29/02/2024
Today, the front page of The Guardian is about a recent study published by the British Medical Journal (Lane et al., 2024), which discusses the effects of ultra-processed food on human health.
The study shows associations between the consumption of ultra-processed foods and conditions such as heart disease, diabetes, mental health and mortality. The findings indicate that the more exposure you have to these ultra-processed foods, the higher your risk of developing these conditions.
What is an ultra-processed food?
The study describes ultra-processed foods as ready-to-eat products, snacks, fizzy drinks and ready meals.
Is dry and wet pet food ultra-processed?
Yes, and No. Anything that changes a whole food from its natural state is classed as a process. So even raw food has some processing. Processing can include cooking, cold-pressing, pasteurisation, dehydration, or freezing. However, ultra-processed food can also contain additives, preservatives, mould inhibitors, flavourings, and texture changes (thickening agents for example). They may also contain ingredients with poor nutrient profiles, i.e., foods high in fat and sugars or low in fibre.
However, human foods such as buns, sweet or savoury packaged snacks, fatty foods, confectionery, desserts, sodas and sweetened drinks are all in essence, ‘junk foods’ and do not resemble complete dog foods. In addition, it is now relatively easy to find a complete commercial dog food that is low fat, sugar-free with no colourings, and either preserved by sealing in an air-tight container or naturally preserved using tocopherols (vitamin E) or rosemary oil extract. Many pet foods are also complete, so they are very different from eating a chocolate bar. If they are complete and balanced, they contain added vitamins and minerals, something not found in ultra-processed food for humans.
Is there a link between processed dog foods and health problems?
Currently, insufficient research exists to draw any conclusions. While a 2021 study by Hemida et al. suggests potential benefits of raw diets for dogs compared to what the authors referred to as ‘ultra-processed’ dry dog food, limitations of the research include reliance on owner-reported data (which can be unreliable and prone to recall bias), and funding provided by a raw food company. Additionally, the authors were unable to study the nutrient profiles of the foods, which is important as commercially cooked foods can vary significantly in ingredient quality and quantity. Moreover, the study examined ideal body conditions alongside diet adjustments, which suggests a possible link between lean body weight and improvements in canine health rather than solely diet influences.
Is all processing bad?
Not at all. Cooking and other processing methods can help make foods safe to eat. For example, cooking kills bacteria and can improve the taste and digestibility of many ingredients. Oba et al., (2019), showed that lightly steamed chicken is more digestible than raw chicken.
In addition, a study from 2023 (Chen et al.) observing ultra-processed food and diabetes in humans found that cereals, whole-grain bread and some fruit and dairy-based processed foods were associated with a lower risk of type 2 diabetes, potentially because of mediation by fibre, compared with refined bread, sauces, condiments, sugary and sweetened foods that increased the risk.
Should I feed home-prepared whole foods?
Several studies analysing hundreds of recipes (as reported on this page previously) have shown that home-cooked or homemade raw diets for dogs and cats are nearly all deficient in at least one nutrient. A better option for a less processed but nutritionally balanced diet is to feed a complete fresh or gently cooked dog food. Complete foods contain all the correct levels and ratios of vitamins and minerals your dog requires.
I’m unable to feed a complete fresh or raw food diet
As discussed, ultra-processed human foods are not the same as complete pet foods, and there is no research to show that processed pet foods are bad for dogs. In addition, the life expectancy of dogs has increased over the last few years rather than declined (Montoya et al., 2022). However, if you feel guilty about not feeding your pooch on a fresh diet, why not swap in some fresh whole foods a few times a week? You can give a home-cooked meal one or two days a week, or you can add daily amounts of fresh green, bright coloured or root vegetables or fruit to your dog's complete diet.
References in the comments below.
