Longevity hacks

How this low-carb diet might be linked to immunity

Keto’s appeal isn’t just limited to “fat-burning.”

There’s a certain feeling you get after eating a heap of fries and a double cheeseburger, drinking a beer, and topping it off with a sleeve of Oreos.

For those of you who haven’t indulged on this level, allow me to fill you in: it’s queasy, fatigued, sluggish — a little nauseous. In other words, you feel sick.

But what if you ditched the Oreos, the fries, the burger, and then cut out almost every other carb in your diet to boot? Would you never feel sick again?

Probably not. But a new study published in EMBO Molecular Medicine finds that there may be a measurable link between ketogenic diets — which advocate adherents minimize or completely cut out carbohydrates — and immune cell activity. This connection helps bolster a case for ketogenic diets as a treatment for certain immune problems.

The study authors write that the ketogenic diet “holds promise as a feasible and effective clinical tool for a large range of conditions intimately associated with immune disorders.”

Keto is a popular diet trend, but critics argue we don’t know enough about its effects for doctors to recommend it. Studies like this one, although it doesn’t go into the long-term effects of going keto, nonetheless help build out the body of research necessary to come to an informed conclusion about what the diet does to the body.

These are some of the most common foods people eat while on a ketogenic diet — the key features being a diet high in meat and fat, and low in carbs and sugar:

  • Seafood
  • Meat
  • Dairy
  • Oils
  • Green vegetables
  • Nuts
  • Seeds
  • Berries

LONGEVITY HACKS is a regular series from Inverse on the science-backed strategies to live better, healthier, and longer without medicine. Get more in our Hacks index.

HOW THIS AFFECTS LONGEVITY — Immune disorders can include a range of diseases from multiple sclerosis to lupus, and they may affect more than 24 million Americans every year. Western diets — typically full of sugar and refined wheat — have long been suspected in the scientific community as the culprit behind the rise in these hard-to-treat problems.

If what these authors find is replicated in further studies — that simply adjusting what you eat could help alleviate chronic immune diseases — then low-carb or ketogenic diets offer a promising alternative to expensive medications and other treatments.

There have been studies that have suggested that ketogenic diets, and the concurrent increase in certain ketones, may have anti-inflammatory properties, and may even improve memory and reduce mortality. But these studies are done primarily in mice.

This new study, according to the authors, is the first to look into the immune effects of keto in humans.

“By complementing classical approaches of modern medicine, nutritional interventions offer new perspectives for prevention and therapy of numerous diseases,” the authors write in the study.

As with any diet, however, keto isn’t for everyone. It’s always best to consult a medical professional before making changes to your diet.

SCIENCE IN ACTION — Reducing carbohydrate intake through a ketogenic diet or, in some cases, fasting, may increase the body’s use of ketones instead of glucose (blood sugar) for energy. Ketones are a byproduct of the breakdown of stored fatty acids in the absence of blood glucose, which comes from carbohydrates.

The researchers behind this study probe the question of whether a ketogenic diet has an effect on human immunity. They take a two-pronged strategy:

  • In vitro testing: The researchers looked at human cells in a lab treated with a kind of ketone that’s generated in people who follow ketogenic diets called BHB.
  • In vivo testing: The researchers put real humans on ketogenic diets and then analyzed their blood samples both before and after the diet.

In the in vivo portion of their study, 44 people practiced a ketogenic diet and received nutritional counseling. Every day for three weeks, they were allowed to eat 30 grams or less of carbohydrates.

At first, the researchers found that ketones increased in the blood of the participants — this was not unexpected, but they also found activity in certain immune cells began to shift.

Both in the cell models and the participants’ blood samples, the activity of an immune cell called a T-cell changed in these specific ways.

In the lab tests (in vitro):

  • BHB, a ketone, improved T-cells’ ability to produce cytokines, which T cells produce to help them function properly.
  • BHB increased the ability of mitochondria, the powerhouse of a cell, to use energy for the T-cells.
  • BHB helped T-cells form “memory cells,” which are specialized T-cells that “remember” an infecting agent so the immune system can rapidly respond to it should it return.

In the human blood tests (in vivo):

  • Certain genes related to inflammation, metabolism, and how both of these things interact underwent major changes following the keto diet.
  • The keto diet appeared to strengthen human T-cells’ ability to respond to an immune threat.
  • The keto diet also appeared to boost T-cells’ ability to harness energy, and bolstered the production of “memory” cells.
  • A blood test showed a better immune response overall after participants followed the keto diet.

WHY IT'S A HACK — Essentially, these critical immune cells appeared to become more active and more productive following a keto diet. But importantly, this boosting effect wouldn’t necessarily be a good thing if the immune system were to then become overactive.

What’s crucial about the results is that the T-cells, part of your body’s natural “adaptive” immune system, show signs of increased activity — but the body’s “innate” immune system doesn’t appear to be fundamentally changed by a keto diet.

The “innate” immune system is the tools the body uses to fight infection generally — while the “adaptive immune system” is what the researchers say the keto diet improved.

Think of a fire that burns up an entire field, compared to a weed-killing herbicide that only targets certain plants. Ketogenic diets seemed to affect only the body’s ability to target specific threats and adapt to pathogens, for example, and to single them out.

This lack of “innate” response indicates, the authors write, that a ketogenic diet “significantly reshaped human T-cell immunity toward a more powerful yet controlled adaptive immune response.”

HACK SCORE OUT OF 10 — 🥩🥩🥩/10

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