Althouse: "If there’s one thing I know for sure, it’s that carbs are evil. This is probably the silliest of all the silly, pop-culture propaganda about diet and health."

August 24, 2018

"If there’s one thing I know for sure, it’s that carbs are evil. This is probably the silliest of all the silly, pop-culture propaganda about diet and health."

"All plant foods are carbohydrate sources. Yeah, but: Carbs are evil. Everything from lentils to lollipops, pinto beans to jelly beans, tree nuts to doughnuts, is a carbohydrate source. Most plant foods are mostly carbohydrate. So if 'all carbs' are evil, then so are vegetables, fruits, whole grains, beans, lentils, nuts, and seeds. Sure, but, I should still avoid carbs, right? Exactly the opposite is true. You cannot have a complete or healthful diet without carbohydrate sources. Why have I been led to believe that carbs are evil? Highly processed grains and added sugar are bad, not because they are carbohydrate, but because they’ve been robbed of nutrients, they raise insulin levels, and they’re often high in added fats, sodium, and weird ingredients. Carbs are not evil; junk food is evil."

From "The Last Conversation You’ll Ever Need to Have About Eating Right/Mark Bittman and doctor David L. Katz patiently answer pretty much every question we could think of about healthy food" (New York Magazine). Lots more at the link.

235 comments:

«Oldest ‹Older 201 – 235 of 235

Freeman Hunt said...: Almond flour pancakes are much better than the regular kind. My kids agree. (As for me, I don't even like the regular kind.); 8/24/18, 5:33 PM
Crimso said...: Your body doesn't know when (or even if) you will eat again, and so it acts accordingly. You can only store so much carbohydrate as glycogen, but your liver is incredibly helpful (to a fault, even).

The primary precursor for fatty acid biosynthesis by the liver is excess dietary carbohydrate. Your liver very helpfully converts this carbohydrate to fatty acids, which are then stored as triglycerides in your adipose (fat) cells.

Triglycerides are a much more efficient storage form of energy than glycogen because: 1) fatty acids are less oxidized to begin with than are carbohydrates, and so produce more energy upon oxidation; and 2) triglycerides aggregate due to the hydrophobic effect, forming very compact globules. Glycogen is hydrated and much more spatially extended. An energetically equivalent amount of triglyceride occupies 1/6 the volume of glycogen.

Fructose is even worse than glucose (but it is indeed all relative, everything in balance and things work well). When metabolized by the liver (as opposed to other tissues), fructose enters the pathway of glycolysis downstream from the major control point(s) of glycolysis (hexokinase or PFK-1, depending upon how you analyze metabolic control), and will continue down that pathway to ultimately become fatty acids in what might be considered a much more poorly regulated fashion (not entirely accurate, but close).

The paper I linked above strongly suggests that the fructose load metabolized by tissues other than liver is great enough that when forced to go through liver instead, the resulting metabolic syndrome is substantially worse than that seen in control mice.

Sorry. It's just how I am.; 8/24/18, 5:34 PM
Birches said...: ace

He's a big believer in intermittent fasting. Bit of an inside joke for those who read Althouse and ace and wouldn't confuse your political views with his.

Eleanor, I used to be able to do that but I have been stymied since #5 came. I run 20 miles a week and am careful about what I eat. I keep gaining weight. I'm trying to make peace with whatever my metabolism is doing but it is annoying. Sometimes people have to have a program because nothing else works.; 8/24/18, 5:36 PM
Hammond X. Gritzkofe said...: Making a promise. From now on I only buy food with "CARB FREE!" on the package. It's the new "GLUTEN FREE!"

Gonna be Carb Free, Gluten Free, Non-GMO, salt free, fat free, and sugar free, and Organic. Protein is also out. Stresses the kidneys and liver.

Fat/oil soluable vitamins? Who needs 'em?; 8/24/18, 5:38 PM
Freeman Hunt said...: Have sweets and desserts changed? Most of them seem way too sweet. Those coffee drinks people get with the syrups in them taste horrible, like cheap scented candles. Pie at many restaurants is inedibly cloying. Many bakery goods at stores are the same. Have these things gotten sweeter over time?; 8/24/18, 5:40 PM
Michael K said...: The good news is that I am going to Italy next spring. And, I hear the food is real good there. Who doesn't like spaghetti and meatballs?

