An recent analysis of UK Biobank data revealed that individuals who frequently consume raw vegetables tend to have a higher total volume of brain white matter. Those with a higher intake of fresh fruit generally have a lower total volume of grey matter. However, they exhibit larger grey matter volumes in brain areas associated with dementia and depression. The findings, published in NeuroImage, suggest that regular consumption of fresh fruits and raw vegetables may have a positive impact on brain structure.
Consuming fruits and raw vegetables offers a rich source of essential vitamins, minerals, and antioxidants, crucial for overall health and well-being. These foods contribute to a lower risk of chronic diseases such as heart disease, certain cancers, and diabetes. Additionally, fruits and raw vegetables, high in dietary fiber, promote digestive health and aid in maintaining a healthy weight by providing a feeling of fullness.
A recent meta-analysis has indicated that a high consumption of fruits and vegetables is linked with a lower risk of depression. Similarly, another study reported an association between high consumption of fruits and vegetables and a reduced risk of cognitive impairment and dementia. Despite these findings, the physiological mechanisms underlying these associations remain unclear.
Study author Santino Gaudio and his colleagues wanted to investigate the relationship between fruit and vegetable consumption and the characteristics of brain structures in healthy individuals from the general population. They were particularly interested in the potential connections between levels of fruit and vegetable intake and the volumes of grey and white matter in the brain, as well as the brain’s total volume.
To this end, they analyzed data from the UK Biobank database, a large-scale biomedical database and research resource containing genetic and health information from over 500,000 UK residents. This data is frequently used in studies to understand the complex interactions between genetics, lifestyle, and various diseases.
White matter and grey matter are the two primary types of tissue in the brain. Grey matter, which forms the brain’s outer layer, comprises neuronal cell bodies, dendrites, and synapses. In contrast, white matter, situated beneath the grey matter, consists of nerve fibers that establish connections between different grey matter areas, facilitating communication across various brain regions.
For their study, the researchers utilized magnetic resonance imaging data from 9,925 UK Biobank participants, collected between 2014 and 2019. These participants also provided dietary information through an online questionnaire. They reported their intake of dried and fresh fruit as well as cooked vegetables and salads/raw vegetables. On average, the participants were slightly overweight and aged between 44 and 80 years.
On average, participants reported consuming 2.10 pieces of fresh fruit and 0.80 pieces of dried fruit per day. They also reported consuming 2.62 tablespoons of cooked vegetables and 1.98 tablespoons of raw vegetables daily. Notably, individuals who consumed more raw vegetables generally had a higher total volume of white matter. However, those who consumed more fresh fruit daily typically had a lower total volume of grey matter.
Upon examining the associations with grey and white matter volumes in specific brain regions, the researchers found that individuals consuming more fresh fruit tended to have larger grey matter volumes in the left hippocampus, bilateral juxtapositional lobule cortex, left postcentral gyrus, and right temporal occipital fusiform cortex. Additionally, a higher intake of fresh fruit was associated with an increased grey matter volume in the right precentral gyrus.
“Fruit and vegetable consumption seems to specifically modulate brain volumes. In particular, fresh fruit intake may have a protective role in specific cortical areas such as the hippocampus, areas robustly involved in the pathophysiology of dementia and depression,” the study authors concluded.
While the study highlights the connections between dietary choices and brain volumes, it is important to note that its design does not allow for cause-and-effect conclusions from the findings. It remains uncertain whether fruit and vegetable consumption directly influences brain volumes, or if individuals with higher volumes in certain brain areas are more inclined to consume fruits and vegetables. Other possibilities also remain open, and it is worth noting that the observed associations are relatively weak.
The paper, “Higher fresh fruit intake relates to larger grey matter volumes in areas involved in dementia and depression: A UK Biobank study”, was authored by Santino Gaudio, Gull Rukh, Vincenzo Di Ciommo, Samuel Berkins, Lyle Wiemerslage, and Helgi B. Schioth.