Natalie D. Riediger

A Systemic Review of the Roles of n-3 Fatty Acids in Health and Disease

Attention to the role of n-3 long-chain fatty acids in human health and disease has been continuously increased during recent decades. Many clinical and epidemiologic studies have shown positive roles for n-3 fatty acids in infant development; cancer; cardiovascular diseases; and more recently, in various mental illnesses, including depression, attention-deficit hyperactivity disorder, and dementia. These fatty acids are known to have pleiotropic effects, including effects against inflammation, platelet aggregation, hypertension, and hyperlipidemia. These beneficial effects may be mediated through several distinct mechanisms, including alterations in cell membrane composition and function, gene expression, or eicosanoid production. A number of authorities have recently recommended increases in intakes of n-3 fatty acids by the general population. To comply with this recommendation a variety of food products, most notably eggs, yogurt, milk, and spreads have been enriched with these fatty acids. Ongoing research will further determine the tissue distribution, biological effects, cost-effectiveness, and consumer acceptability of such enriched products. Furthermore, additional controlled clinical trials are needed to document whether long-term consumption or supplementation with eicosapentaenoic acid/docosahexaenoic acid or the plant-derived counterpart (alpha-linolenic acid) results in better quality of life.

Low n-6:n-3 fatty acid ratio, with fish- or flaxseed oil, in a high fat diet improves plasma lipids and beneficially alters tissue fatty acid composition in mice

BackgroundHealth benefits from low n-6:n-3 fatty acid (FA) ratio on cardiovascular risk have been shown. However, the impact of the source of n-3 FAs has not been fully investigated.AimOur purpose was to investigate cardiovascular benefits of oils with a low ratio of n-6:n-3 FAs, but different sources of n-3 FAs in C57BL/6 mice.MethodsTwenty-one mice were divided into 3 groups (n = 7) and fed a diet supplemented with either a fish or flaxseed oil-based ‘designer oils’ with an approximate n-6:n-3 FA ratio of 2/1 or with a safflower-oil-based diet with a ratio of 25/1, for 16 weeks. Plasma lipids and fatty acid profile of the liver tissue were characterized.ResultsCompared to baseline, plasma triacylglycerol levels declined (>50%) in all groups by week 4. Plasma cholesterol levels were reduced in both fish and flax groups by 27% and 36%, respectively, as compared to controls at endpoint. The levels of EPA and DHA in liver phospholipids were significantly increased in both fish and flax groups as compared to the control group, with more profound increases in the fish group. Arachidonic acid levels were similarly decreased in the liver tissues from both fish and flax groups as compared to controls.ConclusionsOur data suggest that health benefits may be achieved by lowering dietary n-6:n-3 FA even in a high fat diet medium.

Patterns of Fruit and Vegetable Consumption and the Influence of Sex, Age and Socio-Demographic Factors among Canadian Elderly

Objective: The aim of the present study was to: 1) describe the patterns of fruit and vegetable (f&v) intake in Canadian elderly and 2) identify socio-demographic factors that were associated with the low consumption. Methods: Data from the Canadian Community Health Survey cycle 2.1 (2003), Public Use File, were used. Statistical analysis was conducted using SPSS 11.5 for Windows®. Total f&v intake of Canadian elderly (65 years and older) was cross-tabulated between four age groups, by gender, level of household education, total household income, ethnicity, marital status, and geographical locations. Results: Our data revealed that 47% of Canadian elderly sample consume f&v equal to or greater than five times daily. A strong positive association was found between f&v consumption and total household income and highest household education. Gender and marital status were other important contributing factors for f&v intake among elderly. Ethnicity did not influence f&v intake. Younger males reported to consume less f&v than older males did, but consumption of f&v was comparable among all four age groups of females. Elderly living in the Maritime Provinces and the Yukon/Northwest Territories/Nunavut had a lower level of f&v consumption, as compared to elderly living in other provinces. Conclusions: These results indicate that >50% of Canadian elderly do not consume f&v five or more times per day. Gender and several socio-demographic factors significantly influence f&v intake in Canadian elderly. Further studies warrant identifying at risk elderly groups and implementing programs to encourage adequate f&v intake by Canadian elderly.

Factors affecting food selection in Canadian population.

