What’s wrong with lactose?

Lactose is the sugar of mammals and plays a relevant role in the very early life. Besides its role as energy provider, it exhibits several health effects in young children, including a prebiotic effect on the gut microbiota. Basically, during digestion, the enzyme lactase, which is produced by the cells lining the small intestine, breaks down lactose into simple sugar units that can then be absorbed into the bloodstream. Lactase activity reaches a peak during childhood.

If the cause is unclear, it is a fact that lactose maldigestion develops gradually as the body produces less lactase over time. Lactose maldigestion increases with age during adulthood. « About two thirds of the world population undergoes primary lactase deficiency », said Professor Lorenzo Morelli, Chair professor of Food Microbiology and Director, Istituto di Microbiologia UCSC, Piacenza-Cremona, Italy. Additionally, in individuals with lactase persistence, the occurrence of gastrointestinal diseases and other health issues can also cause a decrease in lactase activity (secondary lactase deficiency).

Whatever the cause, lactase deficiency results in unabsorbed lactose being present in the intestinal tract, which has effect that can lead to symptoms of lactose intolerance in susceptible individuals. In fact, the percentage of people concerned by these symptoms due to lactose maldigestion is rather low.

Self-perceived lactose intolerance and dairy avoidance

Nowadays, lactose intolerance symptoms are often reported, but frequently as a consequence of an auto diagnosis. Most people who believe to be lactose intolerant apparently stop consuming dairy products. There are some collateral effects of such a behaviour: avoiding dairy products means missing out on several key nutrients and potential health benefits.

« However, this is not fully justified », argued Lorenzo Morelli. « On one hand, studies have shown that a small dose of lactose can be tolerated (12g/day), even by maldigesters. Higher doses may also be tolerated, if distributed throughout the day. On the other hand, some cheeses contain no lactose at all (hard cheese by example) ». Last but not least, the lactose in yogurt is digested more efficiently than other dairy sources of lactose, because the bacteria inherent in yogurt assist with its digestion.

How yogurt helps managing lactose maldigestion 

« The mechanism is related to the resistance of lactase present in the yogurt bacteria through the digestion », said Morelli. The bacterial lactase survives the acidic conditions of the stomach, apparently being physically protected within the bacterial cells and facilitated by the buffering capacity of yogurt. The increasing pH, as the yogurt enters the small intestine, and a slower gastrointestinal transit time allow the bacterial lactase to be active, digesting lactose from yogurt sufficiently

Yogurt has its own claim in Europe

The generic yogurt EFSA claim is that « Live yogurt cultures in yogurt improve digestion of lactose in yoghurt in individuals with lactose maldigestion ».  The opinion of EFSA, also emphasizes the importance of living ferments contained in yogurt at the ingestion but does not require survival of the bacteria cells during intestinal transit. », concludes Morelli. This species-related trait is also recognized at the regulatory level by the FAO and the WHO.

Highlights

• About two thirds of the world population undergoes a primary lactase deficiency
• Yogurt bacteria are able to hydrolyze lactose thanks to their specific uptake system
• Yogurt bacteria have to be viable at the moment of ingestion to exhibit their positive effect
• The lactose hydrolyzing ability of yogurt bacteria has been successfully recognized by an EFSA Claim in Europe
• The opinion of EFSA confirms the position of other national and international authorities, such as the WHO and FAO

References

• Deng Y. et al., Nutrients, 2015; 7(9): 8020-35.

• EFSA Journal, 2010; 8(10): 1763.

• Lukito W. et al., Asia Pac J Clin Nutr., 2015; 24 Suppl 1: S1-8.

• Savaiano D.A., Am J Clin Nutr., 2014; 99 (5): 1251S-5S.

• Szilagyi A., Nutrients, 2015; 7(8): 6751-79.

• Wahlqvist M.L., Asia Pac J Clin Nutr., 2015; 24 Suppl 1: S21-5.

• MILK and dairy products in human nutrition, FAO, Rome, 2013

SOCIAL MEDIA: Follow the conversation at @yogurtnutrition and by using #yogurt2016

Download here the abstracts

Download here the YINI leaflet

Download here the infographic

Is diet transition between the summer holidays/vacation and going back to school a concern?

For more than 15 million children in the U.S. that are battling hunger on a daily basis, the transition from summer vacation back to school can help provide a vital source of nourishment. The U.S.D.A’s Child Nutrition programs, such as the school breakfast and school lunch, provide food for children that may not be at-risk for hunger. In fact, yogurt that is served in smoothies at breakfast is now part of a reimbursable meal offered in schools.

Furthermore, back to school can also improve overall child nutrition by providing more structure and regular meal times that may not happen regularly during vacation time. Snacks and treats that are accessible at home all day can impact the nutritional quality of overall intake during the summer. Back to school is a great time for families to get back to the routine of eating healthy, balanced meals together.

