• People with both gum disease and cavities faced an 86% greater chance of having a stroke compared to those with healthy mouths.
• Poor oral health was also tied to a 36% higher likelihood of heart attacks and other cardiovascular problems.
• Individuals who visited the dentist regularly were 81% less likely to have both gum disease and cavities.
• Researchers say better oral care could be a simple yet often overlooked way to help reduce stroke risk.

Oral Health Problems Tied to Higher Stroke Risk

People who have both cavities and gum disease may be more likely to experience an ischemic stroke, according to research published on October 22, 2025, in Neurology Open Access, the official journal of the American Academy of Neurology. The researchers emphasized that the study shows a link rather than direct cause and effect.

Ischemic strokes occur when a blood clot or blockage restricts oxygen and nutrient flow to the brain. They are the most common form of stroke.

Cavities form when bacteria erode tooth enamel, often due to sugary or starchy foods, inadequate brushing, or genetic factors. Gum disease, also known as periodontal disease, is a chronic inflammation or infection of the gums and the bone that supports the teeth. Left untreated, it can lead to tooth loss.

"We found that people with both cavities and gum disease had almost twice the risk of stroke when compared to people with good oral health, even after controlling for cardiovascular risk factors," said study author Souvik Sen, MD, MS, MPH, of the University of South Carolina in Columbia. "These findings suggest that improving oral health may be an important part of stroke prevention efforts."

Long-Term Study Tracks Thousands Over Two Decades

The study followed 5,986 adults with an average age of 63, none of whom had experienced a stroke at the start. Each participant underwent dental exams to determine whether they had gum disease, cavities, or both. Based on these findings, they were grouped into three categories: healthy mouth, gum disease only, and gum disease with cavities.

Participants were monitored for 20 years through phone interviews and medical record reviews to identify who later suffered a stroke.

Among 1,640 participants with healthy mouths, 4% had a stroke. In comparison, 7% of those with gum disease alone and 10% of those with both gum disease and cavities experienced a stroke.

Stroke and Heart Disease Risk Rise With Poor Oral Health

After accounting for variables such as age, body mass index, and smoking, the researchers found that people with both gum disease and cavities had an 86% greater risk of stroke than those with healthy mouths. Those with gum disease alone had a 44% higher risk.

Looking beyond strokes, the researchers also discovered that people with both gum disease and cavities faced a 36% higher risk of major cardiovascular events, including heart attacks, fatal heart disease, or stroke.

Routine dental visits appeared to make a major difference. Participants who went to the dentist regularly were 81% less likely to have both gum disease and cavities and had 29% lower odds of having gum disease alone.

"This study reinforces the idea that taking care of your teeth and gums isn't just about your smile; it could help protect your brain," said Sen. "People with signs of gum disease or cavities should seek treatment not just to preserve their teeth, but potentially to reduce stroke risk."

Limitations and Future Research

One limitation of the study is that researchers assessed participants' oral health only once, at the beginning of the study. This means changes in dental health over time were not measured. The authors also noted that other, unaccounted-for health or lifestyle factors may have influenced the results.

Still, the findings add to growing evidence that oral health and brain health are more closely connected than once thought.

By exploiting mosquitoes' attraction to flowers, an international team of researchers engineered a new strain of Metarhizium fungus that releases a sweet aroma similar to real blooms. The modified fungus draws in the insects and infects them, ultimately killing them.

The scientists were inspired by natural fungi that emit a pleasant chemical known as longifolene, which they discovered could attract mosquitoes. Building on that idea, they created a fungus that acts like a lethal perfume for the pests, offering a promising tool against malaria, dengue, and other deadly diseases that are becoming increasingly resistant to chemical pesticides. Their findings were published in Nature Microbiology on October 24, 2025.

How the "Perfumed" Fungus Works

"Mosquitoes need flowers because they provide nectar, a crucial source of food for them, and they are drawn to flowers through their scents," explained paper co-author Raymond St. Leger, a Distinguished University Professor of Entomology at the University of Maryland. "After observing that some types of fungi could trick mosquitoes into thinking they were flowers, we realized we could turbo-charge the attraction by engineering fungi to produce more longifolene, a sweet-smelling compound that's already very common in nature. Before this study, longifolene wasn't known to attract mosquitoes. We're letting nature give us a hint to tell us what works against mosquitoes."

According to St. Leger, the floral-scented fungus provides an easy and accessible method for controlling mosquito populations. The spores can simply be placed in containers indoors or outdoors, where they gradually release longifolene over several months. When mosquitoes come into contact with the fungus, they become infected and die within a few days. In laboratory tests, the fungus wiped out 90 to 100% of mosquitoes, even in environments filled with competing scents from people and real flowers. Despite its potency, the fungus is completely harmless to humans.

