Trends in fatty acid intake of adults in the Minneapolis-St Paul, MN Metropolitan Area, 1980-1982 through 2007-2009

Fatty Acid Diets: Regulation of Gut Microbiota Composition and Obesity and Its Related Metabolic Dysbiosis

Long-term high-fat dietary intake plays a crucial role in the composition of gut microbiota in animal models and human subjects, which affect directly short-chain fatty acid (SCFA) production and host health. This review aims to highlight the interplay of fatty acid (FA) intake and gut microbiota composition and its interaction with hosts in health promotion and obesity prevention and its related metabolic dysbiosis. The abundance of the Bacteroidetes/Firmicutes ratio, as Actinobacteria and Proteobacteria species are associated with increased SCFA production, reported high-fat diet rich in medium-chain fatty acids (MCFAs), monounsaturated fatty acids (MUFAs), and n-3 polyunsaturated fatty acids (PUFAs) as well as low-fat diets rich in long-chain fatty acids (LCFAs). SCFAs play a key role in health promotion and prevention and, reduction and reversion of metabolic syndromes in the host. Furthermore, in this review, we discussed the type of fatty acids and their amount, including the administration time and their interplay with gut microbiota and its results about health or several metabolic dysbioses undergone by hosts.

Association of plasma phospholipid polyunsaturated and trans fatty acids with body mass index: results from the Multi-Ethnic Study of Atherosclerosis

BACKGROUND/OBJECTIVE

Previous research has focused on associations between dietary fat and body mass index (BMI), but the contributions of different types of fat to BMI remain unclear. The purpose of this study is to estimate whether plasma phospholipid omega-3 (n-3), omega-6 (n-6) or trans fatty acids are associated with BMI at baseline and with subsequent BMI changes over time; and whether total phospholipid n-6 or trans fatty acids modify any association between phospholipid n-3 and BMI.

METHODS

Cross-sectional and longitudinal linear mixed models include 6243 participants in the Multi-Ethnic Study of Atherosclerosis (MESA) cohort. Participants were 45-84 years old, had no history of cardiovascular disease at baseline (2000-2002) and were followed for up to 10 years. Plasma phospholipid fatty acids were measured using fasting plasma samples at baseline. Fully adjusted models include demographics, health behaviors and other fatty acids (n-3, n-6 and trans) as appropriate.

RESULTS

In fully adjusted models, phospholipid n-3 fatty acid levels were inversely associated with baseline BMI (Ptrend <0.001). Baseline BMI was 1.14 (95% confidence interval (CI): 0.71, 1.57) kg m-2 lower among participants with total n-3 values in the highest vs the lowest quartiles, but was not associated with changes in BMI. Total phospholipid n-6 was positively associated with baseline BMI in partially adjusted but not fully adjusted models. No overall association was observed between fatty acid levels and changes in BMI. No clear association was observed between trans fatty acids and baseline BMI or BMI change. No effect modification in the association between phospholipid n-3 and baseline BMI or BMI change was observed by either phospholipid n-6 or trans fatty acids.

CONCLUSIONS

Phospholipid total and specific n-3 fatty acid levels were inversely associated with BMI at baseline, whereas associations tended to be positive for total n-6 fatty acids. Significant associations between fatty acid levels and BMI changes were not observed.

A 24-year prospective study of dietary α-linolenic acid and lethal prostate cancer

Several meta-analyses have attempted to determine the relationships between intake of α-linolenic acid (ALA) and prostate cancer, but results were inconclusive. 47,885 men aged 40-75 years without prior cancer in the Health Professionals Follow-Up Study were prospectively followed from 1986 to 2010. Intake of ALA was determined from validated food frequency questionnaires every 4 years. We used multivariate Cox proportional hazards models to estimate hazard ratios (HR) with 95% confidence intervals (CIs) for lethal prostate cancer (distant metastasis or prostate cancer death). 386 lethal prostate cancers were diagnosed in the pre-PSA era (before February, 1994) and 403 cancers in the PSA era. Intake of ALA was associated with increased risk of lethal prostate cancer in the pre-PSA era (comparing top to bottom quintile of intake, multivariate-adjusted HR = 1.78; 95% CI = 1.22-2.06; p_trend  = 0.003), but not in the PSA era (HR = 0.81; 95% CI = 0.56-1.17; p_trend  = 0.53), and the difference in associations was statistically significant (p for interaction = 0.02). Mayonnaise, a primary food source of ALA intake in our cohort, was likewise only significantly associated with lethal prostate cancer in the pre-PSA era. Among many other fatty acids that are correlated with ALA due to shared food sources, none was associated with lethal prostate cancer in the pre-PSA era. In conclusion, higher intake of ALA was associated with an increased risk of lethal prostate cancer in the pre-PSA era, but not in the PSA era. Potential reasons for the differential associations warrant further investigation.

