Your Body's Hidden Inflammation May Be Quietly Damaging Your Brain—Here's What You Can Control

Chronic inflammation throughout your body—often triggered by excess weight—appears to be a major hidden driver of cognitive decline and dementia risk. A new Canadian study found that roughly two-thirds of people with memory and thinking problems showed elevated inflammation levels, compared to only about one-third of cognitively healthy adults. The good news: many of the factors fueling this inflammation are within your control through everyday lifestyle choices.

What Is Inflammaging and Why Does It Matter for Your Brain?

Most people think of inflammation as the redness and swelling that happens after an injury or infection. But there's another type of inflammation happening silently inside your body right now—one that never fully turns off. Scientists call this "inflammaging," and it becomes increasingly common as you age.

Unlike the inflammation that helps your body fight off a cold, inflammaging is a mild but constant immune response with no clear cause. This persistent activation weakens your body's ability to protect organs and tissues. Over time, inflammatory signals can damage blood vessels and interfere with how brain cells communicate with each other. Even when inflammation starts elsewhere in your body—say, in fat tissue—long-term exposure can still affect how your brain functions.

Researchers at Baycrest's Rotman Research Institute analyzed data from 514 participants in the Comprehensive Assessment of Neurodegeneration and Dementia Study (COMPASS-ND), a national study tracking nearly 1,200 Canadians between ages 50 and 90. The team examined blood markers of inflammation alongside cognitive test results and brain imaging. The pattern was striking: elevated inflammation appeared much more frequently in people with cognitive impairment.

Which Lifestyle Factors Drive Inflammation Most?

The study revealed something important: while age plays a role in inflammation, your daily habits have an even larger impact. Researchers identified specific factors that most strongly influence whether your body stays in a state of chronic inflammation.

• Body Weight: Obesity emerged as the strongest contributor to elevated inflammation. Excess fat tissue actively releases inflammatory signals that keep your immune system activated over long periods, making it the most powerful lifestyle-related factor the researchers measured.
• Cardiovascular Health: Among people living with dementia, vascular conditions linked to blood vessel health showed a strong association with higher inflammation. Poor cardiovascular health can limit blood flow to the brain, increasing stress on brain tissue over time.
• Diet and Sleep Quality: While diet and sleep still mattered in the analysis, body weight remained the most influential factor. However, these two areas still play a meaningful role in managing overall inflammation.

"This study provides new evidence that systemic inflammation, shaped by lifestyle and overall health, may be a key mechanism connecting physical health to long-term brain function," said Dr. Bruna Seixas-Lima, lead author of the study.

Can You Actually Reduce Your Dementia Risk by Managing Inflammation?

Scientists still don't know whether directly treating inflammation can prevent dementia. However, the findings strongly support identifying and addressing inflammation risk earlier in life. The encouraging part: many contributors to inflammation remain modifiable through changes in daily habits.

The research team emphasizes that managing body weight, supporting cardiovascular health, improving sleep quality, and maintaining balanced nutrition may reduce long-term inflammatory stress on your brain. Addressing these factors earlier in adulthood—rather than waiting until memory problems appear—may lower your vulnerability to cognitive decline later.

This perspective reflects a significant shift in dementia research. Scientists increasingly view dementia as part of whole-body aging rather than a condition limited to the brain. Changes in metabolism, heart health, and immune activity all play a role in shaping cognitive health later in life. One strength of the COMPASS-ND study comes from its diversity: participants included individuals with mixed dementia, multiple medical conditions, frailty, and complex diagnoses, reflecting real-world aging rather than idealized clinical samples.

What About Early Detection—Can Technology Help?

While lifestyle changes address inflammation, new technology is also emerging to catch cognitive decline earlier. Researchers at BrainScope, a medical neurotechnology company, published a study in Nature Scientific Reports demonstrating that a non-invasive brain scan called EEG (electroencephalography) can identify individuals at risk of cognitive decline up to seven years before standard diagnosis of mild cognitive impairment or dementia.

In the study, researchers collected baseline EEG recordings from 88 older adults who reported only subjective memory concerns but had no formal diagnosis of cognitive impairment. Over time, some participants progressed to mild cognitive impairment or dementia, while others remained cognitively normal. Using BrainScope's proprietary EEG-based biomarker platform, researchers identified distinct patterns of brain electrical activity at the initial assessment that accurately predicted future cognitive decline with high accuracy.

Early identification is critical because by the time traditional diagnostics such as brain imaging detect Alzheimer's pathology, significant and irreversible neurological damage has often already occurred. Identifying risk earlier aligns with a rapidly evolving therapeutic landscape in which many disease-modifying therapies and prevention-focused clinical trials require patients to be identified years before conventional diagnosis.

The bottom line: your physical health and brain health remain closely linked, and everyday choices may quietly shape how your brain ages across a lifetime. Managing inflammation through weight control, cardiovascular health, quality sleep, and balanced nutrition may be among the most powerful steps you can take to protect your cognitive future.