Objective:To establish health-related reasons behind Canadian food choices, and how variables such as education, income, gender, ethnicity and age may affect food selection.Subjects:Approximately 98 733 Canadians responded to the 12 questions regarding food choices in the Canadian Community Health Survey (CCHS) cycle 2.1, conducted by the Canadian Government in 2003. These included 13 727 adolescents (12–19 years), 19 089 young adults (20–34 years), 31 039 middle-aged adults (35–54 years), 25 338 older adults (55–74 years) and 9580 elderly (75+ years).Results:Approximately 70% of Canadian adolescents in the sample indicated that their food choices were independent of health concerns. Body weight management was a major concern for food selection by adolescents and adults, while the elderly stated heart disease as their main concern. Among all participants, females, and individuals with high levels of education and income reported the highest response to choosing or avoiding foods due to health concerns and food content.Conclusions:Our data indicate that several factors significantly affect food choices for health-related reasons in the Canadian population. Among them, age- and gender-related gaps, particularly between adolescents and adults, are profound. This observation may urge authorities to implement effective strategies to educate Canadians, especially adolescents, that selection of appropriate foods may prevent chronic diseases.

Prevalence, risk factors and awareness of albuminuria on a Canadian First Nation: A community-based screening study

BackgroundBoth diabetic and non-diabetic end stage renal disease (ESRD) are more common among Canadian First Nations people than among the general Canadian population. The purpose of this research was to determine the prevalence of and risk factors for albuminuria in a Canadian First Nation population at high risk for ESRD and dialysis.MethodsData from a community-based screening study of 483 residents of a Plains Ojibway First Nation in Manitoba was used. Participants provided random urine samples. Proteinuria was defined as any dipstick positive for protein (≥1 g/L) or those with ACR in the macroalbuminuric range (≥30 mg/mmol) on at least one sample. Microalbuminuria was defined as ACR ≥2 mg/mmol for males and ≥2.8 mg/mmol for females. Other measures included fasting glucose, haemoglobin A1c, triglycerides, cholesterol, blood pressure, height, weight and waist and hip circumferences.ResultsTwenty percent of study participants had albuminuria, (5% proteinuria and 15% microalbuminuria). Of participants with diabetes, 42% (56/132) had albuminuria compared to 26% (7/27) among those with impaired fasting glucose and 10% (30/303) among those with normal glucose tolerance. Only 5.3% of those with albuminuria were aware of any degree of renal disease. In a multivariate logistic regression, independent associations with albuminuria were male gender [p = 0.002], increasing fasting glucose [p <0.0001], years diagnosed with diabetes [p = 0.03], increasing systolic blood pressure [p = 0.009], and increasing body mass index (BMI) [p = 0.04].ConclusionsThe independent association between BMI and albuminuria has not been previously reported among indigenous populations. There is a high prevalence of albuminuria in this Canadian First Nation population; the high proportion of patients with diabetes and undiagnosed kidney disease demonstrates the need for screening, education and intervention to halt the progression and development of albuminuria and ultimately ESRD and CVD.

Hypothesis: Smoking decreases breast feeding duration by suppressing prolactin secretion

A number of studies, including new data summarized here, conclude that breast feeding duration is lower in smoking mothers. Although some have suggested that this merely reflects poor health motivation in those prone to smoke, several lines of evidence support the view that chronic smoking does indeed compromise breast feeding by suppressing prolactin secretion and thereby lowering breast milk volume. Moreover, a recent clinical trial shows that an effective smoking cessation program can boost breast feeding duration in smokers. An analysis of pertinent rodents studies suggests that chronic nicotine administration boosts dopaminergic activity in the tuberoinfundibular tract which functions to inhibit prolactin release; this increase in dopaminergic activity, in turn, may reflect a nicotine-mediated suppression of hypothalamic opioid activity.

A comparison of the effects of fish oil and flaxseed oil on cardiac allograft chronic rejection in rats

Both fish and flaxseed oils are major sources of different n-3 fatty acids. Beneficial effects of fish oil on posttransplantation complications have been reported. The current study aimed to compare the effects of flaxseed and fish oils in a rat cardiac allograft model. Male Fischer and Lewis rats were used as donors and recipients, respectively, to generate a heterotopic cardiac allograft model. Animals were randomly assigned into three groups and fed a diet supplemented with 1) 5% (wt/wt) safflower oil (control, n = 7), 2) 5% (wt/wt) flaxseed oil (n = 8), or 3) 2% (wt/wt) fish oil (n = 7), and an intraperitoneal injection of cyclosporine A (CsA; 1.5 mg.kg(-1).day(-1)) over 12 wk. Body weight, blood pressure, plasma levels of lipids, CsA, select cytokines, as well as graft function and chronic rejection features were assessed. Body weight and blood CsA levels were similar among the groups. Relative to controls, both treated groups had lower systolic and diastolic blood pressure and plasma levels of macrophage chemotactic protein-1. Treatment with fish oil significantly (P < 0.05) lowered plasma levels of triglycerides, total cholesterol, and LDL-cholesterol. HDL-cholesterol concentrations were significantly higher (P < 0.05) in the flaxseed oil-treated group compared with the other two groups. Both flaxseed oil and fish oil may provide similar biochemical, hemodynamic, and inflammatory benefits after heart transplantation; however, neither of the oils was able to statistically significantly impact chronic rejection or histological evidence of apparent cyclosporine-induced nephrotoxicity in this model.

