Saturday 28 February 2015

Five Easy Things You Can Do Now That Will Cause Fat Loss

Most people view fat loss as a chore. This is because they are locked into the false paradigm that states that fat loss can only occur through a calorie restrictive diet and through hours of aerobic exercise. Many people never leave this mindset and as a result fail in their endeavours to improve their body composition because they cannot stick to their regimen. The science behind fat loss is equite clear. It is perfectly possible to lose fat and improve the body composition without the need to restrict energy intake and without the requirement for aerobic exercise. Weight gain is caused by eating the wrong types of foods, not by eating too much food. It therefore stands to reason that if we eliminate these foods by substituting better alternatives, weight loss will ensue. And this is very well evidenced in the nutritional literature. So here are five dietary changes that you can make, that take minimal effort, that will cause improvements in body composition through a decrease in body fat or an increase in lean skeletal muscle.
Avoid Sugar, It’s a Metabolic Poison
Sugar contains a molecule of fructose, and fructose causes insulin resistance. Insulin resistance is in turn a driver of weight gain and obesity. Cutting sugar from the diet is the single most important step in weight loss and the long-term avoidance of sugar is pivotal in successful long term weight loss. Consuming sugar on a calorie restrictive diet will hinder fat loss because the underlying insulin resistance will generally remain as long as sugar is consumed. Low fat processed foods that remove fat and replace it with sugar are obesogenic junks foods.
How Much Protein Should You Eat? All of It!
High protein diets cause weight loss. The reason for this is various. Firstly, protein is the food component that determines stomach emptying rates. As a full stomach causes satiety, protein is a satiating food. Protein also provides nitrogen for building muscle and this allows the maintenance of a positive nitrogen balance that prevents muscle breakdown and favours muscle growth. As muscle determines the resting metabolic rate, high proteins diets are conductive of increased energy utilisation. Protein is also the macronutrient least likely to be stored as fat.
Eat Full Fat Dairy Foods
Those people who eat the most dairy have the lowest body weights. This has been shown time and again in the nutritional literature. Dairy contains a number of fatty acids that may improve insulin sensitivity and thus decrease fasting insulin levels. As insulin is a driver of fatty acid synthesis in the liver, and an inhibitor of fatty acid oxidation, lowering fasting insulin levels is pivotal in fat loss. Dairy also contains calcium which may have weight loss effects by inhibiting the absorption of fat. The ability of dairy products to sit in the stomach for hours following consumption always makes them highly satiating food.
Swap Grains for Beans
Beans have a number of weight loss properties. Firstly they are high in protein and difficult to digest which slows the transit of food through the stomach and causes satiety. Secondly, they are very high in fibre, and this can slow the absorption of glucose to the blood, lowering insulin levels and thus inhibiting fatty acid synthesis and increasing fat oxidation. The fibre in beans can also be fermented in the colon, producing short chain fatty acids which increase satiety. Lastly beans contain enzyme inhibitors that slow the digestion of starch and further lower insulin levels. Substituting grains for beans therefore improves the chance of fat loss occurring.
Drink Green Tea
Green tea is a weight loss food. The weight loss effects of green tea relates to three components it contains. Green tea is a good source of catechins, polyphenols with antioxidant effects. These catechins may inhibit glucose absorption from the gut, lowering insulin levels. Tea also contains L-theanine, an amino acid that reduces anxiety and stress. As stress is a possible cause of overeating L-theanine may lower the risk of eating the poor quality foods that lead to weight gain. Lastly, the caffeine, L-theanine and catechin content of green tea work synergistically to increase energy expenditure and cause fat oxidation.

Sunday 22 February 2015

Tuna: A Good Source of Selenium?

