Why you should ‘feed a cold’: eating primes immune cells for action

The best time to get an infection might be after a meal, suggest experiments in mice and humans that found that certain immune cells, known as T cells, seem to get a boost from food.

The findings, published today in Nature¹, could identify ways to improve immune therapies, help physicians to decide when to give vaccinations and eventually show how diet can improve immunity.

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“There’s the old adage: starve a fever, feed a cold. And we think that there’s some value in this,” says study co-author Greg Delgoffe, an immunologist at the University of Pittsburgh in Pennsylvania. He thinks that researchers should reassess how diet influences the immune response. “We don’t really ask, when have you eaten last and what did you eat?” he says. “But that may make a big difference to how effective those T cells are.”

“I think this is really an exciting study,” says Lionel Apetoh, an immunologist at Indiana University in Indianapolis who was not involved in the work. He notes that previous T-cell research has looked at only long-term interventions of diets.

Well-fed cells

T cells are a group of white blood cells that coordinate the body’s immune responses, activating in response to threats. “The activation of your immune system is incredibly demanding” in terms of energy, says Delgoffe. To investigate this, Delgoffe and his colleagues drew blood from human participants before their first meal of the day and then again after six hours, during which they could eat what they wanted. The team then assessed the metabolic profile of the T cells in the blood.

The researchers found that after people had eaten, their T cells could more easily access the nutrition required to go through the energy-demanding activation process than when they had fasted overnight. After feeding, the cells were better able to take up sugars, had more fats and more-efficient mitochondria. Ultimately, this boosted the T cells’ ability to respond to threats; experiments in mice showed that the cells were better able to proliferate and to provide protection against infection.

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“To me, what is surprising is actually the timing,” says Apetoh. “Six hours is definitely not a long time. And still, that has profound consequences on T-cell immunity.”