In my Science For Smart People speech, I argued that laypeople need to learn a bit about science because there are so many contradictory studies published in the popular media. I gave examples from real headlines: Eggs Linked to Diabetes. Eggs Improve Glucose Control. Processed Meats Linked to Cancer. Hot Dogs May Prevent Cancer.
And so forth.
So let’s say you’re an avid reader of online news sites and are especially interested in health topics. Here’s what you could have learned during the past month:
1. Ketones, a by-product of diets that are low in carbohydrates and very high in fat, may be effective for treating epilepsy, diabetes and Alzheimer’s.
2. Diets high in fat are bad for memory and other cognitive functions, but exercise may offset the damage and restore the brain to normal.
You could be forgiven for thinking something along the lines of Wait a minute … people with Alzheimer’s lose their memory and other cognitive functions, so I should eat more fat. But eating fat is bad for memory and other cognitive functions, so I should eat less fat. Hmmm, I’m confused … but wait … WHY am I confused? I didn’t used to be so easily confused! I’m probably losing my cognitive abilities from eating too much fat! Or is it from not eating enough fat? Am I supposed to eat more fat then go exercise?!
Let’s start with the Ketones Are Good article from the U.K. Daily Mail. It’s titled Could this elixir hold the key to weight loss? Experts hope it’ll also treat diabetes, epilepsy and Alzheimer’s:
There’s a new drink that could not only help you lose weight, but could also treat epilepsy, diabetes and possibly even Alzheimer’s. It might also be an incredible energy booster. When a group of international rowing champions took it, one of them beat a world record.
It sounds far too good to be true, but the drink’s scientific credentials are impeccable. It’s been developed by Kieran Clarke, professor of physiological biochemistry at Oxford University and head of its Cardiac Metabolism Research Group, at the behest of the U.S. Army.
Equally amazing is that the drink doesn’t involve a new drug. It contains something our bodies produce all the time. This key ingredient is ketones — the tiny, but powerful sources of energy our bodies make naturally when we start using up our fat stores for energy because there are no carbs around.
If ketones are so amazing and they’re produced when there are no carbs around, why not just go on a low-carb diet? Don’t worry; they’ll get to that.
We all have slightly raised ketone levels before breakfast because we haven’t eaten for a while.
I’ve tried explaining that to people who warn me that the ketones produced by my diet are going to ruin my kidneys. They often fail to grasp the concept, perhaps because they don’t have enough ketones fueling their brains.
The clever trick Professor Clarke has pulled off is to have found a way to make ketones in the lab. This means that instead of having to follow difficult diets (with unpleasant side-effects such as constipation and bad breath), you can just add ketones to a normal diet — in the form of the Drink, as it’s known.
Figures. You want to get funding to study the benefits of ketones, there needs to some kind of new product at the end of the rainbow.
In a study published earlier this year, Professor Clarke found that rats given the new ketone compound ate less and put on less weight than those getting the same amount of calories from a high-fat or a high-carbohydrate diet.
In the first trial Professor Clarke has run on humans with diabetes, completed within the past few months, the effects were also impressive. In the week-long study, eight people with diabetes had three ketone drinks a day as well as their normal diet.
As with the rats, their weight dropped (an average of nearly 2 per cent of their body weight), but so did their glucose levels, cholesterol and the amount of fat in the blood. The amount of exercise they did went up as they had more energy.
I’m not crazy about the idea of raising ketones with a manufactured ketone drink, but the article paints a pretty positive picture when it comes to ketones, explaining, for example, how ketogenic diets have helped kids with epilepsy control seizures. The takeway message: diets that produce ketones are good for your brain, suppress your appetite, help control blood sugar and raise your energy levels.
But as John Cleese used to say on Monty Python’s Flying Circus, And now for something completely different: a New York Times article titled Can Exercise Protect the Brain From Fatty Foods?
