Health Benefits of Fiber: Overall Health
Eating barley or foods containing barley significantly reduced levels of two types of "bad cholesterol" associated with cardiovascular risk, a St. Michael's Hospital research paper has found.
Barley reduced both low-density lipoprotein, or LDL, and non-high-density lipoprotein, or non-HDL, by seven per cent.
The review also indicated that barley had similar cholesterol-lowering effects as oats, which is often the go-to grain for health benefits.
The research review, published today in The European Journal of Clinical Nutrition, included 14 studies on clinical trials conducted in seven countries, including Canada.
It is the first study to look at the effects of barley and barley products on both LDL and non-HDL cholesterol in addition to apolipoprotein B, or apoB, a lipoprotein that carries bad cholesterol through the blood. Measuring non-HDL and apoB provides a more accurate assessment for cardiovascular risk, as they account for the total 'bad cholesterol' found in the blood.
"The findings are most important for populations at high risk for cardiovascular disease, such as Type 2 diabetics, who have normal levels of LDL cholesterol, but elevated levels of non-HDL or apo B," said Dr. Vladimir Vuksan, research scientist and associate director of the Risk Factor Modification Centre of St. Michael's. "Barley has a lowering effect on the total bad cholesterol in these high-risk individuals, but can also benefit people without high cholesterol."
High cholesterol and diabetes are major risk factors for cardiovascular disease and stroke, historically treated with medications. However, Dr. Vuksan's research and work focuses on how dietary and lifestyle changes can reduce these risk factors.
"Barley's positive effect on lowering cholesterol is well-documented and has been included in the Canadian strategy for reducing cardiovascular risk," said Dr. Vuksan. "Health Canada, the FDA and several health authorities worldwide have already approved health claims that barley lowers LDL cholesterol, but this is the first review showing the effects on other harmful lipids."
Despite its benefits Dr. Vuksan said barley is not as well-established as some other health-recommended foods -- such as oats. Barley consumption by humans has fallen by 35 per cent in the last 10 years. Canada is one of the top five world producers of barley -- almost 10 megatonnes per year -- but human consumption accounts for only two per cent of the crop yield, with livestock making up the other 98 per cent. "After looking at the evidence, we can also say that barley is comparably effective as oats in reducing overall risk of cardiovascular disease" said Dr. Vuksan.
Barley is higher in fibre, has twice the protein and almost half the calories of oats, which are important considerations for those with weight or dietary concerns.
Dr. Vuksan said barley can be enjoyed in a variety of ways. He recommends trying to incorporate barley into existing recipes, using it as a substitute for rice or even on its own -- just like oatmeal.
Barley can help improve blood sugar levels and reduce appetite
A recent study from Lund University in Sweden shows that barley can rapidly improve people's health by reducing blood sugar levels and risk for diabetes. The secret lies in the special mixture of dietary fibres found in barley, which can also help reduce people's appetite and risk for cardiovascular disease.
"It is surprising yet promising that choosing the right blend of dietary fibres can -- in a short period of time -- generate such remarkable health benefits", says Anne Nilsson, Associate Professor at the Food for Health Science Centre and one of the researchers behind the study.
The study was conducted with healthy middle-aged participants who were asked to eat bread largely made out of barley kernels (up to 85%) for three days -- at breakfast, lunch and dinner. Approximately 11-14 hours after their final meal of the day participants were examined for risk indicators of diabetes and cardiovascular disease.
The researchers found that the participants' metabolism improved for up to 14 hours, with additional benefits such as decreases in blood sugar and insulin levels, increases in insulin sensitivity and improved appetite control. The effects arise when the special mixture of dietary fibres in barley kernel reaches the gut, stimulating the increase of good bacteria and the release of important hormones.
"After eating the bread made out of barley kernel, we saw an increase in gut hormones that regulate metabolism and appetite, and an increase in a hormone that helps reduce chronic low-grade inflammation, among the participants. In time this could help prevent the occurrence of both cardiovascular disease and diabetes", says Anne Nilsson.
In a previous related study conducted with a team from the University of Gothenburg in Sweden researchers also found that dietary fibres from barley kernel generate an increase of the gut bacteria Prevotella copri, which have a direct regulatory effect on blood sugar levels and help decrease the proportion of a type of gut bacteria that is considered unhealthy.
The effects from barley kernel are influenced by the composition of the individual's gut microbiota, meaning people with low concentrations of the Prevotella copri bacteria experienced less effect from their intake of barley products. Eating more barley could, however, help stimulate growth of the bacteria.
The results are timely as rates of obesity and type 2 diabetes have significantly increased in the past few years. Researchers hope that more knowledge about the impact of specific dietary fibres on people's health will result in stores keeping more food products with healthy properties such as barley kernels. The ambition is also to get more people to use barley in meals, for example in salads, soups, stews, or as an alternative to rice or potatoes.
The researchers' advice for how to maintain a healthy blood sugar level:
The bread used in the study was 85% made out of barley grains, which had been boiled and mixed with wheat flour. If you want to reduce the amount of barley grains, you can replace some of it with whole grains.