To read more about childhood hunger in the U.S., visit Share Our Strength and the “No Kid Hungry” campaign: https://www.nokidhungry.org/pdfs/nkh-briefing-book-2016.pdf

What are the main benefits of yogurt for kids?

Yogurt is a nutrient-dense food that offers a variety of nutritional benefits to children. Yogurt provides energy, calcium, protein and B vitamins (thiamin, riboflavin) that support optimal growth during childhood. In addition, cultured dairy products may be easier for some children to digest and may also provide a source of probiotics. The beneficial bacteria provided by cultured dairy products can help boost immunity in children and support normal digestion. Not only is yogurt good for children, it tastes great and is a versatile choice at meals and snacks.

Yogurt is a versatile meal addition and ingredient.

What can yogurt replace in order to maintain a healthy diet?

The protein in yogurt can serve as a meat replacement for children who may not be eating enough meat, eggs, beans, fish and nuts. In addition, for children who don’t like to drink fluid milk, yogurt is a calcium-rich alternative.

What are some of the ways to include yogurt in meals (breakfast, lunch, dinner)?

At breakfast, yogurt may be served with fruit and cereal as a parfait. It can also be used as an ingredient when making smoothies to boost calcium and protein.

Yogurt is a great, portable option for lunch boxes and can be eaten as an addition to the meal or as a treat for dessert.

For dinner, plain yogurt can be used as an ingredient in salad dressings or as a condiment on top of tacos, soup, chili or hearty stews. Flavored yogurt or plain yogurt topped with berries and whipped cream is a nutritious and delicious dessert.

Although some studies have suggested an inverse relationship between the consumption of dairy foods and the risk of diabetes mellitus, this relationship from prospective studies is actually inconsistent, particularly concerning dairy fat. Here, researchers from the Harvard School of Public Health, in Boston, tested the hypothesis that dairy fat are associated with lower incident diabetes mellitus.

Diabetes risk after 15 years of follow-up

The researchers looked at circulating fatty acid in the plasma and red blood cells as biomarkers, which reflect the exposition to dairy fat (15:0, 17:0, and t-16:1n-7). They measured these fatty acids among 3333 adults from two large cohorts, the Nurses’ Health Study and the Health Professionals Follow-Up Study. Participants were aged 30 to 75 years, and were free of diabetes mellitus at baseline. The onset of diabetes was identified, during a mean follow-up of 15.2 years. Adjusting was done for demographics, metabolic risk factors, lifestyle, diet, and other circulating fatty acids in pooled multivariate analyses.

Dairy fatty acids associated with less diabetes risk

The results show that a lower risk of diabetes (T2D) is linked to higher biomarkers of dairy fats in plasma and red blood cells. So, higher plasma 15:0 was associated with a 44% lower risk of T2D, higher plasma 17:0 with a 43% lower risk, and higher t-16:1n-7 with a 52% lower risk of T2D. A similar trend was observed for red blood cells 15:0, 17:0, and t-16:1n-7. These findings suggest that dairy fat consumption is associated with lower incident of T2D, and highlight the need to better understand the potential health effects of dairy fat.

To learn more, read the original article.

Source : Yakoob M Y et al. Circulation, April 26, 2016, Volume 133, Issue 17. DOI 

Dr. Adam Drewnowski is a world-renowned leader in the study of obesity and social disparities in diets and health. He is Professor of Epidemiology and the Director of the Center for Public Health Nutrition at the School of Public Health. He is also the Director of the University of Washington Center for Obesity Research, which addresses the environmental, social and economic aspects of the obesity epidemic. Dr. Drewnowski is Adjunct Professor of Medicine and is a Joint Member of the Fred Hutchinson Cancer Research Center in Seattle.

Dr. Drewnowski’ is the inventor of the Nutrient Rich Foods Index, which rates individual foods based on their overall nutritional value, and the Affordable Nutrition Index, which helps consumers identify affordable healthy foods. He has conducted extensive studies on taste function and food preferences, exploring the role of fat, sugar, and salt on food preferences and food cravings. His studies on bitter taste genetics have explored consumer acceptance of bitter phytochemicals in vegetables and fruit.

Dr. Drewnowski has been the leader in studies of spatial epidemiology of diets and health, using innovative GIS approaches to study the geographic distribution of food spending, diet quality and obesity rates. Dr. Drewnowski has served on the Standing Committee to Prevent Childhood Obesity of the Institute of Medicine, National Academy of Sciences and is a public trustee of the International Life Sciences Institute (ILSI). He is the author of over 200 research papers, numerous reviews and book chapters, and a frequent participant and invited speaker at scientific meetings, conferences, and symposia. Dr. Drewnowski has advised government and international agencies, foundations, and think tanks.

