Minerals and Heavy Metal Exposure

whey proteinHumans require a number of essential minerals for correct metabolic function. These minerals are divided into categories based on the amount required in the diet. Macrominerals are required in gram amounts, microminerals in milligram amounts and trace minerals in microgram amounts. It is a well known feature of human nutrition that minerals compete for absorption. Divalent cations such as calcium ions, zinc ions, iron ions and copper irons all compete for absorption in the small intestine. This likely relates to the similarity in charge between the minerals and the transport mechanisms that recognise that charge. In addition, minerals can inhibit one another in metabolic pathways and this likely results from a similar charge related interaction with transport proteins and enzymes. Balancing dietary intake is therefore recommended in order that optimal levels of all minerals is obtained in the diet, and further, that these are then absorbed in the correct amounts to satisfy daily needs.

nuts and seeds

Zinc and cadmium may interact in human nutrition. Evidence suggests that those with the highest dietary intake of zinc, also have the lowest urinary concentration of cadmium. The authors predicted mathematically that for every 10 % increase in total zinc intake, there would be a 0.42 % decrease in cadmium concentrations in the urine. Nuts and seeds can be a source of zinc.

Heavy metals can also interact with essential minerals. In many cases, heavy metals such as lead, mercury and cadmium inhibit essential mineral absorption and this creates mineral deficiencies. Higher intakes of essential minerals including both dietary and supplemental form, can however have the opposite effect and actually block the absorption of heavy metals. The interactions are complex and not fully understood but a few have been described. One interaction is that between zinc and cadmium. For example in one study, researcher observed an inverse association between plasma levels of zinc and dietary levels of zinc, with urinary cadmium concentrations. Those with the highest intake of zinc had urinary cadmium concentrations that were 0.04 μg/g lower compared to those with the lowest intake of zinc. Supplemental zinc was inversely associated with blood cadmium and serum cadmium in a dose and duration response manner. Low zinc may therefore increase the risk of cadmium accumulation.

Eat Well, Stay Healthy, Protect Yourself

RdB

Vance, T. M. and Chun, O. K. 2015. Zinc intake is associated with lower cadmium burden in US adults. Journal of Nutrition. 145: 2741-2748
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Latency Period For Nutritional Changes

whey proteinIncreasingly individuals are realising the importance of good nutrition. Good nutrition not only improves physical performance, but also mental capacity and cognitive processes. Part of the reasons for the awakening with regard good nutrition is the large body of readily available information that is present on the internet. This information allows people to research the topic of nutrition and thereby become their own nutritionists. One questions that is often asked from those who make dietary changes regards the length of time it may take for improvements to be seen. This is a difficult question to answer because the number of variables involved is high. However, it is an interesting question and worthy of consideration. A good place to start with such a question is the nutrition of iron deficiency. Those who develop iron deficient states can be given high iron diets and iron supplements. Yet despite these changes, correcting an iron deficiency can take up to two years. This highlights the slow changes that should be expected.

One of the first considerations that can determine the length of latency period to health improvements can be the initial state of health. Generally those who start from a lower baseline with regard their health will see the most rapid changes. Many studies show that the unhealthiest individuals see significant improvements in health with relatively simple changes such as incorporation of tinned beans into their diets. Radically changing the diet of unhealthy individuals can therefore manifest rapid improvements to health and these can be seen within a few weeks. Those with already good health will likely see much smaller changes, and these changes may take a much longer time period to manifest as physically measurable improvements. However, because the changes are smaller, does not mean they are less important. Often the smaller more subtle improvements that allow the obtaining of optimal health can be the most fulfilling and worthwhile. This is especially true for cognitive changes.

walnuts

Dietary changes can take a considerable length of time to cause physiological changes. In some cases these changes may takes years. In some cases the changes may take a few weeks. This depends largely on the initial state of health of the individual, as well as the initial quality of the diet. Most people will not see considerable improvements in health before 6 months to 1 year of eating high quality foods. Although most changes are continuous, it takes a while for the magnitude of the improvements to be noticed.

Another important variable with regard the rate of improvement from dietary changes is the quality of the baseline diet. Although this relates closely to the state of the health of the individual, the two are in reality distinct variables. Those with already reasonable diets, who likely will have the best health, will see slower improvements that those with poorer quality diets. Again, this does not mean that such improvements are not worth the effort, and often the move from general good health to optimal health can be just as rewarding as the move from ill health to good health. As a rule of thumb, 6 months to 1 year should be allowed for significant improvements in physiological function to manifest after commencing improvements in diet, if the baseline diet is a typical Western diet and the individual is in reasonable health. One last point is that often those consuming a typical Western diet consider themselves healthy because they have no obvious disease, but in reality they are far from optimal health.

