Paradox of hypercholesterolaemia in highly trained, keto-adapted athletes

Objective

A growing number of ultra-endurance athletes have switched to a very low-carbohydrate/high-fat eating pattern. We compared markers of cholesterol and the lipoprotein profile in a group of elite ultra-runners consuming a high-carbohydrate (HC) or low-carbohydrate (LC) diet.

Methods

Fasting blood was obtained from competitive male ultra-endurance runners habitually consuming a very low-carbohydrate (LC; n=10) or high-carbohydrate (HC; n=10) diet to determine blood cholesterol profile, lipoprotein particle distribution and sterol biomarkers of cholesterol balance.

Results

Plasma total cholesterol, low-density lipoprotein (LDL-C) and high-density lipoprotein (HDL-C) cholesterol were all significantly greater (p<0.000) in the LC group (65%, 83% and 60%, respectively). There were also significant differences in lipoprotein particle distribution as evidenced by a greater size and concentration of large HDL and LDL particles, and total LDL particle concentration was significantly greater in the LC group, but they had significantly fewer small LDL particles.

Conclusion

Ultra-endurance athletes habitually consuming a very low-carbohydrate/high-fat diet for over a year showed unique cholesterol profiles characterised by consistently higher plasma LDL-C and HDL-C, less small LDL particles, and lipoprotein profiles consistent with higher insulin sensitivity. There may be a functional purpose to the expansion of the circulating cholesterol pool to meet the heightened demand for lipid transport in highly trained, keto-adapted athletes.

Lack of exercise is a major cause of chronic diseases

Chronic diseases are major killers in the modern era. Physical inactivity is a primary cause of most chronic diseases. The initial third of the article considers: activity and prevention definitions; historical evidence showing physical inactivity is detrimental to health and normal organ functional capacities; cause versus treatment; physical activity and inactivity mechanisms differ; gene-environment interaction (including aerobic training adaptations, personalized medicine, and co-twin physical activity); and specificity of adaptations to type of training. Next, physical activity/exercise is examined as primary prevention against 35 chronic conditions [accelerated biological aging/premature death, low cardiorespiratory fitness (VO2max), sarcopenia, metabolic syndrome, obesity, insulin resistance, prediabetes, type 2 diabetes, nonalcoholic fatty liver disease, coronary heart disease, peripheral artery disease, hypertension, stroke, congestive heart failure, endothelial dysfunction, arterial dyslipidemia, hemostasis, deep vein thrombosis, cognitive dysfunction, depression and anxiety, osteoporosis, osteoarthritis, balance, bone fracture/falls, rheumatoid arthritis, colon cancer, breast cancer, endometrial cancer, gestational diabetes, pre-eclampsia, polycystic ovary syndrome, erectile dysfunction, pain, diverticulitis, constipation, and gallbladder diseases]. The article ends with consideration of deterioration of risk factors in longer-term sedentary groups; clinical consequences of inactive childhood/adolescence; and public policy. In summary, the body rapidly maladapts to insufficient physical activity, and if continued, results in substantial decreases in both total and quality years of life. Taken together, conclusive evidence exists that physical inactivity is one important cause of most chronic diseases. In addition, physical activity primarily prevents, or delays, chronic diseases, implying that chronic disease need not be an inevitable outcome during life.

Exercise-mediated changes in high-density lipoprotein: impact on form and function

The goal of this systematic review was to assess the current understanding of the effects of exercise intervention on high-density lipoprotein (HDL) cholesterol (HDL-C) and changes in HDL function as well as modification of these effects by genomic factors. The reviewed studies demonstrate that exercise has modest effects on HDL-C with limited data suggesting an effect on HDL function. Genetic polymorphisms in proteins associated with HDL metabolism play a role in modifying the HDL-C response to exercise and possibly its function. Exercise as an intervention for patients at risk for cardiovascular events can lead to small improvements in HDL-C and potential changes in HDL function. There is an important modifier effect of genetics in determining these changes.

Personalised nutrition: ready for practice?

The efficacy by which dietary interventions influence risk markers of multi-factorial diseases is mainly determined by taking population-based approaches. However, there exists considerable inter-individual variation in response to dietary interventions, and some interventions may benefit certain individuals or population subgroups more than others. This review evaluates the application of nutrigenomic technologies to further the concept of personalised nutrition, as well as the process to take personalised nutrition to the marketplace. The modulation of an individual's response is influenced by both genetic and environmental factors. Many nutrigenetics studies have attempted to explain variability in responses based on a single or a few genotypes so that a genotype may be used to define personalised dietary advice. It has, however, proven very challenging to define an individual's responsiveness to complex diets based on common genetic variations. In addition, there is a limited understanding of what constitutes an optimal response because we lack key health biomarkers and signatures. In conclusion, advances in nutrigenomics will undoubtedly further the understanding of the complex interplay between genotype, phenotype and environment, which are required to enhance the development of personalised nutrition in the future. At the same time, however, issues relating to consumer acceptance, privacy protection as well as marketing and distribution of personalised products need to be addressed before personalised nutrition can become commercially viable.

Attenuated inheritance of body weight by running in monozygotic twins

PURPOSE

Genetic factors account for 40%-70% of the population variation in body mass index (BMI), suggesting that genetic predisposition is a major risk factor for excess weight. The purpose of this study was to test whether exercise attenuates the inherited risk for excess body weight.

