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Covid-19 has brought the important of a strong immune system into sharp focus. But are customer compromising their immune health by eating an unheathly diet?
Three out of every four people in Britain recognise that immune health is negatively affected by bad diets, but still many people don’t consume the right amount of essential nutrients.
These are among the findings of a new report, published recently by the Health and Food Supplements Information Service (HSIS).
"Many Brits badly need a nutrition reset," says HSIS, "with food portions out of control, comfort eating rife and immunity nutrients, such as vitamin D and iron, in decline."
GP Dr Gill Jenkins, co-author of the Immune Health: Micronutrients Under The Microscope report says: "Good nutrition is essential for optimal immunity but, as far as our diets are concerned, key pieces of the puzzle are missing. Vitamins A and C – from fruit and vegetables – and iron from red meat, beans and green veg, are lower than ideal for some age groups, while most adults don’t take a vitamin D supplement as recommended."
Dr Jenkins also points out that fish intakes across the country are too low. This is, she says, leading to a "massive shortfall" in omega-3 fats, essential nutrients that help the body to calm potentially dangerous levels of inflammation during an immune response.
"These nutrients all play a role in supporting two aspects of our immune function – innate immunity, which creates a barrier against invading pathogens, and adaptive immunity, which helps our bodies to target viruses and create antibodies," explains Dr Jenkins.
"Given that diets in the UK are far from ideal, it’s a good idea to take a daily vitamin and mineral supplement, as well as an omega-3 supplement if you rarely eat oily fish. Supplementation has been shown to improve several specific aspects of immune health, particularly where deficiencies exist."
A micronutrient emergency
Essential for the production and growth of immune cells. Low intakes increase the risk that pathogens will invade the eyes and the respiratory tract.
Who’s at risk?
One in 10 toddlers and primary schoolchildren don’t get the recommended amount of vitamin A. All children under the age of five should be given vitamins A, C and D, according to Government guidelines.
Needed to make the enzymes that extract fuel from food. This feeds the body’s immune cells. A lack of vitamin B6 reduces the production of immune cells and promotes inflammation. Folate deficiency depresses the body’s antibody response, which helps to neutralise invading viruses.
Who’s at risk?
Nine in 10 women of childbearing age have low blood levels of folate (the natural form of folic acid). Vegan diets are particularly vulnerable to low vitamin B12 levels.
Protects immune cells from inflammatory damage caused by free radicals. Low vitamin C levels increase the severity and duration of respiratory tract infections.
Who’s at risk?
In studies of older people, deficiency levels ranged from 14 to 26 per cent, with men at greatest risk. New research suggests we may need four times the currently recommended amount of vitamin C to fight respiratory viruses, says HSIS.
Most immune cells have vitamin D receptors, which suggests they need vitamin D to function well. Deficiency is associated with increased risk of Covid-19.
Who’s at risk?
People from ethnic minority groups are at very high risk of deficiency. In the general population, around 17 per cent of people are vitamin D deficient; among ethnic minority groups, this rises to between 43 and 66 per cent.
This essential mineral promotes the growth of immune cells and helps to regulate the body’s inflammatory response.
Low blood levels are linked to lower numbers of T lymphocytes (essential white blood cells), a reduced antibody response, and impaired killing of pathogens.
Who’s at risk?
Almost half of teenage girls lack iron, and dietary levels have fallen in the past decade, probably because of lower levels of red meat consumption.
Helps to maintain the structure and function of the skin and the gut barrier, and is vital for the growth and function of several types of immune cells. Being low in zinc impairs T cell function and increases susceptibility to respiratory and gastrointestinal tract infections.
Who’s at risk?
Despite a small improvement in recent years, more than one in six teenagers still fail to achieve the minimum recommended zinc intake.
Regulate the protective membranes around the body’s cells, helping to curb inflammation after a major immune response. Low intakes prolong inflammation, which impairs long term immunity.
Who’s at risk?
Anyone who doesn’t eat oily fish (e.g. salmon, mackerel), which is by far the best source.
Dietitian Dr Carrie Ruxton, who co-authored the HSIS report, says: "A recent study from King’s College London confirms that dietary supplementation can give your immune system a helping hand. Amongst almost half a million people subscribing to a Covid-19 app, the incidence of SARS-CoV-2 infection was cut by 14 per cent in those who took probiotics, omega-3 fatty acids, multivitamins or vitamin D.
"We need to urgently dump our comfort eating habits, watch portion sizes, up our vegetable intake, and choose healthier options for snacks. Tackling low levels of immune support nutrients with a daily vitamin and mineral supplement is also a useful health hack."
Key HSIS findings
- A third of survey respondents (34 per cent) ate more comfort foods and snacks during lockdown
- More than a fifth (21 per cent) have been advised by a healthcare professional to change their diet to lose weight
- Intakes of vital immune supporting nutrients, including vitamin A, vitamin D, B vitamins and iron, have declined over the last decade
- Almost half (48 per cent) say they have no idea what the Government’s Eatwell Guide advises (that’s the ‘Bible’ on what a healthy diet looks like)
- Around two thirds (64 per cent) of adults don’t take a vitamin D supplement
- Only half are actively following advice to eat more fruit and vegetables
- Three in five (60 per cent) don’t pay attention to recommended portion sizes or portion control.
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