Wholegrains offer more nutrition than their refined counterparts, but should we all be eating them? And if so, what should we be looking for on the packaging?

Love or loathe them, wholegrains have long been widely considered a healthy choice.

In 2017, for instance, a UK survey (commissioned by breakfast cereal manufacturers) found that 70% of respondents believed it was important to eat wholegrains.

Yet despite what might be considered common knowledge about the health benefits of wholegrains, the scientific jury still appears to be out — at least in part.

Health benefits of wholegrains

Wholegrains contain a range of nutrients that their refined counterparts do not.

In 19th century Java, for instance, it was observed that chickens fed white rice lost the use of their legs whilst chickens fed brown rice did not.

Similar neurological effects were also observed in prisoners, and it was eventually understood that a disease called beriberi was caused by a lack of thiamine (vitamin B1), which is found in brown rice.

In fact, wholegrains — brown rice, whole wheat, whole oats, rye or barley (not pearl barley) — contain a range of nutrients including magnesium, potassium, selenium, vitamins B1, (thiamine), B3 (niacin), B6, and E, as well as fibre.

And the range of associated health benefits are many. Wholegrains have been linked to:

• lower body weight
• lower BMI
• lower cholesterol levels
• lower risk of type 2 diabetes and some cancers
• increased levels of so-called ‘good’ gut bacteria
• lower levels of so-called ‘bad’ gut bacteria
• lower levels of inflammatory markers

However, many reports of health benefits have resulted from the findings of observational studies that rely on people reporting what they eat accurately, without forgetting or lying.

It is also harder to control for lifestyle and genetic factors that can skew results.

This is why, when it comes to making health claims, randomised controlled trials (RCTs) are often considered the gold standard.

They are harder to do but in 2017 a six-week controlled study from Tufts University, USA, found that participants who ate a diet rich in wholegrains had “modest improvements” in gut bacteria and immune response.

Yet in the search for whole grains of truth, not even RCTs always stand up to scrutiny.

In 2017, a review of nine randomised studies concluded that due to study design and low overall quality of evidence, there was insufficient evidence that wholegrains reduced the risk of cardiovascular disease, or lowered blood cholesterol or blood pressure.

These findings confirmed the earlier conclusions of WHOLEheart, a 2010 randomised controlled trial funded by the UK Foods Standards Agency.

However, insufficient evidence does not mean that wholegrains do not have health benefits, but that manufacturers cannot make health claims such as ‘heart healthy’ or ‘lowers cholesterol’ on their packaging.

A current exception is with oats, for which packaging may state that beta-glucan, found in oats, can contribute to lowering cholesterol.

Wholegrains vs. refined

Despite this, if we do want to eat starchy carbohydrates there is a general consensus that wholegrains are a better choice.

In the NHS Eatwell Guide, it is recommended that starchy carbohydrates make up a third of our diet and to choose wholegrain “where you can”.

A ‘wellbeing guide’ published by the British Association for Nutrition and Lifestyle Medicine (BANT), the professional body for registered nutritional therapists, however, recommends less starchy carbohydrate consumption; combining root vegetables with wholegrains on its ‘plate’, at about a quarter of food intake.

For some of us, whether to eat wholegrains may also depend upon our health status.

The worldwide diabetes community diabetes.co.uk states on wholegrains: “Whilst wholegrain foods impact upon blood glucose levels more slowly than other forms of carbohydrate, higher levels of carbohydrate can still raise blood sugar levels substantially.”

An individual approach

At the time of the 2017 review, BANT published a statement saying: “BANT and its members do not advocate for the removal of wholegrains from anyone’s diet.”

However, it added: “Whilst guidelines can be useful as a starting point, promoting a one-size-fits-all dietary model such as ‘the Eatwell Guide’ as a ‘healthy balanced diet’ for everyone, is a concept that is losing the support of healthcare professionals across the board.”

This is because it is being increasingly understood that individuals may respond differently to the same foods.

In his 2020 book Spoon Fed, Professor Tim Spector notes how he and his wife had very different blood sugar responses to the same food.

After eating his “old ‘healthy’ breakfast” that was high in carbohydrates and included wholegrain toast, his blood sugars rose sharply from 5.5 mmol to 9.1 mmol.

Yet after an identical breakfast, his wife’s blood sugars barely moved from 4 mmol to above 5.7 mmol.

Some tips for smart eating

Without access to a continuous blood glucose monitor, most of us won’t know how we respond to starchy carbohydrates, wholegrain or not.

But if we don’t want to cut them out completely, there are potentially better ways of eating them.

Cooking and chilling starchy carbohydrates creates ‘resistant starch’, as molecules are broken down through the cooking process and then reform when cooled.

Because we cannot digest resistant starch, it also means that starchy carbohydrates that have gone through this process will have less impact on blood sugars.

They also pass further along the digestive system, to provide food for our beneficial gut bacteria.

One of the components of wholegrains that many of us could do with adding to our diet is fibre. According to the NHS, most UK adults only take in about 18g a day instead of the recommended 30g a day.

Currently, the BANT wellness guide recommends leafy greens and salads make up a quarter of our food intake and another quarter is made up from other vegetables (not including root vegetables) with one to three palm-sized portions of fruit each day; all of which are good sources of fibre.

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