Archive for the ‘nutrient types’ Category

Common PUFA oil products with linoleic acid increase all cause mortality, and mortality from cardiovascular and coronary heart disease.

Wednesday, February 27th, 2013

A recent report in the British Medical Journal signals the danger of substituting Omega-6 polyunsaturated fats, linoleic acid for saturated fats in diet. 

Advice to substitute linoleic acid for saturated fat is one component of dietary guidelines to reduce the risk of coronary heart disease; however, clinical benefits specific to linoleic acid have not been established. Linoleic acid is one of the commonest polyunsaturated fats in the diet and is present in many consumer products such as safflower oil and safflower polyunsaturated margarine and Corn oil.

A comprehensive analysis of the effects of linoleic acid on death from coronary heart disease and cardiovascular disease was previously not possible, owing to missing outcome data from the Sydney Diet Heart Study, a randomized controlled clinical trial. This is the first prospective randomized control study showing the potential harmful effects of linoleic acid.

In this cohort, substituting omega 6 linoleic acid for saturated fat did not provide the intended benefits, but increased all cause mortality, cardiovascular death, and death from coronary heart disease

An updated meta-analysis incorporating these missing data showed no evidence of benefit, and suggested a possible increased risk of cardiovascular disease from replacing saturated fat with omega-6 linoleic acid.

The proposed mechanism of underlying damage is via the oxidized LA metabolites. Omega-6 LA is the most abundant fatty acid in native low density lipoprotein particles. Oxidized LA metabolites (OXLAMs) are the most abundant oxidized fatty acids in oxidized low density lipoprotein, which is potentially more atherogenic than unmodified low density lipoprotein. A potential mechanism contributing to higher cardiovascular mortality in the LA intervention group is a diet induced increase in the production of bioactive OXLAMs, including 9- and 13-hydroperoxy-octadecadienoic acid, and 9- and 13-hydroxy-octadecadienoic acid. These OXLAMs are enriched in the lipid laden, macrophage foam cells; vascular endothelial cells; and migrating vascular smooth muscle cells of atherosclerotic lesions. OXLAMs, particularly the isomers and enantiomers produced by free radical mediated oxidation, have been mechanistically linked to cardiovascular disease pathogenesis. Mechanisms include inducing the formation of macrophage foam cells; endothelial cell activation;migration, proliferation, and foam cell formation of vascular smooth muscle cells; and inhibition of lysosomal hydrolysis of low density lipoprotein cholesteryl esters.

These findings could have important implications for worldwide dietary advice to substitute omega-6 linoleic acid (or polyunsaturated fatty acids in general) for saturated fatty acids. The key is the use of Omega-3 acid, which has EPA and DHA ; in PUFA that has a good content of Omega 3 FA does not increase the death from coronary heart disease.

Read the full article at this link: http://www.medscape.com/viewarticle/779083_4

Fats – The Good , The Bad and the plain Ugly !

Thursday, June 24th, 2010

Low fat diet, low fat food, no fat food, fats and obesity, fats – cholesterol and heart problems – we have enough  out there to lead you to think that Fats are bad for you. There is enough literature out there to scare you off any kind of fats for life!! True, some fats are really bad for you, but some others in fact some are absolutely health promoting eg fats are needed in your diet to aid digestion of other nutrients like the fat soluble Vitamins A,E,D and K which without fats, may not find their way into your body to do their work even though you may be eating foods rich in those vitamins- it all gets unabsorbed and excreted out.

So, when you are thinking about drastically cutting your intake of fats, think again, shouldn’t you actually be more discerning about the type of fats you take instead. Well to be able to sift out the good from the bad, we must first know the various categories of fats and what they do for and against our well being.

Fats, also called lipids, are hydrophobic –ie insoluble in water, and like carbohydrates are composed of carbon, hydrogen and oxygen. The 3 broad categories of fats are

  1. Unsaturated – form solids at room temperature eg animal fats, butter
  2. Monounsaturated – form solids when refrigerated (5-8deg celcius eg olive oil
  3. Polyunsaturated- remaining liquid even at low temperatures as say in the refrigerator eg oils from grains and seed eg flaxseed oil

Fats are needed for various purposes in the body but mainly as a major component of all the cell membranes. The polyunsaturated fats together with some monounsaturated fats keep the cells healthy and protected by keeping the membranes flexible and moveable. However when saturated fat levels are too high, these cell membranes lose the flexibility and hence weakens its role to protect the inner parts of the cells including the cell DNA.