METHODS

Survey questionnaires of exercise (usual running distance) and BMI were obtained from a national sample of 582 female and 344 male self-identified monozygotic (MZ) twins. Regression analyses were used to test whether running disparity diminished the inheritance of BMI when adjusted for age, education, cigarette use, and selected dietary variables.

RESULTS

The active twins ran between 0 and 10.7 km · d(-1) more than their less active twins if female (mean ± SD = 1.61 ± 1.50 km · d(-1)) and between 0 and 13.7 km · d(-1) more if male (1.88 ± 1.78 km · d(-1)). Average BMIs of the less active twins were 22.38 ± 3.56 and 24.59 ± 3.08 kg · m(-2) in females and males, respectively. Within-twin correlations were significant (P < 0.0001) for usual distance run (females: r = 0.64; males: r = 0.61) and BMI (females: r = 0.67; males: r = 0.71). Greater running differences (Δkm · d(-1)) attenuated the effect of the less active twins' BMIs on their active MZ twins' BMI (females: -14.3% per Δkm · d(-1), P < 10(-7); males: -7.4% per Δkm · d(-1), P = 0.004), such that by 4 Δkm · d(-1), the inherited risk was reduced by 58.8% in females and 29.6% in males.

CONCLUSIONS

These results are consistent with the attenuation of the inherited risk of excess body weight by running, which is remarkable because BMI regulation is assumed to be multifactorial, its genetic inheritance is polygenic, and no single genetic polymorphism currently explains >1% of the BMI variance.

The challenges for molecular nutrition research 1: linking genotype to healthy nutrition

Nutrition science finds itself at a major crossroad. On the one hand we can continue the current path, which has resulted in some substantial advances, but also many conflicting messages which impair the trust of the general population, especially those who are motivated to improve their health through diet. The other road is uncharted and is being built over the many exciting new developments in life sciences. This new era of nutrition recognizes the complex relation between the health of the individual, its genome, and the life-long dietary exposure, and has lead to the realisation that nutrition is essentially a gene-environment interaction science. This review on the relation between genotype, diet and health is the first of a series dealing with the major challenges in molecular nutrition, analyzing the foundations of nutrition research. With the unravelling of the human genome and the linking of its variability to a multitude of phenotypes from "healthy" to an enormously complex range of predispositions, the dietary modulation of these propensities has become an area of active research. Classical genetic approaches applied so far in medical genetics have steered away from incorporating dietary effects in their models and paradoxically, most genetic studies analyzing diet-associated phenotypes and diseases simply ignore diet. Yet, a modest but increasing number of studies are accounting for diet as a modulator of genetic associations. These range from observational cohorts to intervention studies with prospectively selected genotypes. New statistical and bioinformatics approaches are becoming available to aid in design and evaluation of these studies. This review discusses the various approaches used and provides concrete recommendations for future research.

Post-prandial lipid levels for assessing target goal achievement in type 2 diabetic patients taking statin

It is inconvenient to perform serum lipid analysis in fasting state in diabetic patients with drug treatment. In patients with statin treatment and Asian diet, it has not been clearly known whether non-fasting values could be used for the clinical decision making in diabetic patients. In this study, fasting and post-prandial plasma lipid profiles of hospitalized type 2 diabetic patients taking statin, were measured in whom standard diabetic breakfast in traditional Korean style were provided. In repeated-measures ANOVA, there were no significant differences among fasting, post-prandial 2 and 4 hr low-density lipoprotein (LDL) and high density lipoprotein (HDL) cholesterol values. When compared to fasting levels, both post-prandial 2 hr and 4 hr LDL cholesterol levels were misclassified as not achieved target goal only in 4% of patients. Post-prandial HDL cholesterol matched with fasting values in women, without exception. In conclusion, the fasting and post-prandial LDL and HDL cholesterol levels are not significantly different each other and can be used in the assessment of achieving target goal in type 2 diabetes taking statin after Korean diet.

Chemosensory and caloric mechanisms influence distinct components of mortality rate

Both caloric and chemosensory mechanisms influence lifespan, but the relative importance of each of these mechanisms in mediating effects of dietary restriction on lifespan has been unclear. Here we demonstrate that chemosensory mechanisms consistently influence initial mortality rate, whereas caloric mechanisms consistently influence age-dependent acceleration of mortality rate. Based on this analysis, life-extending effects of dietary restriction are mediated primarily by caloric mechanisms in rats and nematodes and by both mechanisms in mice and flies.

The emerging link between nutrition, inflammation and atherosclerosis

A number of dietary components modulate the inflammatory response in humans, thereby affecting cardiovascular risk. As basic research provides a better understanding of the molecular mechanisms of vascular function regulation by nutrients, clinical investigation and outcome studies demonstrate the relevance of dietary factors to the prevention and treatment of vascular disease. Benefits of dietary interventions may be attributable to weight loss or to more specialized mechanisms in which inflammation is targeted directly. Available evidence indicates that dietary intervention should be an integral part of therapeutic approaches for treating conditions such as the metabolic syndrome and, ultimately, for the prevention of cardiovascular disease.