Dairy and cardiovascular disease: no consistent conclusions

CVD is an important public health problem around the world, and several dietary patterns, but also individual foods, can exert some preventive effects on it. In previous systematic reviews and meta-analysis, evaluating dairy consumption and the risk of CVD, the findings were often inconsistent. Indeed, no quantitative analysis has specifically assessed the effect of yogurt intake on the incident risk of CVD. Given that the benefits of yogurt intake have recently drawn a lot of attention, it is relevant to know if this specific dairy could play a role in delaying the development of CVD.

This systematic review and meta-analysis involved a total of near fewer than 300.000 persons from nine independent prospective cohort studies.

A yogurt effect emerged in subgroup analysis

Compared with the lowest category, the highest category of yogurt consumption was not significantly related with the incident risk  of  CVD; however, intake of ≥200g/day yogurt was significantly associated with a lower risk of CVD in the subgroup analysis. 

There was a trend that a higher level of yogurt consumption was associated with a lower incident risk of CVD in the dose-response analysis. It should be noted that in their analysis, when studies reported yogurt intake in serving per day, the authors converted the intake of 244g/unit. So it is possible that the effect of yogurt on CVD also exists for less than 200 g per day.

According to the authors, these findings require further research, with cohort studies and randomized controlled trials, to be established and confirmed.

To learn more, read the original article.

Source: Wu L et al. Consumption of Yogurt and the Incident Risk of Cardiovascular Disease: A Meta-Analysis of Nine Cohort Studies. Nutrients 2017;9:315.

In the intestine during digestion, lactose is usually split into glucose and galactose by the lactase. This enzyme is located in the brush border membrane of enterocytes, the absorptive cells of the small intestine. Lactase, encoded by the LCT gene, becomes normally less active with age. (11) In congenital lactase deficiency, a very rare genetic disorder (affecting fewer than 50 patients in the world, mainly in Finland), lactase activity is drastically reduced or non-existent. (1) Infants with this disease can experience symptoms such as nausea, abdominal cramps and bloating, vomiting, flatulence, diarrhea, dehydration, loose stool, metabolic acidosis, the presence of lactose in urine and a distended abdomen. These infants must completely avoid lactose. (6, 12)

In the normal population, lactase activity reaches a maximum at birth and starts declining after weaning to reach less than 10% of the pre- weaning level. This normal decline is called lactase non-persistence. It is more common in people of Asian, African, South American, Southern European and Australian Aboriginal heritage. However, in some populations of Northern European descent (Scandinavia, the British Isles and Germany) who continue to consume dairy products during adulthood, lactase activity remains in most people.

Lactose maldigestion and lactose intolerance, two different conditions

In case of reduced lactase activity, some lactose is not digested. This is called lactose maldigestion. Non-digested lactose enters the colon where it is digested by the resident microbiota. For most individuals, this lactose maldigestion produces few or no symptoms.

Yet these symptoms can also occur for other reasons and are not specific to lactose intolerance. They can be observed in some gastro-intestinal dysfunctions such as irritable bowel syndrome, inflammatory bowel diseases (Crohn’s disease and ulcerative colitis) and intolerance to FODMAP (Fermentable, Oligo-, Di-, Mono-saccharides And Polyols, which are short chain carbohydrates poorly absorbed in the small intestine). Psychological factors such as somatic anxiety, stress and depression can also cause the occurrence of these symptoms. (15-18)

Lactose malabsorption can also occur temporarily in case of infectious diarrhea, malnutrition, radiotherapy, mucosal damage due to coeliac disease or some medicine use, and give rise to similar symptoms. (19)

Thus the presence of the aforementioned intestinal symptoms cannot systematically lead to the correct diagnosis of lactose intolerance.

References:

1. Misselwitz, B et al. United European Gastroenterol J 2013;1:151-9.

6. Vandenplas, Y. Asia Pac J Clin Nutr 2015;24 Suppl 1:S9-13.

11. Szilagyi, A. Can J Gastroenterol Hepatol 2015;29:149-56.

12. Swallow, DM. Annu Rev Genet 2003;37:197-219.

13. Adolfsson, O et al. Am J Clin Nutr 2004;80:245-56.

14. Szilagyi, A. Nutrients 2015;7:6751-79.

15. Deng, Y et al. Nutrients 2015;7:8020-35.

18. Ledochowski, M et al. Dig Dis Sci 1998;43:2513-7.

19. Usai-Satta, P et al. World J Gastrointest Pharmacol Ther 2012;3:29-33.

There is often a gap between the nutritional recommendations and what is consumed. This study, conducted in French adults, shows that in both cases of acceptable or excessive free sugar intake, plain and sweetened yogurt may improve nutrient adequacy and contribute to better overall diet quality.

