Could metformin increase the risk of dementia?

I recently read about a new study out of Taiwan that claims the diabetes drug metformin could increase the risk of developing dementia.

Metformin is a drug used to combat type 2 diabetes drug and it is taken by millions of people around the world. This drug has been proven to be effective in controlling blood sugar. It has been studied thoroughly over several decades and has a long history of safe use.

So, I can only imagine how alarming it must be for type 2 diabetics who are taking metformin, to read about these alarming results. I’m pretty sure no one will willingly take a drug knowing that it can dramatically increase their risk of developing dementia.

And that’s exactly why I decided to read a bit more about this latest study.

I’m not a research expert but I do know how to spot a badly designed study. And I’m afraid to say, this latest metformin study is one of them.

The researchers examined medical records in the National Health Insurance database of Taiwan and divided the participants into two groups. One group included 4,651 type 2 diabetics who received metformin prescriptions. The second control group included 4,651 patients who did not receive prescriptions for the drug.

Then the researchers broke down the metformin users into two additional categories. In one group, they put those who had taken metformin for less than a year. And all the other patients, who took the drug for longer than a year, were lumped together in another group.

That just doesn’t seem like a fair grouping and it certainly won’t make for a fair comparison, especially since metformin is taken over the long-term.

Then there is also the nature of type 2 diabetes itself, which the researchers fail to even acknowledge in their study. Previous studies have linked type 2 diabetes with an increased risk of dementia. In fact, when researchers first looked into dementia and Alzheimer’s they called it type 3 diabetes.

So the risk of potentially developing dementia when you are a type 2 diabetic already exists, with or without taking metformin.

Despite these two major flaws in their study, the researchers still bravely concluded that, over a period of 12 years, higher rates of dementia (and Parkinson’s disease) were seen in the patients given metformin prescriptions.

These results just don’t sit well with me.

Of course, I know that all drugs have side effects and because of that it is always best to work closely with your doctor in order to incorporate lifestyle changes so that you can tackle the disease from all angles. And if you do experience side effects, speak to your doctor to get the full facts.

The only thing that diabetics and their doctors should pay attention to, which is highlighted in this study, is the fact that it appears that metformin depletes the all-important vitamin B12.

Fortunately, this can easily be fixed by either supplementing with a high quality vitamin B12 supplement or by incorporating more B12-rich foods into your diet like beef liver, sardines, mackerel, salmon, eggs and full fat yoghurt.

To a healthier life,

Thomas Smith