Research
Study reveals strong links between the quality of diet and cognitive ability
Eating a high-quality diet in youth and middle age could help keep your brain functioning well in your senior years, according to new preliminary findings from a study that used data collected from over 3,000 people followed for nearly seven decades.
The research adds to a growing body of evidence that a healthy diet could help ward off Alzheimer’s disease and age-related cognitive decline. Whereas most previous research on the topic has focused on eating habits of people in their 60s and 70s, the new study is the first to track diet and cognitive ability throughout the lifespan — from age 4 to 70 — and suggests the links may start much earlier than previously recognized.
“These initial findings generally support current public health guidance that it is important to establish healthy dietary patterns early in life in order to support and maintain health throughout life,” said Kelly Cara, PhD, a recent graduate of the Gerald J. and Dorothy R. Friedman School of Nutrition Science and Policy at Tufts University.
“Our findings also provide new evidence suggesting that improvements to dietary patterns up to midlife may influence cognitive performance and help mitigate, or lessen, cognitive decline in later years.”
Cognitive performance, or thinking ability, can keep improving well into middle age, but typically begins to decline after age 65. More severe conditions such as dementia can also develop alongside aging-related declines. Researchers say that eating a healthy diet — in particular, a diet rich in plant-based foods that contain high levels of antioxidants and mono- and polyunsaturated fats — can support brain health by reducing oxidative stress and improving blood flow to the brain.
For the new research, scientists used data from 3,059 U.K. adults who were enrolled as children in a study called National Survey of Health and Development. Members of the cohort, called the 1946 British Birth Cohort, have provided data on dietary intakes, cognitive outcomes and other factors via questionnaires and tests over the course of more than 75 years.
Analysing participants’ dietary intakes at five timepoints in relation to their cognitive ability at seven timepoints, researchers found that dietary quality was closely linked with trends in general, or “global,” cognitive ability. For example, only about 8% of people with low-quality diets sustained high cognitive ability and only about 7% of people with high-quality diets sustained low cognitive ability over time compared with their peers.
Cognitive ability can have important impacts on quality of life and independence as we age. For example, at age 68-70, participants in the highest cognitive group showed a much higher retention of working memory, processing speed and general cognitive performance compared to those in the lowest cognitive group. In addition, nearly one-quarter of participants in the lowest cognitive group showed signs of dementia at this timepoint while none of those in the highest cognitive group showed signs of dementia.
While most people saw steady improvements in their dietary quality throughout adulthood, the researchers noted that slight differences in diet quality in childhood seemed to set the tone for later life dietary patterns, for better or worse. “This suggests that early life dietary intakes may influence our dietary decisions later in life, and the cumulative effects of diet over time are linked with the progression of our global cognitive abilities,” said Cara.
To assess diet quality, the researchers used the 2020 Healthy Eating Index, which measures how closely one’s diet aligns with the 2020-2025 Dietary Guidelines for Americans. Study participants who sustained the highest cognitive abilities over time relative to their peers tended to eat more recommended foods such as vegetables, fruits, legumes and whole grains and less sodium, added sugars and refined grains.
“Dietary patterns that are high in whole or less processed plant-food groups including leafy green vegetables, beans, whole fruits and whole grains may be most protective,” said Cara. “Adjusting one’s dietary intake at any age to incorporate more of these foods and to align more closely with current dietary recommendations is likely to improve our health in many ways, including our cognitive health.”
Since the study participants were predominantly Caucasian individuals from across the U.K., the researchers said that further research would be needed to determine whether the results would apply to populations with greater racial, ethnic and dietary diversity. They also noted that changes in study focus and protocols over the course of the long-running study created some gaps and inconsistencies in data collection. Despite these limitations, however, the researchers were able to create global cognitive ability percentile rank scores using data from multiple cognitive domains to evaluate how participants compared to their peers at each age and over time.
NICE will review whether new Alzheimer’s drugs should be offered on the NHS after an appeal found their wider impact was not fully counted.
An appeal found that the National Institute for Health and Care Excellence had failed to properly account for the wider impact of the treatments, including the heavy burden on unpaid carers, when calculating the cost effectiveness of the medicines.
Both treatments, lecanemab and donanemab, will now return to a NICE committee for further consideration.
“Today’s ruling is an opportunity for NICE to consider the real cost of Alzheimer’s on people and their families, and we welcome the decision to look again at whether new medicines could be provided on the NHS,” said David Thomas, head of policy and public affairs at Alzheimer’s Research UK.
