Replacing sugar with allulose

by Peter Attia

Ed note: Brandon Auerbach, MD MPH told us about the Harvard Healthy Eating Plate yesterday in his lecture here. He also mentioned the sugar substitute Allulose which appears to be a nearly ideal choice. It can be purchased on Amazon if you want to give it a try.

My interest in allulose dates back to 2015, when I began using it as a replacement to sugar. At the time, it was almost impossible to acquire, as there was basically no market for it outside of Japan. But I knew someone who knew someone who knew someone at Tate & Lyle, the main US importer of allulose, so I had a pretty good stash of 1 kilo bags of unmarked white powder in my pantry. Not making this up. It hasn’t received as much press as other commonly-used sugar-alternative sweeteners for which we have the most available evidence. I am talking about sweeteners such as acesulfame K (Sunnett, Sweet One), aspartame (NutraSweet, Equal), saccharin (Sweet’N Low), steviol glycosides (Stevia), and sucralose (Splenda). In my opinion, allulose is a well-kept secret that should be shared. It deserves to be in the limelight. But before I get into what it is and why I prefer it to all other alternative sweeteners—let’s start by revisiting why we would want to replace that thing called sugar in the first place. After all, the market for substitutes wouldn’t exist if sugar had not become, in recent decades, inextricably linked to metabolic dysfunction and disease. And if it didn’t taste so damn good. 

Want more content like this? Check out this Ask Me Anything (AMA) podcast where I do a deep dive into sugar and sugar substitutes and my interview with Rick Johnson about fructose.

Let’s take a moment and think about the way we refer to sugars. Sugar is often delineated by “natural” sugars found in fruit and vegetables as opposed to “artificial” sugars that are added to food products like high fructose corn syrup (HFCS). But these categories are not the most useful way to think about sugar and its effects. Here’s why: by the time any type of sweetener leaves the stomach, it’s basically a series of monomers of glucose and fructose. The intestines and liver don’t care if these molecules were originally present in the food that was eaten or added later. 

But if the various sugars are really the same molecule—some combination of fructose and glucose—why do they have such different effects? It’s a question of density and volume, which both contribute to dose. It’s also a function of the rate at which the molecule moves through the upper digestive tract and, specifically, the speed with which they arrive at your liver (velocity). 

Consider a bag of dried mango. This may seem like a healthy choice because it’s all natural with no added sugar, but it’s nonetheless a very high-sugar snack. One of those Trader Joe’s packages (which I can easily finish in one sitting) contain 90 grams of “natural” sugar (i.e., none was added to the food). Similarly, compare eating plums with their dried-out version, prunes. Density says that when you consider the dried out version of the fruit, the density of sugar contained within it is higher so you’ve got the same amount of sugar at a lower volume. As a result, prunes have about 5 times as many calories as plums. Prunes also contain less water volume so the likelihood of eating a larger quantity is greater (the dose makes the poison). 

In this context, velocity can be thought of as the speed it takes sugar to hit our system and affect our metabolism. Fiber plays an important role here. Unlike most carbohydrates, fiber is largely not digested by the human body but is metabolized by bacteria in the colon. It slows digestion of other carbs, which is why it’s better to eat sugar with fiber. So, while the origin of a sweetener is not directly relevant, it could have a secondary importance. A  sweetener that is purely natural is much more likely to be ingested along with water and fiber. I speak about how I think about sugar metabolism on the upcoming AMA episode (#18). I have yet to see a good model (maybe I’ve missed it) out there that clearly explains the difference between, say, eating an apple and apple juice—both naturally occurring fructose sources—but to me, it comes down to: density, quantity, velocity being the variables that matter.

Just like many other things, it is a question of dose and function. In my interview with Rick Johnson, we discussed how fructose—a natural, sweet sugar commonly found in fruit and a few other foods—is used by animals to store energy. An animal eats fructose to store energy in preparation for hibernation, for example. So there is an evolutionary function to the way our bodies store these broken-down carbohydrate molecules. Relatedly, I get into depth on insulin and insulin resistance as an evolutionary adaptation to survive starvation in my conversation with Dr. Gerald Shulman.  In western societies, the most commonly used sweeteners are sucrose (table sugar) and high fructose corn syrup (HFCS), an artificial product made from corn starch. The problem with the cumulative amount of sugar consumed in most modern societies today is that we effectively make our bodies believe it is wintertime all year round. The reality is that we don’t need to store energy as if we are preparing for a time of food scarcity, as animals do before hibernation. In my conversation with Robert Lustig, we spoke in-depth about issues in the food industry, chronic sugar exposure, and the concomitant rise in obesity. I would acknowledge that while excess sugar is without a doubt bad news, I don’t believe it is the only culprit for obesity. There is a lot I can say on this topic and I wrote about some of it in a previous post. In AMA #18 out soon, I  will also revisit other alternatives to sugar (including other non-nutritive and alcohol sugars) as an update to a previous post on the subject, given what we knew at the time. But for now, let’s get back to allulose, accepting the premise that minimizing sucrose, HFCS, and other added sugar intake is a good thing for your health.

Allulose is on the top of my preference list for both objective and subjective reasons. Let’s start with the facts. The molecule has been around for a long time (found naturally in small quantities in some fruits), but it was only in 2014 that it was given a generally regarded as safe (GRAS) food designation by the Food and Drug Administration (FDA)—indicating the general expert consensus on a substance’s safety. Until recently, it was not commonly used in the US because the FDA did not differentiate it from sucrose or HFCS. In other words, it had to be listed on ingredient labels as an added sugar, turning off any potential customers not fully in the know. Not surprisingly, there was little incentive for food producers to include allulose in their products because the FDA  required them to label it exactly as they would label added sucrose or HFCS. (continued on page 2 or here)