From the moment we’re born, the human brain develops at an astonishing pace. It’s one of the factors that sets us apart from other primates. Our brains aren’t considered to be fully developed until our early 20s: according to studies, until the age of around 25, the prefrontal cortex is still immature with neurons still developing and pathways rewiring. After this, however, the brain begins its inevitable ageing process. 

While it’s generally accepted that cognitive ageing is a gradual process, new research shows that our brains age in three distinct stages. This might sound terrifying, but there is good news: there are steps we can all take to manage cognitive decline and enjoy a healthy brain for as long as possible. 

“While there’s no golden bullet to completely prevent brain ageing or cognitive decline, research has found that adjusting several easy-to-modify lifestyle factors can help reduce your risk of cognitive decline,” says Dr Harry Jarrett, head of science and research at brain health brand Heights. “This is because the way your brain ages isn’t just determined by your chronological age but also by many different lifestyle and environmental factors.”

Here, experts explain exactly how the brain ages and which lifestyle factors we can manage to help reduce cognitive ageing. 

The research shows there are three distinct points we’ll experience brain ageing in our lifetimes: at ages 57, 70 and 78. However, these aren’t necessarily the ages at which we’ll experience symptoms of cognitive decline. We now also know that brain ageing occurs much earlier than previously believed. 

“Deterioration in the activity and structure of the brain is a natural part of ageing,” says Dr Jarrett. “The complex interplay between modifiable risk factors and genetics makes it impossible to put a specific age to this as it is very individualistic. However, it is generally recognised that brain atrophy (shrinking) starts to occur in our 30s and 40s.”

Dr Lafina Diamandis, GP and founder of Deia Health, adds: “It’s normal for our brains to undergo changes as we age and these changes can impact cognitive functions such as memory, problem-solving and reasoning skills. However, these changes vary from person to person and not all cognitive processes will be affected at the same time. For example, memory may begin to decrease in midlife whereas vocabulary may remain intact for far longer.” 

Brain changes start to occur in your 30s and 40s and cognitive decline can begin around midlife, even as early as 45 years of age, according to Dr Diamandis, who says brain changes associated with conditions like dementia have been observed up to 20 years before symptoms emerge.

The signs and symptoms of cognitive decline will vary from person to person, but there are some generally accepted indicators to look out for, usually “a noticeable shift in memory, attention, information processing and speed of processing”, says brain and cognition expert Natalie Mackenzie. “These more obvious signs of ageing may occur around 60, and it is often more apparent around 70 or even 80.” 

The good news is there’s plenty we can do to offset the impact of brain ageing. While ageing is inevitable, cognitive decline doesn’t have to be. 

“Cognitive decline is not necessarily part of the ageing process,” says Dr Sabine Donnai, consulting GP and founder of healthy longevity platform Viavi. “The vast majority of underlying drivers are within our lifestyle – only a small percentage of the risk is genetic. While deterioration can start at any age, neuroplasticity ensures the ability of continuous growth.”

1. Stay physically active

Whether you’re a keen hiker or you prefer to hit the weights in the gym, movement is one of the most powerful ways to protect your brain.

“Studies show that people who keep active tend to have healthier brains than those who are more sedentary,” says Mackenzie. “Movement aids skills such as remembering things, how quickly we think and decision-making. Research shows that those who regularly exercise are 20% less likely to develop dementia, while exercise increases the size of our hippocampus. This is the area of the brain responsible for neurogenesis (the growth and development of nervous tissue) and memory, and it has been shown to shrink with age, going hand in hand with cognitive decline. So, get moving to quite literally grow your brain.”

2. Eat a brain-healthy diet

“Adopting a whole foods, plant-based diet rich in fruits, vegetables, omega 3s, lean proteins, whole grains, legumes and nuts and seeds will support brain and cardiovascular health, and it could help to reduce the risk of dementia,” says Dr Diamandis. 

3. Focus on quality sleep 

“Sleep is essential for brain health,” says Dr Diamandis. “Prioritising sleep alongside keeping a consistent sleep schedule and finding ways to improve your sleep quality may reduce the risk of cognitive decline. Try a calming wind-down routine or practise meditation or yoga before bed.”

The amount of sleep we need varies, so the focus here is on quality over quantity. That said, the experts advise aiming for between seven and nine hours a night as a general rule of thumb.

4. Cultivate strong social connections 

We know that good social bonds are the key to healthy ageing, and the science stacks up. 

“Longevity studies, such as those around the blue zones [places in the world where there is a high incidence of centenarians, such as Sardinia and areas of Japan], show that having close relationships, community engagement, and a sense of purpose contributes significantly to our longevity,” says Dr Martin Thornton, chief medical officer at Bluecrest. “People with strong social ties and fulfilling daily activities tend to live longer, healthier lives.”

5. Schedule regular health check-ups

Once we hit a certain age (usually our 40s and 50s), we’re fortunate enough in the UK to be offered standardised screening programmes for some diseases, and it’s vital to keep up with these appointments. 

“So much of our health is connected and conditions like high blood pressure, type 2 diabetes and high cholesterol can all affect brain health,” says Dr Thornton. “Routine check-ups help catch these early, so they can be managed before they impact your cognitive function.”

6. Lower your stress levels

Last but not least, try to keep a lid on your stress levels. It’s easier said than done, but long-term, chronic stress affects brain function and can increase our risk of developing certain conditions. 

“We are living in a world that the human brain is not well-adapted to, and as a result we experience and normalise very high levels of stress,” says Dr Diamandis. “It’s more important than ever before to find ways to manage our stress and close the loop on the stress cycle daily, whether that is through exercise, creative hobbies, meditation or spending time in nature. Taking regular ‘brain breaks’ to do nothing, daydream and allow the brain to rest from constant stimulation is also vital.”

Consider this your permission to switch off. 

Images: Adobe; Getty