14 supposedly harmless everyday habits that your
Ruining your brain – and what you can do about it

Based on his more than 225,000 brain SPECT scans, US psychiatrist Dr. Amen has identified, among others, the following 14 seemingly harmless everyday habits that he believes can cause long-term brain damage.

21.05.2025, by URVI

Important NOTE

This article is for informational purposes only and does not replace professional medical advice. You should always discuss major lifestyle changes with a qualified medical professional first.

Why we are talking about Dr. Daniel Amen

US psychiatrist Dr. Daniel G. Amen, known from the Kardashians' circle, claims to have performed and analyzed over 225,000 brain SPECT scans (single-photon emission computed tomography) in his clinics. Using the data obtained, he claims to have identified everyday behavioral patterns that, in his experience, can impair mental health¹.

According to his clinic's website, SPECT imaging is intended to help better detect and target mental disorders². But this is precisely where the criticism begins: The American Psychiatric Association sees no sufficient scientific basis for using SPECT scans in the regular diagnosis of mental illnesses³. The German S3 guideline on dementia also recommends nuclear medicine procedures only in justified exceptional cases⁴.

Despite these objections, the discussion about Amen's theses can provide an important impetus to critically question one's own lifestyle - even without high-tech imaging.

What you can expect:

We examine Dr. Amen's theories, evaluate them based on independent studies, and present the preventative measures he personally recommends. In addition, we offer scientifically sound findings and practical tips that can be easily implemented in everyday life.

14 habits that strain your brain – and what you can do instead

1. Scroll on your smartphone

Dr. Daniel G. Amen warns that excessive scrolling floods the brain with dopamine—a neurotransmitter for drive and reward—and wears the cerebral cortex "like fine china."¹ A Stanford study found that spending more than seven hours online per day is associated with a measurable thinning of this brain region⁵—responsible for planning, concentration, and impulse control. Meta-analyses, rather than permanent damage, suggest functional dopamine desensitization³: The brain becomes numb to stimuli.

Recommendation: Take an offline phase 60 minutes before going to bed, deactivate push notifications, and set the display to grayscale after 9 p.m.

2. Drink alcohol

Even one "pleasure glass" a day can be risky: A Mendelian randomization study with over 20,000 participants found that just eight alcoholic drinks per week were associated with a measurable reduction in gray and white matter in the brain.⁶ The World Health Organization (WHO) now warns against considering red wine as a "heart-protective medicine." No amount of alcohol can be considered safe. Red wine as a preventative measure for cardiovascular disease is dangerous.⁷

Recommendation: Dr. Amen recommends an eight-week abstinence: In his practice, many patients' blood circulation, sleep, and mood noticeably improved afterward.

3. Drinking too much coffee

Up to three large cups of filter coffee per day—about 300 mg of caffeine—are considered safe. The European Food Safety Authority (EFSA) considers up to 400 mg daily safe for healthy adults; pregnant women should consume a maximum of 200 mg.⁸

Recommendation: Dr. Daniel G. Amen recommends switching to green or rooibos tea instead of coffee. These contain L-theanine – an amino acid that moderates the body's stress response and cushions the "nerve spike" caused by caffeine. He recommends a daily supplement of 150–200 mg of L-theanine. Initial studies show that L-theanine reduces stress and increases alertness.⁹

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4. Use products with plasticizers

Plasticizers in plastics, mold, and benzene fumes can negatively impact brain development. Early childhood exposure to plasticizers correlates with poorer performance in memory and language tests. Slower reaction times and cerebral cortex thinning have been observed in adults.¹⁰

Recommendation:

1. Glass / stainless steel instead of plastic

2. No heat + fat in disposable boxes

3. Ventilate daily

4. Activated carbon/osmosis filter for water

5. Spray-/fragrance-free cleaning

5. Eating sugary foods

Just one week of the so-called Western diet—high in saturated fats and simple sugars—can impair memory. In a randomized study, healthy adults showed significant impairment in memory tests after seven days of this diet.¹¹ Chronically elevated insulin levels, often a result of excessive sugar consumption, can inhibit neurogenesis in the hippocampus. This impairs the formation of new nerve cells and can reduce cognitive flexibility in the long term.¹²


Recommendation: Halve added sugar and consistently replace soft drinks with water or unsweetened tea.

6. Being an asshole

Chronically elevated cortisol levels alter the architecture of the hippocampus, reduce the formation of new nerve cells (neurogenesis), and make the amygdala—the fear center—oversensitive. This has been shown by both human and animal studies.¹²

Recommendations: Dr. Daniel G. Amen lives the "no asshole rule" in his clinics: Avoid toxic relationships, identify stressors, and counteract them with mindfulness, cognitive behavioral therapy (CBT), or a gratitude journal. He also recommends L-theanine as a "stress reliever that simultaneously improves focus and sleep quality." Recommended dosage: 100–200 mg daily.

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7. Don't floss

Inflamed gums can release bacteria and cytokines into the blood, promoting systemic inflammation. A meta-analysis of 14 longitudinal studies involving over 34,000 adults shows that each lost tooth increases the risk of cognitive impairment by 1.4% and a diagnosis of dementia by 1.1%.¹³

Recommendation: Dr. Daniel G. Amen calls flossing "the world's most affordable neuro-upgrade." He recommends daily interdental care—with floss or interdental brushes—as well as semi-annual professional dental cleanings. These measures can help reduce inflammation and thus lower the risk of dementia.

