By Vilhelmiina Haavisto, Deputy Science and Technology Editor
Mushrooms were recently shown to decrease mild cognitive impairment, but they may not be acting alone…
Results from a study published earlier this year by researchers at the National University of Singapore (NUS) suggest that 60+ year olds’ risk of developing mild cognitive impairment could be reduced by eating at least three portions of mushrooms a week. Mild cognitive impairment is the stage between the expected cognitive decline associated with healthy ageing and the more serious diagnosis of dementia, which describes a group of symptoms indicating decreased cognitive abilities. Mild cognitive impairment involves symptoms including a gradual and sometimes subtle increase in forgetfulness and problems with language and attention.
The study was conducted over a six-year period, and lead researcher Lei Feng called the results “surprising and encouraging”; they indicate that eating mushrooms more than twice a week may lower the risk of developing mild cognitive impairment by up to 10%. This beneficial effect was observed independent of several health and lifestyle factors, including gender, smoking habits, physical activity levels, and incidence of non-communicable diseases such as hypertension and diabetes.
Photo by Andrew Ridley / Unsplash
This reduced risk of mild cognitive impairment is likely due to a number of compounds found in mushrooms, such as hericenones and scabronines, which have been shown to promote nerve growth in laboratory models. Mushrooms also contain compounds that contribute to preventing neurodegeneration by halting the production and accumulation of proteins that go on to make up the plaque found in Alzheimer’s patients’ brains. This plaque accumulates between nerve cells and disrupts their normal functioning. Overall, the NUS researchers assert that their findings support the fact that mushrooms and their bioactive compounds may have a “potential role” in delaying neurodegeneration.
So, could going hardcore with the mushrooms now be beneficial to our health in the long run? The life-long effects of eating mushrooms is not a topic that this study touched on, and indeed no such studies appear to have been conducted. Identifying preventative measures such as dietary interventions for diseases that do not yet have cures, including Alzheimer’s, though, is clearly important. On that note, there are several other food groups whose impacts on lifelong brain health have been scientifically investigated and characterised.
The foods that make up the ‘Mediterranean diet’ are just one such example. Sometimes called the MIND (Mediterranean-DASH-diet Intervention for Neurodegenerative Delay) diet, it emphasises the importance of foods including green leafy vegetables, berries, nuts, and whole grains. Olive oil is the main source of fat, and most of the animal proteins consumed come from fish and seafood. It also limits the quantities of foods such as red meat, cheese, pastries and sweets. The MIND diet was developed by combining elements of the Mediterranean and DASH (Dietary Approaches to Stop Hypertension) diets, as well as specific food-based strategies to promote brain health.
The foods included in the MIND diet may seem like no-brainers to some; even if it doesn’t, the research on its beneficial effects on cognition should convince the remaining skeptics. The first-ever study that dealt with the MIND diet found that adults who adhered to it showed slowed decline in cognitive skills than those following only either a Mediterranean or DASH diet. One of many subsequent pieces of research on the effects of a MIND diet on cognition, published in 2018, was conducted on over 16,000 women aged 70+ from the long-term Nurses’ Health Study. Their adherence to the MIND diet was monitored between 1984 and 1998, and cognition was measured later in the women’s lives, from 1995 to 2001. The study found that the longer the women adhered to the MIND diet, the better they tended to perform on the verbal memory component of the cognitive assessment. However, the researchers could not confidently make a link between adherence to the MIND diet and reduced risk of general cognitive decline.
Lei Feng rightly points out that the reduced risk of mild cognitive impairment that the NUS study identified is likely due to a "combination of many factors”, and cites tea, green leafy vegetables, and fish as other foods that may have contributed to the findings. These seem to come up again and again, so they must really have at least some health benefits. Obviously, it can be hard to incorporate all these foods into the student diet, but that doesn’t mean we can’t try - one way of doing so could be to incorporate more seasonal produce into our meals.
Dr James Pickett, head of research at the UK-based Alzheimer's Society, remarks that "up to a third of [dementia] cases could be prevented by changes in lifestyle, including diet”; as we have seen, this is widely agreed upon in the scientific community. He also cautions that we should not "get carried away with the findings of any one single study”, and emphasises the importance of basing healthcare advice on “consistent evidence...built up over multiple studies.” So, based on the NUS study’s results alone, I wouldn’t advise going on an all-mushroom diet right away to ensure mental dexterity in retirement. However, there is something to be said for incorporating even a few more portions of veg, fish, and nuts, among many other foods, into our meal repertoire.
Featured Image: Sara Dubler/ Unsplash
Are you a fan of mushrooms? Let us know your thoughts!
