7 vs 9 hours of sleep: What's the ideal amount and why it might not be what you think
Some swear by long weekend lie-ins, while others feel sharp and energised after just seven hours. So which is actually better: 7 or 9 hours of sleep? Can too much sleep be just as risky as too little? And what does science really say about the right amount of rest for your body and brain? New research reveals that seven hours may be the sweet spot for most adults, not just for feeling fresh in the morning, but for long-term health, mental clarity, emotional balance, and even how long you live.
Let's break down the science, bust a few myths, and help you figure out your own ideal sleep rhythm.
Why seven hours may be the golden number
A large study published in
Nature Aging
examined data from nearly 500,000 adults aged 38 to 73 and uncovered a clear pattern: those who consistently slept for seven hours per night performed significantly better in tests measuring cognitive function, memory, and mental health. Compared to individuals who slept either less or more, the seven-hour sleepers showed sharper attention, quicker processing speed, and more stable moods.
by Taboola
by Taboola
Sponsored Links
Sponsored Links
Promoted Links
Promoted Links
You May Like
Brain tumor has left my son feeling miserable; please help!
Donate For Health
Donate Now
In contrast, both short and long sleep durations were associated with reduced problem-solving skills, poorer memory recall, and higher levels of anxiety and depression.
The findings suggest that even an extra hour or two of sleep beyond the seven-hour mark may not offer added benefits and could actually be linked to declines in brain function and emotional wellbeing. Even the
Journal of Clinical Sleep Medicine
recommends at least seven hours for adults aged 18 to 60.
Consistently getting less than that has been linked to a higher risk of obesity, stroke, Type 2 diabetes, depression, heart disease, and weakened immunity. So why not nine? That's where it gets interesting.
Is sleeping nine hours harmful?
Not necessarily but it can be a red flag. While an occasional long sleep is fine (like after travel or illness), regularly needing more than nine hours may point to poor sleep quality or an underlying health issue. Studies have shown that
long sleepers
are at greater risk for:
Brain fog and slower mental processing
Higher levels of inflammation in the body
Mood disorders, especially depression
Increased mortality risk in some long-term studies
In short: more sleep doesn't automatically mean better health.
If you sleep longer and still feel tired, it might be time to look at your sleep hygiene or consult a doctor.
What happens if you sleep less than seven?
If you're used to burning the midnight oil or waking up early with only 5–6 hours of sleep, your body might be silently suffering, even if you don't feel it right away. Too little sleep, especially over time, can lead to:
Weight gain and metabolic issues
Poor focus, mood swings, and memory lapses
Weakened immune system
Higher risk of heart disease and diabetes
And no, 'catching up' on the weekend doesn't fully reverse the effects of regular sleep loss. Even if you're clocking in your seven to nine hours of sleep, irregular sleep timing like sleeping at different hours every night or shifting your bedtime drastically on weekends can still wreak havoc on your health.
Your body's internal clock, or circadian rhythm, thrives on routine. When that rhythm is disrupted, even the right amount of sleep may not be enough to keep your system in balance.
Recent large-scale research has shown that inconsistent sleep and wake times can raise the risk of developing up to 172 different health conditions, ranging from liver damage and metabolic disorders to obesity, type 2 diabetes, and cardiovascular disease.
What's more alarming is that even people who technically get enough sleep, say seven or eight hours a night, face a 26% higher risk of heart attacks and strokes if their sleep pattern is erratic.
In short, consistency matters just as much as duration, and maintaining a steady sleep schedule could be one of the most underrated health habits you can build. Both 7 and 9 hours can fall into the healthy sleep range but they're not created equal. For most adults, seven hours of consistent, good-quality sleep offers the best mix of mental clarity, physical recovery, and long-term health protection. Instead of just counting hours, pay attention to how you feel, how consistently you sleep, and how well your body performs during the day.
Because when it comes to sleep, it's not just about more, it's about smarter.