Selenium is an important trace mineral in human nutrition. Selenium is perhaps best know as a cofactor for the enzyme glutathione peroxidase, an important component of the cellular reductive system. The glutathione reducing system (which includes glutathione, glutathione reductase, glutathione peroxidase and NADPH) is required for the conversion of damaging hydrogen peroxide to water. Low selenium intakes are associated with a decrease in the activity of glutathione peroxidase, with a resultant increase in free radical damage in cells and tissues. As activity of the glutathione antioxidant system decreases the risk of disease and mortality increases significantly. Dietary sources of selenium are therefore important to ensure optimal function of this important cellular antioxidant system. Brazil nuts are a well known source of selenium, but others exist. Tuna is also a rich source of the trace mineral, with studies suggesting that a tin of tuna (roughly 150 to 200 grams) many contain around 12.5 micrograms of selenium.
If a tin of tuna contains roughly 12.5 micrograms of selenium, it would appear that tuna is a reasonable source of selenium. Certainly consuming tuna regularly would contribute significantly to the selenium intake of most individuals. Of course there is nothing special about tinned tuna that means it accumulates selenium, and so fresh tuna will have a similar selenium content (about 150 parts per billion). However, while the selenium content of tuna is good, tuna is also a rich source of methylmercury. This results from the polluted waters that tuna inhabits. Bioaccumulation of mercury (and other pollutants) occurs as food passes up the food chain, such that large predatory fish such as tuna attain dangerous levels of certain pollutants such as mercury. Current recommendations are to limit consumption of large predatory fish and instead consume fish from further down the food chain (such as mackerel). Therefore sources of selenium such as brazil nuts and supplements are a preferable source of this mineral.

Saturday 21 February 2015

Preptin, Adropin and Irisin: Energy Regulators

The regulation of energy in humans is highly complex and not fully understood. A number of appetite stimulating or orexigenic peptides, and a number of satiating or anorexigenic peptides have been identified and shown to be involved in this complex process of energy regulation. However, while many of the hormones and signal molecules that play a role in energy metabolism have been identified, new players in energy metabolism are being discovered continually. For example, three peptide hormones have only relatively recently been discovered to play a role in mammalian energy metabolism. These include preptin, adropin and irisin. Preptin is a 34 amino acid peptide synthesised primarily in the beta cells of the pancreas, the same cells that are responsible for insulin release, while adropin is a 43 amino acid peptide synthesised mainly in the liver and brain tissue. Both preptin and adropin appear to be involved in the regulation of carbohydrate, protein and fat metabolism, a function that they perform through the regulation of the hormone insulin.
Irisin is a 112 amino acid peptide synthesised primarily in the heart, kidney, liver and salivary glands. Irisin appears to be an anti-obesogenic and anti-diabetogenic agent because it can convert white to brown adipose tissue. Brown adipose tissue is highly metabolically active and contains high concentrations of uncoupling proteins, and these function to uncouple substrate oxidation from energy production. In this way irisin may increase heat production, and thus waste energy, causing anti-obesity effects. Irisin therefore may function as a thermogenic regulator and in this way be heavily involved in the natural regulation of body weight through the regulation of energy efficiency. In mice at least, irisin is a product of exercise. Exercise causes an increase in the peroxisome proliferator activated receptor gamma (PPAR-γ, and this results in the production of a precursor peptide (FNDC5) that is cleaved to form irisin. Therefore an increase in thermogenesis may be one of the benefits of exercise that helps with the regulation of body weight, through modulation by irisin.

