How a Keto Diet Can Boost Immunity

Last Updated on: 16th November 2023, 07:58 pm

It’s probably fair to say that most people looking at a keto diet want to lose weight.

But research is showing keto is the gateway to a whole new world of health benefits.

Including immunity.

Research on keto and immunity

The relationship between keto and immunity has been well studied. After all, it’s important to know the benefits of a diet or lifestyle before you start. And when we look at the sort of benefits people want, the last couple of years have shown us that keeping your immune system strong is top of the list.

T cells

A quick sidenote – Most of the research you’ll hear about below is based around T cells. T cells are another name for the white blood cells that make up our adaptive immunity. In other words, the part of our immune system that learns about pathogens or antigens (the bad things) and how to keep them at bay.

Keto – 7 days to healthy mice

Back in 2019, a group of researchers from the Yale School of Medicine looked at whether a keto diet can help immunity.

The results came back clear and compelling.

After putting mice on a high-fat, low carb keto diet for seven days, they found:

“a ketogenic diet protects mice against influenza virus infection”

Ketogenic diet activates protective γδ T cell responses against influenza virus infection

Now two things jump out when reading this.

  1. First, the study came out conclusively saying that a keto diet can boost immunity.
  2. Importantly, it also found that a period of adaptation was required for it to be most effective. In other words, starting a keto diet after you have caught the flu isn’t going to help. On the plus side, it only took seven days for the protective effects of a keto diet to be effective.

Of course, you probably noticed that this experiment was done on mice, and while mice have been used in experiments because there’s a strong correlation between their biological systems and ours, it’s not always an exact match.

Study summary – Mice on a keto diet are protected from flu1

Type of dietNutrient comparisonResult when mice were infected with flu
Keto diet90% of calories from fat, <1% of calories from carbohydrateImproved survival rates from influenza and protected from body weight loss.
High-fat diet60% of calories from fat, 20% of calories from carbohydrateImproved survival rates from influenza but no protection from body weight loss
Conventional diet18% of calories from fat, 58% of calories from carbohydrateDecreased survival rates from influenza and no protection from body weight loss

Not convinced?

Fair enough, but the good news is there have been a few studies done using humans, which can boost your confidence that following a keto diet can bring benefits to your immune system.

A low-carb diet can be a tool for human immunity2

2021 saw another group of researchers, this time from Germany, produced what they claimed to be the first study of how a three-week keto diet would impact the immunity of healthy volunteers.

Again, the results were clear:

Our data suggest a very-low-carbohydrate diet as a clinical tool to improve human T-cell immunity.

Very-low-carbohydrate diet enhances human T-cell immunity through immunometabolic reprogramming

With comments like “ketone bodies profoundly impact human T-cell responses”, the study authors ultimately concluded that “rethinking the value of nutrition and dietary interventions in modern medicine is required” – it’s very rare to see language as confident as this in published papers.

Study summary – Humans on a keto diet are protected from flu

Type of dietNutrient breakdownResult
Keto diet<30g carbohydrates/day
  • enhanced immunity
  • body weight loss (for the overweight volunteers – BMI>25)
  • COVID – the immunity elephant in the room

    In recent times, when we talk about immunity, COVID is the first thing that springs to mind.

    The good news is researchers have started investigating this too, and in June 2022 have again found some positive benefits.3 The study was concentrated on immunoparalysis – where the body fails to recover properly from an infection and carries on in a weakened condition, making it more likely to catch another strain or other illnesses.

    In other words, the dreaded long COVID.

    Their findings were clear.

    We here report similar strengthening of CD8+ T cells obtained from severely diseased COVID-19 patients.

    Ketone Bodies Improve Human CD8+ Cytotoxic T-Cell Immune Response During COVID-19 Infection

    It’s important to note that the study used cells (in vitro), rather than an actual human trial, but we can look to another study showing that people who were put on a keto after they were admitted to hospital were less likely to need intensive care, and more likely to survive.4

    Study summary – A keto diet lowers intensive care admissions and mortality

    Type of dietNutrient breakdownResult
    Keto dietProtein 16–20%, fat 74%–80%, and carbohydrates 5-6%
  • less likely to need intensive care
  • more likely to survive
  • Mediterranean style dietProtein 16–20%, fat 26%–30%, and carbohydrates 42%–50%
  • more likely to need intensive care
  • less likely to survive
  • Of course, it’s important to note that these studies were of limited scope and there is no guarantee that they will work. That said, it’s exciting to see the frontiers of keto research are expanding, and seem to bring positive results wherever researchers take a closer look.

    So, does keto make your immune system stronger?

    Looking at the studies above, then answer is a clear “yes”.

    The keto diet can not only improve your immune system, it can do it in as little as three weeks and has been shown to be effective even if started after someone has been infected.

    The consensus is there are two parts to a keto diet that seems to make it so effective in building immunity.

    • Firstly, it can inhibit inflammation.
    • Secondly, ketosis protects the body by increasing its ability to create antioxidants.  

    Weight loss and immunity – this one-two punch from a keto diet has been shown to improve immunity and is another reason to embrace the keto lifestyle.

    1. Ketogenic diet activates protective γδ T cell responses against influenza virus infection []
    2. Very-low-carbohydrate diet enhances human T-cell immunity through immunometabolic reprogramming []
    3. Ketone Bodies Improve Human CD8+ Cytotoxic T-Cell Immune Response During COVID-19 Infection []
    4. Clinical efficacy of eucaloric ketogenic nutrition in the COVID-19 cytokine storm: A retrospective analysis of mortality and intensive care unit admission []