Due to a global increase in dementia prevalence, with a 20% addition of 50 million cases annually, Zhang et al. (2021) looked at dietary factors as one of the causative environmental factors associated with this increase. The authors were particularly interested in the relationship between meat consumption and the risk for dementia cases. The scholars’ concentration on meat consumption arises from heightened healthcare interest in this food due to its high consumption and positive relation to colorectal cancer.
Methodology
Using the UK Biobank cohort, the researchers recruited 493,888 participants and subjected them to a short dietary questionnaire and dietary assessment repeated every twenty-four hours. Afterward, they used electronic linkage to link their findings to all-cause dementia in the bio-database. The procedure allowed them to link different dietary meat types to each type of dementia, including Alzheimer’s disease (AD) and vascular dementia (VD). At recruitment, the dietary questionnaire included a brief filling out of 47-day dietary habits on a touchscreen FFQ. A further meat-related questionnaire assessed the consumption of processed and unprocessed meat, including summations of unprocessed red meat. Fish were excluded. Bio-data linkages affirmed the cases of incidence of dementia. The linkage of dietary meat to dementia only included incidences that occurred after the first year of follow-up. Notably, two similar genotyping arrays were used to arrive at two distinct genetic variants that could be associated with dementia incidences. Participants with ε4 alleles were categorized as carriers, while those without as non-carries. The differentiation of two key genetic variants in the UK Biobank cohort was necessary for the association of specific genetics to the increased risk for all-cause dementia.
Results
After the one-year baseline for incidence, the researchers identified 2896 new cases of all-cause dementia, with 1006 AD and 490 VD cases. Results showed that dementia cases were more likely to be older, economically disadvantaged, have less education, smoke, have stroke history, family dementia history, and be ε4 carriers. Men made up a greater chunk of those diagnosed with dementia, and people in the highest category of incidence of dementia were more likely to be men with high processed meat and total meat consumption. Specifically, larger processed meat consumption was associated with heightened AD risk, while unprocessed meat consumption reduced the risk. The linkage of meat types to VD was not statistically significant. On genetics, even without meat consumption, ε4 carriers had a higher risk for all-cause dementia. However, with a 25grams per day increase in dietary processed meat for ε4 carriers and non-carriers, there was an increased risk for all-cause dementia. On the other hand, non-carriers, unlike ε4 carriers, had a reduced risk for all-cause dementia with a 50-gram-per-day increase in dietary unprocessed meat.
Discussion
As a result, the researchers linked the consumption of more processed meat with a heightened risk of all-cause dementia and AD. Unprocessed meat was proven to reduce the risk of all-cause dementia. Also, although ε4 alleles were associated with an increased risk for dementia, the differences between meat consumption linkage to dementia for both non-carriers and carriers were insignificant. The differences in processed and unprocessed meats’ linkage to dementia could be attributable to the high protein intake in unprocessed meat since adequate protein intake has been associated with lower cognitive decline and dementia. Also, high dietary iron in unprocessed meat has been linked as a protective factor in cognitive decline. On the other hand, processed meat is characteristic of nitrites, nitroso compounds, and high sodium, all of which are recipes for accelerating mental hardware declines. However, despite the attribution of the nutritional composition of processed and unprocessed meat to higher and lower risk of dementia, respectively, it should be noted that increased consumption of all meats increases dietary saturated fats and explains the association of meat with increased dementia risk. Finally, irrespective of genetic predisposition, the research links processed meat to a higher risk of all-cause dementia.
Personal Implications
The research is eye-opening on the link of meat consumption and other dietary nutritional components to dementia and lifestyle diseases. The research shows that unprocessed meat is better than processed meat because of its nutritional composition and its benefits for the body. For instance, unprocessed meat has an adequate composition of protein and iron, while processed meats have lesser compositions plus an increase of other unfavorable nutrients, including saturated fats and sodium. However, both processed and unprocessed meats contain saturated fats, which are a risk for lifestyle disorders, including dementia. The research is impactful personally and for public health policy as it unearths processed meats as a risk for dementia, particularly AD, whose prevalence is on the rise. Other than encouraging the consumption of unprocessed meats, the article checks the need for necessary meat consumption.
References
Zhang, H., Greenwood, D. C., Risch, H. A., Bunce, D., Hardie, L. J., & Cade, J. E. (2021). Meat consumption and risk of incident dementia: cohort study of 493,888 UK Biobank participants. The American journal of clinical nutrition, 114(1), 175-184.
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