Shorter days, diets and dementia

It’s very autumnal in London right now, and the clocks ‘fall’ back this weekend. (It happens here a week earlier than in the USA and Canada – so don’t panic if you’re on the ‘other’ side of the Atlantic). While some, like my young adult daughters, welcome the extra hour in bed on Sunday, this twice yearly change upsets our delicate circadian rhythms. Like (too) many things, they get out of whack as we get older. Circadian disruption has been linked to higher inflammation, impaired glucose metabolism, weaker cardiovascular health and shortened telomeres (those shoe-lace-cap-like tips on the end of our chromosomes). All of which correlate with reduced longevity.

Research has found higher short-term risks of heart attack, stroke, and accidents after the spring clock change (when we lose sleep). Luckily for us, it’s now autumn, because the October changes (when clocks go back) don’t show the same sharp rise.

TIME TO ABOLISH?

Although it IS only an hour, it marks the start of shorter daylight exposure, leading to: lower serotonin and vitamin D levels, higher risk of seasonal depression and more sedentary behaviour. We know that long-term brain and cardiovascular health are influenced by these factors. Not to mention sleep. I was unsurprised to learn that the American Academy of Sleep Medicine has declared, ‘these seasonal time changes should be abolished in favour of a fixed, national, year-round standard time.’ Annabel and I both agree with this!

Until that happens, the answer is to stay as consistent as possible with sleep and meal times to anchor circadian rhythms; get natural morning light exposure (especially in darker months), reduce evening light and screen use – and don’t let levels of activity or social connection slip through the winter.

NOURISHING WOMEN’S COGNITION

Of course, it goes without saying that good nutrition supports us at every time of year. Research published recently in The Journal of Nutrition, Health and Aging focussed on the efficacy of healthy dietary patterns. The research team looked at the Mediterranean diet, the MIND diet and the Recommended Food Score, finding that they’re associated with a 24% lower dementia risk. Interestingly, the results were more pronounced in women and older adults.

A study from here in the UK published in August found that women with Alzheimer’s showed a marked drop in key omega-3 fatty acids (EPA and DHA from oily fish) compared to cognitively healthy women. The results were less marked in men. These differences are vital to monitor as women are disproportionally affected by Alzheimer’s and other dementias – twice as many women as men have the disease.

‘JUNK FOOD’

As with all these things, it’s not as simple as saying, ‘get more omega-3 fatty acids and you won’t get Alzheimer’s’. But we know it helps reduce risk. One of the study’s authors said, ‘”Our study suggests that women should make sure they are getting omega fatty acids in their diet – through fatty fish or via supplements. However, we need clinical trials to determine if shifting the lipid composition can influence the biological trajectory of Alzheimer’s Disease.”

Conversely, a study published at the end of September in the journal Neuron, discovered that a high-fat “junk food” diet caused memory-related changes (in mice) very quickly. The mice were fed a diet that matched the nutrient value of typical Western-style junk food, like cheeseburgers and fries (poor mice). Within four days, the memory processing systems of the hippocampus were disrupted – showing how quickly the brain responds to nutritional changes.

FEED YOUR BRAIN BETTER

If you’re looking for a clear, science-backed way to support your brain health through food, my short course Feed Your Brain Better is built to help. I created it after years of studying, and coaching, dementia risk reduction (and supporting my own mum) to make the research actually usable in daily life. Inside, you’ll find nine focused modules, a rinse-and-repeat system for brain-supportive meals, and the practical steps that make healthy habits stick. The course is available instantly – all the details are here