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Ketogenic diets and physical performance. Phinney SD. Nutr Metab (Lond). 2004 Aug 17;1(1):2. PMID: 15507148 doi:10.1186/1743-7075-1-2 Impaired physical performance is a common but not obligate result of a low carbohydrate diet. Lessons from traditional Inuit culture indicate that time for adaptation, optimized sodium and potassium nutriture, and constraint of protein to 15-25 % of daily energy expenditure allow unimpaired endurance performance despite nutritional ketosis. Both observational and prospectively designed studies support the conclusion that submaximal endurance performance can be sustained despite the virtual exclusion of carbohydrate from the human diet. Clearly this result does not automatically follow the casual implementation of dietary carbohydrate restriction, however, as careful attention to time for keto-adaptation, mineral nutriture, and constraint of the daily protein dose is required. Contradictory results in the scientific literature can be explained by the lack of attention to these lessons learned (and for the most part now forgotten) by the cultures that traditionally lived by hunting. Therapeutic use of ketogenic diets should not require constraint of most forms of physical labor or recreational activity, with the one caveat that anaerobic (ie, weight lifting or sprint) performance is limited by the low muscle glycogen levels induced by a ketogenic diet, and this would strongly discourage its use under most conditions of competitive athletics.

Vitamin D and mortality in older men and women. Pilz S, Dobnig H, Nijpels G, Heine RJ, Stehouwer CD, Snijder MB, van Dam RM, Dekker JM. Clin Endocrinol (Oxf). 2009 Nov;71(5):666-72. Epub 2009 Feb 18. PMID: 19226272 DOI: 10.1111/j.1365-2265.2009.03548.x Conclusions Low 25(OH)D levels are associated with all-cause mortality and even more pronounced with cardiovascular mortality, but it remains unclear whether vitamin D deficiency is a cause or a consequence of a poor health status. Therefore, intervention studies are warranted to evaluate whether vitamin D supplementation reduces mortality and cardiovascular diseases.

A comparison of egg consumption with other modifiable coronary heart disease lifestyle risk factors: a relative risk apportionment study. Barraj L, Tran N, Mink P. Risk Anal. 2009 Mar;29(3):401-15. Epub 2008 Nov 4. PMID: 19000074 DOI: 10.1111/j.1539-6924.2008.01149.x Guidelines from the American Heart Association (AHA) recommend that healthy adults limit their intake of dietary cholesterol to less than 300 mg per day. Since a large egg contains about 71% of that amount, the AHA recommends restricting egg consumption unless dietary cholesterol intakes from other sources are limited. We applied a risk apportionment approach to estimate the contribution of egg consumption and other modifiable lifestyle risk factors (e.g., smoking, poor diet, minimal exercise, and alcohol intake) to coronary heart disease (CHD) risk at the population level. Specifically, we categorized the U.S. adult population ages 25+ into distinct risk groups based on the prevalence of modifiable lifestyle risk factors and applied an apportionment model, typically used to assess risk contribution at the individual level, to estimate the contribution of egg intake to CHD risk. Our analysis shows that the combination of modifiable lifestyle risk factors accounts for less than 40% of the population CHD mortality. For the majority of U.S. adults age 25+, consuming one egg a day accounts for <1% of CHD risk. Hence, focusing on decreasing egg intake as an approach to modify CHD risk would be expected to yield minimal results relative to changing other behaviors such as smoking and other dietary habits.

Eggs modulate the inflammatory response to carbohydrate restricted diets in overweight men. Ratliff JC, Mutungi G, Puglisi MJ, Volek JS, Fernandez ML. Nutr Metab (Lond). 2008 Feb 20;5:6. PMID: 18289377 Carbohydrate restricted diets (CRD) consistently lower glucose and insulin levels and improve atherogenic dyslipidemia [decreasing triglycerides and increasing HDL cholesterol (HDL-C)]. We have previously shown that male subjects following a CRD experienced significant increases in HDL-C only if they were consuming a higher intake of cholesterol provided by eggs compared to those individuals who were taking lower concentrations of dietary cholesterol. Here, as a follow up of our previous study, we examined the effects of eggs (a source of both dietary cholesterol and lutein) on adiponectin, a marker of insulin sensitivity, and on inflammatory markers in the context of a CRD. Conclusion A CRD with daily intake of eggs decreased plasma CRP and increased plasma adiponectin compared to a CRD without eggs. These findings indicate that eggs make a significant contribution to the anti-inflammatory effects of CRD, possibly due to the presence of cholesterol, which increases HDL-C and to the antioxidant lutein which modulates certain inflammatory responses.

Single food focus dietary guidance: lessons learned from an economic analysis of egg consumption. Schmier JK, Barraj LM, Tran NL. Cost Eff Resour Alloc. 2009 Apr 14;7:7. PMID: 19366457 Methods A risk apportionment model estimated the increased risk for coronary heart disease (CHD) attributable to egg cholesterol content, the decreased risk for other conditions (age-related macular degeneration (AMD), cataract, neural tube defects, and sarcopenia) associated with egg consumption, and a literature search identified the cost of illness of each condition. The base 795 case scenario calculated the costs or savings of each condition attributable to egg cholesterol or nutrient content. Results Given the costs associated with CHD and the benefits associated with the other conditions, the most likely scenario associated with eating an egg a day is savings of $2.82 billion annually with uncertainty ranging from a net cost of $756 million to net savings up to $8.50 billion. Conclusion This study evaluating the economic impact of egg consumption suggests that public health campaigns promoting limiting egg consumption as a means to reduce CHD risk would not be cost-effective from a societal perspective when other benefits are considered. Public health intervention that focuses on a single dietary constituent, and foods that are high in that constituent, may lead to unintended consequences of removing other beneficial constituents and the net effect may not be in its totality a desirable public health outcome. As newer data become available, the model should be updated.