Sunday 15 February 2015

Water Cress: The Forgotten Brassica Vegetable

Watercress is a semi-aquatic plant with alternate toothed leaves and small white flowers. The watercress plant is native to Western and central Europe, and can be found in the United Kingdom growing in streams and ditches. The popularity of watercress as a food has caused its distribution to spread, and the plant is now cultivated all over the World for use as a salad dressing. Watercress is a member of the mustard (brassica) family of vegetables (also called cruciferous vegetables) that include cauliflower, radish, brussels sprouts, horse radish, cabbage, bok choy and rapeseed. Nutritionally watercress possesses many of the same nutritional quantities of other brassica family vegetables which include a high content of vitamin C, and this explains its historical use as a cure for scurvy. The bitter taste of the herb make it a useful addition to salads. However this bitter taste is caused by the presence of chemicals called glucosinolates, and these give watercress some interesting medicinal properties. Glucosinolates are also found in other brassica family vegetables.
Glucosinolates are a group of naturally occurring sulphur and nitrogen containing compounds that are thought to play a role in the defence of plants from predators. Upon tissue damage to the plant, glucosinolates are brought into contact with a group of enzymes called myrosinases, which convert the glucosinolates to isothiocyanates such as allyl isothiocyanate, benzyl isothiocyanate, sulforaphane and indole-3-carbinol. These isothiocyanates give watercress and other brassica family vegetables their pungent taste. Isothiocyanates are bioavailable and once absorbed are thought to provide a potent anti-cancer effect in mammals. In particular isothiocyanates may improve detoxification pathways in the liver and provide antioxidant defence. In this way isothiocyanates may increase the elimination of and also limit the genetic damage caused by carcinogenic compounds. As well as vitamin C and glucosinolates, watercress also contains high levels of carotenoids, various B vitamins, vitamin D, vitamin E and various minerals including iodine, manganese, calcium and iron.

Saturday 14 February 2015

Antioxidant Synergism

The Wulzen Factor (Stigmasterol)

The Wulzen anti-stiffness factor is a compound that was originally discovered in molasses and unpasteurised cream. Its discoverer Rosalind Wulzen, showed that the compound could reverse the calcification of joints in osteoarthritis. More recently the Wulzen factor has been identified in a larger range of foods including legumes, nuts, seeds, vegetables and unpasteurised dairy produce. Chemically the Wulzen factor is actually a phytosterol called stigmasterol. Stigmasterol along with its chemically related campesterol and sitosterol are produced in plants and are structurally related to cholesterol. A number of 5-alpha saturated derivatives of the sterols called stanols (campostanon, sitostanol and stigmastanol) are also known to be present in plants and have been isolated in the diets of humans. The intake of sterols and stanols in the diet is naturally low in humans and absorption is very poor. However, supplements and fortified foods containing sterols and stanols are now available and this can increase intake considerably.
Recently interest in phytosterols has increased because of research suggesting that they can inhibit the absorption of dietary cholesterol. This may result from the ability of phytosterols to compete with the absorption of cholesterol in the gut, thereby lowering plasma levels. However, as endogenous synthesis of cholesterol accounts for most of the circulating cholesterol, and due to the fact that synthesis increases as dietary intake falls, it is unclear as to how plant sterols such as stigmasterol actually cause changes in plasma lipoprotein cholesterol. Some evidence from human cell culture experiments suggest that some of the dietary sterols actually inhibit human cholesterol biosynthesis, which is a more reasonable explanation for the observed effects of their ingestion. Whatever the mode of action, human studies clearly show a plasma cholesterol lowering effect for dietary sterols. However their long term health benefits for this purpose have not been investigated and are therefore unknown.
Another important health role for sterols and stanols may be as anti-cancer agents. Rats fed carcinogens develop fewer tumours if concomitantly fed plant sterols. Originally it was thought that sterols may alter rates of colorectal cancer by the modification to bile acid production. However, animal studies showing protective effects do not always show changes to bile acid synthesis rates and so other mechanisms of action may be apparent. Other studies have suggested that the addition of sterols to the diets of animals may inhibit carcinogenesis due to a reduction in cell proliferation in the mucosa of the gut. However, plant sterols may also have antioxidant effects, and as the aetiology of cancer may involve the generation of free radicals, the antioxidant capacity of plant sterols may explain some of their therapeutic effects against cancer and other diseases. The ability of stigmasterol to block the breakdown of cartilage explains its original capacity to lessen the symptoms associated with osteoarthritis as discovered by Wulzen.

