Hearing tests can fail to diagnose hearing loss: study

Drinking coffee may help reduce the risk of certain digestive disorders, including gallstone disease and pancreatitis, a new study has suggested.

The study from the Institute for Scientific Information on Coffee (ISIC) also highlighted other beneficial effects that coffee consumption may have on the process of digestion, including supporting gut microflora and promoting gut motility.

"Data indicates benefits against common digestive complaints such as constipation, as well as a potential reduction in the risk of more serious conditions like chronic liver diseases," said study author Carlo La Vecchia from the University of Milan in Italy.

Gallstone disease is a common digestive disorder, caused by the accumulation of gallstones in the gallbladder or bile duct, which affects approximately 10-15 per cent of the adult population.

While the mechanism by which coffee may protect against gallstone disease is not yet known, it has been observed that the risk for the condition declines with increasing daily consumption of coffee, the researchers said.

Caffeine is thought to play a role in these associations, as the same effect is not observed with decaffeinated coffee.

A common question among consumers and focus area for research is whether coffee is associated with heartburn or gastro-oesophageal reflux disease (GORD).

While a small number of studies have suggested an association between coffee drinking and GORD, the majority of studies reviewed suggest that coffee is not a major trigger of these conditions.

The report also reviewed a growing area of health and nutrition research, namely: the effect of coffee on the gut microflora (microorganism populations).

Recent studies suggest that populations of the beneficial gut bacteria Bifidobacterium spp, increase after drinking coffee.

The findings showed the dietary fibre and polyphenols found in coffee, support the healthy growth of microflora populations.

Additional research findings highlighted that coffee consumption is thought to stimulate digestion by encouraging the release of gastric acid, bile and pancreatic secretions.

Coffee is one of the most widely researched components of the diet, and its effect on digestion remains a growing area of research, the researchers noted.

High-protein diets may help people lose weight and build muscle, but there is a downside to it --a greater heart attack risk. Researchers now report that high-protein diets boost artery-clogging plaque.

The research in mice showed that high-protein diets spur unstable plaque -- the kind most prone to rupturing and causing blocked arteries.

More plaque buildup in the arteries, particularly if it's unstable, increases the risk of heart attack.

"There are clear weight-loss benefits to high-protein diets, which has boosted their popularity in recent years," said senior author Babak Razani, associate professor at Washington University School of Medicine in St. Louis, Missouri.

"But animal studies and some large epidemiological studies in people have linked high dietary protein to cardiovascular problems. We decided to take a look at whether there is truly a causal link between high dietary protein and poorer cardiovascular health," Razani added.

The researchers studied mice who were fed a high-fat diet to deliberately induce atherosclerosis, or plaque buildup in the arteries.

Some of the mice received a high-fat diet that was also high in protein. And others were fed a high-fat, low-protein diet for comparison.

The mice on the high-fat, high-protein diet developed worse atherosclerosis -- about 30 per cent more plaque in the arteries -- than mice on the high-fat, normal-protein diet, despite the fact that the mice eating more protein did not gain weight, unlike the mice on the high-fat, normal-protein diet.

"A couple of a scoop of protein powder in a milkshake or smoothie adds something like 40 grams of protein -- almost equivalent to the daily recommended intake," Razani said.

"To see if protein has an effect on cardiovascular health, we tripled the amount of protein that the mice receive in the high-fat, high-protein diet -- keeping the fat constant. Protein went from 15 per cent to 46 per cent of calories for these mice".

Plaque contains a mix of fat, cholesterol, calcium deposits and dead cells. Past work by Razani's team and other groups has shown that immune cells called macrophages work to clean up plaque in the arteries.

But the environment inside plaque can overwhelm these cells, and when such cells die, they make the problem worse, contributing to plaque buildup and increasing plaque complexity.

"In mice on the high-protein diet, their plaques were a macrophage graveyard," Razani informed.

To understand how high dietary protein might increase plaque complexity, Razani and his colleagues also studied the path protein takes after it has been digested -- broken down into its original building blocks, called amino acids.

"This study is not the first to show a telltale increase in plaque with high-protein diets, but it offers a deeper understanding of the impact of high protein with the detailed analysis of the plaques," said Razani.

"This work not only defines the critical processes underlying the cardiovascular risks of dietary protein but also lays the groundwork for targeting these pathways in treating heart disease," he added.