Category Archives: fat

Insulin-boosting effects of natural extract fresh olive leaf

A robust new clinical trial has shown that Fresh Olive Leaf Extract has significant effects on insulin in men who are at risk of developing type II diabetes. The randomised cross-over double blind controlled clinical trial reveals olive leaf extract offers significant improvement in the action of insulin and the way it is secreted in overweight men. Type II diabetes is highest in overweight or obese people and occurs as a result of insulin not working effectively in the body. The findings, published in an international journal, could help the UK’s ageing and increasingly overweight population or “dia-risk” to help prevent onset of the disease.

The clinical trial was conducted at the Liggin’s Institute, based at The University of Auckland in New Zealand. The scientists monitored 47 overweight males who were at risk of developing type II diabetes. The study used Comvita’s Fresh Olive Leaf Extract, a black liquid which is made from the resilient, bitter-tasting leaves of the olive tree. The trial revealed that a 12 week course of the natural supplement improved insulin action to healthier levels. On average a 28% improvement in insulin secretion and a 15% improvement in insulin action was witnessed in the olive leaf group when compared to placebo.

The research suggests that a daily tablespoon of fresh olive leaf extract (or two capsules) holds promise for the millions of “Dia-risk” individuals in the UK as part of a preventative strategy against the onset of Type II diabetes. A condition which recent research suggests costs the NHS nearly £10 billion.

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Fresh Olive Leaf Extract has significant effects on insulin in men who are at risk of developing type II diabetes

Around 1 in 20 people in the UK are Type II diabetics and it is most likely to affect those with a BMI >30, although ethnicity also plays a part. It is also estimated that around 2% of people in the UK have type II diabetes, but are undiagnosed. Further millions of British adults and increasingly teenagers are “dia-risk”, meaning they are likely to develop the condition: such as those with an overweight or obese BMI, older people or those with a genetic predisposition.

Insulin is an essential tool in the body; it allows glucose to pass into the cells of the body to be used as energy. However in Type II diabetes (and to some extent the “dia-risk”) the pancreas cannot produce as much insulin as it needs to or this insulin can no longer be used effectively by the cells (known as insulin resistance). This means the glucose isn’t being used effectively in the body and remains in the blood leading to elevated blood sugar levels.

Diabetes Type II is a serious condition and many UK sufferers rely on prescribed drugs to treat their condition. This is not ideal as many common diabetic medications that are currently prescribed in the UK have been linked to unpleasant side effects such as sickness and diarrhoea – and serious health implications such as increased risk of heart failure.

“We are pleased to report that Olive Leaf was well tolerated by all participants with no major side effects,” Dr Ralf Schlothauer, Chief Technical Officer for Comvita, comments. “The study found on average a 15% improvement in insulin action, a very encouraging result.”

While we are very excited by the findings of the clinical trial, we would not advise any Type II diabetics to use olive leaf in place of medications prescribed by their doctor,” Simon Pothecary, UK spokesperson for Comvita comments “However the research holds promise for the millions of people who are at risk of developing the disease, perhaps they are overweight or there is a family history of the condition.”

While much research has focused on the health benefits of olive oil, new data regarding olive leaf is emerging. Active compounds found in olive oil called ‘polyphenolics’ have been identified, but the olive leaf contains these in much higher concentrations – around 30-40 times stronger.

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Calcium and Vitamin D may reduce abdominal fat

A new trial has found that calcium and vitamin D may decrease levels of abdominal fat in overweight adults.

Abdominal fat is linked with a higher risk of several diseases, including heart disease, hypertension and type 2 diabetes. Reducing excess levels of this type of fat is crucial for those wanting to improve their long-term health.

Fresh Orange Juice fortified with calcium and vitamin D may help reduce abdominal fat
Fresh Orange Juice fortified with calcium and vitamin D may help reduce abdominal fat

The trial, published in the American Journal of Clinical Nutrition, was carried out by researchers at Massachusetts General Hospital, in Boston. It tested the effect of fortified orange juice on the fat levels of 171 healthy overweight and obese adults between the ages of 18 and 65.

The research team carried out two double-blind, placebo-controlled trials. One trial tested a regular Calcium and Vitamin D (CaD) fortified orange juice. The second trial tested a reduced calorie (‘lite’) CaD-fortified orange juice. Abdominal fat or ‘visceral adipose tissue’ (VAT) was measured by x-ray before and after the trial.