Eat Well, Stay Healthy, Protect Yourself

RdB

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Self Reported Dietary Questionnaires: Are They Effective?

whey proteinBoth nutritionists and researchers use self reported dietary questionnaires in order to obtain information from individuals regarding their nutritional intake. The accuracy of this data is invaluable for interpreting the data supplied by the individual, and therein lies the problem. Studies that have assessed the accuracy of self reported nutrition questionnaires have shown that individuals consistently under report energy intakes, and may also provide inaccurate dietary assessments unless prompted by specific questions. This has lead some researchers to conclude that such methods, when applied to a research setting, are pseudoscience, and that such methods have created an erroneous set of nutritional recommendations akin to fraud. While these may seem strong words, there is no smoke without fire, and in this case some of this opinion is valid. Certainly researchers must be very cautious when analysing self reported questionnaires. However, it may be the case that they take such questionnaires at face value.

dietary survey

Dietary questionnaire have inherent problems associated with their use. This relates to the human tendencies to provide inaccurate information to questions. Underreporting energy intake is a known problem with self-reporting nutritional questionnaires.

One of the advantages a nutritionist may have over a researcher is that they deal with a single individual. This allows the nutritionist to spend time with the individual and this attention can provide clarity regarding any ambiguities in their dietary questionnaire. Asking questions and spending time with the individual is pivotal to advancing the questionnaire to a useable form so that data becomes information. However, in research, this is likely not possible and so the data on the questionnaire must be taken at face value. This therefore translates the errors present in the questionnaire onto the information provided in the study, and this leads to erroneous findings and recommendations. Research into the accuracies of questionnaires have been performed and improvements to methodologies have been made. However, the inherent problems of the human tendency to provide inaccurate responses based on conditioning and misunderstanding remain, and so the basic underlying problems of research questionnaires has not been eliminated.

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RdB

Subar, A. F., Freedman, L. S., Tooze, J. A., Kirkpatrick, S. I., Boushey, C., Neuhouser, M. L., Thompson, F. E., Potischman, N., Guenther, P. M., Tarasuk, V., Reedy, J. and Krebs-Smith, S. M. 2015. Addressing current criticism regarding the value of self-report dietary data. Journal of Nutrition. 145: 2639-2645
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Treating Inflammation with Nutrition

whey proteinInflammation is a necessary physiological reaction by the tissues of animals to damage, infection and invasion by pathogens. This process is highly complex, but is designed to provide defence to tissues by supplying immunological components and physical barriers to possible sites of infection. Acute inflammation is generally considered to be beneficial as it provides immediate short term protection to the animal. However, there exists another type of inflammation that may be detrimental to the health. Chronic inflammation of low grade has been suggested to be responsible for, or associated with, a number of Western lifestyle diseases including cardiovascular disease, cancer, obesity, type 2 diabetes and arthritis. Evidence increasingly points to a poor quality diet as the cause of chronic low grade inflammation, and it should be no surprise that nutritional strategies to improve the diet and reduce chronic inflammation have been shown to be successful in preventing these diseases.

alkylresorcinols

Plant foods are rich in antioxidants. Whole grains contain a group of antioxidants called the alkylresorcinols. Fruits and vegetables are rich in carotenoids, as well as polyphenols such as flavonoids and terpenes. Antioxidants limits the oxidative stress that can result from chronic inflammation.

One of the best strategies for reducing the risk of developing chronic low grade inflammation involves the use of antioxidants. Antioxidants are chemicals found in the diet and can be of of either essential or non-essential status. Many such compounds are derived from plant foods and include essential compounds such as vitamin C and vitamin E as well as non-essential compounds such as carotenoids and polyphenols. Antioxidants are useful in treating inflammation because they reduce oxidative stress through their ability to quench free radical activity. Free radicals are chemicals with unpaired electrons that can damage tissues, and antioxidants are composed in such a way that they can donate electrons to these chemicals, thus inhibiting their potential damaging tissue effects. Because one of the side effects of inflammation is the generation of oxidative stress, antioxidants are useful compounds at treating the symptoms of inflammation and thus negating some of its damaging effects.  

fish oils inflammation

Fish oils contain high amounts of omega-3 fatty acids such as eicosapentaenoic acid and docosahexaenoic acid. These fatty acids can limit inflammation by redressing the dietary imbalance that is inherent in Western foods. Western foods supply too many omega-6 fatty acids (such as linoleic acid and arachidonic acid) and this can be a source of proinflammatory reactions through overproduction of omega-6 derived proinflammatory eicosanoids. A balance of around 3 grams of omega-6 to around 1 gram of omega-3 fatty acids is required to maintain cellular health and prevent inflammation.