In recent years, some research has suggested that a high-fat diet may be bad for the brain, at least in lab animals. Can exercise protect against such damage? That question may have particular relevance now, with the butter-and cream-laden holidays fast approaching. And it has prompted several new and important studies.
Ah yes, it’s all that cream and butter that make the holidays a threat to our brains. (If you follow the link, you’ll see a nice picture of a slab of butter to represent the threat.) Couldn’t be all the sugar people eat over the holidays.
The most captivating of these, presented last month at the annual meeting of the Society for Neuroscience in New Orleans, began with scientists at the University of Minnesota teaching a group of rats to scamper from one chamber to another when they heard a musical tone, an accepted measure of the animals’ ability to learn and remember.
For the next four months, half of the rats ate normal chow. The others happily consumed a much greasier diet, consisting of at least 40 percent fat. Total calories were the same in both diets.
I’m wondering how the writer knew the rats were happily consuming the greasier diet. Did the researchers report on the number of happy squeaks the rats produced while eating?
After four months, the animals repeated the memory test. Those on a normal diet performed about the same as they had before; their cognitive ability was the same. The high-fat eaters, though, did much worse.
The article is based on a recent presentation, so I couldn’t find the published study online to look up which high-fat diet the rats with the bad memories consumed — not that I care all that much, since this is a rat study and I’m not a rat. But I have looked up the high-fat diet used in several other rodent studies. The fat consists mostly of Crisco, soybean oil and corn oil. Those aren’t the fats I’d want to put in my brain – or a rat’s.
Then, half of the animals in each group were given access to running wheels. Their diets didn’t change. So, some of the rats on the high-fat diet were now exercising. Some were not. Ditto for the animals eating the normal diet.
For the next seven weeks, the memory test was repeated weekly in all of the groups. During that time, the performance of the rats eating a high-fat diet continued to decline so long as they didn’t exercise.
But those animals that were running, even if they were eating lots of fat, showed notable improvements in their ability to think and remember.
After seven weeks, the animals on the high-fat diet that exercised were scoring as well on the memory test as they had at the start of the experiment.
Exercise, in other words, had “reversed the high-fat diet-induced cognitive decline,” the study’s authors concluded.
You have to read most of the article to learn how the researchers believe high-fat diets cause cognitive problems:
Just why high-fat diets might affect the brain and how exercise undoes the damage is not yet clear. “Our research suggests that free fatty acids” from high-fat foods may actually infiltrate the brain, says Vijayakumar Mavanji, a research scientist at the Minnesota VA Medical Center at the University of Minnesota, who, with his colleagues Catherine M. Kotz, Dr. Charles J. Billington, and Dr. Chuan Feng Wang, conducted the rat study. The fatty acids may then jump-start a process that leads to cellular damage in portions of the brain that control memory and learning, he says.
Well, since our brains are made mostly of fat, I’d say that depends on what kind of fatty acids are reaching the brain. It would also depend on whether the creature in question is biologically adapted to eating those particularly fatty acids. I sure hope they’re not going to take some crazy leap in logic and assume that the effects of rats eating soybean oil tell us something about the effects of humans eating beef and butter.
Of course, lab animals are not people, Dr. Mavanji cautions, and it’s not known if exercise might protect our brains in the same manner as it does in mice and rats.
Still, he says, there’s enough accumulating evidence about the potential cognitive risks of high-fat foods and the countervailing benefits from physical activity to recommend that “people exercise moderately,” he says, particularly during periods of repeated exposure to alluring, fatty holiday buffets.
The amount of exercise required to potentially protect our brains from the possible depredations of marbled beef and cheesecake isn’t excessive, after all, he continues.
Head. Bang. On. Desk.
So there you have it. Ketones and ketogenic diets are good for your brain, but a high-fat diet – which produces ketones – will make you stupid unless you exercise. No wonder people get confused.
I’m going to go eat more of Chareva’s high-fat meatloaf and try to figure this out.