Can yogurt each day keep the doctor away?
Diabetes, heart disease and inflammatory disorders threaten the health of many Americans. University of Nebraska-Lincoln researchers are investigating the gut microbiome in search of answers.
An international team of scientists led by Nebraska food science researcher Robert Hutkins and the University of California's Maria Marco suggests one solution may be to boost beneficial microorganisms by eating more fermented foods.
Scores of studies have shown foods like yogurt, sauerkraut and miso are associated with lower rates of diabetes, gastrointestinal disorders, heart disease and other ailments, said Hutkins, a food science and technology professor who led a 12-member team from science and industry that reviewed the latest findings.
"The data are compelling that there are health benefits associated with fermented foods," Hutkins said. "Our recommendation is that fermented foods ought to be part of a balanced diet. Just like you eat fiber every day, you should eat fermented foods every day."
Hutkins is affiliated with the Nebraska Food for Health Center, established in 2016 to investigate how gut microbes prevent disease and improve health. The university's food, plant, and animal scientists are working with medical experts to develop foods that enhance the human microbiome, the community of micro-organisms that live in the gut and benefit the body's metabolic and immune systems.
The center is an innovative marriage of agriculture and medicine to fight disease, said Andrew Benson, a food science and technology professor who serves as director of the center.
"Because the food we eat feeds these organisms, it's not surprising that diet is one of the biggest factors that influences the gut microbiome," Benson said. "Therein lies a tremendous opportunity to unite agriculture and medicine to transform how we think about preventing and treating disease."
Obesity rates, metabolism disorders and inflammatory problems like celiac disease and irritable bowel syndrome have made more people concerned about their diet and health. Several groups have recommended that fermented foods be included in national dietary guidelines. Yet there is a lack of detailed knowledge about the core properties of various fermentation methods and their comparative health benefits. Only yogurt has been recognized, by European health authorities, to have proven health benefits.
Hutkins and researchers from France, Ireland, Canada, the Netherlands and the United States reported encouraging findings after reviewing recent research involving fermented foods. The group concluded that the heightened interest in the human microbiome's effect on health justifies fundamental research and clinical trials to investigate the functions of microorganisms that enter the gastrointestinal tract through food and beverages.
"It's the original processed food," said Hutkins. "In the past, food either spoiled and made you sick or it fermented to become well-preserved, tasty, nutritious – even intoxicating."
Though fermented foods are among the oldest preserved foods consumed by humans, they have become more popular thanks to several recent trends. Consumers have become more interested in health foods, ethnic foods and artisanal foods while scientists are learning more about the role microorganisms play in digestion and health.
Fermented foods include beer and wine, bread, salami, cheese and fermented pickles. Even coffee and chocolate are fermented foods, said Hutkins, who also writes a food and nutrition newspaper column, "Ask the Food Doc." After beneficial bacteria, yeasts or fungi alter the food, it becomes safe to eat for longer periods and, as it turns out, often is more flavorful and healthful than the food in its original form.
Some of the studies Hutkins' group reviewed showed yogurt and kimchi, a Korean form of pickle, are associated with lower rates of diabetes. One study found that people who regularly consume an odoriferous soybean paste called chungkookjang have reduced obesity. Soy sauce, miso and other fermented soy products have been connected with lower rates of heart disease.
Other research found beneficial relationships between fermented foods and blood pressure, cholesterol, osteoporosis and digestion. A couple found psychological benefits to fermented foods – one study indicated those who drink three cups of coffee a day are less prone to depression and another found those who eat yogurt, cheese and other fermented foods daily are less moody and irritable.