image copyright, Getty Images
-
- reporter, Yasmin Lupo
- reporter, BBC News
Every winter, interest in finding the secret to staying healthy grows.
‘Immunity-boosting’ drinks are popping up on supermarket shelves, cold-water swimming clubs are on the rise, and social media is filled with tips for preventing seasonal colds.
But while there are many ways to prevent colds and flu, how many of them actually work? Is it really possible to strengthen immunity?
Cold water swimming: improves mood rather than boosting immunity
Table of Contents
image copyright, Getty Images
The popularity of cold water swimming has grown rapidly in recent years, and some swimmers believe it is effective in preventing winter illnesses. However, experts point out that the actual increase in immunity is limited and that the main effects come from mood and social connection.
Professor Eleanor Riley, an immunologist, said on BBC Radio 4’s ‘Inside Health’, “The pleasure you feel after swimming in cold water is a phenomenon caused by adrenaline and endorphins,” and explained, “When you take a blood test, your white blood cell count rises, but this is just a movement of white blood cells in preparation for possible infection, and not actually more white blood cells being created. It returns to normal after a few hours.”
Professor Riley added: “One of the benefits of cold water swimming is that it creates a sense of social connection with people. Feeling brighter, more awake and connected to people has real physiological effects.”
Professor John Tregoning, a vaccine immunologist, said: “The effects of cold water swimming are mostly indirect. The reason people feel healthier in winter is because they reduce stress. Spending time outdoors with good people reduces stress, and dancing, singing or running can have a similar effect.”
Additionally, being active in nature lowers blood pressure and stress hormones and helps the immune response. Dr Margaret McCartney, a general practitioner, said: “There is evidence that moderate exercise can reduce viral infections, but it doesn’t have to be cold water swimming.”
Kombucha: Interesting, but lacking evidence
image copyright, Getty Images
Many people are looking for fermented beverages such as kombucha, which are known to help strengthen the intestinal microbiome and even immunity.
However, Dr. McCartney is cautious. “There are many theories as to why a diverse microbiome is good, but there is not enough empirical evidence to recommend kombucha to patients,” he said.
Professor Tregoning added, “It is true that the microbial community changes during infection, but in most cases it returns to its original state.”
“Although drinks like kombucha may provide interesting ideas about the role of the microbiome, there is no clear evidence linking them directly to boosting immunity,” Dr McCartney explained.
Nutrients: Just Expensive Urine
image copyright, Getty Images
Vitamin C has long been marketed as an essential winter supplement, but Dr. McCartney says there isn’t enough evidence to recommend its effectiveness in preventing colds.
The same goes for multivitamins, she said. “They’re really just ‘expensive urine.’”
However, vitamin D is a little different. “There is theoretical basis for a slight decrease in respiratory infections.” However, not everyone will benefit from taking it, and only “those who are deficient in vitamin D or have existing respiratory diseases” are likely to benefit, he explained.
Many people in the UK are still deficient in vitamin D, and Professor Tregoning said getting some sunlight and being outdoors during the winter could help.
Vaccination: The only effective way to strengthen immunity
image copyright, Getty Images
Turmeric juice, ginger drinks, and fancy nasal sprays aren’t effective in boosting immunity, says Dr. McCartney.
Professor Tregoning explains that while nasal sprays can help relieve nasal congestion, what you really need is a simple saline spray. “This solution can dilute a blocked nose, promote mucus circulation and relieve inflammation.”
All three experts agreed that the only way to strengthen immunity is vaccination. Professor Riley recommends getting a flu shot, adding that it takes 7 to 10 days for the effect to take effect after vaccination.
Experts advise that although it is difficult to dramatically increase immunity like the winter wellness trend, avoiding smoking, maintaining a healthy weight, having regular sleep habits, and engaging in activities that help reduce stress can help maintain immunity.
Dr. McCartney also emphasized that you can reduce your risk of catching a cold simply by staying in a well-ventilated space and washing your hands properly and often.
