What? high-fat diets can make you stupid?

Source: Anne Hart, Examiner.com

Can a high-fat diet enlarge your heart and impair its efficiency while reducing your ability to learn or exercise? According to a September 5, 2009 article in Science Daily, "Do High-Fat Diets Make Us Stupid and Lazy? Physical and Memory Abilities of Rats Affected After 9 Days," rats fed a high-fat diet show a stark reduction in their physical endurance and a decline in their cognitive ability after just nine days, a study by Oxford University researchers has shown.
The research, has been funded by the British Heart Foundation and published in the FASEB Journal. Keep in mind that a high-fat diet is not good for athletes. If you have metabolic syndrome, books on "syndrome x" and similar metabolic imbalances that cause insulin resistance frequently instruct you to eat a diet containing about 30 to 35 grams of healthy oils daily. But you need to ask your doctor whether a low-fat diet will or won't worsen your metabolic syndrome and insulin resistance.
Often low-fat diets too high in carbs and vegetables that eventually turn to sugar allow too much insulin to be released in people with insulin resistance. That's why you need to find out whether you have insulin resistance before you lower the amount of oils in your diet. And if you have diabetes, often peanut butter or similar nut oils or olive oil are forbidden by one diet plan and recommended by another diet plan. You need to tailor your diet to your own body's needs and genetic signature.
"We found that rats, when switched to a high-fat diet from their standard low-fat feed, showed a surprisingly quick reduction in their physical performance," Dr Andrew Murray reported to Science Daily. Dr. Murray led the work at Oxford University and has now moved to the University of Cambridge. Dr. Murray told Science Daily, "After just nine days, they were only able to run 50 per cent as far on a treadmill as those that remained on the low-fat feed."
Athletes who are fed high-fat diets, supposedly will be less efficient and run slower, is one theory, if you apply what happened to the rat's performance to what could happen to humans. You could try to run after a high-fat meal, but it's not advised. Eating a high-fat diet at night could put you at higher risk of getting a heart attack in the morning.
According to the Science Daily article, "High-fat diets, such as those that are prevalent in Western countries, are known to be harmful in the long term and can lead to problems such as obesity, diabetes and heart failure. They are also known to be associated with a decline in cognitive ability over long time spans. But little attention has been paid to the effect of high-fat diets in the short term."
How athletic you are depends on eating the type of food that supplies oxygen to your muscles. You could take D-ribose, a muscle sugar, to help prevent the lactic acid from making you feel exhausted, but it's better to burn the fuel based on what you eat. Athletes need to burn glucose as fuel that they get from eating complex carbohydrates. They will be less efficient and run slower if they try to get their fuel from fat.
What's controversial is the various studies of metabolic changes based on different diets. You want to watch how long you can keep exercising on different diets to tailor your diet to your own genetic signature and body type. Each person has a different physical endurance level. The question is will short-term high-fat feeding increase or decrease your own individual and unique physical performance?
The Oxford team set out to investigate whether rats fed a high-fat diet for just a few days showed any change in their physical and cognitive abilities.
The 42 rats in the experiment at first were fed a standard rodent feed with a low fat content of 7.5 per cent. Scientists measured the rats' physical endurance based upon how long they could run on a treadmill.
Then the researchers measured the rats' short-term or 'working' memories by doing a maze task. Half of the rats were then switched to a high-fat diet where 55 per cent of the calories came from fat. After four days of adjusting to the new diet, the endurance and cognitive performance of the rats on low- and high-fat diets were compared for another five days.
The team of scientists reported to Science Daily that on the standard feed, 7.5 per cent of the calories come from fat. If you compare the low-fat standard feed diet for rats, it's a very low-fat diet. Dr. Murray told the Science Daily, "It's much like humans eating nothing but muesli."
On the rats' high fat diet, 55 per cent of the calories came from fat. But by human standards, it's "actually not extraordinarily high by human standards," Dr. Murray explained to Science Daily. "A junk food diet would come close to that."
