The 5 Simple Things I'm Doing Today to Stay Mentally Sharp After 40

I spent most of my thirties feeling like my brain was wrapped in cotton wool. I'd walk into rooms and forget why I was there, struggle to find words mid-conversation, and feel like I was thinking through treacle most days. When I mentioned the constant tiredness and brain fog to my GP, I got the usual blood tests and the predictable "everything's normal" response. I was basically dismissed.

Since then I've learned that your brain doesn't have to decline with age. The everyday choices you make today can be the difference between staying razor-sharp at 70 or struggling to remember your grandchildren's names.

At 45, my brain feels clearer and more focused than it did in my twenties. Strategies like keto and targeted supplements have helped, but I've also learned if you're falling back on the basics, you're going two steps forward, one step back.

Today, I'm sharing the five simple things I'm doing right now to stay mentally sharp after 40. Because the best time to protect your brain was 10 years ago. The second best time is now.

1. I'm Finally Booking That Hygienist Appointment I Keep Putting Off

The brain-mouth connection is real, and it's more important than you think.

I used to think dental health was just about having nice teeth. But we now know there’s far more to it than that. The bacteria in your mouth doesn't stay in your mouth. Poor oral health creates chronic inflammation that can travel straight to your brain, contributing to cognitive decline and increasing dementia risk.

Studies show that people with gum disease have an increased risk of developing Alzheimer's and increased rate of cognitive decline. The bacteria P. gingivalis, commonly found in gum disease, has been discovered in higher concentrations in the in the brains of Alzheimer's patients suggesting it may contribute to worsening symtpoms. (1)

What I'm doing today:

• Booking my 6-monthly hygienist appointment (yes, even though I've been putting it off for weeks)

• Switching to a toothpaste with natural antibacterial ingredients

• Stopping being slack with flossing at the end of the day.

The hygienist appointment feels like a small thing, but it's actually a seriously brain-protective step. Plus, there's something about having to get your gnashers judged by a professional that gives you the kick up the bum to take care of them.

2. Keeping Screens Out of My Bedroom (Finally!)

Your sleep quality tonight determines your brain function tomorrow.

I'll be honest, I was terrible at this for years. Phone on the bedside table, laptop in bed for "just five minutes" of work, falling asleep to Netflix. A classic recipe for rubbish sleep and a foggy brain the next day.

But here's what I know now: the blue light from screens doesn't just keep you awake (2), it actively disrupts the brain's natural detox process that happens during deep sleep (3). Your brain literally cleans itself at night, washing away the metabolic waste that builds up during the day. When you mess with that process, you're essentially letting toxins accumulate in your brain tissue.

This isn’t just an issue that night. The effects of blue light on your sleep one evening still plays out in your sleep patterns for a couple of nights after.

What I'm doing today:

• Moving my phone charger to the kitchen (so I'm not tempted to grab it "just for a second")

• Investing in an actual alarm clock (revolutionary, I know!)

• Going old school and reading an actual book with pages using a red light night light like this one.

The first few nights will feel weird, like something's missing. But within a week, you'll notice you're falling asleep faster and waking up more refreshed. Not only will your brain will thank you for the uninterrupted cleaning cycle, but those that live with you will love your improved mood.

3. Treating Myself to Plastic-Free Food Storage

Every time you reduce toxic load, you're taking pressure off your brain.

This might sound unconnected, but bear with me. Those plastic containers you're using to store leftovers? They're leaching chemicals directly into your food, especially when you microwave them or store anything warm.

Phthalates and BPA from plastic containers act as endocrine disruptors, interfering with hormone function and creating inflammation in the brain. They're also neurotoxins, meaning they directly damage brain cells over time. (4)

What I'm doing today:

• Replacing my old plastic containers with glass ones (Pyrex is brilliant for this)

• Investing in some stainless steel containers for packed lunches

• Never, ever microwaving food in plastic again

Reducing your toxic load where you easily can results in less inflammation and better brain protection over time.

4. Pampering Myself with a Toxin-Free Facial

Your skin is your largest organ, and what goes on it goes into your bloodstream.

I used to slather my face with products full of parabens, sulfates, and synthetic fragrances without thinking twice. But when you realise that your skincare routine could be contributing to the toxic load affecting your brain, it makes you look at that bathroom cabinet very differently.

Many conventional skincare products contain neurotoxins and hormone disruptors that cross the blood-brain barrier, so your evening skincare routine being absorbed by your skin, could be delivering a cocktail of brain-harmful chemicals directly into your system. (5)

What I'm doing today:

• Treating myself to some gorgeous products from brands like Husk & Seed Skincare that only use clean ingredients

• Making a DIY honey and oatmeal face mask (honey is naturally antibacterial and incredibly soothing)

• Checking the ingredients in my current products using an app like Think Dirty

This isn't about spending a fortune on fancy products. Some of the best brain-protective skincare is the simplest - pure oils, natural ingredients, fewer chemicals overall.

5. Swapping My Evening Wine for Herbal Tea

Alcohol and brain health don't mix.

This one hits close to home because I used to be that person who "needed" a glass (or two) of wine to unwind after a stressful day. It felt like such a perfect way to switch off and relax.

But alcohol is neurotoxic. Even moderate amounts disrupt sleep quality, increase inflammation, and interfere with the brain's ability to form new memories and clear out metabolic waste (6). After 40, your liver processes alcohol less efficiently, meaning the toxic effects linger longer and hit your brain harder. I know you’ll be aware of that what with your worsening hangovers.

