There is an increasing interest in understanding how the ‘Western diet’ affects immunity. Many people across the globe have adopted this diet, and epidemiological studies have revealed that it correlates with a high incidence of chronic inflammatory disorders, including diabetes, multiple sclerosis and asthma. Nevertheless, because the Western diet includes a large proportion of red meat, sugars, fats and refined carbohydrates and relatively small amounts of vegetables, fruits and fish, it is likely that the causative component of its associated pathologies is not a single entity but a complex array of unbalanced abundance of micronutrients in the diet. A review paper in Nature Immunology takes some of the emerging data, and mixes it with history and future analytics to provide a good overview of where incidence of confidence lies, and where it is going.
Mechanism, mechanism, mechanism
The immune system is complex in its array of cell types and their functions, but is also highly integrated in all body systems. Beyond their classic role in fighting pathogens and pathogen products, cells of the immune system play important parts in tissue homeostasis. Furthermore, immunological functions are not restricted to cells of the immune system but are an integral part of most cell types. Immunological functions are always active, but they are called upon especially in times of tissue damage and the presence of invading microorganisms. Immune system activity is metabolically demanding, requiring a greater presence of metabolites and substrates. Hence, the typical epidemiological studies used to explore risks and benefits may not always establish a direct link between nutritional deficiencies and classic immunological functions. In addition, the effects of nutritional deficiencies may become apparent only upon challenge of an organism, such as an infection or vaccination, during stress on a particular tissue or when confounding environmental or genetic factors are at play.
Without basic science and mechanistic insights, any guidelines and health claims will remain compromised, open to speculation and of substantial concern to scientists, clinicians and decision-makers. Reliable scientific evidence underpins accurate nutritional advice and effective public-health policies that determine the optimal consumption of macro- and micronutrients in health and disease. Currently, even at the population-wide level, the optimal intake of many nutritional components is uncertain and is based on limited data, with undetermined baseline ranges for physiological concentrations. Nevertheless, some molecular pathways have been studied in sufficient detail to reveal nutritional sensing strategies that shape and define the fate of cells of the immune system and disease outcomes. Some amino acids, fats (such as omega-3 fatty acids) and vitamins (notably vitamin A and vitamin D) can be included in this category.
Plant phytochemicals, bacterial agents and others are gradually revealing their unique role in the generation and maintenance of a healthy human immune system and may also be regarded as having evidence of a substantive nature.
Blood, Bulbs, and Bunodonts: on Evolutionary Ecology and the Diets of Ardipithecus, Australopithecus, and Early Homo
Researchers and contemporary nutrition scientists, media and individuals have long debated how and what our ancestors ate. One of the early proposals by Charles Darwin hypothesised that the hunting of game animals was a defining feature of early hominids, linked with both upright walking and advanced tool use and that isolated these species from their closest relatives (such as ancestors of chimpanzees); contemporised versions of this hypothesis exist to this day. Other insist that while our ancestors’ diets did include meat, it was predominantly scavenged and not hunted. Still others argue that particular plant foods such as roots and tubers were of greater importance than meat in the diets of these species. You know the routine, depending on the veracity of the proponent, one or other tends to become contextualised and propagated as the correct, or at least the closest to correct as someone can be in the 21st century. Read the rest of this entry »
It has been proposed that risk for developing the autoimmune condition coeliac disease (CD) may be linked to the time that the infant is weaned to consume gluten containing foods. However, the timing of gluten introduction into an infant’s diet does not appear to influence a child’s subsequent risk of developing CD investigators report in an article published online January 19 in Pediatrics. The new finding, from a multinational prospective birth cohort study, challenges some current ideas on how best to prevent the onset of the autoimmune disorder. Read the rest of this entry »
It’s always a challenge to take a single, isolated nutrient and try to prove a health benefit within a research study. Unlike drugs, which mostly have a clear mode of action on their own, nutrients generally usually work synergistically with other nutrients and lifestyle factors to generate health benefits. So when a meta-analysis (review of multiple studies) of one vitamin all show a similar clinical outcome, it is a significant finding and offers some clarity on the use of a nutrient in isolation as well as in combination with others.
A 2014 meta-analysis of nine studies on vitamin C for lung health (specifically exercise-induced bronchoconstriction or EIB) showed a positive correlation between vitamin C and lung health. The studies focused on EIB, a specific condition when the airways narrow during vigorous exercise, and are more common when the air temperature is low. It’s a relatively common event in people with asthma and endurance athletes.
The test to determine exercise-induced bronchoconstriction evaluates “forced expiratory volume” (FEV1), measuring the amount of air the lungs can exhale. When the FEV1 is decreased by 10% or more, it is determined to qualify as bronchoconstriction. In this review it was found that vitamin C doses as modest as 200 mg daily (and up to 1,500 mg) consistently reduced the decline of FEV1 and supported healthy breathing. The scientists reviewing the studies concluded that vitamin C supplementation is worth exploring for physically-active people to support healthy lung function in situations where they have EIB or for general lung improvement – albeit that this benefit has yet to be established.
 Hemila H. The effect of vitamin C on bronchoconstriction and respiratory symptoms caused by exercise: a review and statistical analysis. Allergy, Asthma & Clinical Immunology 2014, 10:58 View Full Paper
Are you a half full or half empty person, I ask because those that are half full may actually have a heart health advantage over their more dour partners. Optimism it seems is associated with better heart health than pessimism based on a recent study of 5,100 adults. Read the rest of this entry »
The Ebola epidemic in West Africa appears to be spiralling out of control. More than ever, local and global health authorities want to know how the epidemic will develop and, above all, how to prevent it from spreading further. Certain parameters help them to determine this, such as the reproductive number, which is the average number of infections caused by a single infected individual. The incubation and infectious periods are also highly relevant; i.e. the time from infection to the onset of symptoms and the time from onset of symptoms to the clearance of the pathogen. Read the rest of this entry »
Oh Boy… the journal Nature has this week (9.10.14) identified the insidious effect of consuming ‘diet’ or non caloric sweeteners on the burgeoning mass of human adipocytes and they have really taken a good run at it. Read the rest of this entry »
The journal Phytotherapy Research published an interesting article exploring the use of ginger as a treatment for migraine and comparing it to the commonly prescribed medication sumatriptan – the results are encouraging for those seeking non drug based interventions. Read the rest of this entry »
New research in The FASEB Journal suggests that the postprandial levels of circulating metabolites in the blood of identical twins tends to be similar after a fast food meal, independent of weight difference. Read the rest of this entry »
Saccharomyces is a non-colonising yeast used for the last 70 plus years as a therapeutic agent for the relief and management of gastrointestinal distress. Whilst its community use as a by-product of lychee fermentation was well understood in indo china and other nations, in particular for the relief of choleric dysentery it was after Henri Boulard set up the French pharmaceutical company to exploit its potential that studies began. So the recent publication (July 2014) of a review paper in the well known journal Pediatrics is a helpful means of qualifying its use in the paediatric population