I’m about to tell you about the beginnings of a paradigm change in nutrition and medicine. It will—eventually—change the way both nutrition and medicine are practiced.
See, for all of my lifetime, and likely all of yours, we’ve talked about nutrition in terms of the properties of the food we eat. This food contains these amino acids; it contains this number of fat grams; it has this glycemic index. And our nutritional advice has all been based on that. Stuff like the number and quality of calories, vitamins, amino acids, phytochemicals, protein, fat, and fiber found in the food (or supplement).
We assumed these foods would affect people in the same way. If you ate high-fiber foods, you had better digestion. If you ate steak, you had plenty of B-12. And if you ate high-glycemic processed carbs, your blood sugar would go up a lot and bad stuff would happen.
Except that it’s not.
Calories, for example, affect different people differently, as I’m sure you’ve noticed! Some people can eat anything and not gain weight, others feel like they gain an ounce if they so much as look at Haagen-Daz. A calorie may be a calorie in the test tube—but once it hits the individual gut, it’s a very different story.
Which brings me to the glycemic index. And a pretty important discovery.
The glycemic index is a measure of how much a food raises your blood sugar. It’s determined by giving a fixed quantity of net carbohydrates (50 grams) from any given food to hundreds of thousands of people, measuring their blood sugar, and then averaging the results. It’s based on a ton of testing and measuring and has been validated in many peer review studies.
But recently, scientists have been noticing that individual glycemic response to foods is all over the map, and often very different from what would be predicted from the glycemic index alone. If you and I ate the same 50 gram portion of net carbs from carrots (or any other food), it’s anybody’s guess whether or not the rise in our respective blood sugar would be the same.
Probably, it wouldn’t be. Because studies are beginning to show that the glycemic index of a food is only a so-so predictor of how any given individual will respond to that food.
And here’s where the revolution in personalized medicine begins. Because when you plug an individual’s microbiome data into the equation, your ability to predict a given individual’s blood sugar response to food gets better by about 20%.
In one recent study, scientists asked 327 non-diabetic patients to send in stool samples so they could have their microbiome analyzed. The researchers then plugged that data into the largest microbiome database in the world, in Israel. Now armed with individual microbiome data for the individuals, they started the study
The people in the study wore continuous glucose monitors so were able to measure their blood sugar every five minutes. They kept copious track of every morsel eaten. When the scientists analyzed the food they were eating (for carb content, glycemic index, etc), they found there was around a 40% accuracy in predicting individual glycemic response just from knowing about the food.
But when they plugged in the individual microbiome data, the prediction increased to around 60%.
In other words, it’s not just what you eat that affects your blood sugar—it’s what you eat in combination with what the inhabitants of your microbiome like to eat!
As Louis Pasteur said on his deathbed, “Look to the host”. In other words, after a lifetime of studying the nature of bacteria, he realized it’s not just the bacteria—it’s how they affect a given individual (host).
And this is the beginning of the paradigm changing revolution.
It’s the beginning of the era of personalized medicine.
In fact, Day Two—the company in Israel that developed the microbiome database and analyzed the results for the researchers in the study I just told you about– offers consumers a version of the microbiome test used in the studies. You send in your sample and they plug the results into their vast database to actually predict which foods you personally will do well with and which ones you should avoid. (I recently took the Day Two microbiome test—and I’ll keep you informed about my results and experience.
Expect the results to be surprising. Because on any individual’s list there will be a lot of “healthy” foods that just aren’t matches for that particular individual. And there may be some “iffy” foods that their microbiome likes just fine. (The FODMAP diet is a great example of perfectly fine foods being problematic for certain individuals.)
The point, really, is that as we learn more about the things that make us as individuals unique—our genes, our SNPPS, our gut bacteria/microbiome— we will get better and better at predicting individual reactions to foods, supplements, probiotics, and even medicine.
Most docs I know all believe the day will come when they will have a much better idea of what dose of a given drug will be effective in a given individual.
The days of one-size-fits-all (in medicine OR nutrition) are clearly coming to an end.
And—to use the overused term—that is truly a game-changer.