What I'm doing today:

• Stocking up on calming herbal teas like valerian, chamomile, and passionflower

• Trying adaptogenic drinks like absolutely delicious Mother Root that actually support brain function

• Creating a new evening ritual around preparing and mindfully drinking my herbal tea

The first week is the hardest - you really notice how much you relied on that glass of wine to signal "relaxation time." But the voice in your head announcing “wine o’clock” does quieten before too long, and once you've broken the habit, you'll sleep better, think clearer, and wake up feeling actually refreshed instead of slightly foggy.

The Truth About Brain Health After 40

I wish someone had told me in my thirties that brain decline isn't an inevitable part of ageing (though I'm not sure how much I would have listened!) . The forgetfulness, the word-finding difficulties, the mental fatigue - they're not just "getting older." They can be signs of inflammation, toxicity, poor sleep, and lifestyle factors that are completely within your control.

You don't always need expensive supplements or complicated protocols and diets, though sometimes they are a helpful addition. You do need to remove the things that are actively harming your brain and introduce simple habits that support its natural function.

The science shows:

• Chronic inflammation contributes to cognitive decline

• Sleep quality directly impacts brain detoxification

• Toxic load from everyday products accumulates over time

• Small, consistent changes create compound benefits

Start Where You Are

I'm not suggesting you overhaul your entire life today, though this list is simple enough to get on with. A great start would be to just pick one thing from this list, starting with the one that feels most manageable or most urgent for you at this moment.

Maybe it's finally booking that dental appointment you've been avoiding (I'm terrible at making time for this sort of life admin, but it feels so good when it finally gets done!). Maybe it's moving your screens out of the bedroom tonight. Either way, it is an investment in staying yourself for decades to come - sharp, present, and independent.

Because watching a family member lose herself to cognitive decline taught me that your brain health isn't just affect you. It's about staying connected to the people you love, being the grandmother who remembers stories and can enjoy special moments, the friend who can hold meaningful conversations, the person who remains fully yourself until the very end.

That's worth a few simple changes, don't you think?

FYI - The links in this blog post are not affiliate links. They are here to be useful suggestions of products I love.

Frequently Asked Questions

Q: Do I need to make all these changes at once? 

A: Absolutely not! Start with one change and give yourself 2-3 weeks to establish it as a habit before adding another. Sustainable change happens gradually. It has taken me years to get my diet and lifestyle to where it is now, but I'm really grateful I put in the effort.

Q: How quickly will I notice improvements in my brain function? 

A: Some changes like better sleep can improve focus within days. Others, like reducing toxic load, create slow and sometimes subtle benefits. The key is consistency.

Q: Are expensive brain supplements necessary? 

A: Not at all, but some can be useful (that's for another blog post!). These lifestyle changes are a start in addressing some root causes of cognitive decline - inflammation, poor sleep, and toxicity (7). Focus on removing what's harming your brain before adding supplements.

Q: What if I can't afford to replace all my skincare and storage containers? 

A: Replace items gradually as they run out. Many effective swaps cost the same or less than what you're currently using, and the internet has loads of toxin free recipes for homemade personal and house products.

Q: Is moderate alcohol consumption really that harmful to the brain? 

A: Yes. There's no point trying to sugar coat this. Research shows no amount of alcohol is beneficial for brain health. Even moderate consumption increases inflammation and disrupts sleep quality. The good news is that your brain starts recovering as soon as you reduce alcohol intake.

Booking a dental appointment, putting your phone in another room, swapping a few containers - I appreciate this isn't ground-breaking advice. But that's exactly the point. Brain health doesn't have to be complicated or expensive. It's the result of small, everyday choices like these that add up over time. The dental appointment I book today, the alcohol I avoid tonight, the glass container I use for tomorrow's leftovers are all investments in staying myself for decades to come. And quite frankly, that's worth a bit of effort, don't you think?

Do You Want To Keep Reading?

This blog post might interest you:

The Real Reason Your Brain Feels Foggy (Despite Your Healthy Lifestyle)

References

1. Beydoun, M., Beydoun, H., Hossain, S., El-Hajj, Z., Weiss, J., & Zonderman, A. Clinical and Bacterial Markers of Periodontitis and Their Association with Incident All-Cause and Alzheimer’s Disease Dementia in a Large National Survey. Journal of Alzheimer's Disease. 2020; 75. https://doi.org/10.3233/JAD-200064.

2. Grzelak, A. Managing Blue Light Exposure: Impacts on Sleep Quality and Circadian Health. Quality in Sport. 2024 https://doi.org/10.12775/qs.2024.25.56741.

3. Ibrahim, A., Högl, B., & Stefani, A. Sleep as the Foundation of Brain Health. Seminars in Neurology. 2025 https://doi.org/10.1055/a-2566-4073.

4. Costa, H., & Cairrão, E. Effect of bisphenol A on the neurological system: a review update. Archives of Toxicology. 2023; 98. https://doi.org/10.1007/s00204-023-03614-0.

5. Alnuqaydan, A. The dark side of beauty: an in-depth analysis of the health hazards and toxicological impact of synthetic cosmetics and personal care products. Frontiers in Public Health. 2024; 12. https://doi.org/10.3389/fpubh.2024.1439027.

6. Topiwala, A., Ebmeier, K., Maullin-Sapey, T., & Nichols, T. No safe level of alcohol consumption for brain health: observational cohort study of 25,378 UK Biobank participants. . 2021 https://doi.org/10.1101/2021.05.10.21256931.

7. Dominguez, L., Veronese, N., Vernuccio, L., Catanese, G., Inzerillo, F., Salemi, G., & Barbagallo, M. Nutrition, Physical Activity, and Other Lifestyle Factors in the Prevention of Cognitive Decline and Dementia. Nutrients. 2021; 13. https://doi.org/10.3390/nu13114080.