter holidays around the corner and the festive gatherings in full swing, reducing red meat consumption will be difficult, especially for those who really like the taste. So enjoy these moments without worrying, and where possible, try to consume fibre-rich vegetables with red meat.
Small steps can be taken to reduce your red meat intake by having smaller portions or choosing a day in the week that is meat free (meat-free Mondays, say), or substituting some (or all) of the meat in recipes with chicken, fish, beans, lentils or the like.
And for those days you do eat red meat, try poaching, steaming or stewing it – it’s healthier than grilling or barbecuing.
Gulshanara (Rumy) Begum does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
