Eat well to have a healthy winter

The focus of flu-fighting is moving from the medicine cabinet to the refrigerator.

Dark green vegetables such as broccoli help maintain special immune cells that are vital to fighting off infection. Ravindranath K / The National

Despite the warmer temperatures, the UAE is not immune to the cold and flu season that sweeps across the northern hemisphere between October and April.

"There is definitely a rise in the number of cases of seasonal cold and influenza throughout the winter months in the United Arab Emirates," says Dr Richard Stangier, a consultant internal medicine and diabetologist at Al Rawdah German Medical Center in Abu Dhabi.

He attributes the influx of illness "to the continuous use of air-conditioning throughout these months, the inhalation of dust particles and unsuitable winter clothing".

A growing body of research suggests those hoping to avoid a case of the sniffles, sneezes and aches this winter may want to reconsider the contents of their refrigerator rather than medicine cabinet.

According to Rania Al Halawani, a dietitian at MedGate Centre in Dubai, a balanced diet is vital to staying healthy and avoiding seasonal colds and flu. "To keep colds away, or at least to shorten the period of illness, you should eat a colourful, healthy and balanced diet to ensure your body gets all the vitamins and minerals it needs to build a healthy immune system," she says.

While nothing can replace effective hygiene measures to avoid infection such as proper hand-washing, certain nutrients and herbs may be able to give your immune system an extra boost to keep you healthy.

Vitamin D

The UAE has plenty of one of the immune-boosting vitamins that many other countries in the northern hemisphere lack during the darker winter months: vitamin D. Vitamin D, which is produced in the skin when exposed to sunlight, is well known for its link to lower rates of cancer and multiple sclerosis. But new study findings are shedding light on how this fat-soluble vitamin may also be able to keep the immune system in top form. Findings published last year in The American Journal of Clinical Nutrition found that a daily vitamin D supplement could significantly reduce the number of colds in children.

Researchers randomly assigned a group of children to receive a daily supplement containing 1,200 international units of vitamin D or a placebo during the height of cold and flu season between December and March. At the end of the study, researchers found that children taking the vitamin D supplements were approximately 40 per cent less likely to get sick from influenza A, a common cause of seasonal colds and flu.

Another major study on the subject, published in the Archives of Internal Medicine in 2009, examined data on more than 18,000 adults and found that people with the lowest levels of vitamin D in their blood were significantly more likely to report having a recent upper respiratory tract infection.

The best source of vitamin D, aside from supplements, is sun exposure. Those at risk from vitamin D deficiency include anyone who is over the age of 65, with dark skin, who spends little time outdoors or wears clothing that covers most of their body. For these individuals, many health organisations, including the Canadian Cancer Society and the Department of Health in the UK, recommend a daily vitamin D supplement.

Vitamin C

According to Al Halawani, vitamin C is another nutrient worth stocking up on to help ward off colds and flu this winter.

One of the largest studies on the subject, published in the Cochrane Library in 2010, found that vitamin C could reduce the duration of cold symptoms by 10 per cent in adults and 14 per cent in children. Researchers also found that vitamin C could protect against the onset of illness in people under short periods of physical stress. In fact, researchers found that in marathon runners and skiers, a daily dose of vitamin C reduced the risk of catching a cold by half.

Al Halawani says food is the best source of vitamin C, including citrus fruits, berries, red peppers, leafy green vegetables and broccoli.

Garlic

Garlic may be small, but it is mighty when it comes to fighting off colds and flu. The protective effect is thought to be a result of natural sulphur compounds that have both antibacterial and anti-fungal properties.

In one study, published in 2001 in the journal Advances in Therapy, researchers randomly assigned 146 healthy adults to receive a daily garlic supplement or placebo for 12 weeks between November and February. At the end of the study, researchers found that the group taking the garlic supplement came down with 63 per cent fewer colds, and when they did get sick, had symptoms for just two days, compared with five days in the placebo group.

Chopping or crushing garlic activates an enzyme that helps produce the healthy sulphur compounds found in garlic. To reap the most health benefits, let garlic stand for 10 to 15 minutes after chopping or crushing it, to allow for this chemical reaction to take place.

Probiotics

Probiotics, the healthy bacteria found in many types of yogurt and some supplements, are well-known for their link to gut health, but research shows they may also help ward off the common cold.

One of the first studies to shed light on just how effective probiotics could be at boosting the immune system was published in the journal Pediatrics in 2009. Researchers assigned more than 300 children to one of three groups; one group was given a daily dose of the probiotic Lactobacillus acidophilus, another group received the same organism mixed with an additional probiotic called Bifidobacterium animalis, and a third group received a placebo. After being treated twice daily for six months, researchers found that children receiving the probiotics had considerably fewer colds.

The protective effect was most prominent in children receiving both strains of probiotics. Researchers found they experienced 73 per cent fewer fevers, 62 per cent fewer coughs and a 59 per cent drop in runny noses than children receiving the placebo.

The benefits did not end there: researchers also found that children receiving probiotics required 84 per cent less antibiotics than the placebo group.

Al Halawani recommends two ways to get a daily probiotic boost. "These friendly bugs are available in yogurt products and you can get them in pills from natural health stores." She warns that products containing probiotics should always be refrigerated to help maintain the healthy bacteria counts.

Cruciferous vegetables

Need another reason to eat your greens? New research findings published last month in the journal Cell found that cruciferous vegetables, such as cabbage and broccoli, help maintain special immune cells in the skin and gut that are vital to fighting off infection.

To investigate, researchers fed healthy mice a diet low in vegetables for two to three weeks, and found that during this time the number of protective immune cells had declined by up to 80 per cent, making the mice more susceptible to injury and illness.

Many of the health benefits of cruciferous vegetables, including their protective effect against stroke, heart disease and cancers of the breast, prostate, lung and bladder are thought to be a result of their high content of phytochemicals called glucosinolates. The cruciferous family of vegetables varies pretty widely in terms of shape, size, colour and taste and goes beyond broccoli and cabbage. Other vegetables that belong to this family include bok choy, Brussels sprouts, cauliflower, rutabaga, kale and turnip.

Get moving

According to Stangier, a healthy diet isn't the only way to sidestep those pesky winter colds. "Partaking in regular sport and exercise has been proven by trials to strengthen the immune system," he says.

A study published last year in the British Journal of Sports Medicine found that people who worked out for at least 20 minutes five times a week were almost half as likely to catch a cold compared to people who worked out less than one day per week.

Michelle Gelok is a member of the Dietitians of Canada and holds a BSc in Food and Nutrition. She lives in Abu Dhabi.