Lecanemab and donanemab do not cure Alzheimer’s, but they slow it by targeting and clearing clumps of amyloid proteins, sticky protein build-ups in the brain linked to the disease.
While the drugs are available privately in the UK for people who can afford them, NICE ruled last year that they were too expensive to be made available on the NHS in England and Wales.
It is estimated informal dementia care costs the economy more than £20bn a year.
Alzheimer’s Research UK wants NICE to update how it assesses the value of new dementia drugs and factor in the huge additional costs this condition places on society and the wider economy.
NICE and its expert committees assess whether new drugs are good value for money for the NHS based on a wide range of evidence.
This includes how treatments perform in clinical trials, the experiences of patients and carers, and the costs of new drugs as well as any changes to NHS services needed to provide access.
When NICE weighs up whether a new Alzheimer’s drug is cost effective for the NHS, it carries out a limited assessment of the impact dementia has on the health of carers.
But the condition takes an enormous toll on families and society because caring for someone with dementia can lead people to become more isolated and give up work.
It can have a major emotional impact and put families under financial strain.
Thomas said: “Research has delivered new treatments with the potential to provide people with valuable extra months of independence, lessening the burden on carers.
“While these treatments offer modest benefits and can cause serious side effects, they provide the foundation for a future where dementia becomes a treatable condition.
“Now we need NICE to look again at how these medicines could benefit both people with early Alzheimer’s and their carers.”
Chris, whose mother Shirley is living with Alzheimer’s disease, said: “The real cost of Alzheimer’s is far greater than many people realise.
“In order to give my mum the care she needed, I moved back home to help my dad as the care was too much for him alone. After my dad passed away from Covid in 2021, I became sole carer for my mum.
“It was a very difficult period, working a full-time job, caring for Mum and dealing with the loss of my dad. Eventually I got some in-home care support to help.
“The family has borne most of the cost of Mum’s care, both in time and fees, and the family home has been sold to finance it.”
“The emotional and financial strain Alzheimer’s has taken on our family is horrendous, and I know many families across the UK are experiencing this pressure.”
He is backing Alzheimer’s Research UK’s call for NICE to change how it evaluates new dementia treatments.
The timeframe for the next NICE meetings to discuss the drugs is still to be set, and it is not certain follow-up hearings would change NICE’s guidance on access to the medicines.
But Alzheimer’s Research UK is continuing to push to make sure dementia is now a main priority for political and NHS decision-makers.
The head of the ongoing independent review into adult social care, Baroness Louise Casey, has called on the government to act, show leadership and prioritise dementia.
She has proposed appointing a dementia tsar to drive forward the prevention, treatment and care of dementia.
Baroness Casey has also argued for more funding for dementia treatment trials.
With more than 130 Alzheimer’s drugs in clinical trials worldwide, the charity says it is vital the NHS runs trials of new treatments now to understand how to deliver them to eligible patients in future.
In addition to changing how NICE assesses new medicines, the health service needs to collect real-world evidence on new dementia drugs and prepare for diagnostic tests and innovative treatments that are coming.
“Alzheimer’s Research UK is calling on the government to give dementia the same political determination that transformed cancer care,” Thomas said.
“We urgently need investment and a clear UK-wide plan so new treatments can be assessed in the NHS and reach the people who stand to benefit.”
Health and social care secretary Wes Streeting has said dementia is “one of the greatest challenges of our time” and pledged that the UK should become a world leader in dementia clinical trials.
Osteoporosis drugs may lower dementia risk, with a study suggesting one widely used treatment could help prevent Alzheimer’s and related dementias.
The research found that nitrogen-containing bisphosphonates, drugs widely used to treat osteoporosis, may significantly reduce the risk of Alzheimer’s disease and related dementias in older adults with osteoporosis or fragility fractures.
Osteoporosis and dementia often coexist in older adults and share several risk factors, including advanced age, female sex and reduced physical activity.
Researchers at the University of Hong Kong’s department of pharmacology and pharmacy carried out a large study using the city’s electronic medical records, covering more than 120,000 patients aged 60 and above with osteoporosis or fragility fractures between 2005 and 2020.
The team found that NBP users had a 16 per cent lower risk of developing Alzheimer’s disease and related dementias than untreated patients, and a 24 per cent lower risk than those who received other osteoporosis medicines.
