Alarge bowl of porridge each day may protect against death from cancer, the biggest ever analysis of the benefits of whole grains has shown.
Oats have long been considered a super-food, staving off illnesses like diabetes and heart disease.
But now a major review by Harvard University has found that whole grains also seem to prevent early death and lower the chance of dying from cancer.
A meta-analysis of 12 studies involving nearly 800,000 people found that eating 70 grams of whole grains a day – the equivalent of a large bowl of porridge – lowers the risk of all-cause death by 22 per cent and death from cancer by 20 per cent.
It also reduces the risk of dying from cardiovascular disease by 20 per cent.
Scientists believe that whole grains help lower cholesterol and help regulate blood sugar, as well as keeping people full for longer, meaning they don't snack on unhealthy foods. The same effect could be gained eating bran, quinoa or a mix of grains.
“Based on the solid evidence from this meta-analysis and numerous previous studies that collectively document beneficial effects of whole grains, I think healthcare providers should unanimously recommend whole grain consumption to the general population as well as to patients with certain diseases to help achieve better health and perhaps reduce death,” said Dr Qi Sun, assistant professor at theHarvard T.H. Chan School of Public Health in Boston, Massachusetts.
Whole grains, where the bran and germ remain, contain 25 per cent more protein than refined grains, such as those that make white flour, pasta and white rice.
Previous studies have shown that whole grains can boost bone mineral density, lower blood pressure, promote healthy gut bacteria and reduce the risk of diabetes.
One particular fibre found only in oats – called beta-glucan – has been found to lower cholesterol which can help to protect against heart disease. A bioactive compound called avenanthramide is also thought to stop fat forming in the arteries, preventing heart attacks and strokes.
Whole grains are also widely recommended in many dietary guidelines because they contain high levels of nutrients like zinc, copper, manganese, iron and thiamine. They are also believed to boost levels of antioxidants which combat free-radicals which are linked to cancer.
The new research suggests that if more people switched to whole grains, thousands of lives could be saved each year. Cumulatively, cancer kills around 160,000 people a year while coronary heart disease is responsible for around 73,000 deaths in the UK each year.
Health experts said the study proved that whole grains were essential for good health.
Prof Tim Key, Cancer Research UK scientist at the University of Oxford, said: “We know that eating fibre, including whole grains, can reduce the risk of developing bowel cancer.
"This study suggests that a diet high in whole grains could reduce death from cancer, but it’s difficult to tease apart other lifestyle factors that could be playing a role. If whole grains do reduce the risk of dying from cancer it’s most likely linked to bowel cancer.
“Decades of evidence shows that eating a diet high in fibre, fruit and vegetables and low in processed and red meat, reduces the risk of developing bowel cancer.”
The researchers recommend that people choose foods that are high in whole grain ingredients—such as bran, oatmeal, and quinoa—that have at least 16 grams per serving, while reducing consumption of unhealthy refined carbohydrates. Each 16 gram serving lowered the risk of total death by seven per cent, and cancer by 5 per cent.
Dr Naveed Sattar, Professor of Metabolic Medicine at the University of Glasgow said: “The simplest way to increase would be to alter cereal intakes to bran flakes or whole grain cereals – these are excellent ways to start the day but oatmeal would also be fine – and replacing white bread with whole wheat bread is also advisable
“In general, though, I think many of us need to eat more fibre in one form of the other and this report seems to add more support for this notion.”
Victoria Taylor, Senior Dietitian at the British Heart Foundation said: “Eating more whole grains is a simple change we can make to improve our diet and help lower our risk of heart and circulatory disease.
“Choosing brown rice, whole-wheat pasta, wholemeal or granary bread instead of white and swapping to whole grain breakfast cereals like porridge are all simple ways to help us up our fibre and wholegrain intake.”
BY NUMBERS | Cancer in the UK
10,000
Number of lives which could be saved with earlier diagnosis
352,197
Number of people diagnosed with cancer each year (2013)
161,823
Annual deaths from cancer (2012)
50%
Chance of living at least 10 years after cancer diagnosis (as of 2010-11)
41%
Percentage of cancer cases which are preventable
Source: Cancer Research UK
