Dementia is proving very difficult to treat with medication, but there may already be secret ingredients hiding in our diets that help the brain.
A study of more than 50,000 participants in the British Biobank found that people who eat a handful of nuts every day may reduce their risk of dementia for all causes, Science Alert reports.
Compared to people over the age of 60 who don't eat nuts, those who reported eating up to 30 grams of nuts a day had a 16% lower risk of developing dementia in the future.
If nuts are eaten without salt, this percentage rises to 17%. It didn't matter if the nuts were dried, roasted or shelled.
This sounds like good news, but there are a few caveats. These results have only been found in people who are not considered obese, who get a normal amount of sleep, and who do not smoke tobacco or drink alcohol daily.
No significant associations were found when only men in all age groups were considered or in those who reported other risk factors, such as muscle weakness or feeling lonely.
"Future long-term follow-up studies, both observational and clinical, should evaluate the efficacy of nut consumption as a strategy to prevent dementia in adults," write the researchers from the University of Castilla-La Mancha in Spain.
This isn't the first time nuts have been linked to brain health. They are energy-dense foods rich in anti-inflammatory and antioxidant nutrients and compounds.
Because of this, scientists hypothesize that the properties of nuts could have brain health benefits. Some epidemiological studies certainly suggest that this may be the case.
In a 12-week controlled study, researchers found that a handful of peanuts daily improved short-term memory and verbal fluency in healthy, overweight middle-aged adults.
However, several other clinical trials have found no such benefits.
To clarify the inconclusive results, health researcher Bruno Bizozero-Peroni and colleagues from Castilla-La Mancha used a group from the UK Biobank enrolled between 2007 and 2012.
Participants were followed for an average of 7 years. At the time of the study, the all-cause dementia rate was 2.8%. Those who said they ate 30 grams of nuts a day (equivalent to about a handful) were less likely to fall into this risk category.
The reasons for this association are unclear. At this stage, it is unclear what leads to the various forms of dementia, let alone what is able to prevent them and why.
"So far, pharmacological treatments for dementia have shown only modest beneficial effects, especially in terms of preventing disease progression," Bizozero-Perroni and colleagues write.
However, emerging evidence suggests that up to 40% of dementia cases can be prevented or even delayed by changing certain lifestyle risk factors, such as smoking, drinking alcohol, exercise or social isolation.
Diet seems to be crucial. In the past, several systematic reviews have found that a healthy diet, such as the Mediterranean diet, is associated with a reduced risk of dementia. At the same time, the Western diet, which is high in saturated fat, sugar and salt, appears to be a risk factor for dementia.
A recent study of 60,000 Britons found that following a Mediterranean diet reduced the risk of dementia by as much as 23%.
Further research revealed that olive oil, a staple of the Mediterranean lifestyle, can reduce the risk of dementia-related death by 28%.
These are really promising figures that need to be investigated further, especially as only a quarter of the UK Biobank group reported eating nuts regularly. | BGNES