The trials lasted 16 weeks, during which each participant drank three 240ml glasses of orange juice fortified with 350mg calcium and 100IU vitamin D per day. The control groups drank unfortified regular or unfortified ‘lite’ orange juice.

The results showed that abdominal fat in those drinking the regular fortified orange juice decreased by 12.7cm2 on average. Those who drank the unfortified juice saw a decrease on just 1.3cm2.

In addition, those who drank the fortified ‘lite’ juice saw a decrease in abdominal fat of 13.1cm2, compared with just 6.4cm2 in the unfortified ‘lite’ juice control group.

“Our results suggest that, in overweight and obese adults, a moderate reduction in energy intake and supplementation of calcium and vitamin D in juice beverages lead to a reduction in intraabdominal fat”, concluded the researchers.

Many experts believe that calcium and vitamin D are involved in the healthy metabolism of fat. It is also thought that calcium might accelerate weight loss by binding to fat in the intestine and removing it from the body.

“A large portion of the population is deficient in vitamin D, and dietary calcium intake often does not meet current recommendations,” the researchers stated.

To improve your calcium levels, you should ensure that you are eating plenty of calcium-rich foods, and that you are absorbing the mineral effectively. Rich sources of calcium include dairy, sardines and salmon, leafy greens such as mustard greens, and green vegetables such as broccoli. Calcium absorption also requires adequate dietary magnesium, phosphorus, and vitamin A, C and D.

Calcium citrate is believed by many to be the most efficiently absorbed form of calcium, rather than the cheaper carbonate form. For those supplementing vitamin D, the emulsified form is often considered to be well absorbed.

Written by Nadia Mason, BSc MBANT NTCC CNHC

References

Jennifer L Rosenblum, Victor M Castro, Carolyn E Moore, Lee M Kaplan. Calcium and vitamin D supplementation is associated with decreased abdominal visceral adipose tissue in overweight and obese adults. American Journal of Clinical Nutrition. January 2012.

Image courtesy of Paul

 

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Healthy Gut Flora Could Prevent Obesity

‘Good’ bacteria in the gut may help to control weight, according to a recent study.

Probiotics are bacteria that help to maintain a bacterial balance in the digestive tract by reducing the growth of harmful bacteria. They are an important part of the digestive system, helping to control inflammation and support healthy digestion.

‘Good’ bacteria in the gut may help to control weight.
‘Good’ bacteria in the gut may help to control weight, according to a recent study. (1)

Caroline Karlsson, a researcher in food hygiene at Lund University, has tested the effects of ‘good’ and ‘bad’ bacteria on weight gain in rats (2). One group of rats were given a daily dose of probiotic lactic acid bacteria, Lactobacillus plantarum HEAL19. A second group were given Escherichia coli (E. coli) bacteria, a pathogenic bacteria known to cause inflammation. Both groups of rats were fed the same diet.

When the rats were tested, it was found that the E. coli bacteria had led to changes in the gut flora and increased body fat. The group of rats given the lactic acid bacteria, however, were found to have a better balance of naturally occurring bacteria in their intestines. These rats put on significantly less weight than other rats, even though they ate the same amount of high-energy food.

Previous studies have presented similar findings. A human study, published in the European Journal of Clinical Nutrition, tested the effects of lactic acid bacteria on body weight (3). A milk drink containing lactobacilli was given to 87 participants every day for 12 weeks.  Another group was given a milk drink free from lactobacilli. After 12 weeks, the lactobacilli group showed a greater reduction in abdominal fat and body weight than the control group.

A further study (4) indicated that women were less likely to become obese after giving birth if they had taken probiotics (Lactobacillus & Bifidobacterium strains) during pregnancy. One year after giving birth, the women who were given probiotics had the lower levels of obesity and body fat than those who were given placebo capsules.

Research regarding the role of probiotics in weight loss is in its early stages, and many studies to date have been fairly small. The results look promising, however, and there is increasing evidence that probiotic supplements can be benefical for promoting a healthy digestive and immune system.

