5 A Day: the minimum, not the gold standard

Since the mid-twentieth century, scientists have investigated the causes of non-communicable disease (not caught from another source or person). These include diabetes mellitus, cardiovascular diseases, hypertension, stroke and certain types of cancer. This scientific research established the links between our foods, together with other lifestyle choices, in the development of these types of disease.

The World Health Organisation (WHO) was set up in 1948 to address global health issues and produces reports on diet, nutrition and non-communicable disease. In 1990, the WHO stated that the amount and type of food eaten were ‘fundamental determinants of human health’. Also, that diseases related to lifestyle (diet, alcohol, smoking and level of physical activity) were causes of most illnesses and death in developed countries (1). Unfortunately, in 2022, over 75 per cent of deaths in the UK were due to non-communicable disease, with heart disease and cancers being the most common.

In 2003, a panel of WHO experts reviewed the scientific evidence and reiterated that a healthy diet helps to prevent non-communicable diseases (3). Amongst other recommendations, they stated:

‘Daily intake of fresh fruit and vegetables (including berries, green leafy and cruciferous* vegetables and legumes), in an adequate quantity (400-500g per day), is recommended to reduce the risk of coronary heart disease, stroke and high blood pressure.’ *Cruciferous vegetables (also called brassicas) include broccoli, cabbage, cauliflower, kale, spring greens, rocket and watercress.

This recommendation is also supported by the World Cancer Research Fund. Along with a range of other lifestyle recommendations, it reported that ‘greater consumption’ of non-starchy vegetables and fruit probably decreases the risk of cancers of the mouth, throat, lung, stomach and large bowel:

‘Eat a diet high in all types of plant foods including at least five portions or servings (at least 400g or 15oz in total) of a variety of non-starchy vegetables and fruit every day’ (4).

Given that each portion of fruit or vegetables is about 80g in weight, our 5 A Day gives us the recommended 400g – or does it?

Government guidance actually states that ‘more than 400g of fruit and vegetables a day is associated with a lower risk of heart disease, stroke and some cancers. Therefore, government advice is to consume at least five 80g portions of a variety of fruit and vegetables a day […] implying that this is a minimum consumption recommendation’ (5).

So, should the message be changed to eat MORE than five a day?

It’s tricky. Until recently, there were no guidelines for children. However, in 2023, the WHO issued the following recommendations:

2–5 years old, at least 250g per day
6–9 years old, at least 350g per day
10 years or older, at least 400g per day

The UK advice is that one portion for a child is the amount they can fit in the palm of their hand (7).

What is a portion?

According to the NHS, an 80g portion of fresh, frozen or tinned fruit and vegetables is the edible portion, not the peel, core etc. If the vegetables or fruit are tinned, the 80g portion is the drained contents. Potatoes, sweet potatoes or cassava do not count as a portion of vegetables because they are high in starchy carbohydrates. A portion of dried fruit, as it is concentrated, is much smaller at just 30g. Just 150ml of fruit juice or smoothie counts as one portion, even if more is consumed. Similarly, cooked pulses (beans and lentils) only count once as part of your 5 A Day, no matter how much is eaten (7).

The list below gives a rough guide to 80g portions (8):

1 medium banana
1 medium apple
1 medium pear
2 satsumas
A handful of berries
1 heaped tablespoon dried fruit
3 heaped tablespoons of cooked carrots, peas or sweetcorn
4 heaped tablespoons cooked cabbage, kale, spring greens or green beans
3 heaped tablespoons of baked beans or cooked chick peas
1 cereal bowl of salad
1 medium tomato or 7 cherry tomatoes
150ml fruit and/or vegetable smoothie

The Eatwell Guide is helpful to show how fruit and vegetables should make up about one third of our food intake.

How many people eat 5 A Day?

A recent UK diet survey suggests that more than two thirds of us do not meet the target (9), with 11-18 year olds being the age group who eat the least (only 12% eat five a day). Sixty per cent of adults aged 65-74 years, and seventy three per cent of adults aged 75 years and over, also fall short of the recommendation.

These figures are concerning. According to the Food Foundation, a UK charity which promotes sustainable eating for health, the cost of living crisis has had a major impact on the amount of fruit and veg we consume (10). The British Dietetic Association also suggests that lack of cooking skills, the effort required in food preparation and simply not liking the taste are other barriers (11).

