María Achón

High-dose folic acid supplementation in rats: effects on gestation and the methionine cycle.

There is new evidence that a good folate status may play a critical role in the prevention of neural-tube defects and in lowering elevated homocysteine concentrations. This adequate folate status may be achieved through folic acid dietary supplementation. Folate is a water-soluble vitamin with a low potential toxicity. However, the possible consequences of long-term high-dose folic acid supplementation are unknown, especially those related to the methionine cycle, where folate participates as a substrate. With the aim of evaluating such possible effects, four groups of Wistar rats were classified on the basis of physiological status (virgin v. pregnant) and the experimental diet administered (folic-acid-supplemented, 40 mg/kg diet v. control, 2 mg folic acid/kg diet). Animals were fed on the diets for 3 weeks. Results showed that gestation outcome was adequate in both groups regardless of the dietary supplementation. However, there were reductions (P < 0.001) in body weight and vertex-coccyx length in fetuses from supplemented dams v. control animals. Folic acid administration also induced a higher (P < 0.01) S-adenosylmethionine: S-adenosylhomocysteine value due to increased S-adenosylmethionine synthesis (P < 0.01). However, hepatic DNA methylation and serum methionine concentrations remained unchanged. Serum homocysteine levels were reduced in supplemented dams (P < 0.05). Finally, pregnancy caused lower serum folate, vitamin B6 and vitamin B12 levels (P < 0.05). Folic acid administration prevented the effect of pregnancy and raised folate levels in dams, but did not change levels of vitamins B12 and B6. These new findings are discussed on the basis of potential benefits and risks of dietary folic acid supplementation.

Omega 3 fatty acids in the elderly.

Population ageing affects the entire world population. Also at world level one can observe a sharp increase in the proportion of older people. The challenge posed by population ageing translates into ensuring that the extra years of life will be as good as possible, free from high-cost dependency. Omega-3 fatty acids are now generally recognized as potential key nutrients to prevent the pathological conditions associated to the aging process. Ageing physiological process, its association with quality of life and the impact of omega-3 fatty acids intake and/or status is the focus of the present review. This report deals with the effects of omega-3 fatty acids on normal aging of older adults ( ≥ 65 years) mainly on the effects such as nutritional status itself, cognition, bone health, muscle tonus, and general health status. The preliminary broad search of the literature on the effects of omega-3 fatty acids on normal aging yielded 685 citations. Forty two full text papers were checked for inclusion and thirty six studies were finally included in this review. It may be concluded that paradoxically even though the elderly population is the largest one, the number of studies and the methodology employed clearly lacks of sufficient evidence to establish definite conclusions on the effects of omega-3 fatty acids on aging metabolism without pathological conditions and on quality of life.

Supranormal dietary folic acid supplementation: effects on methionine metabolism in weanling rats.

There are nationwide folic acid (FA) fortification programmes of staple foods established or under consideration in order to prevent neural tube defects. Universal FA fortification still remains controversial because of the concern that additional FA in the diets of population groups (e.g. children and elderly) not initially targeted for fortification may suffer adverse effects. However, dietary surveys regarding folate generally deal with adults and little is known about the consumption and long-term effects of fortified food and supplements in growing individuals. Recent reports from our laboratory show several effects of high-dose folate supplementation in rats. In the present work, we studied the effect of FA on the methionine cycle in weanling (3-week-old) male rats after 4 weeks of supplementation with 40 mg FA/kg diet v. control (1 mg FA/kg diet). FA supplementation resulted in a reduction of homocysteine and creatinine concentrations v. control group. FA supplementation did not alter S-adenosylmethionine/S-adenosylhomocysteine ratio, DNA methylation, enzymatic activities or concentrations of vitamins involved in the nutritional regulation of the methionine cycle, except for folate. FA supplementation of 40 mg/kg did not lead to hepatic or renal damage. In conclusion, there were no apparent adverse effects on one-carbon metabolism after FA supplementation in the studied conditions.

Vitamin B 12 and Folic Acid Imbalance Modifies NK Cytotoxicity, Lymphocytes B and Lymphoprolipheration in Aged Rats

Different vitamin B12 and folic acid concentrations could exacerbate the immune response. The aim was to evaluate different dietary folic acid and vitamin B12 levels on the immune response in aged rats. Male Sprague Dawley aged rats were assigned to three folic acid groups (deficient, control, supplemented) each in absence of vitamin B12 for 30 days. Several parameters of innate and acquired immune responses were measured. Serum and hepatic folate levels increased according to folic acid dietary level, while vitamin B12 levels decreased. There was a significant decrease in natural killer cell-mediated cytotoxicity in the spleen for the vitamin B12 deficient diet and folic acid control diet groups. Significant changes in CD45 lymphocyte subsets were also observed according to dietary imbalance. Lymphoproliferative response to concanavalin A and phytohemagglutinin did not differ significantly between groups. The spleen response to lipopolysaccharide increased significantly, but was unmodified for the other organs. An imbalance between dietary vitamin B12 and folic acid concentrations alters some immunological parameters in aged rats. Therefore, the ratio between folate and vitamin B12 could be as important as their absolute dietary concentrations.