The Impact of Policies to Reduce trans Fat Consumption: A Systematic Review of the Evidence

Background: The consumption of industrially produced trans fatty acids (TFAs) has been associated with an increased risk of heart disease. In recognition of this, countries, states, and cities worldwide have implemented TFA policies aimed at reducing their availability in the food supply. Objective: This article aims to provide an update of the evidence of the effectiveness of policies aimed at reducing TFAs in the food supply. Methods: A systematic review of the literature from 2013 onward was conducted, building on a previously published review that examined the evidence of the impact of TFA policies worldwide from 2000 to 2012. Studies that were 1) empirical, 2) examined a TFA policy, and 3) examined the effect of the policy on TFA amounts and availability pre- and post-policy intervention were included. Modeling studies examining the impact of TFA policies on cardiovascular, equity, and economic outcomes were also included. Results: A total of 18 articles from the updated search were combined with 14 articles from the previous review (total = 32 articles). All types of TFA policies led to their reduction; however, trans fat bans had a larger impact (TFAs virtually eliminated) than did voluntary (range: 20-38% reduction in TFA intakes) or labeling (range: 30-74% reduction in TFA intakes, plasma serum, or breast-milk concentrations) approaches to reducing TFA amounts in the food supply. Product reformulation to reduce TFAs had variable effects on saturated fatty acid (SFA) contents in these foods; however, the combined amount of TFAs and SFAs declined in most products. Overall, the modeling studies indicated that TFA bans would reduce heart disease risk, benefit socioeconomically disadvantaged populations the most, and be cost-saving. Conclusions: Policies aimed at reducing TFAs in the food supply are effective and will likely reduce the burden of diet-related disease, particularly among the most vulnerable socioeconomic groups. Although all policy approaches lead to reductions in TFAs in foods, TFA bans are likely the most effective, economical, and equitable policy approach to reducing TFAs in the food supply.

Trends in dietary fat and fatty acid intakes and related food sources among Chinese adults: a longitudinal study from the China Health and Nutrition Survey (1997–2011)

Objective

Few studies have evaluated the intake trends of fatty acids in China. The present study aimed to describe the profile of longitudinal dietary fat and fatty acid intakes and their related food sources in Chinese adults.

Design

A longitudinal study using data from the China Health and Nutrition Survey (1997–2011) was conducted. Dietary intake was estimated using 24 h recalls combined with a food inventory for three consecutive days. Linear mixed models were used to calculate the adjusted mean intake values.

Setting

Urban and rural communities in nine provinces (autonomous regions), China.

Subjects

Adults (n 19 475; 9420 men and 10 055 women).

Results

Fat intake among men in 1997 was 73·4 g/d (28·1 % of total energy (%TE)), while in 2011 it increased to 86·3 g/d (33·2 %TE). Similarly, for women, this intake increased from 62·7 g/d (28·4 %TE) in 1997 to 74·1 g/d (33·7 %TE) in 2011. Energy intake from SFA grew from 6·8 to 7·6 %TE for both sexes. PUFA intake increased from 18·4 to 22·5 g/d for men and from 15·7 to 19·7 g/d for women, and was above 6 %TE in all survey periods. Intakes of 18:2 and 18:3 fatty acids showed significant upward trends in both sexes. Participants consumed less animal fats and more vegetable oils, with more PUFA intake and less energy from SFA. EPA and DHA intakes fluctuated around 20 mg/d.

Conclusions

Fatty acid intakes and profile in Chinese adults are different from those reported in other countries.

Dietary intake of α-linolenic acid and risk of age-related macular degeneration

Background: The relation between α-linolenic acid (ALA), a plant-derived omega-3 (n-3) fatty acid, and age-related macular degeneration (AMD) is unclear. European researchers reported that ≤40% of ALA can be present as trans forms.Objective: We aimed to evaluate the associations between intake of ALA and intermediate and advanced AMD.Design: Seventy-five thousand eight hundred eighty-nine women from the Nurses' Health Study and 38,961 men from Health Professionals Follow-Up Study were followed up from 1984 to 2012 and from 1986 to 2010, respectively. We assessed dietary intake by a validated food-frequency questionnaire at baseline and every 4 y thereafter. One thousand five hundred eighty-nine incident intermediate and 1356 advanced AMD cases (primarily neovascular AMD) were confirmed by medical record review.Results: The multivariable-adjusted HR for intermediate AMD comparing ALA intake at the top quintile to the bottom quintile was 1.28 (95% CI: 1.05, 1.56; P-trend = 0.01) in the analyses combining 2 cohorts. The HR in each cohort was in the positive direction but reached statistical significance only in the women. However, the positive association was apparent only in the pre-2002 era in each cohort and not afterward (P-time interaction = 0.003). ALA intake was not associated with advanced AMD in either time period. Using gas-liquid chromatography, we identified both cis ALA (mean ± SD: 0.13% ± 0.04%) and trans ALA isomers (0.05% ± 0.01%) in 395 erythrocyte samples collected in 1989-1990. In stepwise regression models, mayonnaise was the leading predictor of erythrocyte concentrations of cis ALA and one isomer of trans ALA. We also found trans ALA in mayonnaise samples.Conclusions: A high intake of ALA was associated with an increased risk of intermediate AMD before 2002 but not afterward. The period before 2002 coincides with the same time period when trans ALA was found in food and participants' blood; this finding deserves further study.

