New research has found that inflammatory bowel disease (IBD) is linked to a six-fold risk of Alzheimer’s disease – and an overall doubling the risk of dementia of all types.
It was also found that dementia was diagnosed seven years earlier in people with IBD than in those without the condition. This suggests that IBD may hasten the onset of dementia.
The research, led by Taiwan’s Taipei Veterans General Hospital, is the latest to explore disruptions in what is known as the gut-brain axis.
This is a complex communication system between the gut and the bacteria living there – the microbiome – and the central nervous system.
An earlier study found that IBD might trigger or somehow play a role in the development of Parkinson’s disease. Other research has “indicated chronic inflammation and an imbalance in gut bacteria as potential contributors to cognitive decline.”
But the link between IBD and a heightened risk of dementia remained unclear.
How they found the connection
According to a statement from the British Medical Journal (BMJ):
- The researchers drew on data for 1742 people aged 45 and above who had been diagnosed with either ulcerative colitis or Crohn’s disease between 1998 and 2011.
- All participants were registered with the Taiwan National Health Insurance program, set up in 1995 and compulsory for all Taiwanese residents.
- The cognitive health of participants was tracked for 16 years following their IBD diagnosis and compared with that of 17,420 people who were matched for sex, age, access to healthcare, income, and underlying conditions, but who didn’t have IBD.
- During the monitoring period, 5.5 per cent (more than one in 20) of participants with IBD developed dementia. Of those without IBD, only 1.5 per cent developed dementia (5.5%), including Alzheimer’s disease, than those without (1.5%).
- Partcipants with IBD were diagnosed with dementia an average seven years earlier than those without IBD.
The risk for Alzheimer’s disease was greatest
After taking account of potentially influential factors, including age and underlying conditions, people with IBD were more than twice as likely to develop dementia as those without.
The risk for Alzheimer’s disease was greatest: those with IBD were six times as likely to develop this as were those without IBD.
The BMJ said the risk of dementia “seemed to be associated with increasing length of time a person had had IBD.”
Limits of the study
This observational study can’t establish cause and effect. The study was unable to gather information “on potentially influential lifestyle factors, such as diet and exercise, or assess the impact of anti-inflammatory drugs prescribed.”
Still, the researchers were moved to conclude that patients with IBD “might benefit from education and increased clinical vigilance,” to slow cognitive decline and improve quality of life.
What’s also missing is a clear answer to what causes IBD.
The BMJ noted: “It is thought to develop from an impaired immune response to changes in the gut microbiome.”
IBS and IBD: High fat diet and antibiotics a risk
Irritable Bowel Disease (IBD) is a complex inflammatory condition.
Irritable Bowel Syndrome (IBS) is non-inflammatory and, despite sharing symptoms with IBD, a different condition entirely.
Aside from abdominal pain and bloating, the speed of one’s bowels is speeded up or slowed down.
When IBS patients develop mucosal inflammation and experience changes in the composition of the microbiome, they’re said to be pre-IBD – and are on the verge of developing a condition of the immune system.
A new small study from the University of California found that people who consume high-fat diet and used antibiotics are at 8.6 times higher risk for having pre-IBD than those on low-fat diet and no recent history of antibiotic use.
There were 92 participants: 43 healthy adults, and 49 IBS patients.
They were tested for fecal calprotectin, a biomarker for intestinal inflammation. Elevated levels of fecal calprotectin suggest pre-IBD condition. The study identified 19 patients with IBS as pre-IBD.
Participants with the highest fat consumption were about 2.8 times more likely to have pre-IBD than those with the lowest fat intake.
A history of recent antibiotic usage alone was associated with 3.9 times higher likelihood of having pre-IBD.