A greasy takeaway may seem like an innocent Friday night indulgence. But our recent research suggests even a single high-fat meal could impair blood flow to the brain, potentially increasing the risk of stroke and dementia.
Dietary fat is an important part of our diet. It provides us with a concentrated source of energy, transports vitamins and when stored in the body, protects our organs and helps keep us warm. The two main types of fat that we consume are saturated and unsaturated (monounsaturated and polyunsaturated), which are differentiated by their chemical composition.
But these fats have different effects on our body. For example, it is well established that eating a meal that is high in saturated fat, such as that self-indulgent Friday night takeaway pizza, can be bad for our blood vessels and heart health. And these effects are not simply confined to the heart.
The brain has limited energy stores, which means it is heavily reliant on a continuous supply of blood delivering oxygen and glucose to maintain normal function.
One of the ways the body maintains this supply is through a process known as "dynamic cerebral autoregulation". This process ensures that blood flow to the brain remains stable despite everyday changes in blood pressure, such as standing up and exercising. It's like having shock absorbers that help keep our brains cool under pressure.
But when this process is impaired, those swings in blood pressure become harder to manage. That can mean brief episodes of too little or too much blood reaching the brain. Over time, this increases the risk of developing conditions like stroke and dementia.
After eating a meal high in saturated fat, levels of fat in the blood rise and peak after around four hours. At the same time, blood vessels become stiffer and lose their ability to relax and expand. This restricts blood flow around the body. But little is known about what happens to the brain during this time and how well its blood supply is protected.
[...] Our findings confirmed previous research that has shown that a high-fat meal impairs the ability of the blood vessels linked to heart health to open in both young and old participants. These impairments reduced the brain's ability to buffer changes in blood pressure. This was more pronounced (by about 10%) in the older adults, suggesting that older brains may be more vulnerable to the effects of the meal.
Although we didn't directly test for the long-term effects of a high-fat meal on mental functioning in this study, we have previously shown that such a meal increases free radicals (unstable, cell-damaging molecules) and decreases nitric oxide (molecules that help blood vessels relax and open up to transport oxygen and glucose around the body).
This may explain the reduced blood flow regulation we observed in our recent study.
[...] This has important clinical implications. While an occasional takeaway is unlikely to cause harm on its own, our results suggest that even one fatty meal has an immediate effect on the body.
Our study highlights the importance of consuming a diet that is low in saturated fat to protect not only our heart health, but also our brain health. This is particularly important for older adults whose brains appear to be more vulnerable to the effects of such a meal and are already at increased risk of stroke and neurodegenerative diseases.
[...] Public health guidance recommends swapping saturated fats for polyunsaturated ones. These are found in foods like oily fish, walnuts and seeds, which are associated with better heart and brain health over the long term. But we don't yet know how the brain responds to a single meal that is high in polyunsaturated fat.
Nor do we know how the female brain responds to a high-fat meal. This is a crucial gap in our knowledge since women face a greater risk of stroke and dementia in later life compared to men.
Our study offers a timely reminder that diet doesn't just shape our long-term health. It also affects our body and brain in real time. And as we're learning, when it comes to protecting brain health, every meal may count.
Journal Reference: Post-prandial hyperlipidaemia impairs systemic vascular function and dynamic cerebral autoregulation in young and old male adults
(Score: 5, Insightful) by Anonymous Coward on Wednesday September 03 2025, @10:49AM (2 children)
Is that about 20-30g of sugar? How about do a similar test without so much sugar? Sugar is not an inert substance.
(Score: 4, Informative) by gnuman on Wednesday September 03 2025, @03:04PM (1 child)
OK, not really a big problem here. Glucode Challenge tests have 50g of sugar. This is half of that. 20-30g of sugar is not very much at all and body can absorb this readily. This was probably added to make it less disgusting to drink :-)
Apparently 50% of calories are suppose to be carbs and 25% fat. Since carbs are 4 calories/g and fat is like 16/g, the ratio in weight should be more like 1g FAT to 8g of carbs. So, for the 130g of fat, they should have 1000g of carbs.... which they didn't. Nutealla is 1g of fat to 2g of sugar and that seems to be something that is used to treat malnourished people because this ratio is easily absorbs. So, the shake needs 250g of sugar to be Nutealla-like.
So, let's just say, what they fed people here were butter sticks with a sprinkle of sugar. It is DEFINITELY NOT the sugar sprinkle that was causing the issues in question. Fat goes in blood -- and too much fat will cause issues. This is known and there is even a term for that -- dyslipidemia. The picture there tells you the problem right away.
https://en.wikipedia.org/wiki/Dyslipidemia [wikipedia.org]
(Score: 2, Interesting) by Anonymous Coward on Thursday September 04 2025, @01:18AM
Sugar/carbs can make a diff: https://en.wikipedia.org/wiki/Ketogenic_diet [wikipedia.org]
So for research should probably do control, high fat + some sugar, high fat no sugar.
But I guess that's for the next paper some years later... Got to publish more to avoid perishing...
