That Fourth of July hot dog may be raising your risk of dementia

As you consider loading your plate with the foods you have come to expect at a Fourth of July cookout, you might want to think twice before grabbing a hot dog or two.

Regularly eating highly processed foods – especially highly processed meats, including hot dogs and bacon – greatly increases your chance of developing dementia and harming your thinking abilities, according to a June 10, 2026 article from Harvard’s T.H. Chan School of Public Health. 

Ultra-processed foods contribute to dementia by changing the gut microbiome – the healthy bacteria and other microorganisms in your intestines – which results in systemic neuroinflammation, said Miguel A. Prieto, MD, an internist at Bourne Primary Care at Bourne Health Center, who was not involved in the study.

“Public health messaging has long been (advising) 'everything in moderation.' But the researchers behind this data are warning us that when it comes to the neurological impacts of ultra-processed foods, there may simply be no safe level of consumption,” he said. “Even moderate intake of these foods can trigger measurable drops in attention span and processing speed.”

The best thing you can do is stop eating these foods, he stressed. “Your body has an amazing ability to regenerate itself.”

58 Percent Higher Risk of Dementia

According to the Harvard study, compared with participants who consumed the least ultra-processed foods, those who ate the most had:

• 58 percent higher risk of dementia.
• 46 percent higher risk of cognitive impairment without dementia.

The study was led by researchers from the Harvard school and published in the July 2026 issue of the American Journal of Public Health. The study included 5,300 adults over 50. Participants had biennial cognitive assessments from 2014-2020.

The researchers wrote that poor overall diet may be partly responsible for the associations with dementia and cognitive impairment. 

Ultra-processed foods contain large amounts of sugar, salt, saturated fats and little dietary fiber, and have been associated with diabetes, obesity, cardiovascular disease and a higher chance of death, the researchers wrote. According to the U.S. Food and Drug Administration, about 70 percent of the nation’s food supply is considered ultra processed, so they can be difficult to avoid.

When deciding whether to eat these foods, Dr. Prieto said people might reflect on the possibility of “admission to a nursing home in the future,” due to cognitive issues from eating ultra-processed meats.

What to Do?

Because ultra-processed foods (UPFs) are everywhere, Dr. Prieto believes we should shift from blaming individuals for eating them to government recognitions of them as a public health threat, much like how tobacco is treated.

“When 60 to 70 percent of the average American diet consists of ultra-processed foods, it is no longer a personal choice problem; it is an environment problem. We must incentivize access to whole foods—which actually reduce dementia risk by 41 percent—and aggressively regulate the marketing of corporate UPFs,” he said.

As an example of the unhealthy, but common nature of these foods, Dr. Prieto described a child’s bag lunch of a ham and cheese sandwich:

“Ham and cheese sandwiches have been shown to be as harmful as smoking, and we would not send our children to school with cigarettes,” he said.

Dr. Prieto recommends following the Mediterranean diet, which emphasizes fruits, vegetables, whole grains, beans and nuts. He also recommends avoiding or eliminating meat, fish, eggs and dairy products, along with using olive oil instead of butter or highly processed oils high in saturated fat.

As for that Fourth of July cookout, hamburgers do not carry the same risk as hotdogs, he noted. “Not that I recommend burgers, but they don’t increase the risk of dementia. Better to just eat a plant-based Fourth of July meal,” he said.