Also read|
Why women suffer more from migraines and why doctors often ignore their pain
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
Time of India
an hour ago
- Time of India
New study reveals simple daily habits that may slow down cognitive decline
As people age, the risk of cognitive decline and conditions such as dementia and Alzheimer's disease becomes significantly higher. However, emerging research continues to show that lifestyle plays a powerful role in protecting brain health. Now, a major U.S.-based study has found that moderate, structured lifestyle changes may delay age-related cognitive decline by up to two years. The US POINTER (Protect Brain Health Through Lifestyle Intervention to Reduce Risk) study, the largest randomized clinical trial of its kind in the U.S., was designed to test whether everyday lifestyle interventions could help older adults maintain cognitive function. The results of the study, funded by the Alzheimer's Association, were published in the journal JAMA and presented at the 2025 Alzheimer's Association International Conference in Toronto. How the study was conducted Researchers followed 2,111 cognitively healthy adults aged 60–79 who were sedentary and had risk factors for dementia, such as prediabetes and borderline high blood pressure. Participants were randomly divided into two groups over a two-year period: Structured Intervention Group: Took part in 38 team-based coaching sessions led by trained facilitators. These sessions focused on exercise, diet, brain training, social activity, and vital sign monitoring. Self-Guided Group: Received general information about brain health and selected their own lifestyle changes, with no structured coaching. Both groups underwent physical and cognitive testing every six months. by Taboola by Taboola Sponsored Links Sponsored Links Promoted Links Promoted Links You May Like Indonesia: Unsold Sofas at Bargain Prices (Prices May Surprise You) Sofas | Search Ads Search Now Undo Key Finding Participants in the structured program showed delayed cognitive aging by 1 to 2 years compared to the self-guided group. However, both groups improved their cognitive scores over time, suggesting that even moderate changes can be beneficial. 5 daily habits that help protect brain health Regular aerobic and strength-based exercise Participants were guided to engage in aerobic activity (like walking, cycling, or swimming) for 30 minutes daily, along with strength training and stretching several times a week. Exercise boosts blood flow to the brain and helps reduce inflammation, which supports memory and learning. Following the MIND diet The study emphasized the MIND diet — a combination of the Mediterranean and DASH diets. This included: Daily consumption of green leafy vegetables and berries Use of extra-virgin olive oil Limited intake of processed foods, fried items, cheese, and sugary desserts This diet is rich in antioxidants and nutrients linked to brain protection and vascular health. Tracking vital signs Participants were taught to monitor their own blood pressure, blood sugar, and other vital metrics regularly. Staying informed about these markers helps manage chronic conditions like hypertension and diabetes, both of which are linked to cognitive decline. Brain training and mental stimulation Participants used web-based cognitive training programs to engage in memory, attention, and problem-solving exercises. While some debate remains on the long-term impact of these tools, researchers noted improvements in mental engagement and task performance among users. Increased social interaction Social isolation is a known risk factor for dementia. The study encouraged regular social activities, including meeting friends, speaking with new people, or joining group events. Frequent social engagement helps stimulate cognitive function and reduces mental stress.A What's next in brain health research? The US POINTER study is being extended for a four-year follow-up phase, backed by an additional $40 million in funding from the Alzheimer's Association. This will allow researchers to better understand the long-term impact of lifestyle changes on brain aging. Lead researchers also collected data on sleep patterns, brain imaging, and biomarkers, which are yet to be fully analyzed. These results could further clarify which lifestyle factors most significantly influence brain health.