Sunday 8 February 2015

Ready Made Breakfast Cereals

A Note on Beetroot

Spinach (Spinacia oleracea) is known for its deep green and succulent leaves that are often added to salads. Spinach leaves are nutritionally packed full of essential nutrients including magnesium, vitamin C, vitamin B6, vitamin K, folic acid and iron. In addition, spinach is also a good source of phytochemicals including the carotenoids beta carotene and the xanthophylls lutein and zeaxanthin. These phytochemicals contribute significantly to the antioxidant capacity of the leaves. The beetroot plant (Chenopodiaceae) is related to spinach and its leaves are of a similar nutritional quality and are a useful alternative for salads. Like spinach leaves, beetroot leaves also contain high concentrations of phytochemicals including a number of carotenoids. Magnesium, folic acid, vitamin B6, vitamin C and iron also characterise the nutritional profile of beetroot leaves. Beetroot consumption has traditionally been associated with improvements in bowel function and liver detoxification.
However, beetroot also contains an edible root attached to its edible leaves, and this makes almost the entire plant available for consumption. The carbohydrate content (10 grams) of beetroot comprises mainly of sugar (8 grams), however the presence of high amounts of fibre and a high water content nullify any negative health effects associated with simple sugars. The purple colour of the root is due to the presence of betalains, pigments present in a number of plants (including beetroot, carnations and cacti) that replace the normal purple anthocyanin pigments common to most plants. Betalains differ from anthocyanins in that the former contains a nitrogen within their structure. Betalains can be further split into the subclasses betacyanins and betaxanthins. Evidence suggests that antioxidant effects of betacyanins may explain the ability of beetroot to protect from colon cancer. Betacyanins may also be able to lower plasma cholesterol levels.

Saturday 7 February 2015

Vitamin D in Multivitamin And Multimineral Formulas

Hawthorn for Cardiovascular Health

Hawthorn (Crataegus oxyacantha) is a European thorny shrub that is often found in hedgerows, hence its alternative name hedgethorn. Its trimmed presence in hedgerows hides its usual size, with the hawthorn three being able to reach heights of around 10 meters. Hawthorn is interesting nutritionally because both its blossom (flowers) and its berries can be used medicinally to treat various forms of cardiovascular disease, including atherosclerosis, angina, congestive heart failure and high blood pressure. The ability of hawthorn to treat cardiovascular disease is thought to relate to the presence of high concentrations of flavonoids in its berries, leaves and blossoms. In particular the berries and flowers are rich sources of the blue, red and purple anthocyanin group of flavonoids, a feature that is common to all berries including grapes. Anthocyanins have been shown to have particularly beneficial effects against the development of cardiovascular disease, possibly because they are strong antioxidants but may also regulate gene function.
The antioxidant activity of hawthorn flavonoids is interesting, because one of the known effects is an ability to raise cellular levels of other antioxidants. In particular, anthocyanins may raise tissue levels of vitamin C and reduced glutathione. This occurs because the anthocyanins can partake in some of the chain quenching reactions normally undertaken by vitamin C or glutathione and in this regard spare the latter and thus boost tissue levels. The flavonoids and their associated higher concentrations of vitamin C may improve the synthesis and integrity of collagen. As collagen is required for the correct formation of healthy blood vessels, flavonoids may help stabilise the vasculature, improve healing rates of micro adhesions, and improve elasticity. The antioxidant effects of anthocyanins may also increase the production of nitric oxide in the endothelial cells of the arteries and this may allow for correct dilation in response to blood flow, thus facilitating normal blood pressure regulation, preventing hypertension.
The antioxidant effects of flavonoids in hawthorn berries and flowers are also likely involved in combating systemic inflammation. Inflammation is increasingly being seen as part of the aetiology of cardiovascular disease, with the end product of the inflammatory process being an increase in the production of free radicals and subsequent tissue damage. Hawthorne anthocyanins, like most dietary flavonoids, may reduce inflammation and thus decrease one of the factors required for the development of lesions in the arteries that may ultimately contribute to atherosclerosis. The flavonoids in hawthorn berries and flowers have also been shown to increase the force of contraction in heart muscle. This effects was however not due to an improvement in blood flow to the heart, but was suspected to be caused by interactions of the flavonoids with particular enzymes in the heart muscle tissue (such as cyclic AMP phosphodiesterase), the result of which was to cause greater energy concentrations within the heart cells. This makes hawthorn a useful treatment for congestive heart failure.