Dawn C. Schwenke

Insulin resistance, low-fat diets, and low-carbohydrate diets: time to test new menus.

Purpose of review Insulin resistance increases the risk of cardiovascular disease and diabetes, and the risk of cardiovascular disease increases further once diabetes has developed. As insulin resistance is a precursor to diabetes, it is critically important to identify cost-effective means, such as dietary changes, by which to reduce insulin resistance. The purpose of this review is to evaluate recent findings concerning dietary composition and insulin resistance, with particular focus on low-fat diets compared with the currently popular low-carbohydrate diets. Recent findings Recent findings indicate little support for the value of low-carbohydrate diets as therapies for insulin resistance. In contrast, the limited data available suggest that the higher fat content of typical low-carbohydrate diets may exacerbate insulin resistance in the long term. Preliminary data indicate that proteins from different sources may have differing effects on insulin resistance. Preliminary data also suggest the potential value of whole grains, fruits and vegetables in therapeutic diets to reduce insulin resistance. Summary Current evidence supports the inclusion of whole grains, fruits and vegetables, and lean sources of animal proteins including low-fat dairy products in dietary therapies for insulin resistance. Those who wish to follow a low-carbohydrate diet should be encouraged to follow a new menu low in fat, and with most of the protein derived from plant sources. Abbreviations HOMA: Homeostasis Model Assessment; QUICKI: Quantitative Insulin Sensitivity Check Index.

Nutrition and metabolism--dietary patterns: evidence for the critical importance of vegetables builds.

Evidence supporting the health benefits of multiple dietary patterns continues to accumulate. These dietary patterns include those consistent with the Dietary Approaches to Stop Hypertension (DASH) diet [1 ], national dietary guidelines [2,3], diets similar to those followed in the Mediterranean region (Mediterranean diet) [4 ,5 ,6 ,7 ], and other dietary patterns characterized by higher intake of fruits and vegetables that have been empirically identified within populations [8 ,9,10]. However, much less is known concerning whether any of these dietary patterns, or yet to be investigated alternate dietary patterns, confer particular benefit for overall survival, specific health outcomes, or quality of life. Important recent advances include the direct comparison of several of these dietary patterns within the same study [1 ,5 ], investigations of the effects of individual dietary components independent of the overall dietary pattern [1 ,11 ], and further studies evaluating the health benefits associated with different components of these apparently healthy dietary patterns [12 ,13 ].

Dietary patterns: time to simplify the message until we can clarify the specifics.

There is much recent interest in dietary patterns, as evidenced by recent articles examining secular trends in dietary patterns [1 ,2], assessing the relationship between self-selected dietary patterns and health outcomes [3 ,4 ,5,6], evaluating health implications of interventions to alter dietary patterns [7 ,8 ,9], and assessing the personal [10,11] and environmental [12 ,13 ,14] cost of differing dietary patterns. These reports further emphasize the importance of dietary patterns to individual and public health and begin to address the integration of dietary patterns into personal and national, if not global, economies. These new data raise as many questions as they answer. What are the critical features of ideal or optimal dietary pattern(s)? How much personalization is appropriate? How much variety is really needed? What are the personal, national, and global costs associated with ideal or optimal dietary pattern(s)? Finally, and importantly, to achieve the benefits that might be expected by widespread improvement of dietary pattern(s), what are opportunities for promoting the public adoption of more healthful dietary patterns?

The plant protein 'package' may be preferred in high-protein diets.

Dietary interventions have established that highprotein diets can induce weight loss. As reviewed [1 ], several of the popular high-protein diets are high in fat. Most investigations of high-protein diets, including a recent study [2 ], have relied primarily on animal sources of protein as indicated by typical menus [1 ] and reported high content of cholesterol and saturated fat [2 ]. The high content of cholesterol and saturated fat in popular high-protein diets raises concerns regarding the long-term impact of such diets on cardiovascular disease as well as other chronic diseases. Importantly, no randomized, controlled clinical trial has demonstrated the long-term safety of high-protein diets. Just as the long-term safety of high-protein diets remains to be established, the long-term impact of the source of dietary protein remains to be determined. However, accumulating evidence suggests that plant proteins, particularly legumes, may be valuable components of high-protein diets.