Time of India
an hour ago
- Time of India
Fake doc in ward: Nursing home's licence suspended
Kolkata: The West Bengal Clinical Establishment Regulatory Commission (WBCERC) has directed the health officials to suspend the licence of nursing home on Diamond Harbour Road after a person who was not a doctor attended to a pregnant woman, who ultimately suffered a miscarriage. A penal amount of Rs 1 lakh has also been imposed on the nursing home. According to the complaint lodged with the health panel, Alka Roy was taken to Bellona Nursing home in Mominpore with severe abdominal pain at night. At the emergency ward, she was attended to by Avinash Kumar, who introduced himself as a resident medical officer. Kumar prescribed a pain relieving injection and administered it to the expecting mother. She subsequently suffered complications and miscarriage. You Can Also Check: Kolkata AQI | Weather in Kolkata | Bank Holidays in Kolkata | Public Holidays in Kolkata "When we got a response from the nursing home, we were taken aback. This Avinash Kumar is not a doctor but an assistant to the medical director of the nursing home, who would check blood pressure of patients," said WBCERC chairperson Justice (retd) Ashim Banerjee. The commission also found that Kumar had prescribed the medicine on a signed letterhead of the medical director. by Taboola by Taboola Sponsored Links Sponsored Links Promoted Links Promoted Links You May Like 20 Historic Cars Every Enthusiast Should Know Undo The medical director said that at that time, he was conducting a procedure in the OT. The health panel said that while not going into whether the injection caused the miscarriage or not, Kumar posing as a doctor, and prescribing and administering an injection itself was a criminal offence. The commission also asked how the medical director could leave blank prescription letterheads bearing his signature which Kumar could access. "We have asked the police to take Kumar into custody and come to a logical conclusion," Banerjee added. Till health officials submit a complete report on the case to the commission, the nursing home has been barred from admitting any new patient. However, it can continue treatment of patients who are already admitted.
Time of India
an hour ago
- Time of India
THIS tea can 'clean' the brain and prevent Alzheimer's
A new study reveals that a combination of nicotinamide and epigallocatechin gallate, found in green tea, can rejuvenate aging brain cells. The treatment restores energy levels and clears harmful protein buildup linked to Alzheimer's disease. Researchers observed improved brain cell function and reduced oxidative stress in treated neurons, offering a potential nonpharmaceutical approach to cognitive decline. Imagine decluttering your brain. Tidying it a bit to get rid of things that are damaging your brain. Is it even possible? Well, yes! You can tidy up your brain and even manage progressive neurodegenerative disorders such as Alzheimer's disease. Wondering how? With the help of a tea! Yes, that's right! A new study has found that a combination of natural compounds will help in brain cleaning. A recent study by researchers at the University of California found that a combination of natural compounds, of which one is found in a tea, restored energy levels in aging brain cells and also cleared harmful protein buildup linked with Alzheimer's disease. The findings are published in the journal GeroScience . Cleaning the brain The new study found that a combination of naturally occurring compounds, nicotinamide (a form of vitamin B3) and epigallocatechin gallate (a green tea antioxidant), can restore the levels of guanosine triphosphate, an essential energy molecule in brain cells. This treatment will remove harmful protein buildup linked with Alzheimer's disease. They added that this promising nonpharmaceutical treatment also rejuvenates aging brain cells. by Taboola by Taboola Sponsored Links Sponsored Links Promoted Links Promoted Links You May Like Biggest Real Estate Discounts Ever at M3M India. Enquire Now! M3M India Book Now Undo They tested the treatment on neurons in a dish and found that it improved the brain cells' ability to clear damaging amyloid protein aggregates linked to Alzheimer's. 'As people age, their brains show a decline in neuronal energy levels, which limits the ability to remove unwanted proteins and damaged components. We found that restoring energy levels helps neurons regain this critical cleanup function,' lead author Gregory Brewer, adjunct professor of biomedical engineering at UC Irvine, said in a statement. Researchers tracked energy molecule levels in brain cells from aged Alzheimer's model mice using a genetically coded fluorescent sensor called GEVAL. They found the free GTP (guanosine triphosphate) levels reduced with age, especially in mitochondria, leading to impaired autophagy, the process by which cells eliminate damaged components. But when they treated the neurons for just 24 hours with nicotinamide and epigallocatechin gallate, the GTP levels came back to normal. This process improved energy metabolism; activation of key GTPases involved in cellular trafficking, Rab7 and Arl8b; and efficient clearance of amyloid beta aggregates. Oxidative stress, which is another major contributor to neurodegeneration, also went downhill. 'This study highlights GTP as a previously underappreciated energy source driving vital brain functions. By supplementing the brain's energy systems with compounds that are already available as dietary supplements, we may have a new path toward treating age-related cognitive decline and Alzheimer's disease,' Brewer said. 'More work is going to be required to find the best way to administer this treatment, since a recent clinical trial involving UC Irvine researchers showed that oral nicotinamide was not very effective because of inactivation in the bloodstream,' he cautioned.