Sugar-sweetened beverages as the new tobacco: examining a proposed tax policy through a Canadian social justice lens

KEY POINTS Intake of sugar-sweetened beverages is consistently, positively associated with obesity.[1][1] A much-discussed policy lever to address obesity is taxation of such beverages. The Canadian Diabetes Association,[2][2] Heart and Stroke Foundation[3][3] and World Health Organization (WHO)[4][

Incident diabetes, hypertension and dyslipidemia in a Manitoba First Nation

Background Diabetes and diabetes complications are substantially higher among Canadian First Nations populations compared with the general Canadian population. However, incidence data using detailed individual assessments from a population-based cohort have not been undertaken. Objective We sought to describe incident diabetes, hypertension and dyslipidemia in a population-based cohort from a Manitoba Ojibway First Nation community. Design Study data were from 2 diabetes screening studies in Sandy Bay First Nation in Manitoba, Canada, collected in 2002/2003 and 2011/2012. The cohort comprised of respondents to both screening studies (n=171). Health and demographic data were collected using a questionnaire. Fasting blood samples, blood pressure and anthropometric data were also collected objectively. Incident diabetes, hypertension and dyslipidemia were determined. Generalized linear models with Poisson distribution were used to estimate risk of incident diabetes and cardiometabolic conditions according to age and sex. Results There were 35 (95% CI: 26, 45) new cases of diabetes among 128 participants without diabetes at baseline (27 or 3.3% per year). While participants who were 50 years and older at baseline had a significantly higher risk of incident diabetes at follow-up compared with participants aged 18–29 at baseline (p=0.012), more than half of the incident cases of diabetes occurred among participants aged less than 40 at baseline. There were 28 (95% CI: 20, 37) new cases of dyslipidemia at follow-up among 112 without dyslipidemia at baseline (25%). There were 36 (95% CI: 31, 42) new cases of hypertension among 104 participants without hypertension at baseline (34.6%). Women had half the risk of developing hypertension compared with men (p=0.039). Conclusions Diabetes incidence is very high, and the number of new cases among those younger than 40 is a concern. Additional public health and primary care efforts are needed to address the diabetes burden in this First Nation community.

Lack of evidence for antiatherogenic effects of wheat bran or corn bran in apolipoprotein E-knockout mice.

Epidemiological studies have suggested that intake of whole grains is inversely associated with coronary artery disease. The mechanisms, however, are not completely clear. We tested the hypothesis that intake of wheat bran or corn bran would (1) increase the plasma concentration of phenolic antioxidants and (2) reduce atherosclerosis in apo E-knockout mice. Apo E-knockout (E-KO) mice were fed for 18 weeks with a 0.1% cholesterol-supplemented diet in the absence of grain brans or the presence of 1.7% yellow dent corn bran or 3.3% hard red spring wheat bran. The concentration of antioxidant ferulic acid in plasma and urine was measured by HPLC to monitor the bioavailability of grain phenolics. Plasma lipoprotein profiles were determined by a combination of HPLC and online enzymatic methods. Urinary 15-isoprostane F(2t), an in vivo LDL oxidation biomarker, and atherosclerotic lesions were analyzed by ELISA and histological methods, respectively. Dietary supplementation with corn or wheat bran resulted in a 4- and 24-fold increase, respectively, in urinary excretion of ferulic acid. The urinary recovery rate of ferulic acid from the two brans in apo E-KO mice was approximately 1.9-2.9%. Dietary corn bran but not wheat bran also significantly increased the concentration of total ferulic acid in plasma. Nevertheless, the supplementation with either bran product for 18 weeks did not significantly alter the urinary excretion of 15-isoprostane F(2t), change the lipoprotein profiles, nor reduce the atherosclerotic lesion development in this animal model. The results suggest that phenolic antioxidants from the two types of bran may not be sufficient to reduce atherosclerosis in this animal model.