Discover here more about Adam Drewnowski’s research on yogurt consumption.

In recent studies, yogurt consumption has been associated with better diet quality and a healthier metabolic profile in adults. However, such association between health effects of yogurt has not been investigated in children. That was the purpose of the work of Zhu et al., which used data from a nationally representative survey in the US: The National Health and Nutrition Examination Survey (NHANES).

Assessing health effects of yogurt for US children

NHANES is a wide and unique survey, which assesses the health and nutritional status of adults and children in the US, by combining interviews and physical examinations. This is why it allows researchers to study a large sample of 5,124 children, aged 2–18 years, in a time lapse of 3 years. They looked at two indicators: diet quality and metabolic profiles. Diet quality was evaluated by the Healthy Eating Index 2005 (HEI-2005), a reference tool created by the U.S. Department of Agriculture which assessed the conformance of the diet, according to Federal dietary guidance. For the metabolic profiles, they considered several indicators, including fasting insulin level, insulin sensitivity, body weight, fasting glucose, and blood pressure.

Lower fasting insulin level and insulin resistance

This study shows that children, who eat yogurt frequently (at least once per week), had a better diet quality, as indicated by a higher score of HEI-2005. Frequent yogurt consumers also had a better metabolic profiles, with a lower fasting insulin level, less insulin resistance and a better insulin sensitivity. The authors didn’t found any association between yogurt consumption and body weight or blood pressure in this study, but this will require further investigations.

To learn more about the health effects of yogurt, read the original article.

Source : Zhu Y et al. European Journal of Nutrition, June 2015, Volume 54, Issue 4, pp 543-550. DOI 10.1007/s00394-014-0735-7

What is your focus? 

I am passionate about simplifying scientific principles of nutrition into simple language that consumers can understand. Most people know it’s important to eat less sugar and salt, and eat more fibre. What’s tricky is how to put that into practice and how to decipher all the food labels and jargon.

Eating well isn’t just about nutrients. You need to consider your culture, your lifestyle, your eating preferences, your emotions, your environment, your family, your peers, your work pressures, the list goes on.

I want to be able to simplify the messages. I want to cut through the confusion and offer people practical ways to eat well, and really enjoy their food! An example is my “what should your plate look like” series. This helps you to visually assess whether what you’re about to eat is healthy (or not!). I’m also keen on a “swaps” approach. If you’re about to reach for something you know is not getting you closer to your goal, think again and make another choice. Swap out sour cream dressing with a Greek yogurt and herb dressing, for example. And another simple concept I find valuable is helping people to keep to appropriate portion sizes. I believe you can enjoy all the foods you love, so long as you have them in the right quantities!

What is for you the most important in nutrition? 

Eating food that you enjoy, that fits in with who you are as a person, and that offers you the most nutrients per calorie, i.e. foods with greater nutrient density. No matter what our age, we all need certain nutrients for that particular life stage. And yet often we eat foods that are rich in calories but poor in nutrition.

Eating mindfully helps us to be more aware of the food choices we make. And this conscious awareness can enable us to make healthier choices. Many of us probably eat quite mindlessly, eating on the go, in front of the TV, or at night-time when no-one’s watching! Becoming aware of what you’re eating is a big step in enabling you to make a better choice.

Why is yogurt interesting for you as a nutritionist?

Ever since childhood, I’ve lived within a culture where yogurt is part of everyday meals. It’s not just for dessert. I’ve been brought up to eat yogurt curry, yogurt raita dip, and yogurt lassi drinks. As a practicing dietitian, I encourage my clients to enjoy three servings of dairy foods each day, and a pot of yogurt is a great way to have one of these servings.

To me, it’s an integral part of the diet – one of your daily essentials. It’s a good source of protein and calcium; that’s something that goes without saying. But in my work as part of the YNI Working Group creating Nutrition Digests, I’ve learnt that there is extensive research on yogurt that goes over and above its nutrient density. Yogurt has been associated with reduction in risks of Type 2 diabetes, reduction in waist circumference, lower BMI, and much more. And the other interesting fact is that yogurt eaters appear to have other healthy lifestyle habits. So, it seems my mum was right when she brought me up on yogurt every day!

What are you expecting from the ICDA event 2016? 

I’m looking forward to networking with colleagues from around the world. I feel I know many of them through my interactions on Twitter. This is an incredible opportunity for like-minded professionals to share insights and knowledge, to learn from each other, to debate, and to socialise. I’m looking forward to the YINI Symposium as I’m keen to learn more about how yogurt can be tolerated by lactose malabsorbers. Also I can’t wait to hear Adam Drewnowski share his insights on yogurt as a sustainable choice.

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