Increasing dietary fruits and vegetables to reduce healthcare costs.

DOI:10.1097/MOL.0000000000000323 Recent literature further strengthens the evidence that diets rich in fruits, vegetables, whole grains, and other plant foods reduce overall and disease-specific morbidity and mortality [1 && ,2 && ,3 & ,4 && ,5 & ]. Importantly, a recent study suggests that the mortality benefit conferred by healthy diets enriched in fruits and vegetables and other nutrient dense foods extends to cardiac patients receiving state-of-the-art medical treatment [1 && ]. Participants aged 60–80 from the Alpha Omega Trial for whom diet was assessed at baseline by food frequency questionnaire median 3.7 years after clinically diagnosed myocardial infarction [1 && ], were followed for 10 years. Almost, all participants received pharmaceutical treatment; 86% used statins, 90% used antihypertensive medications, and 98% used antithrombotic agents. Dietary information was used to compute the Dutch Healthy Nutrient and Food Score (DHNaFS) based on consumption of fruit, vegetables, whole grains, and eight other nutrient dense food groups. A Dutch Undesirable Nutrient and Food Score (DUNaFS), including 13 food groups that were high in solid fats, sodium, and/or added sugar or were highly refined and/or processed was also calculated [1 && ]. After multivariable adjustment for treatment assignment in the Alpha Omega Trial, total energy intake, demographic, lifestyle, and clinical variables and adjustment of each of DHNaFS and DUNaFS for the other, the DHNaFS was inversely associated with all-cause mortality and cardiovascular mortality, with respective hazard ratios of 0.70 (0.55, 0.91) and 0.68 (0.47, 0.99) for the fifth quintile compared with the lowest quintile (P value for trends 0.0006 and 0.0002, respectively). In comparison, the DUNaFS was not associated with either all-cause or cardiovascular mortality (P values for trend both >0.70) [1 && ]. Another article considered whether dietary patterns that emphasize fruits and vegetables would reduce healthcare utilization and lower healthcare costs [6 && ]. Men and women aged 65–79, who participated in the Elderly Nutrition and Health Survey in Taiwan, were studied [6 && ]. Dietary information was determined from a 24-h dietary recall obtained by trained interviewers with appropriate

Improving dietary quality by increasing plant foods when income is limited.

DOI:10.1097/MOL.0000000000000222 Several recent articles further support the notion that a plant-based dietary pattern promotes human health and that dietary quality can be improved without incremental cost. Two recent articles [1 & ,2 && ] report health effects of three or more commonly used a priori measures of dietary pattern in multiple study populations. The Dietary Patterns Methods Project [1 & ] evaluated dietary patterns in three US cohorts, in each case by four measures, the Healthy Eating Index 2010 (HEI-2010) based on the US 2010 Dietary Guidelines for Americans [3], an Alternative Healthy Eating Index 2010 (AHEI-2010) that also considers foods and nutrients associated with decreased risk of chronic disease, a score reflecting relative similarity to a traditional Mediterranean diet (aMed), and a score representing relative concordance with the Dietary Approaches to Stop Hypertension (DASH) diet. The second article provides results of a meta-analysis including reports that evaluated dietary pattern by one or more of the HEI (HEI-2010 as well as the earlier HEI and HEI-2005), the AHEI (AHEI-2010 as well as the earlier AHEI), or the DASH dietary patterns [2 && ]. Fifteen cohorts comprised persons from the USA, Europe, and Taiwan that also met strict quality criteria were included [2 && ]. Both articles found higher dietary quality as assessed by higher concordance with all investigated measures of dietary pattern to be associated with reduced all-cause mortality and reduced incidence/mortality because of cardiovascular disease and cancer [1 & ,2 && ] with relatively small differences between methods of assessing dietary quality. These results, together with a body of prior literature concerning individual food groups, strongly support the notion that dietary components similarly and favorably evaluated for each of the HEI-2010, the AHEI-2010, aMed, and DASH dietary patterns, namely plant foods including vegetables, fruits, and whole grains [4 & ], are key to the health benefits associated with greater adherence to these dietary patterns. Important to achieving higher dietary quality by increasing consumption of vegetables, fruit, and whole grains are overcoming/circumventing financial barriers to these dietary changes. Two recent

Designing dietary patterns to minimize overall disease burden.