Topping up your levels of healthy gut flora is simple. A good quality probiotic supplement such as Biocare’s Acidophilus Forte provides good levels of lactic acid bacteria. Those looking to increase their levels of probiotics through diet can also enrich their meals with probiotic foods. Try fermented foods such as kefir, kimchi and miso – or even a simple probiotic yoghurt with your morning cereal.

References

1.  Image courtesy of  luigi diamanti.

2.  Lund University. “Healthy gut flora could prevent obesity, rat study suggests.” ScienceDaily, 26 May 2011. Web. 29 May 2011.

3.  Kadooka Y, Sato M, Imaizumi K, Ogawa A, Ikuyama K, Akai Y, Okano M, Kagoshima M, Tsuchida T. “Regulation of abdominal adiposity by probiotics (Lactobacillus gasseri SBT2055) in adults with obese tendencies in a randomized controlled trial.” Eur J Clin Nutr. 2010 Jun;64(6):636-43.

4.  Luoto R, Laitinen K, Nermes M, Isolauri E. Impact of maternal probiotic-supplemented dietary counselling on pregnancy outcome and prenatal and postnatal growth: a double-blind, placebo-controlled study. Br J Nutr. 2010 Feb 4:1-8.

Written by Nadia Mason

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A protein-rich breakfast may prevent food cravings and overeating

A recent study has found that eating a protein-rich breakfast reduces feelings of hunger throughout the day (1).  Skipping breakfast has been linked with overeating, weight gain and obesity. Those who regularly skip breakfast have 4.5 times the risk of obesity as those who consume breakfast regularly (2).

Protein Rich Breakfast
A recent study has found that eating a protein-rich breakfast reduces feelings of hunger throughout the day. (3)

Researcher Heather Leidy recently conducted a study to determine whether the type of breakfast we eat might also affect hunger and feelings of fullness.  She assessed hunger and satiety by measuring self-perceived appetite sensations. The researchers also used functional magnetic resonance imaging (fMRI) to identify activity in specific areas of the brain related to food motivation and reward.

The study was conducted on overweight teenage girls who habitually skipped breakfast. One group of participants was given a regular breakfast of cereal and milk for seven days, while a second group ate a higher protein breakfast. On the seventh day, the participants completed appetite and satiety questionnaires. They were also given a brain scan which recorded the brain’s response to images of food prior to lunch.

Compared to skipping breakfast, both types of morning meal led to increased fullness and reduced appetite before lunchtime. The brain scan confirmed that activity in regions of the brain that control ‘food motivation and reward’, or the desire to eat, was reduced at lunchtime when breakfast had been eaten earlier.  Additionally, the protein-rich breakfast led to even greater changes in appetite, feelings of fullness and desire to eat.

Leidy advises caution in interpreting the results of this preliminary study, as the sample size was small. The initial findings indicate that eating a protein-rich breakfast might help to control appetite and prevent overeating in young people.  “People reach for convenient snack foods to satisfy their hunger between meals, but these foods are almost always high in sugar and fat and add a substantial amount of calories to the diet.” Liedy said. “Incorporating a healthy breakfast containing protein-rich foods can be a simple strategy for people to stay satisfied longer, and therefore, be less prone to snacking,”

Protein-rich breakfasts can be simple and quick to prepare. Try a couple of poached eggs on a slice of wholegrain toast, unsweetened museli with natural yoghurt, or a couple of slices of rye bread spread with peanut butter. Or for those who love their usual breakfast cereal, you can boost the protein content by sprinkling on a protein powder such as Higher Nature’s Hemp Protein.

References

1.  Heather J. Leidy, et al. Harris. Neural Responses to Visual Food Stimuli After a Normal vs. Higher Protein Breakfast in Breakfast-Skipping Teens: A Pilot fMRI Study. Obesity, 2011; DOI: 10.1038/oby.2011.108.

2.  Ma, Y., Bertone, E., Staneck, EJ., et al. Association between Eating Patterns and Obesity in a Free-living US Adult Population. American Journal of Epidemiology, 2003; DOI: 10.1093/aje/kwg117.3.

3.  Image courtesy of  Simon Howden.

Written by Nadia Mason

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Good cholesterol linked to reduced risk of bowel cancer

New evidence (1) suggests that high levels of HDL (high density lipoprotein) cholesterol, known as ‘good’ cholesterol, are associated with a reduced risk of bowel cancer.  The study aimed to examine the association of different blood components such as : total cholesterol, high density lipoprotein cholesterol (HDL), low density lipoprotein cholesterol, triglycerides (blood fats) as well as other markers and the incidence of colorectal cancer.