The association was especially marked in women and patients with hip fractures.
The researchers estimated that treating 48 patients with NBPs for five years could potentially prevent one case of dementia, underlining the possible public health value of NBPs in high-risk groups.
Professor Cheung Ching-lung, associate professor in the department of pharmacology and pharmacy at the University of Hong Kong, said: “Our study provides evidence that NBPs may offer dual benefits in strengthening bones and reducing fracture risk, as well as potentially preventing ADRD.
“Their potential neuroprotective role provides an empirical basis and supports future research on the actual effectiveness of this medication in preventing or delaying cognitive decline associated with ADRD.
“These findings are significant as they demonstrate a potential approach for reducing dementia risk in a vulnerable population using safe and widely available NBPs.
“In our rapidly ageing society, these findings suggest that while waiting for the novel therapies, existing medications can also provide additional protection for high-risk populations.”
The same research team has previously found that osteoporosis and fractures are independent risk factors for dementia, and that patients with dementia are at higher risk of falls and fractures.
This suggests treating osteoporosis may also help reduce the burden of dementia.
NBPs, including alendronate and zoledronate, are well established and commonly prescribed osteoporosis drugs.
Emerging biological research suggests the pathways affected by NBPs may also play a role in the development of Alzheimer’s disease and related dementias, raising the possibility that they could be repurposed for prevention.
A prebiotic fibre supplement may ease arthritis pain and improve grip strength in people with knee osteoarthritis, a study suggests.
The daily supplement, made from inulin, a dietary fibre found in chicory root, Jerusalem artichokes and other vegetables, also lowered pain sensitivity and saw fewer people drop out than a digital physiotherapy programme tested alongside it.
Dr Afroditi Kouraki, lead author of the study from the University of Nottingham, said: ‘Our findings suggest that targeting gut health with a prebiotic supplement is a safe, well-tolerated, and effective way to reduce pain in people with knee osteoarthritis.
“The very low dropout rate compared to the exercise group is also encouraging from a public health perspective, people were able to fit this supplement easily into their daily lives.’
Osteoarthritis of the knee, a wear-and-tear joint condition, affects hundreds of millions of people worldwide and is a leading cause of pain and disability, particularly in older adults.
Current treatments rely heavily on pain medication, which can cause side effects, or exercise programmes, which many patients find hard to maintain.
The INSPIRE trial, led by researchers at the University of Nottingham, involved 117 adults with knee osteoarthritis and tested four groups: inulin alone, digital physiotherapy-supported exercise alone, a combination of both, and a placebo. Both inulin and physiotherapy independently reduced knee pain.
However, inulin alone improved grip strength and reduced pain sensitivity, measures linked to how the nervous system processes pain, while physiotherapy did not.
The dropout rate for those taking the supplement was just 3.6 per cent, compared with 21 per cent for the physiotherapy group, suggesting a daily supplement may be easier for people to stick with than an exercise programme.
Inulin works as a prebiotic, meaning it feeds beneficial bacteria in the gut.
This leads to the production of compounds called short-chain fatty acids, particularly butyrate, which can affect inflammation and pain pathways throughout the body.
Participants taking inulin also showed increased levels of both butyrate and GLP-1, a gut hormone linked to pain regulation and muscle health.
Higher GLP-1 levels were associated with improved grip strength, pointing to a possible gut-muscle connection.
Senior author Professor Ana Valdes added: ‘The link we observed between GLP-1 and grip strength is particularly intriguing and points to a broader gut-muscle-pain axis that warrants further investigation. This could have implications not just for osteoarthritis, but for understanding how gut health influences ageing and physical resilience more broadly.’
Professor Lucy Donaldson, director of research at Arthritis UK, said: “The pain of arthritis can severely impact quality of life. Our recent lived experience survey showed that six in ten people are living in pain most or all of the time due to their arthritis.
“Researchers are starting to explore the role of the gut microbiome in our experience of pain.
“This exciting preliminary research highlights how diet and physiotherapy can act in different ways to have benefits for people with arthritis.
“We know a variety and balance of healthy foods, including fibre, and regular physical activity matter, and we’re glad to be supporting research that explores how they work to help people with arthritis.”
Gut-friendly foods may damage heart, charity warns
Diabetes patients face increased risk of undiagnosed heart failure
UK government announces £6.3m fund to boost men’s health
Brain health collaboratory launches in Gulf South
