Vitamin C And Immunity – A Healthy Outlook
Tuesday, September 12th, 2017 | 439 Views
Enjoying high consumer awareness, the backing of an EFSA Article 13.1 health claim, and regularly the subject of studies designed to unlock its full potential, vitamin C remains firmly associated with positive health benefits. What has recent research gleaned of the vitamin’s role in enhancing immune response, and how can it be incorporated into our foods? By Professor Manfred Eggersdorfer, senior vice-president, Nutrition Science & Advocacy, DSM
An Essential For Maintaining Health
Also known as ascorbic acid, vitamin C is an essential micronutrient which the body cannot produce itself and needs to absorb through diet or supplements.
Widely found in fruits and vegetables, such as blackcurrants, peppers, broccoli and kiwi, vitamin C was first isolated in the 1930s but came to prominence in the 1970s when Nobel laureate Linus Pauling concluded from earlier placebo controlled trials, that vitamin C would prevent and alleviate the common cold. Since then, it has been the subject of numerous trials to fully understand its role in human health.
Through extensive research, the vitamin has been found to act as a powerful antioxidant to neutralise free radicals, support the production of collagen in the body and it also helps to reduce the risk of certain cardiovascular disorders.
Vitamin C is also one of the best known nutrients for boosting the immune system, in a bid to fight off colds and flu and science continues to emerge for its role in immunity. Each year, adults and children are regularly affected by symptoms which may include a runny nose, congestion, sneezing, sore throat, coughs and a high temperature. In fact, adults worldwide are thought to suffer on average 2-5 colds per year, while for children it may be as high as 7-10 episodes.
Not surprisingly, the impact on the economy can be significant. In a study on productivity losses related to the common cold, it was estimated that each cold experienced by a working adult caused an average of 8.7 lost work hours (2.8 absenteeism hours; 5.9 hours of on-the-job loss). It was concluded that the economic cost of lost productivity due to the common cold approaches US$25 billion, of which US$16.6 billion is attributed to on-the-job productivity loss, and US$8 billion is attributed to absenteeism.
The Battle To Boost Immunity Levels
Since the common cold is usually caused by a respiratory virus, antibiotics are not an effective treatment; meaning other potential ways to prevent or minimise the duration are of strong public interest. This demand translates to a sizeable market opportunity, as evidenced by the solid performance of immunity-related products over recent years.
According to Frost & Sullivan, demand for immune health ingredients in Asia is growing at an annual rate of 6.2 per cent, with revenues expected to reach US$1.46 billion, up from US$959 million in 2009. Furthermore, Japan, Australia & New Zealand, Singapore, South Korea and Taiwan are relatively developed markets for immune health ingredients with Good Manufacturing Practices (GMP) catering to local demand, robust regulatory structure, high consumer awareness and increasingly aging populations.
Literature has revealed that vitamin C accumulates in white blood cells such as leukocytes, which play an important part in immune defence. A DSM research study demonstrated that the vitamin particularly improves the mobility of white blood cells to localise and attack invading bodies, such as viruses. This was the first time that the mechanism behind the role of vitamin C in increasing white blood cell function had been evaluated.
As a result, with the vitamin’s positive reputation and proven science to support its immune stimulating effect, products that incorporate the vitamin are popular among concerned consumers.
The Key To Immunity Defence
Vitamin C is one of only a select few nutrients to be approved with health claim relating to immunity by the European Food Safety Authority (EFSA). After stringent review of the scientific evidence, vitamin C gained authorisation for an Article 13.1 health claim for its role in the maintenance of the normal function of the immune system. This is an important endorsement and formal recognition of vitamin C’s positive effect on the immune system.
Despite this concrete evidence of the vitamin on health, data from several countries in Asia indicate that deficiencies of vitamin C and zinc continue to be at alarming levels in children. Overall, there is increasing evidence that deficiency of vitamin C and zinc adversely affects the physical and mental growth of children and can impair their immune defences. Nutrition should be the main vehicle for providing these essential nutrients, with supplementation representing a valid support method, especially in developing regions.
This was also the case for a recent Cochrane review. It found that daily vitamin C supplements may reduce the risk of developing the common cold among people exposed to brief periods of severe physical exercise by over 50 percent. Data from five trials with 598 marathon runners, skiers and soldiers on subarctic exercise indicated that the risk of the common cold was reduced by 52 percent following vitamin C supplementation of 0.2 g per day or more. In terms of the general population, it was found that vitamin C had a modest but consistent effect in reducing the duration of common cold symptoms – based on 31 study comparisons with 9,745 common cold episodes.
The authors concluded: “Given the consistent effect of vitamin C on the duration and severity of colds in the regular supplementation studies, and the low cost and safety, it may be worthwhile for common cold patients to test on an individual basis whether therapeutic vitamin C is beneficial for them. Further therapeutic RCTs (randomised control trials) are warranted.”
Dynamic Duo: Vitamin C + Zinc
Vitamin C is not alone in helping to fight against infections. Zinc – also the subject of a positive Article 13.1 immunity health claim from the European Union – has been proven to play an important functional role.
The potential health benefits from zinc are supported by numerous studies; in particular a review from the Cochrane Collaboration reported that after seven days, more patients taking zinc had cleared their symptoms compared to placebo. As a result, attention is increasingly starting to focus on the impact of combining both essential micronutrients in one supplement.
Another study for example, presented the findings from two preliminary, double-blind, randomised, placebo-controlled trials, conducted with a combination of 1000 mg vitamin C plus 10 mg zinc in patients with the common cold. In pooled analyses of both studies (n=94), vitamin C plus zinc was significantly more efficient than placebo at reducing rhinorrhea (the most common symptom of a cold) over five days of treatment. Results also showed that symptom relief – including discomfort due to nasal obstruction, sneezing and eye watering – also improved with active treatment.
“Together these findings indicate that high dose vitamin C plus zinc could make a tangible contribution to improving quality of life and speeding up recovery in patients with symptoms of the common cold… Supplementation may represent an efficacious measure, with a good safety profile, to help ameliorate the symptoms of this infectious viral disease,” wrote the authors.
These positive findings are likely to encourage further research to establish whether the immune stimulating effect of vitamin C can be magnified, when used in combination with other complementary nutrients.
Food Fortification The Solution?
The fastest growing markets for vitamin C in Asia from 2008-2013 were China, Indonesia, Vietnam and Malaysia, with a compound annual growth rate (CAGR) of 17 percent. In China, the increase in sales of vitamin C is fuelled by consumers seeking to boost their immune systems while in Indonesia, consumers are taking vitamin C to prevent coughs, colds and the flu in response to the increasing level of pollution and extreme weather changes.
In spite of the recognition that an increase in the level of vitamin C intake is highly beneficial, consumers are finding it difficult to keep up with their daily nutritional needs because of their busy lifestyles. They have become master multi-taskers, and expect their food to do the same. In response, manufacturers have developed a vast range of products fortified with vitamin C – encompassing supplements as well as food and beverages – which are designed to keep pace with today’s consumer trends and fit into lifestyle patterns. The choice available now goes far beyond conventional or effervescent tablets. From chewing gum and gummies to juice, breakfast cereals and dairy drinks, vitamin C is now being used to boost health credentials either alone or as part of a multivitamin platform.
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