You don't catch a cold; a cold catches you. When your immune system isn't functioning at its best, viruses and bacteria can take over, and that tickle in your throat sets in. The best way to winter-proof your body is to arm your immune system with full fighting power. Read on to find out which foods and nutrients can help protect you this winter!
Vitamin C is most people's go-to nutrient for avoiding colds. Unfortunately, research shows that taking even 200mg (more than four times the recommended daily intake) as a preventative measure won't reduce your chances of catching a cold.
However, regular vitamin C intake before you catch a cold can have several benefits, including reduced cold severity and reduced cold duration, decreasing average recovery time by 8% in adults and 14% in children.
It is essential to consume foods that are rich in vitamin C on a daily basis, as our bodies can neither produce nor store this vitamin.
The recommended intake is 45mg per day for adults, or up to 200mg per day for added cold-fighting benefits. Intakes over 1000mg per day from supplements can have some unpleasant gastrointestinal side effects and are therefore not recommended.
By consuming a variety of vegetables and fruit daily you can easily achieve the recommended intake of 45mg per day, and with just a bit of extra planning 200mg per day for added benefits during winter.
Cutting and heating foods changes vitamin C making it less effective. Try to eat vegetables raw or only lightly cooked, and delay cutting fruits until you are ready to eat them.
Starting to sniffle? Research has found that zinc may actually stop cold viruses in their tracks.
Close to 30 years of research on colds and zinc have yielded mixed results, however a 2017 review of those studies indicated that zinc supplementation may help you get over a cold faster than you would without it. On average, cold duration was reduced by a significant 33%!
It's important to note though that the dosages used in these studies were much higher than the recommended daily maximum (40mg per day). High doses come at a price, often causing nausea and taste changes.
A better solution is to eat a diet rich in zinc-containing foods, as there is no evidence for adverse effects from naturally-occurring zinc in food. Recommended intakes are 8mg per day for women and 14mg per day for men.
Many of us will associate vitamin A with good eyesight - we've all heard that eating carrots will help you see in the dark! What we often don't realise is that vitamin A is also a key nutrient for immunity.
Vitamin A is essential for the creation of B- and T-cells which play central roles in protecting our bodies against disease. A deficiency of vitamin A has the reverse effect - leading to increased levels of pro-inflammatory molecules which diminish immune response and function.
In the context of dietary requirements, the term vitamin A includes both preformed vitamin A (known as retinol, found only in animal-derived foods) and provitamin A (known as carotenoids, found primarily in fruits, vegetables and oils). Our bodies can convert carotenoids into vitamin A. Processing of plant foods (cutting, cooking) improves availability and absorption of carotenoids.
Vitamin A requirements are usually expressed in terms of retinol equivalents (RE). The recommended intakes of RE are 700mcg per day for women and 900mcg per day for men.
As vitamin A is stored in the body, it can reach unhealthy and even toxic levels over time if excessive amounts are consumed frequently. For this reason a maximum limit of 3,000mcg per day from supplements and animal sources is set. This amount does not include carotenoids from plant foods, as the body converts only as much as it needs.