Diabetes, Depression and Dementia: lifestyle-related 3D’s

3D movies which were all the rage when I was much younger have made a bit of a comeback in recent times. Wikipedia defines a 3D movie as — “…a motion picture that enhances the illusion of depth perception, hence adding a third dimension”. There is a another definition of 3D that has nothing to do with the movies. I’m talking about the 3D’s of disease: Diabetes, Depression and Dementia — the ‘ 3 ugly sisters’ and stars of a real-life tragedy that is increasingly being played out across the world stage.
Few people realise that most type 2 diabetes goes undiagnosed and untreated. This situation is further compounded when the so-called ‘pre-diabetes’ conditions — high blood sugar levels in a fasting state or after meals — are added to the mix. In 1998, researchers predicted that by 2025, approximately 5.4% of the world’s adults would have type 2 diabetes. They were woefully wrong. The International Diabetes Federation revealed that 8.3% of adults had type 2 diabetes in 2014 — some eleven years before the earlier and much lower predicted prevalence figure of 5.4%. The stark reality is that the prevalence of type 2 diabetes has skyrocketed. And the same can be said for depression and dementia, especially Alzheimer’s disease. As the world-wide prevalence of all three D’s are increasing in tandem, then this might just suggest the existence of a common denominator for all three conditions, even though on the face of it they all present with different symptoms.
In 1988 Dr Gerald Reaven, a professor of medicine and world-renowned researcher, delivered a lecture that forever changed the way in which clinicians and medical scientists view a cluster of diseases that have come to be known as the metabolic syndrome. Dr Reaven suggested that the conditions of the metabolic syndrome, namely, high blood pressure, type 2 diabetes, obesity and certain blood fat abnormalities have a common cause called insulin-resistance, which is an abnormal condition in which the cells of the body do not respond to insulin as they are meant to. Recent research has expanded the definition of the insulin-resistance related conditions to include heart disease, certain cancers, Alzheimer’s and depression.
I recently wrote an article that suggested that we should consider Alzheimer’s to be mainly a disease of young women. Now this may seem counterintuitive because the condition is most often diagnosed in older persons. Research shows that almost two thirds of people diagnosed with the condition are female and although it only presents in later life, it begins to rear its ugly head much earlier on.
A study published recently in the Journal of Endocrinology and Metabolism reveals that people with poorly controlled type 2 diabetes are at greater risk of developing Alzheimer’s than those who do not have diabetes. Similarly, a number of studies have also shown that people with type 2 diabetes are much more likely to be depressed than those who don’t have diabetes.
The prestigious Journal of the American Medical Association said in April 2015, that people with type 2 diabetes have a 20% greater risk of developing dementia, while those with depression have an 83% increased risk. The study also showed that for individuals who are both clinically depressed and have type 2 diabetes the risk of developing Alzheimer’s increases to 117%, and that the increased risk is greater in people under the age of 65.
While there appears to be good evidence of an association or link between the 3D’s of diabetes, depression and dementia, the authors of this important study make the point that further research is needed in order to unequivocally confirm the common thread linking the 3D’s. Is it obesity, given that most people with type 2 diabetes are overweight or obese? Is it the sustained high blood sugar levels associated with type 2 diabetes? Is it insulin resistance, which is the primary metabolic dysfunction that drives both obesity and type 2 diabetes? Or is it a combination of all three risk factors? And then, most importantly, what is to be done to combat the dreaded and growing 3D pandemic?.
If there are biological mechanisms linking type 2 diabetes, depression and dementia — and it most certainly looks as though this is the case — then is makes a lot of sense to focus attention on preventing these dreaded diseases at source. We can institute a ‘preventative strike’ in the war on the 3D’s by bringing our most cost-effective weapon to bear: No, it’s not medication but lifestyle modification that leads to weight loss, improved blood sugar control and the elimination of insulin resistance.
If you are overweight or obese, depressed and have pre-diabetes or type 2 diabetes, then you can’t afford to ignore this offer of help. And even if you are not depressed, and don’t have type 2 diabetes but are overweight or obese, you still may be at risk. I encourage you to take the necessary steps and get yourself on the path to improved metabolic health before it’s too late.
Peter Hill, PhD
