Seven servings of whole grains a day keep the doctor away

http://www.eurekalert.org/pub_releases/2016-06/nuos-sso061516.php

Public Release: 15-Jun-2016
Seven servings of whole grains a day keep the doctor away
Throw away that white bread -- whole grains are the way to go
Norwegian University of Science and Technology

Eating three more portions of dietary fiber a day--say, two pieces of whole grain bread and a bowl of whole grain breakfast cereal--is associated with a lower risk for all cardiovascular diseases and for dying of cancer, diabetes, and respiratory and infectious diseases, a study just published in the BMJ has shown. The study is strong proof that consuming lots of whole grains is good for our health, says first author Dagfinn Aune, a PhD candidate at the Norwegian University of Science and Technology who is currently working at Imperial College, London.

The meta-analysis isn't the first study that links whole grains to positive health effects, but it is the first one to look at how much whole grain one should eat to minimize health risks and that has examined the connection with various causes of death. In general, the study showed that the higher the consumption, the better protected you are.

"We saw the lowest risk among people who ate between seven and seven and a half servings of whole grain products a day, which was the highest intake across all the studies. This corresponds to 210-225 grams of whole grain products in fresh weight and about 70-75 grams of whole grains in dry weight, and is about the same as the health authorities in Norway and other Nordic countries recommend as the minimum daily allowance," says Aune.

Applies only to whole grain products

The researchers' analyses showed fewer risk factors for people who consumed more bread and cereal with whole grains, as well as foods with added bran. On the other hand, people who ate a lot of white bread, rice or cereals with refined grains did not show reduced risk.

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"We found the greatest risk reduction in people who consumed 0 grams up to those who ate 50 grams of whole grain products a day. The risk continued to decrease - but to a lesser extent - up to an intake of 225 grams a day," said Aune.

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Nine studies with a total of more than 700,000 participants examined the risk for all types of cardiovascular disease and correlated cardiovascular deaths. The half of the study subjects who ate the most whole grains had a 16% lower risk than those who consumed less, and every third portion more of whole grain a day reduced the risk by 22%.

The seven studies that looked at coronary heart disease (heart attack and angina) showed similar risk estimates, whereas the reduced risk of stroke was slightly lower in the combined analyses of the six studies that examined this. Analyses of whole grains and mortality from stroke showed a statistically significant 14% reduction in risk.

The risk of dying prematurely from all causes was 18% lower for individuals who consumed a lot of whole grains compared to those who consumed lesser amounts, while three additional servings each day were associated with a 17% reduction in mortality. The risk for deaths associated with cancer (15%), respiratory diseases (22%), diabetes (51%) and infectious diseases (26%) was also lower the more whole grains individuals consumed.

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Aune says that much of the research on whole grains so far has been focused on the most widespread illnesses such as cardiovascular diseases, cancers (mainly colorectal cancer) and type 2 diabetes. "However, our results suggest that consuming whole grain products may have beneficial effects on several other diseases, like mortality from respiratory diseases and infections, and the literature suggests that whole grains may even protect against rare cancers.

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