Watch out for Venice.

I once had two cokes and a beer at the outdoor cafe in Piazza San Marcos.

$70.

Still worth it. If you go, you have to eat at Quadri's.

Famous and very old. Good food, too.; 8/24/18, 5:44 PM
Michael K said...: We used fructose in IVs in 10% solution for very sick patients as fructose does need insulin to enter the cell.

Let's see if Blogger eats this one.; 8/24/18, 5:47 PM
Bay Area Guy said...: The paper I linked above strongly suggests that the fructose load metabolized by tissues other than liver is great enough that when forced to go through liver instead, the resulting metabolic syndrome is substantially worse than that seen in control mice.

Nobody.cares.about.mice.studies.

NOBODY!; 8/24/18, 5:50 PM
Crimso said...: "Nobody.cares.about.mice.studies."

Nobody.creates.gene.knockouts.in.humans.

NOBODY!

Pretty sure if you want a potential drug therapy to be used in humans that the FDA will not only care about animal models, they will insist upon them.

But...you do have a point. Just because we observe something in an animal model is no guarantee that it will translate into humans. Bexarotene looks impressive in mouse Alzheimers, doesn't touch it in humans.; 8/24/18, 5:56 PM
Bay Area Guy said...: @Crimso,

You're alright! A bit nerdy and overeducated, but nonetheless alright.

I hereby retract my ignorant critique of your PNAS mouse/fructose study.; 8/24/18, 6:14 PM
Birkel said...: Crimso,
Help me understand, please.
Is the idea that fructose metabolizes a whole helluva lot better than glucose?
Is that a big part of what I read at your link?; 8/24/18, 6:58 PM
Francisco D said...: "Have these things gotten sweeter over time?"

Interesting question. At the very few times I taste something sweet, it seems cloying.

I suspect ones taste buds change when they give up certain types of food, cigarettes, alcohol, etc.; 8/24/18, 7:00 PM
Birkel said...: Francisco D: “...give up... alcohol...”

*shudder*; 8/24/18, 7:18 PM
Freeman Hunt said...: When I was growing up, we never had extremely sweet foods. We had desserts occasionally, but they weren't as sweet as what I usually encounter in restaurants now. Didn't know if they had changed.; 8/24/18, 7:38 PM
Birkel said...: I have sweets almost never.
Salty foods are much more my bag.; 8/24/18, 7:42 PM
DEEBEE said...: Avoid them, because you cannot deny them. Otherwise you get charlatons from either extreme singing their siren songs; 8/24/18, 8:02 PM
Birkel said...: Crimso,
Can you help me understand what that link said?; 8/24/18, 8:45 PM
Howard said...: let me splain to too you. White carbs are weeds. If you eat weeds, the body stors as much fat as possible because you are down to eating weeeds. Sugar shit is weeds on steroids. If you eating fats and protein, the body does not need to store fat because it's raining nutrition.; 8/24/18, 9:10 PM
Howard said...: Birkel: no. you can't fix stupid.; 8/24/18, 9:11 PM
Inga...Allie Oop said...: Freeman, desserts do seem sweeter, but for many years now. European desserts are much less sweet and more buttery. European buttercream frosting is so much better than American style with all that powdered sugar.; 8/24/18, 9:46 PM
Birkel said...: Howard,
If I want a comment out of you, I’ll slap it out.
K?; 8/24/18, 9:51 PM
DWPittelli said...: Bittman's position is more correct than "all carbs are evil." But he assumes that by "carb" a person means any food with carbohydrates. However, people also use the term in another way, to divide up food into food groups, such as in the notion that dinner should include a protein, a vegetable and a carbohydrate or starch. In this case, beans and vegetables are not "carbs"; grains and potatoes are. And "all carbs are evil" is a perhaps useful shorthand for informing us that the mainstream or easy way to eat these days does routinely involve eating carbs to such excess that evils result.; 8/24/18, 10:19 PM
Crimso said...: "Is the idea that fructose metabolizes a whole helluva lot better than glucose?"

Not "better." More unregulated, perhaps? And in biochemistry, regulation is everything. You can think of it as fructose upsetting a normal metabolic balance. It isn't that fructose isn't supposed to be there, it's that there's way too much there.