DOI:10.1097/MOL.0000000000000187 Interest in health effects of dietary patterns continues. Recent literature extends prior literature beyond the prevention of cardiovascular diseases, major forms of cancer, and all-cause mortality to report on relationships between dietary patterns and total disease burden as assessed by the disability-adjusted life year (DALY) [1 && ] as well as longitudinal changes [2] and a novel measure [3] of the cardiovascular risk factor blood pressure. Of particular value to the literature, multiple recent articles reporting on important health outcomes have provided comparative data for multiple dietary patterns previously associated with health benefits [1 && ,4 && ,5 & ,6 && ,7 & ] including Mediterranean-like dietary patterns [1 && ,4 && ,5 & ,6 && ,7 & ], dietary patterns similar to the Dietary Approach to Stop Hypertension (DASH) diet [1 && ,4 && ,5 & ,6 && ], and dietary patterns consistent with national and/or regional governmental recommendations [1 && ,4 && ,5 & ,6 && ,7 & ]. Among these articles, one also provided comparative data for a low-carbohydrate high-protein dietary pattern [5 & ] whereas another also provided comparative data for a novel index of dietary pattern based on theoretical inflammatory properties of the diet [6 && ]. Several of these reports also included comparative data for prudent/healthy and Western/unhealthy dietary patterns extracted from participant’s dietary information using principal component analysis [1 && ,7 & ].

Nutrient-rich fruits and vegetables: key for preventing cardiovascular and all-cause mortality in those with pre-existing cardiovascular disease?

DOI:10.1097/MOL.0000000000000102 effects of dietary quality beyond primary prevention of cardiovascular diseases, cancer, and all-cause mortality to other important health outcomes [1 & ,2,3] and secondary prevention of total and cause-specific mortality among those with pre-existing coronary [4 && ] or cardiovascular disease [5 && ]. These include articles assessing dietary quality by concordance with a Mediterranean dietary pattern [1 & ,5 && ,6 & ], the Dietary Approaches to Stop Hypertension (DASH) dietary pattern [1 & ,6 & ], the dietary component of the 2006 American Heart Association Diet and Lifestyle Recommendations [2], and the Alternative Healthy Eating Index 2010 (AHEI2010) [3,4 && ]. Although differences exist between these methods of assessing dietary quality, all overlap considerably concerning dietary components weighted favorably. In particular, all favorably evaluate fruits and vegetables. Recent articles concerning men from the Health Professionals Follow-Up Study (HPFUS) and women from the Nurses’ Health Study (NHS) reported on longitudinal associations between dietary quality and mortality in individuals who had survived a myocardial infarction (MI) [4 && ] or with pre-existing cardiovascular disease (history of myocardial infarction, coronary bypass, coronary angioplasty, angina pectoris, or stroke) [5 && ]. Median follow-up for male and female survivors of MI were 9.0 years and 8.7 years [4 && ], respectively, whereas those for men and women with cardiovascular disease were 7.7 years and 5.8 years, respectively [5 && ]. For one of the reports, dietary quality was assessed by concordance with a Mediterranean diet [5 && ], whereas for the other report dietary quality was assessed with the AHEI2010 scoring system [4 && ]. After multivariable adjustment for relevant covariates including medications, persons with cardiovascular disease (men and women combined) in the highest (best) quintile for dietary quality had 19% (95% CI 9–28%) lower all-cause mortality risk than those in the lowest quintile. Risk reductions for cardiovascular mortality, cancer mortality, and death from other causes were numerically similar [5 && ]. After

Converging on critical dietary components: are specific fruits and vegetables key?

This section provides a rapid update service, covering the whole field of lipidology, and lists papers entered into the publisher’s database between 1 October 2010 and 30 September 2011. Key articles are selected for comment by specialists and are highlighted in the following way: Papers considered to be of specialist interest Papers considered to be of outstanding interest A bibliographic listing follows each comment and selected papers are accompanied by an annotation in which the scope and context of the article are summarized briefly. Current Opinion in Lipidology 2012, 23:72–81 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins 0957-9672