Another nutritional strategy that is highly effective at treating chronic low grade inflammation is the use of fish oils. Fish oils are long chain marine oils such as eicosapentaenoic acid (EPA, C20:4 (n-3)) and docosahexaenoic acid (DHA, C22:6 (n-3)) that are found as oils in the flesh of cold water fish. Both EPA and DHA belong to the omega-3 family of fatty acids and they can feed into the omega-3 essential fatty acid pathway. This is useful at treating inflammation because inflammation is regulated by localised hormones called eicosanoids and these hormones are created from omega-3 and omega-6 fatty acids. The balance of omega-3 to omega-6 fatty acids in the diet can strongly influences the direction of inflammation. A ratio of 3 grams of omega-6 to 1 gram of omega-3 fatty acids is required for optimal health, but the Western diet supplies too many omega-6 fatty acids. This creates a proinflammatory state, which can be corrected by supplying the necessary omega-3 fatty acids to redress the dietary 3:1 balance.

ginger turmeric

Compounds found in both ginger and turmeric may inhibit the cyclooxygenase-2 and lipoxygenase enzyme systems that synthesise proinflammatory eicosanoids. In this way regular consumption of either may reduce chronic inflammation. The compounds in ginger (gingerols, shogaols and gingerdiones) and turmeric (curcumin) work in a similar way to non-steroidal anti-inflammatory drugs.

A number of herbs have been shown to possess potent anti-inflammatory effects. Comparisons between herbs and pharmaceuticals shows that herbs can be as effective as pharmaceutical drugs at treating inflammation, but often with much fewer and less severe effects. Ginger is a herb that has consistently been shown to produce potent anti-inflammatory effects. Ginger contains chemicals called gingerdiones, gingerols and shogaols that have a similar activity to non-steroidal anti-inflammatory drugs. In this regard they may inhibit pro-inflammatory eicosanoid synthesis by binding to the cyclooxygenase-2 and lipoxygenase enzymes and thus limit the capacity for tissues to undergo the inflammatory reaction. Turmeric too has been shown to have potent anti-inflammatory effects. Turmeric contains active compounds called curcumin, and these can also inhibit the cyclooxygenase-2 and lipoxygenase enzyme systems, acting in the same way as ginger to inhibit inflammation.

Eat Well, Stay Healthy and Protect Yourself

RdB

Posted in Antioxidant, Curcumin, Docosahexaenoic Acid, Eicosapentaenoic Acid, Fish Oils, Ginger, Inflammation, Turmeric | Comments Off on Treating Inflammation with Nutrition

Poverty Associated with Disease: More Evidence

whey proteinThere is a large body of evidence that shows that poverty is associated with disease. This should not be a surprising finding with regard to communicable diseases, because as socioeconomic status increases, housing quality and lifestyle conditions improve significantly and this elevates most away from the squalor that is known to be a causative agent in the spread of disease. By creating sewage systems and clean drinking water for most of the population, the Victorians did much to eradicate communicable diseases from Great Britain for example. It is also not surprising that as socioeconomic status increases, access to higher quality nutrition, particularly protein, increases, and this has beneficial effects on the immune system, lowering the risk of infection. As nation states develop economically therefore, their populations become less susceptible to communicable disease, and this is reflected by are large disparity in such diseases between the rich countries of the West, and the rest of the World.

However, more surprising perhaps is the association between poverty and non-communicable diseases in Western countries. For example, it has been shown that those with the lowest socioeconomic status, living in Western nations, are at higher risk of Western lifestyle diseases such as cardiovascular disease, obesity and type 2 diabetes. This association is difficult to explain because Western lifestyle diseases are associated with the affluence of Western society, making it unclear as to why the poorest in these countries are at highest risk. One explanation is that those with low a socioeconomic status are less able to access high quality foods, and more likely to consume ready made foods containing sugar and refined starches. Recently a study published in the Journal of Nutrition reported that those children living in United States households with an absence of food security had a 4 % higher odds of having asthma. Male children, hispanics, blacks, low birth weight and overweight children had the highest odds of having asthma.

asthma

Food insecurity in households of United States residing children increases the odds of having asthma. This fits with other data showing that poor socioeconomic status is associated with Western lifestyle diseases such as obesity, cardiovascular disease and type 2 diabetes. One possible cause for this association may be access to ready made foods containing processed ingredients.