Eating unrefined foods may help to raise levels of HDL Cholesterol
Eating whole and unrefined foods may help to raise levels of HDL (Good) Cholesterol

The study was conducted as part of the European Prospective Investigation into Cancer and Nutrition (EPIC), which is a cohort of over than 520 000 participants from 10 western European countries including the UK.  Over 1200 people who developed bowel and rectal cancers (779 bowel and 459 rectal cancer) were matched with an equal number of participants (control participants) of the same age, gender and nationality.  Blood samples were taken and specialised dietary questionnaires were also collected from both groups.

The results showed(1) that those participants who had the highest levels of HDL cholesterol had the lowest risk of developing bowel cancer.  Further analysis showed that each rise of 16.6 mg/dl in HDL cholesterol reduced the risk of bowel cancer by 22% after taking account of diet, lifestyle, and weight and other factors.  However, it was found that HDL and apoA levels  had no impact on the risk of rectal cancer.  The association between high HDL and lowered risk of bowel cancer remained irrespective of other indicators of inflammation, insulin resistance, and oxygen free radicals levels, all of which are associated with the development of cancer (1,2).

In their discussion the authors of the study explained that low HDL levels have been linked to higher levels of proteins involved in inflammation, while higher levels of proteins that dampen down the inflammatory response have also been linked to high HDL levels.  The pro inflammatory proteins boost cell growth and proliferation while curbing cell death, so HDL may alter the inflammatory process in some way, they suggest.  They conclude that “These findings show that high concentrations of serum HDL are associated with a decreased risk of colon cancer. The mechanism behind this association needs further elucidation”.  Further studies are certainly needed before any firm conclusions can be made.

Fish Oils are rich in Omega 3
Fish Oils are rich in Omega 3, which may help to keep blood fat levels within healthy ranges

I have previously written about cholesterol levels and the way that diet can impact both HDL (good) cholesterol as well as LDL (‘bad’) cholesterol.  Exercising and eating a healthy balanced diet rich in unprocessed, unrefined foods, vegetables, fruits, wholegrains, nuts/seeds, pulses/beans, unprocessed meats and fish, especially oily fish which is rich in omega 3 fats, is a good way to begin to provide the body with optimal nutrition which can help to keep blood fat levels within healthy ranges.

(1)Van Duijnhoven  FJBet al.   2011.  Blood lipid and lipoprotein concentrations and colorectal cancer risk in the European Prospective Investigation into Cancer and Nutrition.  Gut.  E-Pub.   7 March 2011 DOI: 10.1136/gut.2010.225011

(2)Press Release.  BMJ-British Medical Journal (2011, March 7). High levels of ‘good’ cholesterol may cut bowel cancer risk. ScienceDaily. Retrieved March 8, 2011, from http://www.sciencedaily.com­ /releases/2011/03/110307184638.htm

Written by Ani Richardson

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Omega 3 fats linked to a lower risk of endometriosis

In October 2008  I wrote a piece which looked at how nutrition may be able to help women suffering with endometriosis.  A newly published study (1) has found that eating a diet rich in omega 3 fats seems to reduced the risk of developing endometriosis, whereas eating a diet containing trans-fats may actually increase the risk.

Endometriosis is a painful disease that affects women during their reproductive years and is caused when the tissue lining the uterus starts to grow in other parts of the abdomen, outside of the uterus, such as the ovaries.  The tissue behaves in the same way as it does in the uterus, growing during the menstrual cycle in response to oestrogen in anticipation of an egg being fertilized and shedding blood when there’s no pregnancy.  For some women the pain can be excruciating.  Endometriosis can sometimes lead to infertility.  The precise mechanism for the development of endometriosis in the pelvis and abdominal cavity has not been full uncovered.  There is currently no cure and symptoms are usually treated with pain medication, hormone medication or surgery.

