Posts Tagged: diet

Should there be more microbes on your plate?

Scientists make the first large-scale estimate of live microorganisms consumed in the U.S. diet

Our diets provide us with the building blocks we need to stay healthy and fight disease. The nutrients in foods and beverages can be tallied up to know if we are getting what our bodies need. Yet what if a nutrient has been overlooked? For instance, friendly microbes in raw and fermented foods have not been measured as part of our diets — until now.

“Ultimately we want to understand if there should be a recommended daily intake of these microbes to keep us healthy, either through the foods or from probiotic supplements,” said Maria Marco, a professor in the food science and technology department at UC Davis. “In order to do that, we need to first quantify the number of live microorganisms we consume today in our diets.”

Marco co-authored a new study with a group of scientists that examined the number of living microbes per gram of more than 9,000 different foods consumed by nearly 75,000 adults and children. It found that around 20% of children and 26% of adults consumed foods with high levels of live microorganisms in their diet. Both children and adults increased their consumption of these foods over the 18-year study period. The study, published in the Journal of Nutrition, is the first large-scale estimate of how many live microbes are consumed by Americans every day.

“This trend is going in the right direction. Exposure to friendly microorganisms in our foods can be good for promoting a healthy immune system.” said Marco.

Foods for gut health

Study authors examined the National Health and Nutrition Examination Survey to create the estimate. The health and dietary database contains extensive information on the foods consumed by Americans daily. Food science and fermentation experts assigned each food an estimated range of live microbes per gram, creating categories of foods with low, medium and high levels of live microbes. Foods in the high category included fermented dairy foods such as yogurt, fermented pickles and kimchi. Fresh, uncooked fruits and vegetables were also good sources of live microorganisms, represented in the medium category.

The analysis was funded by a grant from the International Scientific Association for Probiotics and Prebiotics, or ISAPP. The microorganisms quantified in this study are not necessarily probiotics.

“By definition, a probiotic must be well-defined and have a demonstrated health benefit at a quantified dose. Live microbes associated with food as a category, however, do not generally meet the criteria of a probiotic,” said corresponding author Mary Ellen Sanders, executive science officer for the ISAPP.

The publication is part of a larger global effort to determine how live dietary microbes might contribute to health.

“There is no doubt that the microbes we eat affect our health. When we think of microbes in our food, we often think of either foodborne pathogens that cause disease or probiotics that provide a documented health benefit,” said co-author Colin Hill, a professor of microbial food safety with University College Cork, Ireland. “But it's important to also explore dietary microbes that we consume in fermented and uncooked foods. It is very timely to estimate the daily intake of microbes by individuals in modern society as a first step towards a scientific evaluation of the importance of dietary microbes in human health and well-being.”

Other scientists co-authoring the paper were ISAPP board members Robert Hutkins, Dan Merenstein, Daniel J. Tancredi, Christopher J. Cifelli, Jaime Gahche, Joanne L. Slavin and Victor L. Fulgoni III.

Editor's note: Maria Marco is affiliated with UC Agriculture and Natural Resources as an Agricultural Experiment Station faculty member.

Hackathon movement connects consumers to food

On a Friday evening in a San Francisco conference room, food and technology leaders – including nutrition expert Carl Keen, a UC Davis professor affiliated with the UC Agriculture and Natural Resources Ag Experiment Station – spoke to a mixed audience on the need for innovation in adapting populations across the world to changing food systems.

In the crowd, one inspired undergraduate student from UC Davis thumbed together some notes on his phone. The next day he stood in front of everyone at the event – more than 250 in all – and pitched his newly formed idea for a nutrition app.

It drew a small team: a Silicon Valley entrepreneur, a UC Davis nutritionist and a UC Berkeley student. Over the next 40 hours they developed a software application that matches safe foods to patient medications. With the final presentations Sunday evening, the judges announced the winners.

Their project, called Took that? Eat this., won first place at the 2015 Food Hackathon. They now have sponsors and are developing their idea into a real consumer product. They are also flying out to the World Expo in Milan, Italy, in September – the first devoted to food and where an even larger food-themed hackathon will take place.  