Four on ten adults consume too much free sugars

Excessive sugar intake is pointed out as a public health issue, especially because of its involvement in weight gain. In addition, several studies have suggested that high intakes of added sugars are associated with a poorer diet quality. One of the goals of this study was to characterize the diet of French adults with excessive free sugar intake. WHO recommends a reduced intake of free sugars throughout the life course. In both adults and children, WHO recommends reducing the intake of free sugars (defined as added sugar, but also sugars from fruit juices and concentrates) to less than 10% of total energy intake. The authors examined the diet of 1.717 French adults, according to their free-sugar intake, as acceptable (≤ 10 % of energy – FS-ACCEPTABLE) or excessive (> 10 % energy – FS-EXCESS). It appears that the “excess” group, which represents 41 % of the population, had a lower quality diet and consumes more calories, particularly in snacks and beverages.

Yogurt may improve diet quality

The second goal of the study was to determine the minimum and specific dietary changes, needed to achieve a balanced, nutritionally adequate diet, both in people with acceptable and excessive free sugars intake. Overall, the models were ensuring that a broad set of 33 nutritional recommendations were met without changing the energy level. They found that in both groups the main dietary changes to meet nutritional targets were increases in fresh fruits, starchy foods, water, hot beverages and plain yogurts, and decreases in mixed dishes/sandwiches, meat/eggs/fish and cheese. At the yogurt-category level, for both FS-ACCEPTABLE and FS-EXCESS individuals, plain yogurts significantly increased for both groups (respectively + 10 g and + 7 g/day), whereas sweet yogurts increased significantly only for FS-ACCEPTABLE individuals (+ 7 g/ day). In other words, despite their free sugar content, the model selected sweet yogurts as a source to favor regarding its high nutrient density.

Additional changes for people, who consume too many free sugars, include more vegetables and less sugar-sweetened beverages, sweet products and fruit juices.
In conclusion, the diet quality of French adults with excessive intakes of free sugars can be optimized by food changes, like more yogurt consumption, that do not overly challenge their eating habits. Such results do confirm past data coming from another study showing that favoring high nutrient dense foods like yogurt will help individuals in this population reach nutritional adequacy.

To learn more, read the original article.

Source: Lluch A et al. Individual Diet Modeling Shows How to Balance the Diet of French Adults with or without Excessive Free Sugar Intakes. Nutrients 2017;9:162.

Our knowledge on the microbial communities that inhabit the human gut has grown exponentially during the last few years, and there is a profusion of novel information flowing from basic science laboratories into the clinical scenery. The YINI Symposium at ICN 2017 aims at translating the most recent advances to the nutrition community. Prof. Sharon Donovan, University of California, Davis, will introduce the event with an overview about the association between gut dysbiosis and non-communicable diseases incidence. She will also focus on how nutrition, in general, may impact gut microbiome and prevent dysbiosis, as well as on the benefits of the live microbes on gut microbiome, including probiotics.

Who is Sharon Donovan ?

Sharon Donovan received her B.S. and Ph.D. in Nutrition from the University of California, Davis. She completed a post-doctoral fellowship in Pediatric Endocrinology at Stanford University School of Medicine, then accepted a faculty position at the University of Illinois, Urbana in 1991. She is actively involved in her professional societies and served as the 2011-2012 President of the American Society for Nutrition (ASN) and is currently President-elect of the International Society of Research on Human Milk and Lactation (ISRHML). In addition, she has served as co-Chair of the Yogurt in Nutrition Initiative (YINI) since its inception in 2012.

