The IV World Public Health Nutrition Congress in Madrid

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The IV World Public Health Nutrition Congress held within NUTRIMAD in Madrid from October 24 – 27, 2018 at the Melia Castilla Hotel. As with its predecessors in Barcelona (2006), Oporto (2010), and Las Palmas in the Canary Islands (2014), an Iberian setting hosted the event. Sponsored by the Spanish Society of Community Nutrition (SENC), the meeting was organized by CEU San Pablo University of Madrid, with Prof. Gregorio Varela-Moraias presiding. Some 450 speakers, professionals and students were registered; the majority was from Spain, along with attendees from Austria, Belgium, France, Finland, Greece, Iran, Ireland, Israel, Italy, Portugal, the Netherlands, and the UK. Additionally, Argentina, Brazil, Canada, Guatemala, Mexico and the USA from the Western Hemisphere had attendance at the WPHNC. African and Asian nations were not represented.

Packed into a diverse and dense Program over the four days were a total of 51 sessions: 4 plenary lectures; 4 lectures; 21 symposia; 12 conferences; 5 round tables; 4 presentations; and 1 workshop. Fifty-four free papers were distributed among 6 topical oral-presentation sessions and 196 posters were scheduled over the course of two of the congress days. A plurality of sessions was devoted directly or tangentially to the issues of overweight/obesity and metabolic disorders. This report focuses primarily on micronutrient aspects, but the Mediterranean diet science and policy is a cross-cutting linkage between the two domains. 

Notable Lectures

The opening night’s inaugural sessions were highlighted by the Keynote Plenary lecture “What have we learned from Nutrigenomics?” by Prof José Ordovás of Tufts University and the Nutrition and Genomics Laboratory at the Jean Mayer USDA Human Nutrition Research Center on Aging in Boston. His discipline examines the interaction between genetic traits and nutritional exposures. He began by taking a 3-decade tour of advances in both domains. On the genetics side, the human genome was sequenced allowing precise and exact localization of genes both by single-nucleotide polymorphisms (SNP) and genome-wide association studies (GWAS). By contrast, the exactness of quantifying dietary intake is lacking. This can vitiate the stability of associations between the domains, limiting achievements in nutrigenetics. His laboratory is working on sensors aimed at quantifying the foods and beverages (and their nutrients) as they pass from the diet to the host.

Ordovás’ nutrigenetics approach has shown interactions between the fat content of the diet and HDL cholesterol and triglycerides in relation to the genetic polymorphism of the hepatic lipase (LIPC) gene. The dominant allele is CC or CT, whereas the TT is the minor form. In the Boston Puerto Rican Health Study, an unfavorable association between dietary saturated fat intake and lipid status was found in those with the TT modification. To confirm causality in an intervention study, Hispanic subjects were randomized to a Western (high-fat) or Caribbean (low-fat) for 4 weeks; those with the major allele showed a protective effect against HDL elevation on the higher fat exposure.

Dr. Ordovás also mentioned the advent of methylomics (methylation omics), which is the subdivision of epigenomics that assesses the degree of methylation of DNA in the nuclear material of cells. Epigenetics is the alteration of the original genetically-determined transcription for proteins due to acquired changes along the structure of the DNA helices. Insofar as DNA methylation is influenced by the dietary intake of specific constituents (folate, vitamin B12, betaine, choline and others), its relevance to micronutrient nutrition is obvious.

Another important plenary lecture was that of Dr. Mario Arevlo, Chairman of the FAO’s Committee on World Food Security entitled ”Food and Nutrition Security in a Globalised World.” In a historical context, the concept of food as a human right is a precept dating to 1947, two years after the founding of the United Nations and the Food and Agriculture Organization. 

The second goal of the Sustainable Development Goals (SDGs) is touted as the embodiment of the food and nutrition agenda; the speaker asserted that elements related to food security could be identified across all 17 SDGs. Three major threats to food security and barriers to its resolution are extraordinarily menacing.  The first is conflicts, notably the confrontations in the Middle East as in Yemen, Syria and Palestine. Climate change offers a host threats soil and waters, the natural flora and fauna, the abundance of food harvested from the sea, and the yield of crops and other edible plants across the world. Mass migrations, occurring all over the world in both visible and less obvious manners, displace people from agricultural pursuits, while creating a tenuous relationship between food stocks and people. 

Food policy has a small – and largely reactive – role to play in the face of the aforementioned obstacles of conflict and migration. A food systems approach, which links agriculture, food production and trade with the nutritional needs of the human and non-human population, is currently being developed and refined.  It is fundamental to assuring food security despite the paradoxical situations that pre-harvest, post-harvest and in-home losses affect up to 50% of all edible items grown, raised or captured and that over half of the adult population in the world suffers from overweight or obesity.

The Symposia

The symposium entitled “Coping with Vitamin D Deficiency: Benefits and Safety of Additional Vitamin D Intakes” first provided an overview on vitamin D nutrition, function, dietary sources, intake recommendations, safety and tolerable limits. It then provided a case history on contemporary research and policy in Iran. Because their traditional garments exclude solar exposure in schoolgirls, the Iranian government has begun a school-level intervention providing a monthly mega-dose of 50,000 IU in each of the 10 months of the school year to female students. The efficacy and safety of this measure had not been evaluated before his became national policy. A presenter outlined a nested placebo-controlled intervention in adolescent boys conducted to determine the efficacy among males. Over a 6 month period, the rate of low vitamin D levels fell from greater than 30% to less than 10% in the treatment group, whereas the no-treatment group of boys had a persistent low-status rate in three in ten subjects. Meanwhile, the Iranian government is exploring the feasibility of fortifying wheat flour universally with the vitamin; this is based on poor status and buoyed by a trial in which 25 µg of vitamin D3 (1000 IU) within 50 g of bread raised circulating 25 hydroxy-vitamin D by 30 nmol/L over 8 weeks in healthy adults. A final fortificant dose has yet to be assigned. 