(Score: 2) by VLM on Wednesday September 03 2025, @12:12PM (5 children)
Certainty about this exists primarily outside medical research
Mostly only true because of the weasel word "can". Which also implies "can not". Generally the newer and better the research the stronger the evidence for "can not". It seems very hard to have CVD without high A1C, T2 diabetes symptoms, high-to-ridiculous carb intake...
https://pmc.ncbi.nlm.nih.gov/articles/PMC10495817/ [nih.gov]
Only in scientific research. Never in legacy public media, ever, its a religious belief of people who generally historically give VERY bad advice. Isn't that interesting?
(Score: 2) by gnuman on Wednesday September 03 2025, @03:06PM (4 children)
I kind of have to agree with you. Diet is NOT a milkshake either. So, if they wanted to compare eating a whole pizza vs. their butter-milkshake, they should have let people eat whole pizza instead.
(Score: 2) by mcgrew on Wednesday September 03 2025, @07:04PM (3 children)
What I've wondered when reading the blurb is "pizza?" Where in pizza is there any fat, except the grease from the meat?
I'd think more of stuff that's deep fried, like French fries. Do people eat deep fried pizza?
The Stupid-Ass Voter Evisceration act: SAVE Trump and his family from prison
(Score: 3, Informative) by HiThere on Wednesday September 03 2025, @09:46PM
There are lots of sources of fat in pizza. Cheese, for one, but also olive oil in any decent pizza. Meat is an optional extra, and not present in all pizzas.
Javascript is what you use to allow unknown third parties to run software you have no idea about on your computer.
(Score: 2) by hendrikboom on Wednesday September 03 2025, @10:09PM
There's fat in the cheese.
(Score: 2) by gnuman on Saturday September 06 2025, @05:24PM
There's a lot of fat in pizza, but there is also a lot of carbs -- from the dough. When I make 3 pizzas, I use about 400g of flour (220g water) + 250g of cheese (16% fat content) + 150g of salami (32% fat content) + some pesto and vegetables which I will not count, since irrelevant. There's also probably about 20g of olive oil.
This gets me, not counting protein,
1600 cal carbs
40+50+20=110g of fat, which also can be rounded off to 1600 cal fat. So, a less than healthy ratio of about 40:40:20 carbs:fat:protein calories ratio. Too much fat. I could cut the fat by using ham instead of salami.
But this also gives me 1000 calories per pizza here. And I can easily eat one. Maybe even 2 if I'm really hungry. Hell no can I eat 3 of them. And that would be 110g of fat in 3. So I'm not sure what they were comparing here, but it's not a normal-ish diet by any stretch of imagination.
(Score: 4, Touché) by pTamok on Wednesday September 03 2025, @02:36PM (4 children)
Obviously, what one needs to do after a high-fat meal is for several hours to minimise activities that raise blood-pressure - so wallowing in the sofa like a beached whale is the way to go. Having a couple of alcoholic drinks also produces a temporary drop in blood pressure - all to the good.
(No, this is not meant seriously: but cherry-picking the 'good' effects of inactivity and alcohol ingestion is exactly the same technique as cherry-picking the bad effects to try and convince people to do or not do stuff. Life is a lot more complicated than that.)
(Score: 3, Insightful) by krishnoid on Wednesday September 03 2025, @04:38PM (2 children)
Comparatively, I wonder how the blood pressure would trend over time if they took a brisk walk right afterwards.
(Score: 2) by Reziac on Thursday September 04 2025, @02:07AM (1 child)
I'm wondering how they explain Eskimos, and other folks who routinely eat a very high fat diet.
And there is no Alkibiades to come back and save us from ourselves.
(Score: 3, Insightful) by jelizondo on Thursday September 04 2025, @03:00AM
The explanation is simple, they aren't sitting [nih.gov] all day in an office:
When hunting and just burning calories just to keep you body temperature, so can get away with a lot of things that a sedendtary person can't. It's late here and I just don't have the energy to find a different study on modern Inuit (we don't call them Eskimos anymore!) and if memory serves me right, they were in trouble: heated homes, lots of couch surfing, and a traditional diet that is killing them.
Kind of the same shit happening to Samoan people: their new "western-style" diets are making them overweight, prone to diabetes and heart decease. We (we as in people) can see that lack of physical activity, high-sugar high-fat diets are driving people to be severely overweight and the associated problems. It is nor kind the same when you are out and about all day fishing (Samoa), hunting (Inuit) or tending the fields (USA), than when you sit on a chair for half the day.
(Score: 5, Insightful) by Thexalon on Wednesday September 03 2025, @05:46PM
To me the salient point remains that there are basically no studies blared in media regularly that are about backing up what everybody knows to be healthy: Eat your fruits and veggies like your mom told you along with the other stuff, and get some moderate exercise at least a few times a week. Do those regularly, and something else will kill you before your diet and lifestyle does.
But a lot of these studies are funded by people trying to sell some fancy product, so they can't just say "Eat more green salads and get a good walk in!"
"Think of how stupid the average person is. Then realize half of 'em are stupider than that." - George Carlin
(Score: 0) by Anonymous Coward on Wednesday September 03 2025, @02:57PM
Being unable to properly digest lactose, there's a good chance I'd blowup if I even attempted consuming this. :p
(Score: 2) by DadaDoofy on Wednesday September 03 2025, @08:59PM
Whacked by Bobby Booze and Frankie Foie Gras.
https://nypost.com/2013/06/21/sopranos-star-james-gandolfini-guzzled-at-least-eight-drinks-during-his-final-meal-source/ [nypost.com]