Her Ongoing Research

The Donovan laboratory conducts basic and translational research in the area of pediatric nutrition. Ongoing work in the lab is focusing on optimizing intestinal and cognitive development of neonates, development of the gut microbiome and prevention of childhood obesity and picky eating in children. Sharon Donovan (and her team) has published ~175 peer-reviewed publications and book chapters and has garnered ~ $31M in research and training grant funding from NIH, USDA, private industry and foundations. She currently serves on the Food and Nutrition Board of the National Academies of Sciences, Engineering and Medicine and the Food Advisory Committee for the FDA Center for Food Safety and Applied Nutrition.

Lactose is the principal sugar (or carbohydrate) naturally found, in various amount, in milk and dairy.

Lactase, an enzyme present in the small intestine, is necessary to split lactose into glucose and galactose, two simple sugars.

Glucose is the body’s main source of energy, and can be found in several types of foods.

Conversely, lactose is the only source of galactose among life. It is a component of several macromolecules (cerebrosides, gangliosides and mucoproteins). Galactose has various biological functions and serves in neural and immunological processes. It is also a component of the molecules present in blood cells that determine the ABO blood types. (2)

Lactose, an essential nutrient during childhood

Lactose is a necessary substrate, as evidenced by human milk content, which contains 7.2% of lactose and provides up to 50% of an infant’s energy needs, while cow’s milk contains only 4.7% of lactose and only provides up to 30% of an infant’s energy needs. (3) (4)

Lactose, a useful nutrient

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The health effects of foods, such as dairy, can no more be viewed as the sum of their individual constituents. That’s the main conclusion of an international experts* workshop held in Gentofte, Denmark, 28–29 September 2016, whose results are published in the American Journal of Clinical Nutrition. This workshop was supported by the European Milk Forum.

A diet does not consist of single nutrients

Traditionally, the nutritional evaluation of the relation between diet and health has focused on individual food constituents or nutrients separately. This reductionist approach, which links one nutrient to one health effect, may partly explain some of the discrepancies between a food’s predicted health effect on the basis of its nutrient content and its actual health effect, when consumed as a whole food. Foods have complex structures both physically and nutritionally, which affect digestion and absorption and may generate interactions within the food matrix, thereby altering the bioactive properties of nutrients in ways that are not predictable from the nutrition-label information. This appears more and more evident for the dairy matrix, which was the main topic of a consensus workshop of international experts. They reached an agreement on several aspects related to the dairy food matrix. For instance, despite the high level of saturated fatty acids in dairy fats, experts agree that there is no association between the intake of dairy products and the risk of cardiovascular disease or even with type 2 diabetes.

The dairy matrix has higher beneficial effects on health than single nutrients

The paper reports that there are differences between the metabolic effects of whole dairy, and those of single dairy constituents, on body weight, cardiometabolic disease risk and bone health. They also pointed to the fact that the relationship between dairy and health differs, according to the subtype of dairy product. In addition, different processing methods and dairy structures can enhance interactions in the dairy matrix, thereby modifying the metabolic effects of dairy consumption. Therefore, the nutritional value of dairy products should be considered as the biofunctionality of the sum of nutrients within dairy matrix structures.

The authors call for further research on the health effect of whole dairy foods, alongside studying the health effects of single nutrients. According to them, such research would help to support dietary guidelines that consider the effect of whole foods on health, rather than only focusing on a few individual nutrients within a food.

To learn more, read the original article.

Source:

Kongerslev Thorning T. et al. Whole dairy matrix or single nutrients in assessment of health effects: current evidence and knowledge gaps. American Journal of Clinical Nutrition. First published ahead of print April 12, 2017.

*Tanja Kongerslev Thorning, Hanne Christine Bertram, Jean-Philippe Bonjour, Lisette de Groot, Didier Dupont, Emma Feeney, Richard Ipsen, Jean Michel Lecerf, Alan Mackie, Michelle C McKinley, Marie-Caroline Michalski, Didier Remond, Ulf Riserus, Sabita S Soedamah-Muthu, Tine Tholstrup, Connie Weaver, Arne Astrup and Ian Givens.

Looking at Specific Dairy Foods Effects

Dairy products have been studied for their effect on breast cancer risk. Some recent studies have shown that women with a high intake of dairy products have a lower risk of breast cancer. In this study, investigators used the data from 1.941 women diagnosed with breast cancer and participating in the Roswell Park Cancer Institute Databank and BioRepository, which gathers and stores medical information and blood samples from cancer patients and healthy individuals. Their objective was to evaluate specific dairy food effects on cancer within a sample of 1.237 control participants. Food dairy was separated into total dairy, milk, yogurt, low-fat cheese, other cheeses, and sweet dairy.