Clearly associations between socioeconomic status and disease exist. However, the cause and effect in these associations are hidden with many confounding variables. Just why the poorest living in the West are at high risk of Western lifestyle diseases, yet the poor living in developing countries are at low risk of these diseases, is not clear. That cheap food in the West often contains high amounts of refined starch, trans fats and sugar is the most likely explanation. While the poor in developing countries can afford only basic ingredients based on whole plant foods, those in the West have access to cheap but processed foods. Education may play a role in this as many individuals living in the West do not understand the requirement for good nutrition, and even those that do may not understand the nuances of creating a healthy eating plan. Whatever the reasons, the association between poverty and Western disease is well established, with asthma being another such disease that may be linked to food insecurity.

Eat Well, Stay Healthy, Protect Yourself

RdB

Mangini, L. D., Hayward, M. D., Dong, Y. Q. and Forman, M. R. 2015. Household food insecurity is associated with childhood asthma. Journal of Nutrition. 145: 2756-2764
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Contribution of Antioxidants in Blood

antioxidants

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More Evidence That Traditional Diets Provide Health

whey proteinIt is interesting that traditional diets around the World, spatially and temporally, vary considerably. However, analysis of these diets shows that they provide health to their populations despite being very different nutritionally. A closer look at the contents of these diets show some to be high in carbohydrates while others are high in protein and fat. The traditional diets eaten by populations living in Asia and South America are relatively high in rice and corn (maize), respectively. While the traditional diet consumed by Eskimos is high in protein and fat from marine origin, the traditional diet consumed by the Maasai of Kenya is high in protein and fat of ruminant origin. The traditional Mediterranean diet is more of a balance and can be considered closer to an isocaloric diet. Despite these differences traditional populations consuming these diets are healthy and there is little evidence that they develop modern Western lifestyle diseases such as cardiovascular disease and cancer, when consuming traditional foods.

However, introduction of Western foods to these populations causes the development of Western lifestyle disease. Generally, adoption of a typical Western diet is counterproductive to health, because it is a pro-inflammatory diet, and this inflammation increases oxidative stress. In turn this oxidative stress leads to Western diseases such as cardiovascular disease, cancer, type 2 diabetes and obesity. Studies have investigated the effects of consuming varying degrees of Western food on ethnic populations. For example, in one study, researchers assessed the diets of ethnic Mexicans living in the United States. Those individuals who consumed a diet that most closely reflected the traditional Mexican diet (tortillas, beans, soups, Mexican mixed dishes (e.g., tamales), fruits, vegetables, full-fat milk, and Mexican cheeses and low in refined grains and added sugars) had 23 and 15 % lower serum C-reactive protein (a marker of inflammation) and insulin, respectively, compared to those who consumed a non-traditional diet.

Mexican food

Traditional diets are protective of Western lifestyle diseases. This is likely because although they differ in composition, they are devoid of the sugar and refined starch that are a cause of tissue inflammation and oxidative stress. Oxidative stress is now implicated as a causative factor in many Western lifestyle diseases.

Therefore these findings suggest that adherence to traditional Mexican food is associated with a reduction inflammation and insulin levels. Further, amongst obese women, adherence to the traditional Mexican diet was associated with a lower degree of insulin resistance and a lower plasma insulin concentration. A traditional Mexican diet is therefore associated with improvements to the insulin system. This is supported by evidence that shows that oxidative stress, resulting from inflammation, is a primary driver of insulin resistance. Many studies have highlighted the benefits of antioxidants at improving insulin resistance, and this likely stems from the ability of antioxidants to reduce the oxidative stress that drives the development of insulin resistance. One common feature of traditional diets is that they provide anti-inflammatory compounds, including antioxidants, essential fats and non-essential components such as conjugated linoleic acid, that may decrease such oxidative stress.

Eat Well, Stay Healthy, Protect Yourself

RdB

Santiago-Torres, M., Tinker, L. F., Allison, M. A., Breymeyer, K. L., Garcia, L., Kroenke, C. H., Lampe, J. H., Lampe, J. W., Shikany, J. M., Van Horn, L. and Neuhouser, M, L. 2015. Development and use of a traditional Mexican diet score in relation to systemic inflammation and insulin resistance among women of Mexican descent. Journal of Nutrition. 145: 2732-2740
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Adaptogenic Herbs as Antistress Supplements

Posted in Anxiety, Brahmi (Bacopa monnieri), Depression, Ginseng (Panax ginseng), Mimosa (Albizia julibrissin), Rhodiola rosea (roseroot), Siberian Ginseng (Eleutherococcus senticosus), Sour date (Zizyphus jujuba), Stress, Withania (Withania somnifera) | Comments Off on Adaptogenic Herbs as Antistress Supplements