8. Eat fried foods

A meta-analysis links high trans fat levels to faster cognitive decline, while higher levels of monounsaturated fatty acids have a protective effect.¹⁴

The World Health Organization (WHO) aims to ban industrially produced trans fats worldwide by 2027.¹⁵

Recommendation: Dr. Daniel G. Amen recommends replacing frying oil with virgin olive or rapeseed oil. These contain valuable monounsaturated fatty acids that can promote brain health.

9. Not moving enough

In a randomized controlled trial, a six-month aerobic exercise program significantly increased hippocampal volume in older women with mild cognitive impairment. This increase is biologically comparable to a two-year brain rejuvenation.¹⁶

Recommendation: For those short on time, Dr. Daniel G. Amen recommends three ten-minute power walks per day. It's important that your heart rate increases noticeably – almost as if you were running late. These short, intense sessions can already have positive effects on brain health.

10. Smoking & vaping

Data from the UK Biobank show that regular smoking causes the brain to age prematurely by an average of two to three years – even when genetic risk factors are taken into account.

Just 24 hours of quitting smoking measurably improves oxygen transport; after one year, the risk of stroke is reduced by almost half.¹⁷

Recommendation: A concrete plan with a set quit date increases the chances of success. Dr. Amen recommends preparing for that day and planning supportive measures.

11. Failure to examine head injuries

Even mild traumatic brain injuries (mTBI) can leave long-term deficits in attention and executive functions. A meta-analysis shows that individuals with complicated mTBI (with abnormal imaging findings) exhibit significant impairments in processing speed, memory, executive functions, and language even after three months.¹⁸

Recommendation: Dr. Amen calls for mandatory helmet use for high-risk sports, technical training, and head-free workouts to reduce cumulative damage.

12. Not getting enough sleep

Less than seven hours of sleep per night halves the efficiency of the glymphatic system—the brain's "garbage disposal" system that removes metabolic waste during deep sleep. MRI data show that short sleepers are more likely to have white matter lesions—an indicator of cognitive impairment.¹⁹

Recommendations:
Improve sleep hygiene: Keep a cool, dark bedroom, set bedtimes, avoid alcohol or sugar, and avoid screen time for at least one hour. Supplement L-theanine: Dr. Amen recommends 100–200 mg daily. The amino acid from green tea has a calming effect, improves focus and sleep quality—without causing drowsiness.

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13. Being lonely

Prolonged solitude is as harmful to the body as high blood pressure. A meta-analysis of 23 studies involving over 180,000 adults shows that people with poor social relationships have a 32% higher risk of stroke than those with good relationships.²⁰


Recommendation: Daily meaningful community through volunteering, team sports, or study groups. Real conversations, either in person or at least on the phone, not just via chat. Regular daily meetings help reduce stress hormones and keep the brain and blood vessels healthy.

14. Smoking cannabis

Although medical cannabis is gaining popularity, an analysis of 982 regular users at Amen Clinics showed reduced blood flow to almost all brain areas, especially the hippocampus.²¹

Independent fMRI data support mild working memory impairment with long-term use.²²

Recommendation:
Dr. Amen recommends a four-week abstinence trial, combined with endurance exercise or cold showers as natural dopamine kicks.

Sources

1. Amen DG Memory Rescue. Tyndale; 2017.

2. Amen Clinics. "Why Brain SPECT Imaging?" Accessed May 20, 2025.

3. American Psychiatric Association. Resource Document on Neuroimaging. 2018.

4. German Society of Neurology. S3 Guideline on Dementia, Version 2025.

5. Stanford Longevity Center. “What Excessive Screen Time Does to the Adult Brain.” 2024.

6. Topiwala A, et al. "Alcohol Use and Gray Matter Structure." Mol Psychiatry. 2023.

7. World Health Organization. "No level of alcohol consumption is safe for our health." 2023.

8. European Food Safety Authority. "Scientific Opinion on the Safety of Caffeine." EFSA Journal. 2015.

9. Gonzalez O, et al. "Safety and Efficacy of L‑Theanine Supplementation for Stress Management." Nutrients. 2024.

10. StatPearls. "Phthalates Toxicity." 2023.

11. Beilharz J, et al. "High-Fat-Sugar Diet Impairs Hippocampus-Dependent Memory." Nutr Rev. 2023.

12. Lupien S, McEwen B. "Stress Effects on the Hippocampus." Nat Rev Neurosci. 2015.

13. Rong Z, et al. "Periodontal Health and Dementia: Systematic Review." J Clin Periodontol. 2022.

14. Zhang Y, et al. "Trans Fatty Acids and Cognitive Decline." Nutrients. 2022.

15. World Health Organization. "REPLACE Trans Fat: An Action Package to Eliminate Industrially Produced Trans Fat." 2018.

16. ten Brinke L, et al. "Aerobic Exercise Increases Hippocampal Volume." Br J Sports Med. 2014.

17. Lee S, et al. "Polygenic Risk Scores and Accelerated Brain Age in Smokers." Sci Rep. 2024.

18. Rahman A, et al. "Cognitive Impairment after Mild TBI." Front Behavior Neurosci. 2024.

19. González K A, et al. "Sleep Duration and Brain MRI Measures: SOL‑INCA MRI Study." Alzheimer's dementia. 2024.

20. Harvard-HRS Cohort. "Chronic Loneliness and Incident Stroke." eClinicalMedicine. 2024.

21. Amen DG, et al. "Reduced Brain Perfusion in Regular Cannabis Users." J Alzheimer's Dis. 2016.

22. Winokur K, et al. "Brain Function Outcomes of Recent and Lifetime Cannabis Use." JAMA Network Open. 2025.