Carrying excess body weight, especially around the belly, has long been linked with an increased risk of Alzheimer’s disease. But now, researchers have found that it may be a specific type of belly fat that is causing this increased risk.
The type of belly fat in question is known as visceral fat, and is found deep within the abdominal cavity around the organs.
It’s also sometimes called ‘toxic’ fat and can cause many health issues including heart disease, high blood pressure and certain cancers.
What is visceral fat?
Visceral fat, like most fat buildup, is caused by consuming more calories than you burn through activity. Or put more bluntly, it’s caused by eating too many fatty foods and not exercising enough.
People who are visibly fat (have a lot of subcutaneous fat) will also have visceral fat, but it’s also possible for people who are visibly skinny to be carrying a large amount of visceral fat on the inside.
Because visceral fat is buried deep within the body, it’s possible to have a large amount of it around the organs without appearing to be overweight. This phenomenon is known as being ‘skinny fat’.
Skinny fat refers to people whose body mass index (BMI) is in the normal range for their height, appear lean, but who carry a very high percentage of body fat versus muscle.
The culprit in these instances is usually visceral fat. So, your friend who seems to be able to eat any junk food they like but still stay skinny is potentially living with a false sense of security.
Link between visceral fat and Alzheimer’s
Now, even the brain may be under threat from visceral fat. Research presented to the Radiological Society of North America (RSNA) has linked visceral fat to a significantly increased risk of developing Alzheimer’s disease starting many years before symptoms appear.
“This hidden abdominal fat is related to changes in the brain up to 15 years before the earliest memory loss symptoms of Alzheimer’s disease occur,” the RSNA says in a statement.
In the study, researchers analysed data from 54 people aged between 40 and 60 with no signs of any cognitive deficiencies or decline. All participants in the study had an average BMI of 32, or the middle of the ‘obese’ category.
All participants had their volume of visceral fat measured using an abdominal MRI and underwent glucose and insulin measurements.
Another MRI then measured the cortical thickness of brain regions most commonly affected by Alzheimer’s and looked for an accumulation of protein fragments between neurons that are typical of the lead-up to the disease.
The results showed that a higher visceral to subcutaneous fat (visible belly fat) ratio was associated with “higher amyloid PET tracer uptake in the precuneus cortex”, which is the region known to be affected early by Alzheimer’s disease.
The researchers found the relationship was stronger in men than in women. They also found that higher visceral fat measurements were related to an increased burden of inflammation in the brain.
Associate Professor Cyrus A. Raji, lead author of the study, says the results have important key implications when it comes to earlier detection and treatment of Alzheimer’s.
“This study highlights a key mechanism by which hidden fat can increase the risk of Alzheimer’s disease,” he says.
“It shows that such brain changes occur as early as age 50, on average – up to 15 years before the earliest memory loss symptoms of Alzheimer’s occur.”
So, if you consume a lot of fatty foods and don’t exercise, you may be setting yourself up for trouble down the line, even if you appear to be skinny now.
Is there a history of Alzheimer’s in your family? How much exercise do you do each week? Let us know in the comments section below.
Also read: Sugary diet linked to fatty liver disease in non-drinkers