Safe, Targeted, and Environmentally Friendly

"The fungus is completely harmless to humans as longifolene is already commonly used in perfumes and has a long safety record," St. Leger said. "This makes it much safer than many chemical pesticides. We've also designed the fungus and its containers to target mosquitoes specifically rather than any other insects and longifolene breaks down naturally in the environment."

In addition, unlike chemical alternatives that mosquitoes have gradually become resistant to, this biological approach may be nearly impossible for mosquitoes to outsmart or avoid.

"If mosquitoes evolve to avoid longifolene, that could mean they'll stop responding to flowers," St. Leger explained. "But they need flowers as a food source to survive, so it would be very interesting to see how they could possibly avoid the fungus yet still be attracted to the flowers they need. It'll be very difficult for them to overcome that hurdle, and we have the option of engineering the fungus to produce additional floral odors if they evolve to specifically avoid longifolene."

Affordable and Scalable Global Potential

What also makes this new fungal technology particularly promising is how practical and affordable it is to produce. Other forms of Metarhizium are already commonly cultivated around the world on cheap materials like chicken droppings, rice husks and wheat scraps that are readily available after harvest. The affordability and simplicity of the fungus could be key to reducing mosquito disease-related deaths in many parts of the world, especially in poorer countries in the global south.

Finding effective new weapons against mosquitoes could be more important than ever. St. Leger warns that in the future, mosquito-borne diseases currently limited to tropical regions could threaten new targets, including the United States. With rising global temperatures and the growing unpredictability of weather, disease-carrying mosquitoes have begun to spread to new areas beyond their usual habitats.

"Mosquitoes love many of the ways we are changing our world," St. Leger said. "Right now, we're hoping to use these approaches in Africa, Asia and South America. But one day, we may need them for ourselves."

Next Steps in the Fight Against Mosquito-Borne Disease

St. Leger and his colleagues are now testing the fungus in larger outdoor trials to prepare it for regulatory review.

"It's not as if you're going to necessarily find a silver bullet to control mosquitoes everywhere, but we're trying to develop a very diverse and flexible set of tools that people in different parts of the world can use and choose from," St. Leger said. "Different people will find different approaches work best for their particular situation and the particular mosquitoes they're dealing with. In the end, our goal is to give people as many options as possible to save lives."

Researchers Track a Century of Longevity Data

The study, published in the Proceedings of the National Academy of Sciences, was conducted by Héctor Pifarré i Arolas of the La Follette School of Public Affairs, José Andrade of the Max Planck Institute for Demographic Research, and Carlo Giovanni Camarda of the Institut national d'études démographiques. Drawing from the Human Mortality Database, the researchers examined data from 23 high-income, low-mortality countries using six independent methods to forecast mortality trends.

According to Pifarré i Arolas, "The unprecedented increase in life expectancy we achieved in the first half of the 20^th century appears to be a phenomenon we are unlikely to achieve again in the foreseeable future. In the absence of any major breakthroughs that significantly extend human life, life expectancy would still not match the rapid increases seen in the early 20th century even if adult survival improved twice as fast as we predict."

A Century of Uneven Gains

Between 1900 and 1938, life expectancy in wealthy nations rose by roughly five and a half months per generation. Someone born in 1900 could expect to live an average of 62 years, while a person born in 1938 could expect to reach about 80 years -- a dramatic improvement over just a few decades.

For generations born between 1939 and 2000, however, progress slowed to around two and a half to three and a half months per generation, depending on the statistical model used. Mortality forecasting models -- analytical tools that predict future lifespans using past and present mortality data -- allowed the researchers to project multiple possible futures for human longevity.

"We forecast that those born in 1980 will not live to be 100 on average, and none of the cohorts in our study will reach this milestone. This decline is largely due to the fact that past surges in longevity were driven by remarkable improvements in survival at very young ages," according to corresponding author Andrade.

In the early 20th century, rapid declines in infant mortality -- brought about by medical innovation, improved sanitation, and higher living standards -- significantly boosted average life expectancy. Today, infant and child mortality rates in high-income countries are already extremely low, meaning future gains must come from improved survival at older ages. The study concludes that such advances are unlikely to match the explosive pace of progress achieved a century ago.

Implications for Policy, Healthcare, and Planning

Although forecasts can never be fully certain, the authors emphasize that their results provide essential insights for policymakers preparing for the future. Unexpected developments such as new pandemics, medical breakthroughs, or major societal shifts could alter these trends, but current evidence suggests a long-term slowdown.

This slowdown has consequences that go beyond national statistics. While the study focuses on populations rather than individuals, slower life expectancy growth may influence how people approach saving, retirement, and long-term care. As Pifarré i Arolas and his colleagues suggest, both governments and individuals may need to adjust their expectations and plans for the decades ahead.