Inverse Association Between Yogurt and Breast Cancer Risk

After taking into account several confounding factors (age, race, BMI, menopausal status, energy intake…), authors found a non-significant 15 % reduction in breast cancer with total dairy intakes. The inverse association between total dairy food intake and breast cancer appears to be mainly attributable to higher yogurt consumption. Therefore, the researchers suggest that higher yogurt consumption may be favourably impacting immune function and subsequent cancer risk. However, higher intake of creamy cheese was associated with a marginally significant increased risk.

If Yogurt Protects, Milk Does Not

Associations with dairy foods were mixed, when stratified by estrogen receptor status, and in general reflected those of overall breast cancer. However, we observed positive associations between milk intake and risk of ER-breast cancer (+ 58%). Specific dairy foods may thus contribute to breast cancer risk in women, although risk varies by sources of dairy. The authors called for further studies to warrant the protective potential of yogurt in cancer.

To learn more, read the original article.

The food that you eat can affect your bone health and consequently your upcoming quality of life. Researchers from the Netherlands investigated whether specific dietary patterns, linked with bone mineral density (BMD) and hip-bone geometry, are associated with fracture risk. They found several favorable effects from fruit, vegetables, and dairy pattern.

Bone Density and Food Patterns

Data on food intake, BMD, bone width and other measures reflecting bending strength and bone instability were obtained from 4.028 subjects aged 55 years and more, enrolled in the Rotterdam Study, a prospective, population-based study in the Netherlands. Based on the consumption of 28 food groups, the authors identified 4 different dietary patterns, among which 2 were used in this analysis: the first was named “fruit, vegetable, and dairy” pattern, the second “sweets, animal fats, and low meat” pattern.

Dairy as Part of 3 Bone-Friendly Foods

The results show that adherence to the ‘fruit, vegetables, and dairy pattern’ is associated with a favorable bone health profile (high BMD and bending strength, lower bone instability and risk of osteoporotic fractures). In contrast, adherence to the ‘sweets, animal fats, and low meat’ pattern was associated with, on the one hand, high bones width and strength, but, on the other hand, with a higher bone instability and risk of fractures (osteoporotic fracture and hip fractures), independently of BMD. Finally, this study suggests that a fruit, vegetables, and dairy could provide some benefits on bone health and aging.

To learn more, read the original article.

Source: de Jonge E A et al. The American Journal of Clinical Nutrition. First published November 30,2016.

Low socio-economic position (SEP) has often been associated with less healthy foods habits, overweight and obesity in the literature. Here, Peggy Drouillet-Pinard et al. pins several socio-economic disparities in the diet of a representative sample of French children and adolescents. Unfortunately, lower SEP is associated with lower yogurt, fruits and vegetables consumption.

Fewer Healthy Foods in Youth From Lower SEP

The study involved 574 children of 3 to 10 years and 881 adolescents of 11 to 17 years. 7-day food record and SEP data (socio-economic position like occupation, education, income or household wealth) used to evaluate the link between dietary intake and socio-economic category. Data for children and for adolescents were analyzed separately. The results showed that several healthy foods or food groups are less consumed in both children and adolescents from lower SEP, compared to youth of SEP: it’s the case for fruits, vegetables and yogurt.

A Need for Customized Messages Towards Specific SEP Populations

Other results indicate an association between a lower SEP and higher intake of starchy foods, meat, milk, sugar-sweetened beverages and pizza/sandwiches in children. Similar results were observed in adolescents for fruit and vegetables, yogurts and sugar-sweetened beverages. Adolescents also had lower intakes of cakes/pastries and higher intakes of processed meat and dairy desserts. Neither energy nor protein intake was associated with SEP. Adolescents from a lower SEP had higher carbohydrates and lower lipid intakes. Social disparity trough SEP indicators were therefore more clearly pronounced in terms of food choices than in terms of energy or macronutrient intakes.

In present study the strong associations observed between the families educational level and dietary choice. The author emphasizes the need for customized messages to help poorly educated families adopting good eating habits.

To learn more, read the original article.

Source: Drouillet-Pinard P et al. Public Health Nutrition 2017;20:870-882.