People may get away with eating a nutritionally poor diet for a time, but eventually the damage it causes to the body will appear as heart disease, dementia, cancer and other chronic, debilitating diseases.

None of this is up for any scientific debate. But what has shocked researchers is just how quickly unhealthy food choices damage the body.

The latest research shows that just one single high-fat meal is enough to wreak havoc within the blood vessels and the brain in a matter of hours.

Bad for the Heart – Bad for the Brain

A well-known scientific fact in Alzheimer’s research is that what’s good for the heart is also good for the brain. So, it follows that what’s bad for the heart is also bad for the brain.

The connection between the health of the heart and the brain was brought into sharp focus during a study by researchers from the University of Edinburgh, Scotland last year.

After performing brain scans on study participants, researchers found that the more vascular risk factors a person had apart from high cholesterol, such as smoking, high blood pressure, high pulse pressure (the difference between your systolic and diastolic blood pressure numbers), diabetes, and obesity, then the more likely they were to develop structural changes in the brain that lead to dementia.

Researchers have long believed that these risk factors inflict damage to blood vessels over decades and trigger diseases of the heart and brain. Yet two recent studies found that even a single high-fat meal can set the stage for cardiovascular and neurodegenerative disease.

Promotes Enzyme Linked to Heart Attacks

In a study carried out by scientists at Augusta University, healthy young men were given either a milkshake made with whole milk, ice cream and heavy whipping cream containing 80 grams of fat (that’s over the maximum recommended for the whole day) or one with very little fat.

Just four hours later, marked negative changes were seen in the blood, blood vessels, red blood cells and immune system of the high-fat foods group. For instance:

  • Red blood cells got smaller, changed shape and developed spikes.
  • White blood cells promoted inflammation.
  • An enzyme called MPO was expressed that at high levels is linked to rigid blood vessels, oxidative stress and heart attacks. One of the research team described this as “a really powerful finding.”
  • The plasma – the fluid portion of the blood – thickened, was off-color and filled with fats.

The research gives new meaning to the old adage, “You are what you eat.” The good news is that all of these changes will resolve after about eight hours.

“The take home message,” said vascular biologist Julia Brittain, “is that your body can usually handle this if you don’t do it again at the next meal and the next and the next.”

Fat Sinks Ability to Focus by Eleven Percent

In a second study published in May, 51 women were provided with a meal high in either palmitic acid oil, a saturated fat, or sunflower oil, which is lower in saturated fat and higher in unsaturated fat. Both meals were high in total fat.

The high-saturated-fat meal consisted of eggs, turkey sausage, gravy and biscuits containing 60 grams of fat. This is near the upper range of the recommended daily intake of fat for women. It was designed to mimic a typical fast food restaurant meal.

Prior to eating this meal, researchers gave the women tests to measure sustained attention, concentration and reaction time, and then tested them again five hours after the meal. Researchers repeated this process between one and four weeks later except this time each person ate the opposite of what they’d previously consumed.

The main finding was that the women lost their ability to focus easily when they ate high amounts of saturated fat. On average, all the participants were eleven percent less able to sustain attention.

Lead author Annelise Madison from Ohio State University was surprised. “Most prior work looking at the causative effect of the diet has looked over a period of time. And this was just one meal – it’s pretty remarkable that we saw a difference.

“Because both meals were high-fat and potentially problematic, the high-saturated-fat meal’s cognitive effect could be even greater if it were compared to a lower-fat meal,” she said.

Food has Powerful Effects on the Body

The main point of these studies is to show that food is powerful, and even a single meal can have profound effects on body chemistry.

While these studies tell us to avoid very high-fat milkshakes and foods high in palmitic acid oil, they can’t be generalized to include all types of saturated fat.

In fact, the findings should be taken with a grain of salt. The studies were small, the first involving only ten young men and the second one only 51 women. These are not representative groups.

What’s more, the studies did not take into account the flavorings, chemicals or hormones that could have been in one meal compared to another, so the effects noted may not all relate to fat but to other factors.

There could even be a stimulant in sunflower seeds – who knows? Stranger things have happened. We don’t know much about the hundreds of compounds found in every plant. And palmitic oil strikes me as an odd choice for the women’s study.

Meanwhile, we know that even eating a single high carbohydrate meal has been shown to boost inflammation in young, lean, healthy subjects, so it may be the sheer size of a single macronutrient that’s causing the problem.

The research of the last ten years or more points to carbs – not fats, and not even saturated fats – as the main culprits in most of the degenerative diseases.

As Dr. Brittain remarked, eating some high-fat foods occasionally is not a problem, but do it too often and you’re setting yourself up for chronic cardiovascular disease and dementia. These two studies do provide evidence of probable harm.

I agree, moderation is the key. I don’t think it’s a good idea to eat too much of anything, unless it’s a wide variety of vegetables. Most important, when you do eat saturated fat, stick with fats from whole foods such as meats, avocado, nuts, coconut oil, etc. Don’t eat hydrogenated oils and trans-fats found in processed foods and fast foods. Research suggests that there’s no safe level of consumption for trans-fats—all of them are bad for your heart.


  1. https://www.medicalnewstoday.com/articles/324668
  2. https://jagwire.augusta.edu/just-one-high-fat-meal-sets-the-perfect-stage-for-heart-disease/
  3. https://news.osu.edu/our-ability-to-focus-may-falter-after-eating-one-meal-high-in-saturated-fat/