An apple a day really might keep the doctor away!

An apple a day keeps the doctor away is how the saying goes — and researchers say there’s some truth to it.

Apples, along with berries, grapes and tea, protect heart health when consumed daily.

Scientists now advise people consume the equivalent of an apple, some berries and two cups of tea per day.

This combination contains roughly 500mg of flavan-3-ols — a ‘bioactive’ compound said to be good for your heart.

A review of more than 150 studies concluded that the chemical, also found in red wine and dark chocolate, can improve blood pressure, cholesterol and blood sugar levels.

Professor Gunter Kuhnle, an expert in nutrition at the University of Reading, said the data shows flavan-3-ols can boost health.

As it stands, dietary recommendations are focused on preventing deficiencies in essential vitamins, minerals, proteins, fats and sugars. 

The only non-essential nutrient people are told to eat based on its health benefits, rather than a risk of deficiency, is fibre. 

Fibre is linked with a lower risk of heart disease, stroke and type 2 diabetes, leading UK and US health chiefs to advise eating 30g per day.

But dieticians have argued that dietary recommendations should include other compounds that boost health.

Dozens of studies have highlighted the health benefits of flavan-3-ols in maintaining wellbeing and preventing disease — which the researchers said made it the ‘strongest candidate’ for investigating. 

The international experts, funded by the US Academy of Nutrition and Dietetics,  examined data from 157 randomised controlled trials and 15 cohort studies.

The results showed the bioactive compound was linked to lower blood pressure, in turn lowering the risk of heart disease, heart attacks and strokes.

It also improved levels of cholesterol, as well as ‘bad’ HDL cholesterol, which can harm the heart if levels are too high. 

Flavan-3-ols were also linked with lower blood sugar, reducing the risk of nerve and eye damage.

Dr Kuhnle said: ‘To reduce your risk of cardiovascular disease, we recommend consuming 400mg-600mg of flavan-3-ols, per day.

‘This is equivalent to a couple of cups of tea, some red or purple berries, and an apple.

‘It is far more effective to take in your daily amount as healthy food or beverages than to take a supplement’.  

Green tea has the highest flavan-3-ol content per cup (320mg), followed by black tea (280 mg), blackberries (65mg per 160g) and dried cranberries (35mg per 80g).

Dark chocolate is also packed with the bioactive (20mg per 18g), as is red wine (15mg per 150ml glass), apples (15mg per small apple) and blueberries (10mg per 150g). 

The team noted that the health risks from alcohol and high fat and sugar items, such as dark chocolate, ‘is likely to outweigh the benefits’ from flavan-3-ols.

And they warned that their findings apply to flavan-3-ols contained in food, rather than supplements.

The latter can cause liver damage and stomach problems when taken in high doses, the researchers said.

The team said they hope the results will help inform doctors, policy makers, public health bodies and the public. 

Dr Kuhnle told MailOnline: ‘For most people in the UK, it will probably be easy to meet this as three cups of tea are usually enough.

‘But those who don’t drink (much) tea could consider [picking] their five-a-day from a group of fruits and vegetables that are high in flavanols such as apples. 

‘Ultimately, it would be great if there could be some movement in the development of dietary recommendations and an inclusion of bioactive compounds such as flavanols — but this is likely to be a longer process.’

He added: ‘The impact of consuming that amount of flavanols is broadly comparable with switching to a Mediterranean diet or a moderate reduction in salt intake — both dietary changes that are based on official recommendations.’