Greater body fat a risk factor for reduced thinking and memory ability

Sonia Anand


Lead author Sonia Anand is a professor of medicine of McMaster University’s Michael G. DeGroote School of Medicine and a vascular medicine specialist at Hamilton Health Sciences (HHS). CREDIT McMaster University

 A new study has found that greater body fat is a risk factor for reduced cognitive function, such as processing speed, in adults.

Even when the researchers took cardiovascular risk factors (such as diabetes or high blood pressure) or vascular brain injury into account, the association between body fat and lower cognitive scores remained. This suggests other not yet confirmed pathways that linked excess body fat to reduced cognitive function.

In the study, 9,166 participants were measured by bioelectrical impedance analysis to assess their total body fat.

As well, 6,733 of the participants underwent magnetic resonance imaging (MRI) to measure abdominal fat packed around the organs known as visceral fat, and the MRI also assessed vascular brain injury – areas in the brain affected by reduced blood flow to the brain.


“Our results suggest that strategies to prevent or reduce having too much body fat may preserve cognitive function,” said lead author Sonia Anand, a professor of medicine of McMaster University’s Michael G. DeGroote School of Medicine and a vascular medicine specialist at Hamilton Health Sciences (HHS). She is also a senior scientist of the Population Health Research Institute of McMaster and HHS.

She added that “the effect of increased body fat persisted even after adjusting for its effect on increasing cardiovascular risk factors like diabetes and high blood pressure, as well as vascular brain injury, which should prompt researchers to investigate which other pathways may link excess fat to reduced cognitive function.”

Co-author Eric Smith, a neurologist, scientist and an associate professor of clinical neurosciences at the University of Calgary, said that “preserving cognitive function is one of the best ways to prevent dementia in old age. This study suggests that one of the ways that good nutrition and physical activity prevent dementia may be by maintaining healthy weight and body fat percentage.”

Smith is head of the brain core lab for the two population cohorts used for this new analysis– the Canadian Alliance for Healthy Hearts and Minds (CAHHM) and PURE Mind- a sub-study of the large, international Prospective Urban Rural Epidemiological (PURE) study.

The participants were in the age range of 30 to 75 with an average age of about 58. Just over 56% were women; they all lived in either Canada or Poland. The majority were White European origin, with about 16% other ethnic backgrounds. Individuals with known cardiovascular disease were excluded.

Understanding Brain Fog & How to Fix It

Understanding Brain Fog & How to Fix It - YouTube


If you’ve ever experienced instances of extreme mental fatigue, difficulty concentrating, and feeling like your brain is short-circuiting during conversations, you may be dealing with brain fog. Learn more about the symptoms, causes, ways to fix brain fog.

Diet may help preserve cognitive function

Pescheria (fish market), Rialto Markets, Venice
Pescheria (fish market), Rialto Markets, Venice


According to a recent analysis of data from two major eye disease studies, adherence to the Mediterranean diet – high in vegetables, whole grains, fish, and olive oil – correlates with higher cognitive function. Dietary factors also seem to play a role in slowing cognitive decline. Researchers at the National Eye Institute (NEI), part of the National Institutes of Health, led the analysis of data from the Age-Related Eye Disease Study (AREDS) and AREDS2. They published their results today in the journal Alzheimer’s and Dementia.

“We do not always pay attention to our diets. We need to explore how nutrition affects the brain and the eye” said Emily Chew, M.D., director of the NEI Division of Epidemiology and Clinical Applications and lead author of the studies.

The researchers examined the effects of nine components of the Mediterranean diet on cognition. The diet emphasizes consumption of whole fruits, vegetables, whole grains, nuts, legumes, fish, and olive oil, as well as reduced consumption of red meat and alcohol.

AREDS and AREDS2 assessed over years the effect of vitamins on age-related macular degeneration (AMD), which damages the light-sensitive retina. AREDS included about 4,000 participants with and without AMD, and AREDS2 included about 4,000 participants with AMD. The researchers assessed AREDS and AREDS2 participants for diet at the start of the studies. The AREDS study tested participants’ cognitive function at five years, while AREDS2 tested cognitive function in participants at baseline and again two, four, and 10 years later. The researchers used standardized tests based on the Modified Mini-Mental State Examination to evaluate cognitive function as well as other tests. They assessed diet with a questionnaire that asked participants their average consumption of each Mediterranean diet component over the previous year.

Participants with the greatest adherence to the Mediterranean diet had the lowest risk of cognitive impairment. High fish and vegetable consumption appeared to have the greatest protective effect. At 10 years, AREDS2 participants with the highest fish consumption had the slowest rate of cognitive decline.

The numerical differences in cognitive function scores between participants with the highest versus lowest adherence to a Mediterranean diet were relatively small, meaning that individuals likely won’t see a difference in daily function. But at a population level, the effects clearly show that cognition and neural health depend on diet.

The researchers also found that participants with the ApoE gene, which puts them at high risk for Alzheimer’s disease, on average had lower cognitive function scores and greater decline than those without the gene. The benefits of close adherence to a Mediterranean diet were similar for people with and without the ApoE gene, meaning that the effects of diet on cognition are independent of genetic risk for Alzheimer’s disease.

Does the cold weather make your brain fog or fibro fog better or worse? Find out what others think here…………..




Cognitive dysfunction (also called brain fog , fibro fog or clouding of consciousness) was a big topic in the early days of Patient Talk.

Brain fog

Brain fog

And at the same time we were also interested in the impact of the reasons ( and the weather) on pain levels. You can see the results of our poll on the subject here.




So I was very interested when Kelly asked “Since the weather has changed to cold, my cognitive function is getting way worse, where I can’t get words out of mouth. Does anyone else experience this the cold?” in our Multiple Sclerosis group yesterday morning.

The feedback was very interesting.

Tracet replied “Yes. Does anyone else have trouble getting people to understand this happens to you? I think people are starting to assume I’m just an idiot, even after explaining cognitive dysfunction.”

For Roberto it is the other way round ” I experience this but it happens when the weather gets warm”.




” Definitely far worse with the cold, I like the heat, thought I was strange as the ‘norm’ is the opposite. I practise Bikram Yoga in the heat which helps me a lot, my neurologist freaked when I told her, but now she thinks its wonderful!” was Brendan’s suggestion.

But for Kristine “I love all the seasons. snow and sun are both fun! Humidity is my killer…”.

No the other hand for Charlene ” For me it is the extreme weather. Extreme cold and heat both make it worse. Of course extreme is a relative term! Lol extreme heat is like 80 and extreme cold is like below 45. Lol”.

But for some ” Doesn’t matter what season it is my mind is one purr muddle I nix up words loose train if thought an forgot what a conversation is I stair in to space like no one is home …but hay I can’t argue with anyone as I forget what has made me mad !!! The joys hay”

So what about you?




Even better could you share your story in the comments section below.

Cognitive dysfunction refers to the loss of intellectual functions such as reasoning, memory , and general thinking which together impair day to day living.. People with brain fog have difficulty with verbal recall, basic arithmetic, and overall concentration.

It can be caused by a variety of medical conditions which include multiple sclerosis, fibromyalgia (hence the term fibro fog), lupus, chronic fatigue syndrome, depression, hypothyroidism, Lyme’s disease and stress. What is interesting , at least to me, is how many of these disorders are auto-immune conditions.

Many thanks in advance for all your help!