Dementia research has made great strides compared to just a few years ago. There is now a blood test that can correctly diagnose Alzheimer’s in 90% of cases, and we now know more about the factors (many of which are lifestyle habits) that can increase the risk of the disease.
A new dementia report published by researchers from the Lancet Commission in the journal The Lancet has identified two new modifiable risk factors: high cholesterol after age 40 and untreated vision loss.
In 2020, the same researchers identified 12 modifiable risk factors known to put people at higher risk of developing dementia. These are:
- Physical inactivity
- Smoke
- Excessive alcohol consumption
- Air pollution
- Head injury
- Rare social contact
- Less education
- obesity
- hypertension
- diabetes
- depression
- Hearing impairment
According to the report, these 12 factors, together with the two new factors, are responsible for 49% of all dementia cases worldwide. The researchers identified these two new risk factors based on recent meta-analyses and studies on these topics. They examined 14 papers on vision loss and 27 on high cholesterol.
“Mechanistically, this makes a lot of sense,” said Dr. Arman Fesharaki-Zadeh, a behavioral neurologist and neuropsychiatrist at Yale Medicine in Connecticut. “Many of these factors are closely linked.” (Fesharaki-Zadeh is not involved in the report.)
“Of course, there are many causes of vision loss, but it tends to be much more common in people who have metabolic risk factors such as high blood pressure, poorly controlled diabetes or high cholesterol, which is the other risk factor (cited in the report),” he said.
What’s more, sight is our most important sense organ – it’s how we process the world around us – and when you can’t see clearly, you’re less likely to spend time doing brain-boosting activities like doing puzzles, reading or even socializing, Fesharaki-Zadeh said. And those activities have been shown to help prevent dementia.
High levels of LDL cholesterol (so-called bad cholesterol) can lead to hardening of blood vessels in the heart and brain, Fesharaki-Zadeh said, adding that high blood pressure and untreated diabetes also affect blood vessels.
This can result in less oxygen reaching the brain, which over time can lead to neuronal damage – “and dementia is essentially an end product of neuron death, so it is a neurodegenerative process,” explains Fesharaki-Zadeh.
“I can’t tell you how often I see in our patients, especially people over 60, that there are certain parts of the brain that are more susceptible to damage… and those are the areas that are particularly susceptible to atherosclerosis. In someone who… has high cholesterol, the correlation between that and atherosclerosis is quite high, and we see that very frequently in our clinical setting as well.”
“I like to use the saying often with my patients: What affects your heart also affects your brain. And we see that again and again,” said the doctor.
Olena Ruban via Getty Images
You can reduce your risk. First, make sure you have a good medical team and a good family doctor.
“I cannot stress enough the importance of a collaborative model between primary care physicians and specialists,” said Fesharaki-Zadeh. A primary care physician who understands your health condition and is willing to share relevant information with specialists such as cardiologists and neurologists will help you stay on top of any issues that threaten your well-being.
Your doctor should also be proactive in helping you control risk factors such as high cholesterol and high blood pressure, through medication, a healthy diet or exercise.
Fesharaki-Zadeh says you and your doctor should focus on these lifestyle changes as early as possible, at least in midlife, rather than when dementia begins to show itself.
“The first point of contact for medical care is the family doctor. These people can do a lot to prevent the onset of dementia through early discussions,” he explained.
There are also tests that can detect early signs of neurodegeneration and genetic markers of the disease. Your primary care doctor can help you learn more about these possibilities.
“Up to 40% of all dementia cases are potentially preventable,” he added. However, it is important to note that dementia can also be genetic, making prevention more difficult. But even someone diagnosed with dementia or mild cognitive impairment can benefit from treating these risk factors.
“Research also shows that if you compare two groups of people – a person with comorbid metabolic diseases such as high blood pressure, high cholesterol or diabetes – and a person without these diseases, and both people have dementia – dementia tends to progress more slowly in the person without metabolic risk factors,” explained Fesharaki-Zadeh.
It is never too late to make changes and corrections, he noted, whether one is a young, apparently healthy person, in one’s eighties or nineties, or whether one has already been diagnosed with dementia.
Our brains are very malleable, Fesharaki-Zadeh said, so if you decide at some point to make a healthier lifestyle, your brain will respond and be healthier.