Previously I wrote about fish oils being useful due to their anti-inflammatory effects in the body and also wrote about anti-oxidants and how they may be useful to women suffering from the condition.  Please read the post for more detailed information

This most recently published study (1) is interesting as it deals with risk reduction.  The study scientists wanted to investigate the relation between the type of dietary fat consumed in the diet and the risk of endometriosis.  They analysed 12 years of data from a very large study called ‘the Nurses’ Health Study II’ which began in 1989.  The intake of dietary fat was assessed via specialised questionnaires at various intervals over the 12 year period.  Over the study period over 1000 cases of confirmed endometriosis were recorded.  The study authors found that total fat consumption was not associated with endometriosis risk but that women with the highest long chain omega 3 fatty acid consumption were 22% less likely to be diagnosed with endometriosis compared with those women with the lowest intakes.  In addition to this the study scientists found that women with the highest consumption of trans-fat intake were 48% more likely to be diagnosed with endometriosis (for more on trans fats please see my previous post).

This is the largest study to have investigated the link between diet and endometriosis risk and the first study to identify a risk factor that may be modifiable for the condition.  Again it is important to note that total fat was not associated, it was the type of fat that mattered.  Individuals who eat ultra-low fat diets may actually be putting themselves at risk for a number of conditions. 

Long chain omega 3 fatty acids, EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), are found in oily fish such as trout, salmon, mackerel and sardines.  Eating at least 2 portions a week will go far in providing the body with these fats which seem crucial for disease prevention and maintenance of optimal health.  The short chain omega 3 fat, alpha linolenic acid, can be found in walnuts and flaxseeds/linseeds.  The body can convert the short chain version to the long chain but the process is very inefficient.

Trans fats are artificially produced through a process known as hydrogenation, which turns liquid vegetable oil into solid fat.  These kinds of fats are used in many processed foods, from snacks to ready-meals, they have been strongly linked to an increased heart disease risk.  Some countries have banned their use. The major sources of trans fats in this study were from fried restaurant foods, margarine and crackers.  Trans fats are known to increase levels of inflammation in the body and inflammatory factors have been associated with endometriosis.  It may be that trans fats are increasing the risk of endometriosis development through chronic inflammation.  Further studies would be needed to confirm this.

The authors conclude that “These data suggest that specific types of dietary fat are associated with the incidence of laparoscopically confirmed endometriosis, and that these relations may indicate modifiable risk. This evidence additionally provides another disease association that supports efforts to remove trans fat from hydrogenated oils from the food supply”.

Dr. Stacey Missmer, an assistant professor of obstetrics, gynaecology and reproductive biology at Brigham and Women’s Hospital and Harvard Medical School in Boston, Massachusetts, USA said in a press release (2) “Millions of women worldwide suffer from endometriosis. Many women have been searching for something they can actually do for themselves, or their daughters, to reduce the risk of developing the disease, and these findings suggest that dietary changes may be something they can do. The results need to be confirmed by further research, but this study gives us a strong indication that we’re on the right track in identifying food rich in Omega-3 oils as protective for endometriosis and trans fats as detrimental,”

Further studies are needed to confirm the link and it would be very interesting to see intervention studies were women with endometriosis were supplemented with omega 3 oils to see if this could reduce their symptoms.

As you will see from reading my blog posts, Omega 3 fatty acids are beneficial to health for so many reasons and are essential to the body.  If you do not regularly eat oily fish, at least twice per week, I would suggest that you seriously consider taking an omega 3 supplement.  Fish oil supplements provide the long chain EPA and DHA fatty acids that seem to be vital for health.  For vegetarians and vegans linseed/flaxseed oil supplements will provide the shorter chain omega-3 fat alpha-linolenic acid, unfortunately the body finds it quite difficult to bioconvert this to the longer chain forms but it is still an important source.  Vegan EPA/DHA supplements made from algae are now becoming increasingly available and are certainly worth considering.

For more information on endometriosis please contact Endometriosis UK www.endometriosis-uk.org, a charity dedicated to supporting women with the condition, or www.endometriosis.org a global forum for information about endometriosis.

