Extensive research shows that a high degree of belly fat increases the risk of cognitive impairments. Muscle mass, on the other hand, appears to have a protective effect.
Fat Sucks… Harder Every Time
Researchers are very good at finding reasons why you shouldn’t be overweight. Or rather: Why you shouldn’t have too much body fat. They are so good at it that we could write a new article every week about the disadvantages of obesity. I think I see about two to three new studies on the negative effects of obesity on average every week. Most of them are left untreated. First, because they often confirm what we’ve known for a long time. Second, because we don’t want to be such a ‘doom blog’: “Everyone is getting fat, the end is near!!” Unfortunately, researchers are better at demonstrating the dangers of obesity than finding solutions. Not that they’re not looking hard for them. It happens continuously, often with hopeful results. But they pale in comparison to all the bearers of bad news. However, I thought I should share this bad news. It points to a danger from perhaps an unexpected direction.Overweight and Cognitive Ability
‘Cognitive impairment’ is a collective term for various neurological problems such as learning difficulties, attention problems, and memory problems. Problems that often occur with old age and can be a precursor to dementia. Earlier studies had already shown that people with overweight perform worse on various cognitive tests. Think of memory tests, problem-solving skills, and the ability to plan [1,2,3,4]. Many of these studies were conducted among middle-aged people. Researchers used data from the Irish Trinity Ulster Department of Agriculture to learn more about this relationship in the elderly. A worrying relationship given that more than half of the Irish population over 50 is overweight. Only 16% of men and 26% of women have a BMI within normal values.The Real Culprit? Belly Fat
The researchers had access to information from thousands of older people in Ireland and Northern Ireland. As far as the researchers know, this is the largest study to date to look at this relationship in the elderly. They found that a high waist-to-hip ratio was associated with reduced cognitive ability. According to the researchers, this can be explained by an increased release of inflammation-promoting elements by belly fat. A relationship that had already been demonstrated in research. However, BMI was found to have a protective effect on cognitive function. BMI cannot distinguish between lean mass and fat. Therefore, the researchers suspect that it is mainly lean mass that is responsible for the protective effect. The researchers therefore conclude that combating overweight (more specifically: belly fat) could be a relatively inexpensive way to prevent the decline in cognitive abilities in old age.While we have known for some time that obesity is associated with negative health consequences our study adds to emerging evidence suggesting that obesity and where we deposit our excess weight could influence our brain health. This has significant public health implications. Conal Cunningham
Weight: More Than Fat
So I wonder if there will be people who are even more motivated by this to work on their body fat percentage. Perhaps there are people who weren’t impressed by the chance of, for example, diabetes or all the other doomsday scenarios, but are very afraid of becoming forgetful later on. Maybe this is just the right button for some. For me, it shows more how important it is in studies on overweight never to use weight itself (whether or not translated into BMI) as the main variable. Effects of more muscle mass can be attributed to fat mass and vice versa. It says little about body fat percentage while total body fat percentage says little about distribution. In this study, the researchers also looked at the waist-to-hip ratio as an indication of that distribution of fat mass. Then it becomes clear again how important it is to make that distinction.References
- Nilsson LG, Nilsson E. Overweight and cognition. Scand J Psychol. 2009 Dec;50(6):660-7. doi: 10.1111/j.14679450.2009.00777.x. PubMed PMID: 19930267.
- Gunstad J, Paul RH, Cohen RA, Tate DF, Spitznagel MB, Gordon E. Elevated body mass index is associated with executive dysfunction in otherwise healthy adults. Compr Psychiatry. 2007 Jan-Feb;48(1):57-61. Epub 2006 Jun 30. PubMed PMID: 17145283.
- Lokken KL, Boeka AG, Yellumahanthi K, Wesley M, Clements RH. Cognitive performance of morbidly obese patients seeking bariatric surgery. Am Surg. 2010 Jan;76(1):55-9. PubMed PMID: 20135940.
- Whitmer RA, Gunderson EP, Barrett-Connor E, Quesenberry CP Jr, Yaffe K.Obesity in middle age and future risk of dementia: a 27 year longitudinal population based study. BMJ. 2005 Jun 11;330(7504):1360. Epub 2005 Apr 29. PubMed PMID: 15863436; PubMed Central PMCID: PMC558283.
- Ontefetse Ntlholang, Kevin McCarroll, Eamon Laird, Anne M. Molloy, Mary Ward, Helene McNulty, Leane Hoey, Catherine F. Hughes, J. J. Strain, Miriam Casey, Conal Cunningham. The relationship between adiposity and cognitive function in a large community-dwelling population: data from the Trinity Ulster Department of Agriculture (TUDA) ageing cohort study. British Journal of Nutrition, 2018; 1
- https://www.cambridge.org/core/journals/british-journal-of-nutrition/article/relationship-between-adiposity-and-cognitive-function-in-a-large-communitydwelling-population-data-from-the-trinity-ulster-department-of-agriculture-tuda-ageing-cohort-study/92B48D9F2754CE425A88482506CAAED6