Fat soluble nutrients need fats to aid in absorption in intestines into the body. Diets which are excessively low on ALL types of fats have been associated with increased risk of hormone abnormalities, cardiovascular disease, decreased brain function and decreased immune function. Interestingly enough, fat soluble vitamins like vitamins A, D, E and K all need some level of fats in the diet to help transport it into the body in the intestines to its storage facilities in the liver. Without fats in your diet, you may end up deficient in these vitamins.

Saturated Fats

However, excessive consumption of saturated fats does negatively affect your health. There are volumes of research and articles written linking excessive intake of saturated fats to elevated LDL cholesterol levels with implications for heart disease and atherosclerosis. While this is indeed a valid concern, generalising the effects of excessive saturated fats to ALL types of fats is equally concerning. Your body needs the other fats to function efficiently. Saturated fats are found in processed food and meat (chicken, lamb, pork, and beef) products that have the white solid fat on them.

Minimising the intake of saturated fats is a good idea, but minimising the intake of ALL fats is just not. So the challenge is to balance the types of fats you take with more of the good ones.

Let’s look at the “good fats”

Monounsaturated Fats

These are commonly found in the traditional Mediterranean diet. This diet contains high amounts of olive oil which is high in oleic acid – a monounsaturated fat. Other MUFAs include myristoleic acid and palmitoleic acid (found in some skin care products). Besides olive oil, other good food sources include canola oil, avocadoes, almonds, macadamia oil and cashews – just think, these nuts are also rich sources of amino acids too! Research continues to support the theory that diets high in monounsaturated fats are health promoting.

Polyunsaturated Fats

This class of fats is rapidly gaining recognition for its health promoting benefits. We recognise it best perhaps as fish oils with omega 3 perhaps being the best known. Many different types of polyunsaturated fats exists but currently the ones getting lots of attention in research are the essential fats linolenic acid (LA- an omega 6) and alpha-linoleic acid (ALA an omega 3)and the omega 3 and 6 fatty acids.

With just LA and ALA, the healthy body can synthesise all the different PUFA it needs. For example Dha (docosahexaenoic acid which is an omega 3) which is the main fats in your brain and AA (arachidonic acid which is an omega 6) which is the main fats in the cell membrane can all be synthesised from ALA and LA respectively.

Food sources of LA include oils from grains, nuts and legumes eg sunflower oil, safflower oil, corn oil, soy oil and peanut oil. GLA (gamma linolenic acid which is another omega 6) can be found in evening primrose oil and borage oil. Omega 6s are also found at high levels in corn fed livestock (beef and poultry especially).Omega 6s are vital to good health but up to a point where  excessive levels of omega 6 relative to omega 3s begin to have damaging effects on the body. The proper balance of omega-3 to omega-6 is extremely important not only for healthy cell membranes, but also because omega-6 fats are the precursors for pro-inflammatory conditions leading to diseases like cardiovascular diseases, rheumatoid arthritis, ADHD, inflammatory bowel disease . You need to have a good balance between Omega 3s and 6s. Excellent Omega 3 sources are found in fish, algae and nuts and leafy green vegetables. Omega 3 is a precursor of anti-inflammatory molecules. The inflammatory reaction in the body is the body’s process of protection against infection and promotes healing but it must be able to turn itself off once the job is done otherwise, chronic inflammation may result.

When “good fats turn bad”

Trans Fats

Trans fats may be either monounsaturated or polyunsaturated but never saturated. These can be found in trace (very small amounts) in natural meats too but these days they are often found in processed food. Trans fats have no known benefit to human health and on top of that, also said to lower levels of HDL cholesterol hence increasing risk of Cardio Vascular Disease. Note too that saturated fats and trans fats increase the levels of LDL cholesterols. So what are trans fats? To commercially present monunsaturated and polyunsaturated fats in solid form at room temperature, trans fats are created in an industrial process that hydrogenates say liquid vegetable oils to turn them into solids at room temperature. Another name for trans fats is “partially hydrogenated oils”.