More Benefits for High Fibre Diets?

whey proteinFibre is a heterogeneous group of non-digestible carbohydrates that show beneficial health effects. Broadly fibre is divided into soluble and insoluble fibre types, but in reality these groups do not accurately describe the wide variety of dietary fibres frequently ingested by humans. Evidence suggests that dietary fibre is beneficial to the health. The traditional view is that fibre provides roughage to the diet and this decreases transit time through the gut, preventing the putrefaction of other foods within the gut. However, as more is learned about fibre, novel functions have been elucidated. Fibre is now known to provide a considerable contribution to daily energy needs, and may also be a requirement for correct immune function, through the supply of gut bacteria with an energy source. Fibre may also provide beneficial glycaemic effects by delaying the digestion of starch and the absorption of glucose. Fibre may be considered a conditionally essential nutrient, as it appears to be a requirement of health if starch is consumed.

whole grain diets

High fibre diets have been shown to be inversely associated with periodontal disease. This does not mean that fibre prevents periodontal disease per se. High fibre diets tend to be low in sugar and refined carbohydrates, and it is these factors that likely cause periodontal disease. Those who eat high fibre diets are therefore less likely to eat the causative components in periodontal disease. High fibre diets tend to be high quality diets and in combination with other healthy nutrients, fibre provides a number of health advantages.

While many studies have been performed on individual fibre components, and much useful information has been obtained in this way, it is nutritionally more useful to look at the diet at a whole. In this respect, high fibre diets have been shown to be healthy because they are usually of high quality and contain other foods that are beneficial to the health. At the same time, high fibre diets are often low in disease causing nutrients such as sugar and refined starch. In a recent study, the consumption of high fibre diets was shown to be inversely associated with the risk of periodontal disease, amongst a group of over 6000 individuals living in the United States of America. In particular, periodontal disease was associated with a low intake of whole grain cereals (but not fruit and vegetables). This sort of study is useful because although it does not prove that dietary fibre is beneficial at protecting from periodontal disease (associations are not cause and effect), it does show that eating a high fibre diet provides a health benefit.

Eat Well, Stay Healthy, Protect Yourself

RdB

Nielsen, S. J., Trak-Fellermeier, M. A., Joshipura, K. and Dye, B. A. 2015. Dietary fibre intake is inversely associated with periodontal disease amongst US adults. Journal of Nutrition. doi:10.3945/jn.116.237065
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Don’t Forget Your Chromium

whey proteinChromium is an essential trace mineral in human nutrition. Dietary chromium is required for the correct function of the insulin system. It is not fully understood how chromium functions at the cellular level, but a number of hypotheses have been suggested. Chromium forms a complex with nicotinic acid and some amino acids to form the glucose tolerance factor (GTF). This glucose tolerance factor has been hypothesised to bridge the gap between insulin and its receptor, thus facilitating the signal from hormone to cell. Other potential functions may include a direct effect on insulin release from the pancreas, an ability to increase the fluidity of cell membranes, and thus improve the internalisation of the insulin signal from the interior of the cell, as well as a direct effect on the expression of insulin receptor numbers. Animal models show that chromium deficient diets cause the development of insulin resistance and ultimately diabetes.

chromium

Individuals consuming chromium supplements have a lower odds of having type 2 diabetes. This does not prove that the chromium is the beneficial agent, and there may be other nutrients in the supplements that aid health. In addition, those taking a supplement are more likely to consume a healthy diet or have other lifestyle factors that reduce disease risk. However, animal models are clear. Chromium deficiencies cause diabetes in mammals.

Results from human clinical trials using chromium have been inconsistent, and this likely relates to poor study design. It is very difficult to control human diets and behaviour and the number of variables makes some nutritional studies difficult to assess. However, animals models are far clearer, and deliberately feeding mammals chromium deficient diets does induce diabetes. These symptoms are then reversed by addition of chromium back to the diet. A recent epidemiological study investigated the association between chromium intake and type 2 diabetes risk in over 60,000 subjects living in the United States. The results of the study showed that 28.8 % of the subjects consumed a chromium containing supplement in the previous 30 days. Those who consumed a chromium containing supplement in the previous 30 days had a significantly lower odds of having type 2 diabetes compared to those who did not consume a chromium containing supplement. However, this does not prove cause and effect.

Eat Well, Stay Healthy, Protect Yourself

RdB

McIver, D. J., Grizales, A. M., Brownstein, J. S. and Goldfine, A. B. 2015. Risk of type 2 diabetes in lower in US adults taking chromium-containing supplements. Journal of Nutrition. 145: 2675-2682
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