Cognitive decline refers to the slowing or dulling of our memory, concentration and ability to think. It’s quite common to become more forgetful as we age – failing to remember someone’s name, say, or what we set out to buy at the shops.
Increasingly frequent episodes might, though, indicate cognitive impairment – when the rate of decline is faster than we would expect as part of the normal ageing process. This can be scary for the person experiencing symptoms, as well as for family and friends.
Some of the most common signs of cognitive impairment include:
- Forgetting important dates or events
- Losing your train of thought
- Becoming increasingly overwhelmed by making decisions or planning tasks
- Having trouble finding your way around familiar places
- Becoming more impulsive
We all experience cognitive decline as we get older. However, the degree and rate of decline are different for everyone, largely determined by genes and family history.
So two people with the same level of age-related changes to their brains might perform very differently on cognitive tasks. And two people with Alzheimer’s disease can have a similar cognitive ability, but vastly different changes in the brain.
What can I do now to prevent cognitive decline?
Some people seem to be more resilient to the effects of ageing, possibly because they’ve developed a larger capacity – or ‘cognitive reserve’ – to cope with changes.
Research shows that cognitive reserve is built up through experiences during our lifetime. This can include educational attainments, having an engaging occupation or taking part in stimulating activities. Education and occupation may be determined, in part, by socioeconomic status.
But participation in activities – leisure pursuits, learning, social interactions – is within our control.
Other health conditions – such as high blood pressure, diabetes, depression and vascular disease – can exacerbate cognitive decline. Some are avoidable or manageable through lifestyle changes:
- Eat a nutritious, balanced diet with lots of leafy and green vegetables
- Stay physically active
- Limit alcohol intake
- Avoid tobacco products
Making positive changes in one area of life can produce benefits in another. Conversely, adopting unhealthy habits can cause a chain reaction or negative spiral of health outcomes.
Habits to avoid
Research in the US shows that a high-fat diet increases the risk of obesity, diabetes and the development of cognitive impairments. Many converging studies show that a low-fat diet is protective against cognitive decline.
Smoking can compromise lung capacity, making it harder to engage in physical activity, which can lead to further health issues and cognitive problems.
We can’t prevent cognitive decline – at least, not yet, and probably not any time soon. But there are things we can do throughout our lives that have the potential to increase that cognitive reserve, in the hope of slowing the decline. And research is finding out more about the factors involved.
Aim for a holistically healthy lifestyle
Some of the changes we can make to live a more ‘holistically healthy’ lifestyle are little more than common sense. Advice on diet, exercise, smoking and drinking will be familiar. But less-known lifestyle factors can also affect brain function as we age, including social and sexual connections.
Research indicates that social activities can help slow cognitive decline by challenging people to communicate, which stimulates the mind. You might go swimming with a friend and chat every few lengths. Or, pass the time of day with fellow dog walkers in the park.
Combining social activities with meaningful social connections is a great boost for overall well-being, simultaneously stimulating many of our cognitive functions.
Sex on the brain
Not often discussed, but equally important for cognitive health, is the importance of maintaining romantic and intimate relationships.
Studies have shown a correlation between sexual activity and cognitive function in men and women over the age of 50. A follow-up study on a group of 73 older adults showed that, overall, higher frequencies of sexual activity were indicative of better scores on tests of cognitive function.
The link between sexual activity and cognitive function could be due to the inherent social connection. Or, to the release of sex-related hormones such as oxytocin and dopamine affecting brain function.
Dopamine, the so-called ‘feel-good hormone’, is part of the brain’s reward system. It promotes positive feelings by connecting learning, memory and emotions. (Intriguingly, research has also linked excess dopamine production with addiction and substance misuse.)
Oxytocin, sometimes called the ‘love hormone’, is involved in social and sexual interactions. It's also involved in bonding, such as between a mother and a newborn baby.
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Of course, according to the age-old nature-nurture debate, the link between sexual activity and cognitive function could be the combined result of both the social and the biological impacts of intimate behaviour.
Indulge in your hobbies to help prevent cognitive decline
There’s also good reason to stimulate your brain with challenging activities and hobbies. Reading books and magazines, playing board games, going to museums and playing musical instruments all help combat cognitive decline.
Some activities can increase your capacity to learn, and the benefits can spill over into other cognitive abilities, too. For example, activities that include complex memory tests can also improve other cognitive functions such as vocabulary.
A study involving a sample of Australian adults found notable gender differences in the components of ‘cognitive lifestyle’ in older age, with women being more likely to engage in social activities, reading and volunteer work. This research shows that sociocultural values and stereotypes drive gender differences across a lifetime and that these gender-role attitudes can influence cognitive outcomes for men and women in later life.
Get good quality sleep
Sleep is important, too. Many studies show that sleep is significantly linked to cognitive function across a lifetime.
The Medical Research Council Cognitive Function and Ageing Studies (CFAS) have shown that daytime napping is associated with a lower risk of cognitive decline at two- and ten-year follow-ups. Getting less than 6.5 hours of sleep is associated with a higher risk of cognitive decline at a ten-year follow-up.
Another study has shown that too much sleep and poor quality sleep are both associated with worse memory in men and women aged 65 years and over. These studies all tend to produce similar advice: we should be getting around eight hours of restful sleep each night.
Periods of not sleeping well can contribute to a cycle of negative physical and cognitive health. For example, poor sleep can cause low mood, anger and irritability, which can then impact our relationships, causing further stress – which further impacts sleep.
On the flip side, the benefits of sleeping well include improved concentration, creativity, social skills and decision-making.
Regular dental check-ups can help prevent cognitive decline
Perhaps the most unexpected place where improvements can safeguard cognitive health is your mouth. Research shows that the bacteria associated with gum disease – which affects up to half of UK adults – are also associated with the development of Alzheimer’s disease and dementia.
If left untreated, the bacteria causing gum disease can build up and prompt an inflammatory response in the body.
Small laboratory studies have shown that bacteria and inflammatory molecules travelling through the bloodstream to the brain comprise one way in which poor oral health can lead to dementia. Large population studies in humans to confirm this relationship haven’t yet been conducted.
However, to be on the safe side, it’s a wise idea to adopt good oral health habits. These include daily flossing, brushing twice a day and having regular dental check-ups.
So, though there may be no miracle drug on the horizon, there are plenty of things we can do that could help decrease the rate of cognitive decline we experience as we get older. The important thing to remember is that if you’re worried about your cognitive abilities, or someone else’s, there might be some underlying health issues that can be treated.
If you’re concerned about your own cognitive function or that of a loved one, seek advice from your doctor, who may be able to help.
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