Trans fats are easy to use, longer lasting, may taste better and have “better” texture and above all, inexpensive to produce. In some fast food outlets and some restaurants, oils with trans fats can be used over and over again to deep fry foods.

Trans Fats can be found in foods like French fries, doughnuts, pastries, pie crusts, biscuits, pizza dough, cookies, and crackers. Look at the labelling on the packaging – these are sometimes labelled as “partially hydrogenated oils”.

So even though Trans Fats may be cheaper and easier to use in cooking ,it  has no known benefit to human health, damaging to health in terms of increasing LDL levels and also lowering HDL levels  (hmm,  a double whammy). It is clear we should reduce if not eliminate altogether the intake of transfats – it may be more costly in the long run to fix up the damage caused by consumption of trans fats.

Summary:

Avoid trans fats, lower intake of saturated fats, increase intake of monounsaturated and polyunsaturated eg olive oil, fish oils but ensure a balance of eg omega3s against 6s.

I hope I have at least made you aware of the importance of fats for our well being, the good fats and the bad fats, how good fats can turn bad, and the need to have the right balance. The Metamatrix labs Fatty Acids Profile tests will help you determine the levels and ratios (balance) of these various fats in your body. With these readings will help your physician work objectively with you to address dysfunctions early before these turn to diseases. Takes away a lot of the guesswork.

The following are some notes on the Metametrix website regarding research on fatty acids.

Fatty Acids Research

Increased Consumption of Fatty Acid Supplements

Evidence of the adverse effects of fatty acid deficiencies has led to sharply increased consumption of essential fatty acid supplements. When incorporated into the cell membranes of the body, these omega-3 and omega-6 fatty acids function as precursors for eicosanoids that control a host of cellular functions and responses. The balance between the pro-inflammatory and anti-inflammatory eicosanoids is influenced in large part by the balance of fatty acids we consume. Since inflammation has now been shown to be integral to so many disease processes, nutrients which counteract inflammation can have profound health benefits. But your patients need an answer to a critical question about their fatty acid supplementation- are they taking too little to be effective or such an excess that they are causing other health problems?

Anti-inflammatory and Pro-inflammatory Eicosanoids

Cold water fish oils contain a high concentration of the omega-3 fatty acids EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). EPA is the precursor for the Series 3 eicosanoids, which have potent anti-inflammatory effects. The oil from certain plant seeds, particularly borage, evening primrose, and black currant, have high concentrations of the omega-6 fatty acid GLA (gamma linolenic acid), the precursor to the anti-inflammatory Series 1 eicosanoids.

The omega-6 fatty acid AA (arachidonic acid) is found in high concentration in the fat of red meats. AA is converted to the pro-inflammatory Series 2 eicosanoids, increasing the risk for various disease and inflammatory processes in the body. The Bloodspot Fatty Acid Profile can guide patients to the right balance of FA intake.

Statins Negatively Impact Fatty Acids Status

Recent research has shown that HMG-CoA reductase inhibitors (“statins”) can increase the relative amounts of AA in the blood, resulting in an increase in the AA:EPA ratio.(1) “High fish oil consumption is now recommended for individuals at high risk for heart disease, and our findings suggest that increased dietary n-3 FAs-LNA, EPA, and DHA-may result in a more favorable FA profile during statin treatment.” Routine monitoring of the AA:EPA ratio-an early marker of inflammation-would be particularly important for patients on these cholesterol-lowering drugs.

Excessive Intake of PUFAs Induces Free Radical Production

The free radical pathology induced by excessive intake of polyunsaturated fatty acids (PUFAs) develops insidiously. Researchers found that PUFA-induced lipid peroxidation is common among patients who supplement high doses of fatty acids without adequate antioxidant protection.(2) Clinical management of fatty acid and antioxidant supplementation is aided by testing for fatty acid balance and measuring markers of oxidant damage.

