Diabetes Rates Have Been Falling For Over A Decade

If you look at the present pseudoscientific movement that has taken over the United States, you’ll notice a few peculiarities. They seem to particularly appreciate ivermectin, which is a really beneficial treatment when used for some parasite infections, but it is also not a magic cure for all poor health. There’s also a clear thread in all of the MAHA articles that Americans are less healthy than other nations and doing far worse than they used to. This is often ascribed to a range of food additives — the infamous Red Dye 3 — but also to the fact that the US has been becoming overweight for some time.

The trouble is, if you look at the data carefully, it doesn’t actually support this idea. Type 2 diabetes is a wonderful example*. The condition is directly caused by obesity, and you may mainly cure the symptoms by reducing a lot of weight.

The number of persons with diabetes has also been growing in the US for a long time. The CDC projected in 1980 that 5.8 million US citizens had diabetes. The most current 2021 predictions show that this has climbed to a staggering 38.4 million, with the majority of these cases being made up of Type 2 diabetes.

So why do I state that diabetes rates are falling? Well, it has to do with the vagueness of the phrase "rates" and also how these things are computed.

Rates

The first problem we have to consider is the numerous ways that we use the word rates. It’s a rather vague term, and there are various ways to interpret it. There are two crucial concepts that you have to learn at the outset here:

Incidence: the rate of new diagnoses of an illness in a population.

Prevalence: the rate of existing diagnoses of an illness in a community.

Both incidence and prevalence are generally assessed at a moment in time or in a certain time range. With diabetes, the incidence is the percentage of persons who acquire a new diagnosis of the condition during, say, a year. Conversely, the prevalence is the rate most people normally think of first — the percentage of persons in a population who have an illness at a period in time.

If you look at the crude prevalence of diabetes, it has gone from 2.5% in 1980 to roughly 11.3% in 2021. This is, of course, a big growth, even if we don’t incorporate the number of undetected cases of diabetes.

But occurrence is a whole different story. The 1980s CDC study sadly didn’t disclose precise incidence rates, but it did give rough incidence estimates. In 1980, they calculated that 541k persons were newly diagnosed with diabetes. In 2021, the CDC instead predicted that it was 1,211k, thus little over double.

This is still an increase, but it’s not quite as huge. The prevalence of diabetes has grown by more than 4x. If you account for population growth, incidence has only grown by around 0.5x.

This provides us our first substantial insight into diabetes rates. The only way you can have prevalence growing considerably faster than incidence for a chronic condition that is never treated is if individuals are surviving longer after diagnosis. The only way to avoid being counted as part of the prevalence stats after you’re diagnosed with diabetes is to die. So we can state with quite a deal of confidence that a big portion of the rise in diabetes numbers is because the condition is far less deadly than it historically was.

That gets us on to our next rate-related topic – what about age? We know that age is extremely strongly associated with diabetes and that the US population has, on average, aged by nearly a decade since 1980. Since growing older substantially increases your risk of diabetes, it could be in part that the rise in prevalence is attributable to the ageing population rather than other causes.

It is still an increase, but it’s a dramatically lesser one than the simple data we began with. Obviously, it’s not exactly the same time span, but it still illustrates that age is a key influence in the growing diabetes prevalence. For some background, obesity rates throughout this era grew by nearly 50%.

So despite growing obesity numbers, the probability that a person would be diagnosed with diabetes in the US is now the lowest it’s been since the early 90s. The rate is presently 5.9 new diagnoses per 1,000 persons, which is still higher than the rate of 3 per 1,000 from 1983 but fairly low and has been getting better for over a decade.

Complexity

I want to make it clear that this does not imply that fat and diabetes are unconnected. Some component of the rise in incidence of diabetes is definitely driven by the enormous increase in obesity.

We also know that decreasing weight is a highly effective therapy for Type 2 diabetes. Whether you can get patients to drop 10–15% of their body weight, they generally reverse their diabetes indicators, but it’s questioned whether this indicates that the illness is gone or whether the underlying damage produced by diabetes is still a problem.

That being said, there’s a significant misconception regarding the state of diabetes and how this connects to chronic illness. Most of the rise in diabetes incidence since the 80s in the US is likely related to higher age and greater survival. Older persons are more likely to have diabetes, and those with diabetes live substantially longer lives in 2025 than in 1980.

There’s also another element I haven’t touched on much here — advancements in diagnosis — which have had a huge effect on these diabetes rates. Somewhere in the range of 50% of the rise between 1980 and 1999 is probably attributable to changing from onerous glucose tolerance tests, which take hours to conduct and are fairly unpleasant, to much simpler fasting glucose testing. The fasting glucose threshold was also decreased in the late 80s, which likely resulted in millions more Americans being diagnosed with diabetes soon after who would not have been deemed to have the condition in 1980.

Obesity has obviously played a role, but to a large degree the rising number of people with diabetes is a sign of health becoming better. In the 80s there was a tiny handful of medications available to treat Type 2 diabetes – today we’ve got dozens. GLP-1s like Ozempic and Mounjaro not only improve blood sugars; they lessen the risk of heart disease and renal disease long-term. SGLT2is like Invokana offer a similar spectrum of advantages.

None of this disputes the reality that more people acquiring diabetes is a burden on the healthcare system and generally not ideal, but some of the primary reasons for that pressure include people becoming older — i.e., not dying young — and being treated better.

It’s also crucial to note that whether things are getting better or worse in terms of diabetes in the US very much depends on the measures you choose to use. The greatest explanation is that diabetes is complicated and mixed, but if you simply select a single number, you can say practically anything you want. If you compare the crude number of individuals with diabetes between 1980 and 2021, it appears like a horrifying rise – if you instead look at age-adjusted incidence over the previous 20 years, it seems like we’ve practically addressed the diabetes issue already.

The phrases “More people have diabetes in the US than ever before” and “Fewer people are getting diabetes than in the 90s” are both accurate and both deceptive.

The title of this work indicates exactly this difficulty. It’s true that the rate — the incidence rate — of diabetes has been declining in the US for over a decade. If I had merely stated that rate, I may have conveyed the erroneous impression that diabetes isn’t a problem any longer.

It’s not that chronic illness isn’t a concern. It’s because chronic illness is a complicated issue that has numerous causes and no quick treatments.