Eating whole grains - such as brown rice, oats and Weetabix - could prevent an early death, research suggests.
Experts at Harvard found just one 16g serving per day of whole grain cuts the risk of dying from any cause, heart disease or cancer. And, they argued, the more whole grains people eat, the bigger the benefits.
Their analysis of studies showed that for every single serving (16g) of whole grains, there was a 7% drop in risk of death from any cause, a 9% drop in death from cardiovascular disease and a 5% drop in the chance of dying from cancer.
When three servings (48g) was eaten daily, people had a 20% lower chance of dying from any cause, a 25% reduced risk of a cardiovascular death and a 14% reduced chance of dying from cancer.
The research was published in the journal of the American Heart Association.
A slice of whole grain bread acts as one serving, while two Weetabix (37.5g) is just over two servings.
Half a cup of cooked brown rice or 100% whole grain pasta also count as one serving.
Experts agree that people do not eat enough whole grain foods and fibre.
The recent Eatwell Guide published by Public Health England (PHE) says people should consume 30g of fibre per day from fruit, vegetables and whole grain foods.
Currently people only consume around 19g of fibre per day - less than two-thirds the recommendation.
Previous studies have shown that whole grains can help reduce the risk of heart disease, stroke, obesity and Type 2 diabetes.
In the latest analysis, 12 studies were included from the US, Scandinavia and the UK.
The combined studies involved 786,076 men and women and included 97,867 total deaths, 23,597 deaths from cardiovascular disease and 37,492 deaths from cancer.
Qi Sun, assistant professor in the department of nutrition at the Harvard T.H. Chan School of Public Health in Boston, who led the research, said low-carbohydrate diets that ignore the health benefits of whole grains foods "should be adopted with caution".
He said they may be linked to a higher risk of cardiovascular disease and death.
"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," he said.
Victoria Taylor, senior dietician at the British Heart Foundation, said: "Eating more wholegrains is a simple change we can make to improve our diet and help lower our risk of heart and circulatory disease.
"Unlike in the US, the UK doesn't have specific recommendations for the number of portions of wholegrains we should eat every day, but we do have a recommendation on the amount of fibre we should eat. Wholegrains are a great way of increasing the level of fibre in our diets and, on average, our intake of fibre is not meeting guidelines.
"Choosing brown rice, whole-wheat pasta, wholemeal or granary bread instead of white and swapping to wholegrain breakfast cereals like porridge are all simple ways to help us up our fibre and wholegrain intake."
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."