Some doctors prescribe high-fat, but low carb diets that have a 60 percent fat content, for certain health issues that respond to high fat diets. One type of similar diet is prescribed for weight loss for some body types that respond to high-fat diets by losing weight. Other body types respond to high-fat diets by gaining weight. It's difficult to make scientific conclusions on diets prescribed for individual health situations.
The research team fed a high-fat diet to the rats that was not very low in carbohydrates. According to the Science Daily article, on the fifth day of the high-fat diet (the first day back on the treadmill), "the rats were already running 30 per cent less far than those remaining on the low-fat diet. By the ninth day, the last of the experiment, they were running 50 per cent less far."
The research team also noted the rats seemed to making mistakes sooner on the high-fat diet as they ran through their maze tasks. This suggests that cognitive abilities are changed for the worse or slowed-down by high-fat diets. According to the article, "the number of correct decisions before making a mistake dropped from over six to an average of 5 to 5.5."
What metabolic changes did the high-fat diet induce in the rats? Levels of a specific protein increased. This protein is called the 'uncoupling protein' in the muscle and heart cells of rats on the high-fat diet.
What the specific protein does is 'uncouple' the process of burning food stuffs for energy in the cells, reducing the efficiency of the heart and muscles. This could at least partly explain the reduction in treadmill running seen in the rats.
On the high-fat diet, the rats developed a bigger heart (enlarged hart) after only nine days. The heart perhaps had to increase in size in order to pump more blood around the body and get more oxygen to the muscles.
If you apply this to humans, it suggests that developing an enlarged heart might be worsened by eating high-fat diets. The research using rats now has begun using humans.
The Oxford team and Andrew Murray's new group in Cambridge are now carrying out similar studies in humans, looking at the effect of a short term high-fat diet on exercise and cognitive ability. But the people on the high-fat diets should also see whether their own hearts are becoming enlarged with less ability to pump blood after they stop the high-fat diet.
If so, will the enlarged hearts decrease when the high-fat diet is stopped? Will they go back to normal size and pumping ability? Or does a short-term high-fat diet permanently change the human body's efficiency?
"The results will be important not only in informing athletes of the best diets to help their training routine, but also in developing ideal diets for patients with metabolic disorders such as diabetes, insulin resistance or obesity," according to the Science Daily article.
If you have any of these conditions, find out whether you have high levels of fat in your blood, whether that's the reason you might show poor exercise tolerance and/or some cognitive decline. If you're on a high-fat diet, the question is will you develop dementia over time? And can it be reversed by a lower fat diet? Or do you need a specialized, high-fat diet for your individual health issue?
What the study showed is that high-fat feeding even over short periods of time can markedly affect gene expression, metabolism and physical performance. If you're an athlete, then optimize your diet.
Your goal, athlete or not, is to increase or maintain your endurance. If you have metabolic syndrome, you need to adjust your diet to help you walk or exercise more so you don't end up with an enlarged heart and so much fats in your blood that you slow down cognitively and physically.
It only took a few days for a change in diet before the rats' hearts ended up a lot less efficient. The human volunteers will show the reasearch team what short-term high-fat foods are doing to human hearts. The British Heart Foundation funded the research. If you're looking for long-term heart health, there are plenty of scientific studies showing that humans need to cut down on foods high in saturated fat.
On the other hand, are some forms of plant-based saturated fat heart-healthy? For example, are saturated fats from coconut milk which have medium-chain fatty acids healthier than the deadly long-chain fatty acids found in fatty animal meats?
Do the medium-chain fatty acids turn to fuel in the body or slow the body down long long-chain fatty acids do? These are questions nutritionists want answered. Or should people stay away from all saturated fats to prevent loss of cognitive abilities and an enlarged heart?
And if we read books such as the Genotype Diet, is it true that people with blood type O, often called 'thin' blood have an enzyme that removes cholesterol from the animal fat they eat from their blood that people with the 'thicker' blood type A and AB (vegetarian and/or fish types, according to some naturopaths) don't have? All these questions need to be answered, and the first step is to validate the research on all these topics.