The supplement market

In the meantime, the UK supplement market has steadily grown with the sales value of over-the-counter vitamins and minerals reaching £492 million in 2023 (12). Around half of adults take food supplements or vitamins on a regular basis (13). Although some vitamins and minerals (such as vitamins D, B12 and folic acid) are recommended for certain population groups, can we replace the health benefits of eating fruit and vegetables by taking supplements?

Bioavailability is the amount of a nutrient that is absorbed and then used by the body. It varies according to the nutritional status of the person as well as the type of supplement. It is easy to take too much of a vitamin or mineral – for example, taking a Vitamin D tablet as well as a multivitamin (unless advised by a health professional) could cause levels of calcium in the body to become too high. Too much zinc can interfere with the absorption of copper, which can then cause a type of anaemia. Some herbal supplements have also been found to cause liver damage (14).

For those seeking clearer information, the British Dietetic Association has produced a helpful resource on supplements (15). They also state that ‘it may be better to focus on enhancing dietary quality before considering supplements’ and repeat the government and NHS advice to aim for at least five a day of a variety of fruit and vegetables. In other words, think twice before wasting money on potentially unnecessary supplements.

Fruit & Veg – what’s the magic ingredient?

Fruit and vegetables contain essential fibre, vitamins, minerals and phytochemicals (biologically active compounds of which there are over 20,000). Different types of fruit and vegetables help to keep the gut healthy by encouraging growth of ‘good’ bacteria in the gut microbiome.

Green leafy vegetables, such as spinach, rocket and certain types of lettuce as well as beetroot are naturally high in dietary nitrate Dr Ann Ashworth

Health benefits are thought to be from a mix of different fruit and vegetables. This is why we are advised to eat ‘a variety’ or to eat ‘a rainbow’ of different coloured fruit and vegetables.

Interestingly, recent research has identified that one naturally occurring substance, dietary nitrate, could be a key factor in their health-giving benefits. Green leafy vegetables, such as spinach, rocket and certain types of lettuce as well as beetroot are naturally high in dietary nitrate. The dietary nitrate is absorbed by our gut and then converted in the mouth by good bacteria to nitrite, which can then be processed to nitric oxide.

This nitric oxide may help to reduce blood pressure as it is involved in many processes which may slow the development of atherosclerosis (clogging of the arteries), a factor in the development of heart disease (16). Other key ingredients, such as sulphur containing compounds in cabbage, kale and broccoli and may also be anti-inflammatory.

Research supported by Riverford Organic and carried out at the University of Exeter showed that blood levels of nitrate and nitrite markedly went up on high-nitrate vegetable diets. There was a significant drop in blood pressure in young healthy women (17), but this was not significant in young, healthy men, perhaps due to the small numbers in the trial (18).

A much larger study in middle-aged adults showed that eating the amount of nitrate in just one portion of high-nitrate vegetables was linked with lower blood pressure, reduced risk of cardiovascular disease and stroke (19). This is the roughly amount in a cereal bowl of raw spinach, or a small handful of rocket or a portion of beetroot.

So – what should we be aiming for?

Aim to eat more than five portions a day, of a rainbow of fruit and vegetables, including a portion of green leafy vegetables and/or beetroot. Start by adding just one portion a day.

The British Heart Foundation suggests we choose from:

Red – tomatoes, raspberries, strawberries, red apples, red grapes

Orange – carrots, squash, sweet potato, melon

Yellow – swede, yellow peppers, sweetcorn, peach

Green – spinach, rocket, kale, broccoli, lettuce

Blue/purple – beetroot, aubergines, blackberries, purple grapes, red cabbage

White/beige – bananas, celeriac, mushrooms, onions, turnips

Is there anyone who should not eat five a day?

The 5 A Day advice applies to healthy children and adults in the UK. It does not apply if you have been advised by your doctor, dietitian or other healthcare professional to follow a specific diet or to avoid certain fruits and vegetables for your health condition.

Dr Ann Ashworth PhD is a retired clinical dietitian who worked for over 20 years in the NHS. Her PhD focused on the effects of dietary nitrate on health.

Disclaimer
The information in this article should not be used to replace any treatment or to cure any existing disease. Please consult your doctor or health care professional before making any changes to your treatment or medication.

Financial support/conflict of interest
Veg boxes were provided free of charge by Riverford Organic Farms Ltd, to Dr Ann Ashworth for her research into dietary nitrate. Riverford had no role in the design, analysis or writing of the research conducted by Dr Ashworth at the University of Exeter.

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