Breathe in the scent of trees to dodge colds

IT’S cold and flu season — and Covid hasn’t gone away, either. Preserving your immune system in and beyond middle age will help you to avoid days in bed feeling miserable as winter trudges on.

Luckily, there are tried and scientifically tested ways to do so.

One lovely option is to take a walk through a forest. So called ‘forest bathing’ — surrounding yourself with trees — lowers the stress hormone cortisol and elevates natural killer cell activity. Trees produce aromatic volatile compounds called phytoncides that you breathe into your lungs when in nature.

Ironically, they are part of the tree’s own immune system, which we seem to be able to commandeer. Researchers suggest these compounds may contribute to low death rates from breast and prostate cancer in heavily forested regions of Japan.

Sleep is important too. In a very direct demonstration, researchers at the Mayo Clinic dripped cold viruses into people’s noses, and those who slept fewer than seven hours a night were three times more likely to come down with a cold than those who slept for eight hours or more.

While infection rates were the same, the well-rested participants were able to clear the virus quickly and were less likely to become symptomatic.

Sprinkle some blueberries — or if you want to get fancy, goji berries — on your porridge each morning to boost your immune system efficiency. Goji berries have been proven to ramp up the antibody response to the flu vaccine, making it more effective, while blueberries can increase the number of those crucial killer cells.

Broccoli is another booster. One study, which sounds like something from a sci-fi novel, found that broccoli activates an ‘execution’ enzyme that self-destructs to wipe out virusinfected and cancerous cells.

Researchers concluded that cruciferous vegetables (such as broccoli) may be a ‘low-cost and low-risk measure’ for reducing the impact of a cold.

Seaweed works too. Nori, the sheets used to make sushi rolls, is probably the most accessible form. It’s hard to beat the nutrient density, they make a quick and easy snack, and each sheet has as little as a single calorie.

Study participants who ate seven sheets per day had a notable increase in killer cell activity and fought off colds more easily. A perfect excuse for a sushi takeaway!