(Food Hackathon from FounderLY on Vimeo) 

Breaking down the silos 

“It's powerful how much happens in such a short period of time,” says Bob Adams, innovation adviser for the UC Davis World Food Center and a mentor for the hackathon teams. “It was a great experience for all the UC Davis students who participated, because they don't normally interact in projects with students from other programs.”

With nearly 9,000 total hours spent in developing the 18 different projects, the hackathon was declared by the organizers a success and a testament to the power of crowd sourcing.

A group of passionate techies, foodies, scholars, investors and entrepreneurs shut in a room for two days pushed them like never before to apply their diverse expertise toward tackling some of the biggest problems facing food and ag. 

A university connecting ag and nutrition 

Research and industry leaders are looking to this model as one way to seed California's innovation ecosystem across the state's agricultural horizons. As another example, Mars, Inc., which co-sponsored the hackathon, is investing in a new type of university-industry partnership with UC Davis and the World Food Center by establishing the Innovation Institute for Food and Health.

“All of us win from these new and needed collective investments in innovation in food, agriculture and health,” writes Mars chief scientist Harold Schmitz in a recent Sacramento Bee op-ed.

Howard-Yana Shapiro, also a Mars chief scientist and a UC Davis fellow, sees innovative food technology projects like those crafted at the hackathon as this decade's biggest investment arena.

“The next, larger human generation will face food challenges ranging from climate change and water stress to growing demands for upmarket foods,” he wrote in a LinkedIn article. “But from what I saw at the hackathon, the next generation is on it.” 

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See the original story by the UC Davis World Food Center.

Paleo diet not as simple as it sounds

Around the Internet, on TV talk shows and in some fitness centers, people are touting a new weight-loss trend – the Paleolithic diet. Proponents suggest the modern Stone Age nutrition plan mirrors the diet on which humans evolved over millions of years. Adherents swear off farmed foods like wheat, dairy, sugar and legumes and rely on a hunter-gatherer menu of meat, nuts, fruit and vegetables.

“The Paleo Diet is a lifestyle based on the idea that in the past 40,000 years, our DNA has changed very little,” says the Dr. Oz Show website. “Therefore, eating processed foods like cereals, dairy products, and refined sugars invite disease and weight gain.”

When new diet fads hit the airwaves, UC Cooperative Extension’s nutrition educators hear questions. The nutrition educators are in schools, neighborhood centers, community gardens and health fairs teaching the evidence-based Dietary Guidelines for Americans, established by the USDA, to low-income Californians. At an annual training session held this month in Davis, nearly 200 UCCE educators were briefed on the Paleo diet by Sheri Zidenberg-Cherr, UC Cooperative Extension specialist in the Department of Nutrition at UC Davis.

She said she’s open to new nutrition trends, but has some doubts about copying the dietary habits of our cavemen ancestors.

“After all, they only lived for 15 or 20 years,” Zidenberg-Cherr said. “Dr. Oz is going to say anything to get people excited.”

Ancient diets varied widely by location and historic period, making it difficult to accurately reconstruct eating patterns. And some of the published rationale for the Paleo diet is wrong.

“Scientists have discovered traces of seeds and grains on the teeth of fossilized humans,” she said. “Scientists have discovered remnants of grains on stone cooking tools.”

Zidenberg-Cherr said researchers are now beginning to explore the complex interplay of genes and lifestyle on an individual’s weight and health - a field called epigenetics. Ultimately, the research may one day provide personalized nutrition therapies that maximize genetic potentials, prevent chronic disease and improve treatment outcomes.

Epigenetics might explain the rave reviews by some who have been successful with the Paleo diet.

“Some people feel better when they eat a Paleo diet. It might have metabolic effects. It might improve glucose tolerance. It might be in their minds or it might be epigenetic,” Zidenberg-Cherr said.

The constant drumbeat of diet breakthroughs and fads, however, does tend to confuse the public and erode their confidence in nutrition messages.

“It’s our responsibility as nutrition scientists and educators to act as credible sources of science-based nutrition recommendations,” Zidenberg-Cherr told the UCCE nutrition educators.

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