Early Signs of Cognitive Decline Most People Miss

By Dr. Marie Starling | The Healing Center Denver

Functional Medicine Doctor | Root Cause. Root Healing.

Reading time: 7 minutes

Category: Brain Health | Hormones & Metabolism | Gut-Brain

What if “normal” forgetfulness isn’t normal at all?

There is this common discussion that once you reach a certain age it is “normal” to forget things. It’s “normal” to lose your keys. It’s “normal” to walk into a room and completely forget why you walked in there. And while these scenarios are common, it is most certainly not normal.

I know we have all experienced watching loved ones lose their memory. They aren’t who they were before. While they may not have suffered from Alzheimer’s or dementia, they can’t seem to recall the right words. Often people accept that they are going to experience the same symptoms and it has become such a normal piece of life.

But what if it wasn’t?

Imagine being in your 70s and your brain is sharper than a two-edged sword. You remember your children, your grandchildren, and what you went to the grocery store for. You even remember how to get to the grocery store…and back home. It’s achievable. I promise. One step is being able to recognize the signs. I am going to walk you through the most common signs of cognitive decline, why they actually happen, and what you can do about it — so that you can beat memory loss instead of just accepting it.

The Signs We’re Taught to Brush Off

Here’s the problem: most of the signs of early cognitive decline get filed under “getting older” instead of “something my brain is trying to tell me.” That mislabeling is exactly why so many people don’t catch it until it’s harder to reverse. Let’s walk through each one — and what’s actually happening underneath it.

Losing the thread mid-sentence. Not just forgetting a word here and there — everyone does that — but consistently losing your train of thought in conversation, or feeling like the right word is “on the tip of your tongue” far more often than it used to be. Word retrieval is one of the first cognitive functions to falter when the brain isn’t getting steady, stable fuel, or doesn’t have enough “fire fighters” to combat inflammation. It’s less about memory and more about processing speed.

Misplacing things in places that make no sense. Losing your keys is normal. Finding your keys in the freezer, or your phone in the mailbox, is different. This kind of misplacement reflects a breakdown in the brain’s ability to encode the context around an action — you weren’t just forgetful, your brain didn’t fully register what you were doing in the moment.

Struggling with tasks that used to be automatic. Following a recipe you’ve made a hundred times, balancing a checkbook, remembering the steps to a familiar route — when these start requiring real effort, that’s a shift worth paying attention to. Automatic tasks rely on procedural memory, which is typically resilient. When it starts to slip, it’s usually a sign that inflammation or energy metabolism in the brain has already been under strain for a while.

Withdrawing from conversations and social plans. When keeping up with a group conversation or a plot in a show becomes exhausting, many people quietly retreat rather than admit it’s gotten harder. That withdrawal itself is often one of the earliest signs — sometimes appearing years before more obvious memory symptoms.

Mood and personality changes. Increased irritability, apathy, or anxiety that doesn’t match someone’s usual temperament can be a cognitive symptom, not just “getting grumpier with age.” Mood regulation depends heavily on neurotransmitter balance, which is deeply tied to gut health, blood sugar stability, and hormone levels — not just “brain aging.”

Poor judgment in decisions. Uncharacteristic financial decisions, falling for scams more easily, or dressing inappropriately for the weather can point to changes in the brain’s executive function — the part responsible for planning, weighing consequences, and impulse control.

If any of these sound familiar — in yourself or someone you love — take a breath. Recognizing the sign is not a diagnosis. It’s information. And information is what lets you actually do something.

The Gut-Brain Connection Nobody Talks About

Here’s something that surprises most people: your gut and your brain are in constant, direct communication through what’s called the gut-brain axis. Roughly 90% of your body’s serotonin — a neurotransmitter tied to mood, focus, and cognitive clarity — is produced in your gut, not your brain.

When the gut is inflamed, when the microbiome is imbalanced, or when the gut lining has become more permeable than it should be (“leaky gut“), that inflammation doesn’t stay contained. It travels. It reaches the brain through the vagus nerve and the bloodstream, contributing to the very brain fog, word-finding trouble, and mental fatigue we just walked through.

This is why so many people who come to us for “brain fog” leave with a gut health protocol. The brain symptom was real. The gut was the root cause.

Hormones, Blood Sugar, and Your Brain’s Fuel Supply

Your brain is one of the most energy-hungry organs in your body, and it runs almost entirely on glucose. When blood sugar becomes unstable — spiking and crashing throughout the day — your brain experiences that instability as fog, fatigue, and difficulty concentrating.

Over time, chronically elevated blood sugar can lead to a condition where brain cells become resistant to insulin, meaning they can no longer efficiently use glucose for fuel — even when there’s plenty available. This is part of why we talk about Alzheimer’s as “Type 3 Diabetes.” So much of what we call cognitive decline traces back to how well, or how poorly, the brain is able to use insulin and glucose for energy.

Hormones compound this. Estrogen, progesterone, and thyroid hormones all play direct roles in brain function, memory formation, and mood regulation. This is exactly why so many women notice cognitive changes during perimenopause — it isn’t “just hormones,” and it isn’t “just aging.” It’s a fuel and signaling problem that can be identified and addressed.

Your brain is not broken. It is signaling you. And that signal is worth listening to, long before it gets louder.

What You Can Actually Do About It

The good news is that none of this is permanent. Root-cause functional medicine looks upstream of the symptom to find what’s actually driving it, which typically means:

Testing, not guessing. Comprehensive labs that look at blood sugar regulation (not just a basic glucose check), inflammatory markers, hormone panels, and gut health give us a real picture instead of a guess.
Stabilizing blood sugar. Steady, balanced meals with adequate protein and fat reduce the glucose swings that leave your brain running on fumes.
Healing the gut. Addressing dysbiosis, inflammation, and gut lining integrity often produces noticeable cognitive improvements within weeks, not years.
Supporting hormone balance. Whether it’s perimenopause, thyroid dysfunction, or adrenal dysregulation, bringing hormones back into range takes pressure off the brain.
Reducing toxic and inflammatory burden. Environmental toxins, chronic stress, and poor sleep all add to the inflammatory load your brain has to manage.

This isn’t about chasing a diagnosis. It’s about identifying what’s actually driving the symptoms you’re experiencing — and giving your brain what it needs to function the way it’s supposed to.

The Bottom Line

“Normal” and “common” are not the same thing. Forgetting where you put your keys once in a while is normal. A pattern of memory lapses, word-finding trouble, or personality shifts is common — because so many people are walking around with an unaddressed root cause — but it is not something you have to accept as your future.

What if the fog lifted? What if you got your sharpness back? It starts with one conversation. Schedule your consultation and let’s find your root cause together.

You don’t have to do this alone.

Root Cause. Root Healing.