Nature vs Nurture: Fat Cats and the Threat of Diabetes
Attention all fur-parents! Do you have an overweight cat? Or a greedy little Burmese? Well this is the article for you. Diabetes is perhaps one of the most common endocrine diseases seen today in modern domestic cats. It’s most prevalent in indoor cats and chubby cats, and has been shown to be over-represented in Burmese cats. In this article we will cover everything you need to know about diabetes and its relation to overweight cats, feline diet, pedigree and breed and environmental risk factors. Important stuff, so do read on!
What is Feline Diabetes
A quick science lesson: The pancreas is an organ that has both an endocrine and exocrine function. The endocrine cells are called Islets of Langerhans and are of most importance as they include is alpha, beta and delta cells. The two most important cells we will focus on are alpha cells, which secrete the hormone glucagon in response to low blood glucose levels. Glucagon stimulates the production blood glucose during times of starvation. The beta cells, on the other hand, secrete insulin in response to high blood glucose levels.
Insulin is a very important hormone when it comes to understanding diabetes. When an animal consumes excessive amounts of carbohydrates, that leads to the production of excess glucose. That can be quite catastrophic to health.
Insulin’s job is to increase the utilization of glucose by allowing the muscles and fat cells to take up as much glucose as possible. Insulin also increases the formation of glycogen stores, decrease the breakdown of protein and decrease the breakdown of fat. Diabetes mellitus means that there are increases in the amount of glucose in the blood. Insulin production can be either decreased or insulin is simply not generating an appropriate response to bringing down blood glucose. Type 1 diabetes is characterized by a decreased production of insulin. Whereas Type 2 diabetes is more commonly occurring as a result of lifestyle factors and results in insulin no longer generating an adequate response to blood glucose levels.
Cats, the Obligate Carnivores
Ongoing genetic research demonstrates that cats are considered obligate carnivores, whereas dogs are more-or-less considered omnivores. A 2014 study did a comparative analysis of a household cat and compared its genome to that of a wild cat in order to understand the evolution of our fur-babies.
As it turns out, there are many factors that prove cats are best suited to a high protein, high-fat diet. To start, they lack an enzyme called Delta-6 desaturase which is responsible for converting linoleic acid to arachidonic acid. This is an essential amino acid as it’s role is to generate immune and inflammatory responses and to aid in reproduction. Now, since our kitties can’t make Arachidonic acid they will have to consume animal fats in order to get it.
But wait, there’s still more proof! Vitamin A plays a significant role by stimulating growth, muscle, and skeletal development. A cat who lacks vitamin A will exhibit clinical signs such as blindness, weakness and may have severe neurological damage.Unfortunately, cats actually can’t make Vitamin A and so the only way they can get it is from animal meat.
What Studies Say...Carbohydrates
Now, last but not the least….Carbohydrates. We know that in our human body, carbohydrates undergo this spectacular biochemical breakdown of glucose. Cats are actually unable to break down carbohydrates efficiently as they lack the enzyme salivary amylase and have very small amounts of intestinal amylase and disaccharidases. It’s not impossible, but it does pose a problem for cats and carbs.
Various studies have shown that cats can actually digest many complex carbohydrates but feeding your feline-fur baby an excess amount of carbohydrates (greater than 25%) can increase their risk of diabetes.
One study showed that feeding a healthy cat a diet that contained 12.9g of carbohydrates per 100 kcal increased blood glucose concentrations. This can be quite an important finding. Burmese cats, for example, genetically have diabetes overexpressed in their genome and are thus 4 times likely to get diabetes; think of this as 10% of newborn Burmese kittens being susceptible to insulin sensitivity.
Remember, carbohydrates aren’t all bad. Every animal's brain relies on glucose for function and energy. But it’s all about moderation and the right type of carbs. Studies showed that cats who consume rice-based diets tend to have a relatively significant increase in blood glucose and insulin.
Let’s look at rice: Rice is a carbohydrate that has a high glycemic index, therefore feeding foods with a high glycemic index can reduce satiety and increase over-eating which can lead to you getting a chubby little kitty. Whereas, it has been speculated that feeding a diet where the main carbohydrate is sorghum or corn, with a low glycemic index may decrease the likelihood of diabetes. Next time you go to feed your kitty some kibble, have a look at what kind of carbs are in their food.
Nature or Nurture: Current Risk Factors
The cause of diabetes from a genetic standpoint is still a little bit of a mystery. As of now, geneticists believe that it is a polygenic disease (controlled by many genes) that can be caused by not only genetics but also the lifestyle. It’s believed that 1 in every 50 cats to 1 in 400 is likely to get diabetes. Well, what are the current known risk factors that predispose our beloved cats to this disease? Many things…
First, our modern day domesticated cat lives mainly indoors, very rarely hunts and thus lives a very sedentary lifestyle. At least over 90% of domesticated cats live of high-carb dry cat food diets that may have a high glycemic index. This can result in them over-eating which predisposes them to obesity. Lack of exercise means that some lazy kitties aren’t allowing their muscle cells to utilize the excess blood glucose. Remember, the wild cats lived of high-protein, high-fat diets and spent most of their time hunting and stalking prey.
Another risk factor has to do with gender. Studies showed that male cats were more likely to have decreased insulin sensitivity and were more likely to gain weight.
Let’s pose the question like this - is the threat of diabetes Nature or Nurture? Well, strong evidence suggests that modern-day cats are more susceptible to diabetes due to domestication and human involvement. Thus, this increased epidemic is sadly a disease, at least in part, nurtured by humans. However, it does not mean that we are fur-parents can’t do something about it!
Interesting fact: Burmese cats from mainly Australia, New Zealand and the United Kingdom tend to be highly susceptible to diabetes. Genetics experts are still not sure what genes control this mutation seen in Burmese cats. There is a LOT more for us to learn around genetics and feline health, and Basepaws wants to be on the frontline of new discoveries.
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