Health myths debunked: Do we need less sleep as we get older?

Good quality sleep is so important for almost every aspect of our health, from metabolism and immune resilience right through to brain function, cardiovascular health and even longevity.

One of the most common questions I'm asked by people over 50 is whether we actually need less sleep as we get older. The short answer is: no. Our biological need for sleep doesn’t dramatically shrink with age. Instead, what changes is the structure and quality of our sleep.

Most adults, including those over 50, function best on around eight hours of sleep a night. To understand why sleep can feel lighter or more broken as we age, it helps to briefly explore the science.

How sleep takes care of our physical and mental health

There are two main types of sleep: rapid eye movement (REM) sleep and non-rapid eye movement (non-REM) sleep. Non-REM sleep has three basic stages. The first two are lighter: the body begins to relax, our heart rate slows and brain activity shifts away from wakefulness. The third stage is that all-important deep sleep, sometimes called slow-wave sleep.

Deep sleep is the most physically restorative phase of the night. Growth hormone is released, tissues are repaired, immune function is supported and many of the body’s recovery processes take place. 

After cycling through these three non-REM stages, we enter REM sleep. REM is closely associated with dreaming and is vital for memory, learning, emotional regulation and cognitive resilience. Across a typical night, we move through these three non-REM stages and one REM stage in repeating cycles, each lasting around 90 minutes.

What happens to our sleep after 50

After 50, the time we spend in the restorative deep sleep phase gradually begins to reduce, while lighter stages become more dominant. This makes us more vulnerable to waking in the night. Our day-to-night circadian rhythms also tend to shift, often leading to earlier evening sleepiness and earlier waking in the morning.

Hormones, as you would expect, also play a central role. For example, melatonin production, the hormone that signals darkness and promotes sleep, tends to decline with age. In women, the menopause transition can also quite dramatically disrupt sleep, with falling oestrogen and progesterone levels influencing temperature regulation, mood and the stability of the sleep cycle. Night sweats, anxiety and palpitations can all break up sleep too. But men are not immune to hormonal changes either, with a gradual reduction in their testosterone also affecting sleep quality,  increasing the risk of conditions such as sleep apnoea.

How a chronic lack of sleep affects metabolic and brain health

There’s a persistent myth that older adults need less sleep. In reality, we need much the same as when we were younger, but getting consistent, high-quality sleep becomes more challenging. The result is that many people can build up a chronic sleep debt over time without realising it. A sleep debt is the difference between the hours of sleep you need each night, and the hours you actually got. 

Sleep debt impacts metabolic health. Poor sleep elevates cortisol, our primary stress hormone, which in turn can impair glucose control and increase unhealthy visceral fat around the organs. This is likely to then trigger insulin resistance, which in turn raises the risk of type 2 diabetes and cardiovascular disease. All in all, a pretty unhealthy cascade of metabolic issues. Poor sleep also disrupts appetite hormones such as leptin and ghrelin, driving hunger and cravings for refined carbohydrates, which further undermines metabolic health.

The brain is sensitive to sleep loss. During deep sleep, the glymphatic system becomes more active. This is a specialised waste clearance pathway in which cerebrospinal fluid flows through brain tissue, helping to remove harmful metabolic byproducts like tau proteins. When deep sleep is regularly cut short, this waste clearance becomes less efficient and harmful proteins can accumulate, increasing the risk of Alzheimer’s disease. Sleep is not the only deciding factor for cognitive decline, but it’s a powerful one that’s in our control.

Broken sleep is also linked to mood disorders, reduced immune function and slower physical recovery. For anyone interested in healthy ageing and longevity, sleep is not optional. It’s fundamental. 

How to take care of your sleep as you get older

The good news is that simple lifestyle changes can improve your sleep. 

Start with a regular sleeping pattern. The circadian system thrives on regularity. Going to bed and rising at the same time each day strengthens your internal clock. Exposure to natural daylight in the morning anchors circadian rhythms, while minimising bright and blue light in the evening protects melatonin release, which is exactly what we want at bedtime to help us drift off to sleep. Ideally, screens should be avoided after 8pm, or at least filtered.

Meal times matter – so does alcohol. Late evening meals can impair sleep by raising body temperature and stimulating digestion at a time when your body should be preparing for its repair phase. The idea that alcohol helps you sleep is one of the most persistent myths in health, and it really does need to be put firmly in the bin. While it may make you feel drowsy, it suppresses REM sleep, breaks up the second half of the night, and leaves both brain and body in recovery the next day. 

Your sleep environment should be cool, dark and quiet. Core body temperature needs to fall slightly for deep sleep to happen, so avoid overheating your bedroom, even if it feels comfortable at first. Blackout curtains and minimising ambient light can also improve sleep quality.

Nutrition plays a subtle but important role. For example, magnesium supports muscle relaxation and nervous system balance. Foods rich in the amino acid tryptophan, such as dairy, turkey, nuts and seeds, provide the building blocks for serotonin and melatonin. Stable blood sugar, achieved through balanced evening meals with protein, fibre and healthy fats, will also help reduce the risk of 3am wake-ups driven by cortisol surges.

Ageing doesn’t mean surrendering to poor sleep 

Our sleep may change as we get older, but our basic need for it doesn't change at all. By understanding a little about the science and making small changes to our habits and diets, we can protect deep sleep, support brain health and strengthen the foundations that underpin healthy ageing. Few health interventions are as powerful, or as underestimated, as a consistently good night’s sleep.

Dr Max Gowland, PhD is the founder of Prime Fifty.