The basic metabolic strategy for the most common dietary monosaccharides (other than glucose, which you might think of as the average cell's preferred fuel) such as mannose, galactose, and fructose is to turn them into metabolic intermediates in the breakdown of glucose. This allows most of the breakdown of those sugars to "piggyback" on the pathway for glucose.

Fructose in non-liver tissues, galactose, and mannose all feed into the glucose metabolic pathway pretty much at the beginning (galactose is a bit more complicated, so I'm simplifying it somewhat). Fructose in the liver goes through a different set of reactions to lead to an intermediate in glucose metabolism, and that intermediate is well "downstream" of where that glucose metabolic pathway is regulated.

The analogy might be a movie theater, where they're counting the no. of people coming in the front doors to be sure they don't exceed the fire marshal's stated limit. Fructose is sneaking in the back door, and so isn't getting counted. The natural feedback mechanisms that would whoa up conversion of carbohydrate to lipid are being short-circuited with fructose in the liver.

Even in the absence of excess dietary fructose, your body will try to store as much excess fuel (carbs) in the form of triglycerides as possible. All of that is regulated, so it will only go so far, but even with just excess glucose in your diet "so far" can still be "way too far."

And all of what I've written here is a drastic oversimplification of how it all really works. And exactly how well it all works will certainly vary from one person to the next.; 8/24/18, 11:11 PM
Openidname said...: "Inga...Allie Oop said...

"Hunter gatherers ate whatever they could get their hands on that was edible which included whatever was growing at the time."

It also included each other.; 8/24/18, 11:37 PM
Birkel said...: Thank you, Crimso.
That makes good sense.; 8/25/18, 6:05 AM
Ann Althouse said...: Here's a word that does not appear in the linked article: fructose.

There's a lot about sugar, but the topic of different sugars isn't mentioned.

Those of you who are going on about fructose, specifically: Can you state in a scientific way why fructose is importantly different from other sugars, such as sucrose?

I'm very skeptical.

Isn't the answer just that a lot of junk food has fructose, that it's cheap and plentiful and all over the place, and so it is consumed in large quantities and along with a lot of other crap and instead of good things?; 8/25/18, 6:35 AM
Birkel said...: Althouse,
Read the link Crimso left on the first page of comments.
I wasn’t sure how to organize what I was reading but the study makes sense.
Different sugars ar metabolized differently, in mice anyway.; 8/25/18, 7:48 AM
Crimso said...: "Isn't the answer just that a lot of junk food has fructose, that it's cheap and plentiful and all over the place, and so it is consumed in large quantities and along with a lot of other crap and instead of good things?"

Yes, although sucrose contains fructose. The argument has been that since fructose is converted into an intermediate in glucose metabolism, it is really no different metabolically than glucose. But the way your liver utilizes fructose is crucially different than the way it uses glucose (or mannose or galactose).

The reactions themselves are not as important as how they are regulated. Having come to biochemistry from a chemical engineering background, I fully appreciated this from day one. Process control (i.e., regulation) in a chemical processing plant is absolutely critical. The regulation of the use of fructose by the liver is such that your body will be more affected by excess fructose than excess glucose, but excesses are bad in any case.

It isn't just that so much excess fructose has been added to our foods, there is an issue with carbohydrate intake in general. This is largely due to the poor understanding of nutritional biochemistry, especially with regard to where the fat in our bodies comes from (it is not primarily from fat in the diet). We were told 30-40 years ago that we eat too much fat, and that we should eat more bread, pasta, etc.

I'm glossing over other possible issues associated with lipid intake for the sake of staying on the subject of carbohydrate metabolism. There may be other reasons to limit fat intake, but elevated serum triglycerides probably isn't one of them.

Basically, it all comes down to the correct balance of what you eat. That balance will be a bit different for each person, and possibly greatly different for some. There will come a day when nutritionists work up each person's metabolism, and then gives them recommendations and guidelines on what that individual should aiming for in terms of amounts and types of food.