Contribution of Trans-Fatty Acid Intake to Coronary Heart Disease Burden in Australia: A Modelling Study

Trans-fatty acids (TFAs) intake has been consistently associated with a higher risk of coronary heart disease (CHD) mortality. We provided an updated assessment of TFA intake in Australian adults in 2010 and conducted modeling to estimate CHD mortality attributable to TFA intake. Data of the 2011–2012 National Nutrition and Physical Activity Survey was used to assess TFA intake. The CHD burden attributable to TFA was calculated by comparing the current level of TFA intake to a counterfactual setting where consumption was lowered to a theoretical minimum distribution of 0.5% energy. The average TFA intake among adults was 0.59% energy, and overall 10% of adults exceeded the World Health Organization (WHO) recommended limit of 1% energy. Education and income were moderately and inversely associated with TFA intake (p-value ≤ 0.001), with one in seven adults in the lowest income and education quintile having >1% energy from TFA. Australia had 487 CHD deaths (95% uncertainty interval, 367–615) due to TFA exposure, equivalent to 1.52% (95% uncertainty limits: 1.15%–1.92%) of all CHD mortality. The relative impact of TFA exposure on CHD mortality in Australia is limited, but, in absolute terms, still substantial. Policies aimed at reducing industrial TFA exposure can reduce socioeconomic inequalities in health and may therefore be desirable.

Fatty acid dietary intake in the general French population: are the French Agency for Food, Environmental and Occupational Health & Safety (ANSES) national recommendations met?

Quantity and quality of fatty acids (FA) in diet influence CVD risk. Consequently, health authorities promote recommended dietary intakes for FA, looking for optimal intakes in a primary prevention of CVD perspective. In parallel, a few data are available detailing intakes in national populations. The objective of the present study was to perform a large analysis combining the data of the French National Survey INCA 2 on food consumption performed in 2006 and 2007, and the nutritional content of food consumed in France updated in 2013 by the French Information Centre on Food Quality, to explore in details the FA intakes in French adults using the most recent available data. To compare the discrepancies in the observed intake levels with the French recommended levels, a weighted fat adherence score was built combining intakes of the different FA. Individual scores were computed in relation to official recommendations, and potential explanatory factors were identified. These data show that SFA intakes are persistently higher than national recommendations, combined with low intakes of MUFA and PUFA, particularly long-chain n-3 FA. Only 14·6 % of the French population met DHA intake recommendation, 7·8 % for EPA and 21·6 % for SFA. This situation remains unfavourable in terms of primary prevention of CVD. Consuming fish and other sources of n-3 FA, living in the south of France, being female, having a higher education level, and low alcohol consumption were associated with a healthier fat adherence score.

The Effects of Dietary Omega-3s on Muscle Composition and Quality in Older Adults

This review will focus on findings from the few studies performed to date in humans to examine changes in muscle protein turnover, lean or muscle mass and physical function following fish oil-derived omega-3 fatty acid treatment. Although considerable gaps in our current knowledge exist, hypertrophic responses (e.g., improvements in the rate of muscle protein synthesis and mTOR signaling during increased amino acid availability and an increase in muscle volume) have been reported in older adults following prolonged (8 to 24 weeks) of omega-3 fatty acid supplementation. There is also accumulating evidence that increased omega-3 fatty acid levels in red blood cells are positively related to strength and measures of physical function. As a result, increased omega-3 fatty acid consumption may prove to be a promising low-cost dietary approach to attenuate or prevent aging associated declines in muscle mass and function.

Low-fat and low-protein diets are associated with hearing discomfort among the elderly of Korea

Research on the effect of low-fat intake on hearing is limited. This study aimed to elucidate the relationship between fat, carbohydrate and protein intake and the presence of hearing discomfort among the elderly. The Korean National Health and Nutrition Examination Survey was conducted from 2009 through to 2012. A total of 4615 participants ranging in age from 60 to 80 years underwent a pure-tone audiometric evaluation, a physical examination and a nutritional survey. The associations between the participants' hearing thresholds and their protein/fat/carbohydrate intake/total energy intake were analysed using simple and multiple regression models with complex sampling adjusted for confounding factors, such as BMI, income level, smoking status and a history of hypertension, hyperlipidaemia and diabetes. Low fat and protein intakes were associated with hearing discomfort (OR 0·82, 95 % CI 0·71, 0·96, P=0·011; OR 0·81, 95 % CI 0·67, 0·96, P=0·017, respectively). This study revealed that low fat and protein intakes are associated with hearing discomfort in the elderly Korean population.