Why Smart, Busy Adults Start Losing Their Memory in Their 30s-40s and How to Get it Back
The most common causes of memory problems in midlife and how to fix them.
Welcome to the Beyond The Labs Newsletter, a weekly deep-dive into solving your health mysteries. I help adults in their 30s-40s solve their mysteries such as brain fog, fatigue, and stubborn weight, to reclaim their energy and focus. I’m Dr. Ashori, a board-certified MD. I look Beyond the Labs through virtual Direct Primary Care in California and personalized health coaching for professionals worldwide.
A 38 year old entrepreneur came to see me because her memory was failing.
She ran a successful business, exercised regularly and labs were all “normal.” But she was forgetting conversations, had to reread emails, and would lose words during a meeting.
While she was worried about dementia, it was clear that something in her routine was affecting her cognitive abilities. We eventually pinpointed it to her late-night eating, worsening insulin resistance, and very interrupted sleep patterns.
This isn't a one-off story in my practice. As a health coach, I often see people who experience dramatic improvements after making a few subtle lifestyle changes. That's exactly what happened with this businesswoman - she's now back to her old self.
Memory Problems
Memory problems worry people of every age. Adults in their 30s and 40s often notice distraction, stress, and poor sleep affecting their memory. Adults in their 60s and 70s worry about looming dementia.
This guide is a goldmine for troubleshooting memory issues. It's crucial to distinguish between brain fog and mild cognitive impairment, which is the stepping stone to dementia.
Memory Formation & Recall
Memory is the brain’s ability to encode, store, and retrieve information.
The 3 main stages:
Encoding to take in information.
Storage to safeguard the information over time.
Retrieval to access the information effectively.
If any of these steps fail, you experience a memory problem. For example, you never encoded the information because you were distracted. Or, as in the case of the businesswoman, she stored it poorly because of sleep deprivation and she couldn’t retrieve it because of her high level of stress.
In your 30s and 40s, attention problems are at the source of most memory problems.
Don’t Underestimate Memory
Without good memory your day is so much harder. You’ll have to do double duty to get the same amount of work done. Frustration accumulates, your sleep will be affected, and your stress hormones rise.
Memory allows us to:
Learn and improve skills
Build meaningful relationships
Make important decisions
Maintain independence as we age
Memory is the canary in the coal mine. It is also one of the earliest brain functions affected by poor neurological function.
I repeat this phrase a lot to my clients, “Most memory complaints in midlife are not dementia.”
You don’t have years to wait for “normal” labs to finally catch up to how you feel. Let’s fast-track your cognitive recovery with a personalized plan tailored to your unique biology.
Brain Fog vs Memory Loss
What many label as a memory problem is often an attention problem. If you never properly stored a memory because of inattention, you can’t recall it.
Brain fog is usually a problem with attention and focus. I’ve written about it in the following articles:
The symptoms of brain fog often are:
Difficulty concentrating
Slower thinking
Trouble finding words
Needing to reread things
Feeling mentally exhausted
With brain fog, the brain often never encoded the information clearly in the first place. If information is never encoded, it cannot be remembered later.
Memory loss is different. Here, the person is doing everything right to consolidate the memory but is unable to and therefore can’t recall it.
Symptoms of memory loss are:
Repeating the same stories or questions.
Forgetting recent conversations completely.
Getting lost in familiar places.
Difficulty managing medications or finances.
This type of memory problem may be associated with conditions such as mild cognitive impairment or dementia. The reassuring reality is that most memory complaints in adults in their 30s and 40s are brain fog, not neurodegeneration.
It’s never too late to catch early symptoms of dementia. I’ve written about strong evidence on it here:
Current Evidence on Improving Memory
Large reviews from groups such as the Lancet Commission on Dementia Prevention (2020) and recent WHO consensus statements consistently highlight the same modifiable factors.
Evidence‑supported habits that protect memory include:
Improving neurovascular circulation.
Improving quality of slow-wave sleep.
Addressing sensorineural deficits early.
Addressing any cardiometabolic disease.
Improving cognitive skills.
Increasing social engagement.
Limiting neurotoxic substances.
These factors influence both day‑to‑day memory performance and long‑term dementia risk.
6 Reversible Causes of Memory Problems
1. Multitasking Overload
Modern work and lifestyles are an assault on the senses. Attention is like cooking, you can’t shortcut it, or else information never gets encoded into memory.
Classic inattention is forgetting what you just read, walking into rooms and forgetting why, or re‑reading the same email several times.
What you can do to improve focus and attention:
Single‑task whenever possible. This trains your focus and memory.
Turn off notifications.
Write things down to address later.
2. REM Sleep Disruption
Memory consolidation happens during sleep, especially REM sleep. This happens later in the night, so if you get up early or have too much noise in the house you’ll miss out on it.
REM problems show up as forgetting conversations, trouble recalling recent information, brain fog, decreased creativity, slow thinking, and irritability.
Protect your sleep architecture:
Aim for a consistent sleep schedule and protect the last 90 minutes of your sleep.
Reduce or avoid alcohol, especially close to bedtime.
Screen for sleep apnea.
Look for potential REM disruptor medications.
3. Chronic Stress
The hippocampus is at the core of memory formation and recall. If it’s overloaded with cortisol, it can’t do its job.
Common symptoms are losing words mid sentence, forgetting familiar names, and inability to stay concentrated.
In my TREND framework I talk about D, which stands for downtime. You need a break from thinking and stress the same way you need a break from exercise. And what better break than exercising! Another great tool is breathing exercises.
4. Too Many Stimulants
Caffeine, sugar, supplements and some medication can improve alertness but worsen memory if you’re already overloaded.
This might show up as racing thoughts, feeling jittery or overly stimulated, trouble focusing on a task long enough to get anything done, and feeling wired later in the evening.
5. Alcohol
It might have been okay in your 20s and 30s but now in your 40s or 70s - not so much. But it’s always worth testing because you might not be affected by alcohol at all.
We know that alcohol suppresses glutamate, a neurotransmitter involved in memory. We just don’t know how sensitive each person is to fluctuating glutamate levels.
I love a good IPA but I have to deal with 2 days of bad sleep, anxiety, and terrible exercise recovery. Maybe it’s my Middle Eastern genes or just age.
6. Medical Problems
Several medical conditions impair memory. They require closer management to improve memory.
Examples include sleep apnea, thyroid disorders, hormone decline, vitamin deficiencies (rare), mood disorder like depression, and side effects from medications like beta blockers, benzodiazepines, and even certain antidepressants.
Disclaimer:
Dr. Mohammad Ashori is a U.S.-trained family medicine physician turned health coach. The content shared here is for education and general guidance only. It is not personal medical advice, diagnosis, or treatment, and it does not create a doctor–patient relationship. Humans are complicated and context matters. Always talk with your own healthcare team before making medical decisions, changing medications, or ignoring symptoms. This information is to help you add more depth to those conversations.
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