Dementia haunts the United States. There’s no one without a personal story about how dementia has touched someone they care for. But beyond personal stories, the broader narrative is staggering: By 2050, we are on track to have almost 15 million Alzheimer’s patients in the US alone. That’s roughly the population of NYC, Los Angeles, and Chicago combined. Now add a few more cities to take care of them.

It’s an epidemic that’s already underway—but we don’t recognize it as such. The popular conception of Alzheimer’s is as an inevitable outcome of aging, bad genes, or both.

The popular conception of Alzheimer’s disease is as an inevitable outcome of aging or bad genes.

From a scientist’s perspective, it’s important to remind everyone that we all once believed the same thing about cancer. But just a few days ago, doctors around the world have been considerably shaken up by the breaking news linking cancer to processed foods. In a large-scale study, researchers found that a 10% increase in consumption of ultra-processed foods led to a 12% increase in overall cancer events.

At the Alzheimer’s Prevention Clinic at Weill Cornell Medical, this latest cancer research had our full attention. The findings line up so closely with research in the field, including our own work, linking diet and risk of Alzheimer’s—and underscore how important lifestyle changes can be to delaying or even avoiding the onset of the disease.

In an age of inexpensive personal genomics, there’s a general and persistent sense that as with cancer, Alzheimer’s is an essentially genetic outcome. But in reality, less than 1% of the population develops the disease due to genetic mutations in their DNA. To be clear, the vast majority of Alzheimer’s patients is simply not born of those mutations.

The consensus among scientists is that over one third of all Alzheimer’s cases could be prevented by improving our lifestyle.

For Alzheimer’s, as with cancer—but also as with other conditions like heart disease and diabetes—much of the risk is related to behavioral and lifestyle factors. The consensus among scientists is that over one third of all Alzheimer’s cases could be prevented by improving our lifestyle. This includes ameliorating cardiovascular fitness, keeping our brains intellectually stimulated, and perhaps most of all: eating better.

“Eating better” means addressing the American ultra-processed diet. Ultra-processed is a technical term, and exists in a spectrum of food processing. An apple straight from the tree is wholly unprocessed. Dry the apple, and store it away with common preservatives like sulphur dioxide, and it becomes a processed food.

Ultra-processed foods by some measures account for half of the American diet.

But ultra-processed foods are the extreme in the scale, and by some measures account for half of the American diet. These include mass produced, packaged foods, as well as foods containing manufactured substances like hydrogenated oils (aka trans-fats), modified starches, and protein isolates. In plain English, this means commercial breads and buns; packaged snacks; industrialized confectionery and desserts; sodas and sweetened drinks; meat products like cold cuts and chicken nuggets; instant noodles and soups; frozen or shelf stable ready meals; margarine, processed cheese, and most creamers.

These are the foods whose consumption triggered an increase in cancer cases in the BMJ study. And these are the foods whose consumption increases your risk of cognitive decline and dementia too. While some argue that “organic” processed food may be less harmful than non-organic processed food, it is still processed food and as such, should be minimized.

In epidemiological studies, people who consumed as little as two grams a day of trans-fats had twice the risk of those who ate less than two grams. Alarmingly, most people in those studies ate at least two grams a day, with the majority of participants eating more than double that dose on a regular basis.

The implications are clear. If, as a nation, we have become aware of the role of nutrition relative to cancer, it’s urgent that we develop a corollary awareness of the role of nutrition and Alzheimer’s. It’s terrifying news because of the numbers we see ahead. But it’s very good news, in terms of our individual and collective abilities to reduce those numbers drastically.

Alzheimer’s doesn’t simply “turn on” when we’re old; it begins decades earlier with changes to the brain.

Collectively, the ways we address a disease has always been shaped by what we understand it to be. So it’s important to realize that Alzheimer’s doesn’t simply “turn on” when we’re old; it begins decades earlier with changes to the brain. In other words, the Alzheimer’s population of 2050 will either start to develop, or not, right around now. As a nation, if a meteor was going to hit 15 million people in 32 years, we’d set aside our resources and brainpower to stop it. We must therefore bring the national attention not only to the treatments and vaccines that may someday arrive (or not) but to the urgent interest in upgrading the American diet.

We have acted on behalf of collective nutrition-related outcomes before, by demanding mandatory labeling for trans-fat in 2003. We must take similar action at scale, and immediately. At the same time, each and every one of us would do well to act in our own interests (which are, after all, aligned) and take steps to modify our diet for a youthful, healthy, resilient brain.

My hopes are to be able to one day affect what happens in Washington, but also to affect what happens in your kitchen. The road to an Alzheimer’s epidemic is real, but there is no reason that it needs to be the only way forward.