But here's something to really screw it all up: you can't assume that everything you swallow ends up in your body. There is evidence that a large percentage of the calories you eat never makes it into your body (work done by Sir Denis Burkitt decades ago). The key is in understanding that the interior of your intestine is actually outside your body.; 8/25/18, 9:58 AM
Etienne said...: Ann Althouse said...Can you state in a scientific way why fructose is importantly different from other sugars, such as sucrose?

1. Only the liver cells can metabolize fructose.

2. The liver creates fat droplets and this is called lipogenesis.

With enough fructose, these tiny fat droplets begin to accumulate in liver cells
(fatty liver). It is identical to the livers of chronic alcoholics.

As a point of reference, a 12 oz. soda contains about 22 g fructose, while a typical apple, pear or cup of grapes would contain about 12 g fructose.

The typical American diet is rich in sugars and contains on average 48 g fructose/day of which only 8 g are from natural sources such as fruits.

This difference of 40 g of added fructose is the amount found in approximately 80 g sucrose (sucrose is 50% glucose, 50% fructose).

A healthy diet limits added sugars to 25 g/day for women (6 tablespoons, 100 calories).; 8/25/18, 10:20 AM
LA_Bob said...: Crimso,

Nicely said. It's extremely difficult -- no, impossible -- to explain these issues in a blog post, much less a blog comment. You do very well.

A couple of other fructose "factoids":

Fructose more effectively glycates or "poisons" proteins than almost any other sugar, especially glucose (think the diabetic's concern with HbA1C, which is glycated hemoglobin). It appears glycation is part of the normal aging process, so more fructose tends to accelerate aging.

When the liver handles fructose, it results in the production of uric acid, which can cause gout. Hence, increased dietary fructose, whether from sucrose or high fructose corn syrup, can lead to or aggravate gout.

Here are a couple nice little summaries of fructose and gout:
http://high-fat-nutrition.blogspot.com/2006/12/which-drink-causes-gout.html
http://high-fat-nutrition.blogspot.com/2008/02/fructoase-and-gout.html; 8/25/18, 10:54 AM
LA_Bob said...: Crimso said, "There is evidence that a large percentage of the calories you eat never makes it into your body..."

Great piece of info, and it really throws a wrench into the concept of calories-in-calories-out (CICO).

There is evidence diabetics absorb sugar more effectively than non-diabetics.

http://kindkehealthnotes.blogspot.com/2014/10/increased-glucose-transport-in-duodenum.html; 8/25/18, 11:04 AM
Etienne said...: Uric acid = gout AND kidney stones. Either will ruin your day.; 8/25/18, 11:12 AM
RigelDog said...: Rigel,
As somebody above mentioned, look to Pinterest.}}}

Thanks for the crab cake suggestion...that's the kind of real-life report I was wondering about. As I mentioned in my post, I have hundreds and hundreds of almond flour and coconut flour recipes Pinned. I'm intimidated about plunging in and figure that a vouched-for, simple recipe would encourage me. I have 2 big strikes against me too: I hate the taste of eggs and also hate the taste of seafood. So many recipes look like this: Low Carb pancakes, add 3/4 cup of almond flour to four eggs. That's going to taste like an omelet to me.; 8/25/18, 2:56 PM
RigelDog said...: Those of you who are going on about fructose, specifically: Can you state in a scientific way why fructose is importantly different from other sugars, such as sucrose?

I'm very skeptical.}}} Althouse

I understand your skepticism because I shared it until I read/listened to Dr. Jason Fung explain the problem with fructose (he's a good source, but it's not the only place I've gotten my information). It's amazing to discover that ONLY the liver processes fructose, and that table sugar is half fructose. The liver is easily overwhelmed by the amount of fructose we've been eating, and converts the excess into fat that is crammed into the liver. Fatty liver disease is bad, bad thing and similar to what happens to alcoholics. It appears, fortunately, that eliminating fructose from the diet, along with EXCESS carbs, will cause the liver to begin to burn that stored fat and return liver function. https://medium.com/@drjasonfung/the-deadly-effects-of-fructose-b4d0128f3b39; 8/25/18, 3:05 PM
OnlyInCA said...: I have to say I never in my life thought I would agree with Inga on anything but she in “bang on” with all her dietary comments! I think there is so much yet to be learned about the gut and its organisms regarding the regulation of obesity and metabolism and this will be a big topic for research over the next decade.; 8/25/18, 4:50 PM