Present Food Shopping Habits in the Spanish Adult Population: A Cross-Sectional Study

Information on grocery shopping patterns is one key to understanding dietary changes in recent years in Spain. This report presents an overview of Spanish food shopping patterns in the adult population. A cross-sectional, nationally representative telephone survey was conducted in Spain. Individuals were asked about food shopping responsibility roles, types of visited food stores, time spent, additional behaviors while shopping, the influence of marketing/advertising and, in particular, fresh produce shopping profile. Binary logistic regression models were developed. The final random sample included 2026 respondents aged ≥18 years, of which 1223 were women and 803 were men. Women reported being in charge of most of the food shopping activities. Looking for best prices, more than looking for healthy or sustainable foods, seemed to be a general behavior. Supermarkets were the preferred retail spaces for food price consideration, convenience, variety and availability. Fresh produce shopping was associated with traditional markets and neighborhood stores in terms of reliance and personalized service. It is essential to highlight the importance of the role played by women. They are the main supporters concerned in preserving adequate dietary habits. Economic factors, more than health or food sustainability, are commonly considered by the population. Traditional markets may play an important role in preserving some healthy dietary habits of the Mediterranean food culture in Spain.

Mild methionine excess does not affect thymidylate synthesis or inflammation markers expression in human aortic endothelial cells.

Background: Recent studies in animal models have shown that high methionine intakes induce atherosclerotic changes that may be exacerbated when deficiencies of vitamins B6, B12 and folate are present. However, the mechanism underlying this possible atherogenic effect remains unknown. The aim of the present study was to evaluate the effects of methionine on the folate-dependent thymidylate-DNA synthesis, as a possible mechanism of atherogenicity, as well as the effect of high methionine/low folate on several key inflammation markers, such as vascular cell adhesion molecule-1 (VCAM-1), receptor for advanced glycation end products (RAGE) and matrix metalloproteinase-9 (MMP-9) in human aortic endothelial cells. Methods: Deoxyuridine suppression test was performed in order to evaluate thymidylate synthesis. To examine the expression of inflammation markers, cells were exposed to high methionine/low folate media for 9 days. Results: The assayed methionine levels (0.1, 0.5 and 5 mM) did not affect the de novo thymidylate-DNA synthesis. Consistent with this result, methionine (1 and 2.5 mM), alone or in combination with folate deficiency, increased homocysteine levels but did not induce the expression of the inflammation markers evaluated. Conclusion: Under the study conditions, methionine was not able to exert the atherogenic mechanism proposed and did not have the hypothesized inflammatory consequences in human aortic endothelial cells.

Omega-3 Fatty Acids in Aging

Abstract Increasing the intake of omega-3, particularly the long-chain n-3 PUFA may be one strategy to prevent and/or reduce morbidity in the elderly. It is becoming increasingly evident that these fatty acids appear to be neuroprotective. In general, longitudinal studies are mainly positive, indicating a protective effect against subsequent cognitive decline. In intervention studies there are some discrepancies, but it seems that when DHA is given to individuals with mild cognitive impairment or age-related cognitive impairment the data appear to be positive, whereas when Alzheimer’s disease was already established no clear benefit is achieved. Results are promising and encourage further research in order to establish a safe and effective treatment solution. In the early 2000s, evidence from large-scale epidemiological studies suggested that people at risk of cardiovascular heart disease (CHD) benefit from consuming omega-3 fatty acids. Nowadays, some authors propose that the beneficial effects of omega-3 FA are not as large as previously implied and recommendations for widespread use should be tempered. Generalizability of the overview finding may be questioned and more studies are needed to evaluate specific outcomes and populations stratified by sex, age, CV risk, medication use, race, etc. This chapter also deals with the effects of omega-3 fatty acids on immune function, bone health, muscle tonus, cancer, and general quality of life in aging. Results are limited and in their initial stages—even though the elderly population is the largest group—but they could be considered as promising. It may be concluded that the number of studies and the methodology employed clearly lacks sufficient evidence, and that further specific and larger trials, as well as prospective studies, are required to definitely determine the effects of omega-3 fatty acids on aging and on quality of life.

Identifying Factors Related to Food Agency: Cooking Habits in the Spanish Adult Population—A Cross-Sectional Study

This study focuses on understanding factors that influence food agency in the Spanish population, specifically with regard to cooking habits, knowledge, and determinants and their possible relationship with body weight. A cross-sectional telephone survey was conducted. Individuals were asked about their cooking responsibilities, how they learned to cook, factors that affect their food choices, and their preferred cooking techniques. Anthropometric data were also recorded. Participants were randomly selected, and we finally had 2026 respondents aged ≥18 years (60% women, 40% men). A total of 90.5% of participants stated that they had cooking skills. Women were mainly responsible for cooking tasks (p < 0.05) at all ages. A significantly higher proportion of people under 50 years self-reported that they were “able to cook” in comparison with groups over 50 years. Regardless of age, most participants learned to cook either by practice (43.3%) or from a family member (42.2%). Men tended to be more autodidactic, whereas women reported learning from family. No relation was found between weight status and the evaluated factors investigated. In conclusion, women bear the responsibility for the entire cooking process in families, indicating a gender gap in the involvement of men in cooking responsibilities and competence. More research is needed to assess the influence of cooking knowledge on obesity prevention.