Immunosuppressive Effects of Omega-3 Fatty Acids

As a result of all of the positive research on the health benefits of fish oil and/or GLA rich oils, the nutrition industry has seen an explosive growth in consumption of these supplements. But taking too much and in the wrong balance is potentially dangerous, a fact not well appreciated or understood. The anti-inflammatory effects of omega-3 fatty acids can actually suppress immune function, leading to increased infections, poor wound healing, and possible tumor growth.(3) The EPA:DGLA ratio in the Bloodspot Fatty Acid Profile can help fine tune intake of these Series-1 and -3 eicosanoid precursors

Proteins and Amino Acids- understanding a little more

Wednesday, June 16th, 2010

Proteins are involved in almost every function within the body eg building new tissues, breaking down old tissues, breaking down toxins and waste and removing them, providing channels in cell membranes to let in necessary nutrients. Our bodies continuously make (synthesize) new proteins to replenish those lost from tissue damage, to provide for growth, to fight invaders so as to protect our bodies and more …  antibodies in our immune system, some hormones eg adrenalin,T3 and T4 , enzymes and blood coagulating factors are all made of proteins.

Proteins are made up of smaller molecules called AMINO ACIDS which are strung together by chemical bonds. Proteins come in various sizes with some of them eg the hormone-insulin being a protein of only 51 amino acids long and the immunoglobulins which are the antibodies that fights off infectious invaders having 1320 amino acids.

Individual proteins can also join together to from large protein complex eg the proteins in bone, skin, nails and hair.

Amino acids are the building blocks of proteins.

Amino acids composed of CARBON, HYDROGEN, OYGEN and NITROGEN. It is your body’s way of getting nitrogen necessary to the body. As in the example of the simple sugar, the single amino acid is the single unit the body works with to form larger protein chains. Similar to the example of the digestion of carbohydrates, the body breaks down the proteins we consume into small single units (sometimes 2 or 3) of amino acids during the digestion process for absorption into the body. Enzymes produced in the pancreas is secreted during digestion which are specifically for the breaking down of proteins include the enzymes trypsin,chymotrypsin, carboxypeptidase and elastases -these are sometimes collectively called proteases.

Proteins are found both in animal and plant based foods. Free form amino acids which are also found in whole foods are those amino acids which are already in very small forms which are all ready for absorption through the small intestines ie doesn’t need to be further broken down during digestion before absorption takes place.

If you do not get all of the amino acids you need to support your body systems, your body will begin to break down some of its own muscle tissue to support its need for amino acids. If you have inadequate intake of amino acids over an extended period, depending on the type of essential amino acid that is severely deficient, your body will start to dysfunction and you may suffer symptoms and conditions like poor muscle formation, poorly functioning immune system, skin lesions, stunting , mood disorders to name a few possibilities.

Your body synthesizes nearly all of the amino acids from other molecules except for 8 amino acids which are considered essentials because the body needs to get it externally (eg supplied in a diet) as it cannot produce these. These 8 are Isoleucine, Leucine, Lysine,, Methionine, Phenylalanine, Threonine, Tryptophan and Valine. There is another group of 12 that are also very important and considered essential in certain cases.

These essential amino acids are found in all proteins but in different quantities and different ratios. It is said that an 8 ounce glass of milk provides 8 grams of protein while 1 cup of black beans provides twice this amount. The difference however lies in the ratio of the essential amino acids found in each of these. It is said that animal based foods are closer match to our human body than plant based in terms of ratios eg chicken eggs provide all the amino acids in a pattern that is well matched to human needs.

Sometimes amino acids compete for absorption as in the case of tyrosine (also synthesised from phenylalanine) and tryptophan. Among their many uses, tyrosine for example is a precursor to the catecholamine hormones eg adrenalin and noradrenalin and also to the thyroid hormones eg T3 and T4. Tryptophan is a precursor to serotonin (which in turn is also a precursor of melatonin) and also niacin (also known as Vitamin B3). Absorption of tryptophan is improved with carbohydrate intake. Digestive disorders like fructose intolerance or lactose intolerance can cause improper absorption of tryptophan in the intestines hence reduced level of tryptophan in the blood which may cause symptoms like mood and sleep disorders. These are only some of the examples.

Roughly, the average adult female needs 46 grams of proteins and the average adult male needs 56 grams of protein.