A series of issues arose in the discussion. It was suggested that the lifestyle conditions of boys are distinct from those of girls, such that the response documented in the male cohort may not represent how girls would respond – or have responded. Analyzing a random sample among the girls already enrolled in the periodic supplementation would indicate if the current dosage is sufficient for them. A second point of contention was whether or not there was any rationale plan to transition from the school-based supplementation to reliance on the forthcoming programs of fortification of flour and bread. The current plan was to suspend school intervention when fortification is implemented, but no research to assure desirable outcomes has been planned. 

The symposium on “Dietary Surveys: An Overview” combined a researcher from France, from the United Kingdom and from Spain considering the social determinants and quantitative findings in relation to dietary surveys. On the quantitative side, an array of national surveys across the European Union – and in particular, a survey of Spanish consumers – outlined the adequate and deficient intakes of macro- and micronutrients through combined food records and 24-hour recall. Common to all, to a greater or lesser degree, however, was a lower than expected average, daily energy intake. This is attributed to systematic underreporting of food and beverage intake by the participants. This is paradoxical in light of the ascending prevalence of overweight and obesity. The presenters readily accepted the suggestions from the audience that inclusion of the doubly-labeled water method in a subgroup of the surveyed could allow a proportional energy adjustment to the nutrient intakes, and expression of nutrient density would be a better standpoint for comparison across international surveys.

The symposium on “Activating Nutrition Recommendations by Understanding Breakfast Habits” summarized a comparative, multi-centric study including the standardized analysis of national nutrition surveys from Canada, Denmark, France, Spain, UK and the US. It looked to establish normative values for the energy and macronutrient contribution of the morning meal to the total daily energy, finding a range of 16 to 21%. Using the make-up of the top tertiles for nutrient-richness and healthful pattern, a set of recommendations for breakfast composition was advanced. It was lamented that the hydration implications for the liquids consumed as breakfast was not included in the agenda. A cautionary note for the extrapolation and generalization to a wider geography was expressed insofar as breakfast habits in countries like Brazil and Guatemala diverged greatly from this Western pattern.

The Mediterranean Diet as a traditional cuisine has been declared a World Cultural Heritage by the UNESCO in Paris. The Mediterranean diet is based around fish and seafood, whole grains, fruits, vegetables and legumes with wine and ultra-virgin olive oil being the essential – albeit processed – items at the center  of the cuisine. Two symposia dealt with this as their central topic: “Mediterranean Diet in the 21st Century: A Holistic View” and “The Mediterranean Diet and Cardiovascular Prevention: The PREDIMED Trial.” Described in the first symposium was the geographic extent and variation within the general cuisine, and the ecological advantages for a sustainable environment as compared to other European and industrialized-nation cuisines. Both the anti-oxidant and anti-inflammatory properties and the various applications of omic techniques being applied to the study of consumers of the Mediterranean diet were reviewed. The PREDIMED trial compared cardiovascular mortality across three study groups.  Participants were randomly assigned to education on a low-fat diet (control group) or to one of two MedDiets, supplemented with either free virgin olive oil (1 liter/week) or nuts (30 g/day). With the trial results, published in, retracted from and republished in the New England Journal of Medicine, it can now reasonably concluded that both of the treatment diets equally reduced the risk of cardiovascular death. For those of us focused on micronutrients, these symposia underscore the obligation to broaden the focus to patterns of dietary selection.

Insights from the Free Papers

Of the 240 free-papers programmed, some 20 (9%) were directly or indirectly endowed with the name of a micronutrient (vitamin D, vitamin E, folate; omega-3 fatty acid, calcium, iron, zinc and selenium) or the implication of multiple micronutrients in the title. The most noteworthy and newsworthy free-paper came from the oral-papers series; it had the self-explanatory title of “Betaine homocysteine S-methyltransferase deficiency increases susceptibility to noise-induced hearing loss correlating with plasma homocysteinemia.” Since human deficiency of this enzyme had not been associated with altered homocysteine levels, this may represent a landmark observation. It has a provisional functional consequence (auditory acuity), and has theoretical implications for choline intake by persons with this polymorphism.

The Workshop

Photo Credit: Noel Solomons

The sole workshop of the Congress was relevant to nutritional quality and micronutrient intakes. It was sponsored by Nestlé and the Sant Joan de Deu Hospital in Barcelona, and presented a tool for fostering healthful dietary consumption in children. Called the NUTRIPLATO (Nutritious Plate), it is the latest generation of an idea pioneered by the American Institute for Cancer Research (the New American Plate) and the US Dietary Guidelines(MyPlate), which conceptualized the relative selection of food groups. The Spanish initiative involves the distribution of actual, reusable dinner plates with the partition of food groups and their proportion in meals depicted on the surface as shown in the Figure. About 350 of a targeted 1000 Catalan children have so far been enrolled; the primary outcome is the maintenance or achievement of a normal body weight with guidance form the NUTRIPLATO.