Oh yes, excess essential amino acids consumed in relation to how much your body uses them up, CANNOT be stored in its original form as amoino acids for future use. It will be broken down and stored as FATS while the acidic amine group is filtered from the body which may overwork  the kidney- protein breakdown creates urea which causes stress on the renal system. So too much isn’t necessarily good for you too!!

The Metamatrix Amino Acids -Plasma 40 Profile can illuminate problems in amino acid absorption by determining essential amino acids imbalances. Additionally, evaluation of essential amino acid derivatives shows neuro endocrine metabolic disorders as well as functional vitamin and mineral deficiencies. Also assessed are amino acid derivatives focusing on energy, sulfation, muscle wasting, and bone loss.

So you see, protein isn’t just for body builders! Also starvation diet to lose weight isn’t healthy. It is so critical to have amino acids in the right amount and in the right ratios – the building blocks of proteins need to be in the right balance for your health and wellbeing.

Knowing a little more about Carbohydrates, Fats and Proteins

Monday, June 7th, 2010

To successfully manage your weight healthily, it would be very useful to understand the nutrient groups that you consume daily. When you are aware of what actually goes into your body as food and what it does and how it  get digested and absorbed in the bloodstream, you are more likely to be compliant about following the weight management plan that you have worked out with your health coach and make better food choices in your diet.

These days, the macronutrients Carbohydrates, Fats and Proteins are household terms but with the advancement of science, we now know much more about them.

These three classes of macronutrients are complex groups, each of which containing a variety of components. You can eat the same quantity of protein, carbohydrate and fat, but deliver very different nutrition to your body depending on the sources of these molecules. Too often, we erroneously focus on the quantity of each of these groups rather than the quality. Let’s look further into each of these  groups to help us understand what, why and how best we should eat as regards healthy weight management.

Let’s get to some of these basics starting with the carbohydrates.

Carbohydrates

Carbohydrate molecules range from very small (simple) to very large (complex) molecules and are said to provide 40-45% of the body’s energy needs. Other carbohydrates like those in fibre and resistant starches don’t get absorbed in the body for energy but plays a very important role in the health of the gastro-intestinal tract, support digestion and absorption, and also the elimination of toxins and waste products.

Simple carbohydrates composed of CARBON, HYDROGEN and OXYGEN arranged into small units called sugar or monosaccharide. These composed of one or two sugar units and are called the simple sugars because they are quickly digested and provide immediate energy to the body. These are the molecules that give food the sweet taste. You often hear these being referred to as being high GI (glycaemic index) foods.

The complex carbohydrates, fibres and starches are larger carbohydrate molecules and may contain several hundred or even thousands of monosaccharide linked together. As the body takes time to  break down the very large molecules (low to moderate GI) to individual sugar units for digestion and subsequent conversion to energy, these are generally considered  better for health and energy release as when compared to consuming the simple sugars, your body is spared from immediate sugar spikes and its ensuing health challenges- eg insulin surges.

Let’s now look closer at each of these carbohydrate categories.

The Simple Sugars: Monosaccharide and Disaccharides.

Monosaccharide is simply 1 sugar unit only and doesn’t need to be broken down further during digestion. It is simply absorbed into the bloodstream, ready for conversion to energy. This simple sugar is found in most foods but particularly high in ripe fruit and honey and of course in sweetened drinks and syrups. When large quantities of monosaccharide are consumed at once, it can cause a large increase in blood glucose followed by an abrupt drop. The result is a quick burst of energy followed by being tired, shaky and even malaise. This unwelcomed fluctuation if it happens too frequently can lead to blood sugar dysfunctions leading to various conditions including hypoglycaemia, diabetes type II and insulin resistance. Processed foods often add high amounts of monosaccaride in the form of glucose and fructose  eg corn syrup to promote a popular sweet taste in sodas.

Disaccharide as the name suggests contain 2 sugar units bonded together and are found in foods eg lactose (sugar in milk), sucrose (table sugar), maltose and isomaltose (sugars from the breakdown of starches). Like monosaccharide, these are also sweet to taste and frequent overconsumption will lead to the same challenges as for the other simple sugar- monosaccharide. However, disaccharide unlike monosaccharide needs some digestion to break the 2 bonded sugar units to 2 individual units for digestion. And, since each type of disaccharide is unique, each type has its own digestive enzyme eg sucrase can cut sucrose into its 2 individual sugar units and likewise lactase for lactose (milk sugar). These enzymes are secreted into the intestines during a meal and the digestion of the disaccharides proceeds rapidly. Lactose appears to be the only exception.

Consumption of dairy products is a problem for some people especially as we age. This is commonly due to a condition called Lactose Intolerance as the body lack the enzyme lactase. If untreated, there is a vicious cycle to this problem with the consumption of more dairy products. People who are lactose intolerant lack the enzyme lactase to digest lactose and undigested lactose promote the growth of certain unfriendly bacteria which ferments the lactose in the upper intestinal tract. These invariably lead to problems eg gas in the small intestine causing nausea and heartburn, degradation of the lining of the gut injuring the intestinal cell (leaky gut) and in turn compromising the ability of the intestinal cells to aid in the production more enzymes for digestion.

The Complex Carbohydrates – Polysaccharides: Starch, Fibre and Resistant Starch

Humans store energy in fat cells but plants store their energy by stringing together many sugar units into a complex chain of several hundreds to thousands of sugar molecules. Plant foods that contain stored energy eg seeds, are high in starch. When seedlings start growing, these starches as stored energy in seeds is broken down into glucose (sugar) for energy.

Starch

Likewise, these starches (e.g. corn, potato, nuts) you consume need to be broken down in your body for digestion i.e. the large complex molecules need to be broken down to its form as simple sugars before being absorbed into the blood stream. This process will take longer (hence lower glycemic index –lower GI) than the disaccharides. These are thought to be healthier sugar alternatives as they do not lead to immediate bloodsugar spikes.

Starches can be further categorised to amylose and amylopectin. Their differences lie in how the individual sugars are linked together and hence different breakdown rates – amylopectin digestion is quicker than amylose.

In its natural state, starch is folded together with proteins, fats and/or other molecules. These starches for example can be encased in protein or fibre which must be digested first before the starch itself becomes available for digestion, hence lengthening the process and time before sugar from these starches gets into the bloodstream. Processed food most times remove these layers hence the starch becomes more readily available ie increases its GI which generally is not what we favour.

Fibre

Dietary fibres are also complex carbohydrates (polysaccharides) but their molecules are bound in such a manner that your body finds it hard to breakdown if at all for digestion. Fibres transit intact through the small intestines to the large intestines. These fibres have the ability to bind and remove toxins. Food with fibres includes vegetables, grains and legumes. However in their commercially processed forms, eg as in commercial bran, most of these fibres are stripped away when the grains are processed. Fruit skins too are high in fibre.

Recent studies suggest that these fibres are also food sources for friendly bacteria (and sometimes unfriendly in some cases). These friendly floras feed on the nutrients in the fibre and they in turn support the health of the intestinal tract and immune functions. Also, through their own metabolism, they produce short chain fatty acids which have been associated with a decrease in cancerous colonic cells, reduction of serum cholesterol, maintenance of healthy blood sugar levels and healthy intestinal tract cell walls. Good sources of prebiotic fibres include rice fibre and soy fibres.

Resistant Starch

This complex carbohydrate is resistant to digestion in the small intestines and travels to the large intestines intact providing food for the bacteria in the colon. These bacteria in the process of fermenting the resistant starch promotes the generation of SCFA (short chain Fatty acids) which are beneficial to our overall health. Food sources of resistant starches include brown rice, barley, whole wheat and buckwheat.

Summary

To avoid blood sugar spikes, it is preferable to take complex carbohydrates that take a longer time to breakdown into its single sugar molecule form. Also, as carbohydrate molecules are usually bound to other molecules eg proteins and fats, food in its natural form is preferred over commercially processed forms as these layers are usually stripped away hence increasing the GI (glycaemic index). Also, fibres and resistance starches are beneficial to general health as they provide food for friendly bacteria which produces SCFA for our bodies and help maintain gut health. Additionally, fibres have an important role of helping the body excrete toxins in the body.

In short, when consuming carbohydrates, it is preferable to choose low GI foods (as opposed to high GI), food with fibre and resistant starches, and natural foods (as opposed to those commercially processed).

Let’s look at Proteins and Fats in the next few articles.