(1)Missmer SA et al.  2010.  A prospective study of dietary fat consumption and endometriosis risk. Human Reproduction.  E-pub prior to print.   March 23, 2010 DOI: 10.1093/humrep/deq044

(2)Press release.  European Society of Human Reproduction and Embryology (2010, March 23). Trans fats linked to increased endometriosis risk and omega-3-rich food linked to lower risk. ScienceDaily. Retrieved March 24, 2010, from http://www.sciencedaily.com¬ /releases/2010/03/100323212146.htm

Written by Ani Kowal

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UK doctors call for trans-fat ban

Two doctors have recently written an editorial piece in the British Medical Journal (1) and have called for a ban in trans fats.  In their piece the authors mention that the UK Faculty of Public Health and Royal Society for Public Health proposed that consumption of trans fatty acids (TFAs) should be virtually eliminated in the United Kingdom by next year, the doctors quote the following from that paper: “it has been proven that industrially-produced TFA can damage health,”there is no known safe level of consumption,” “banning TFA from foods is a relatively easy way to help protect the public.” 

Trans fatty acids are created through manufacture when liquid vegetable oils are hardened, to a solid or semi-solid state, via a process known as hydrogenation.  (Hydrogenation is when naturally occurring cis-unsaturated double bonds are converted into trans unsaturated double bonds).  The process of hydrogenation also destroys the essential short chain omega 3 fatty acid alpha-linolenic acid from oils (for more information about the health benefits of omega 3 fats please read through my numerous posts on the subject).

Trans fatty acids have been linked to various adverse health effects.  The authors of the editorial note (1) that trans fat consumption has been linked to several cardiovascular risk factors.  The trans fats are associated with lowering levels of good cholesterol (HDL cholesterol) and increased levels of ‘dangerous’ LDL cholesterol as well as triglycerides (blood fats) and other risk factors.  Heart disease, inflammation and heart attacks are all linked to consumption of trans fats.  Risk occurs even at low levels of consumption.  Baked goods, deep fried foods, snacks, margarines and products made with margarines are all sources of trans fats.  The average consumption in developed countries is around 2-4% of total daily energy intake but some people eat as much as 5-8% of total energy intake as trans fats (1).  Trans-fat are already banned in Denmark, New York, California, Switzerland and Austria.  It would be good to see the UK follow the example and ban these dangerous fats.

The authors write in their editorial:“Because industrial TFAs are not part of our natural food supply, their regulation does not alter individual consumer choice, being similar to regulations that prohibit adulterated foods. With increasing supplies of alternatives, the commercial and cost advantages of partially hydrogenated oils are now small. Thus, removing industrial TFAs is one of the most straightforward public health strategies for rapid improvements in health. On the basis of current disease rates a strategy to reduce consumption of industrial TFAs by even 1% of total energy intake would be predicted to prevent 11 000 heart attacks and 7000 deaths annually in England alone”.

In a press release Libby Dowling from the charity Diabetes UK comments (2) “We always encourage people to follow a healthy, balanced diet which is low in fat, sugar and salt,” “People should also aim to eat at least five portions of fruits and vegetables a day to help them maintain a healthy weight.  The FSA has stated that current consumption of trans-fat in the UK is low and that the food industry is already being encouraged to cut down on the amount of the product they use, which we welcome.”

Looking at food labels, especially the labels on processed foods and baked goods like biscuits is a good way of checking your own consumption of these trans fats.  I would suggest that avoiding any foods that contain trans fats, or hydrogenated vegetable oils in their ingredients list is a good idea for health.

(1) Mozaffarian D & Stampfer MJ.  2010.   Editorials: Removing industrial trans fat from foods.  A simple policy that will save lives.  BMJ.  340:c1826 Published 15 April 2010, doi:10.1136/bmj.c1826

(2) Diabetes UK press release.  16 April 2010.http://www.diabetes.org.uk/About_us/News_Landing_Page/Doctors-call-for-trans-fat-ban/  Doctors call for trans-fat ban

Written by Ani Kowal

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Replacing dietary fat with sugar and refined carbohydrates is probably damaging to health

Heart disease is a topic I have written extensively about here in these blog posts.  In 2008 I wrote two posts entitled ‘Do you know how to look after your heart’ part 1 and part 2.  In part two I wrote extensively about refined carbohydrates and blood sugar levels and how these appear to be a greater risk for heart disease than dietary fat.  Eating a diet loaded with foods with a high glycaemic index or high glycaemic load has been increasingly linked with a raised risk for heart disease and other health problems.  High glycaemic index foods (foods that release sugar quickly into the body) include most refined carbohydrates like white bread, long-grain rice, sweets, biscuits, sugary foods and many other processed carbohydrates and processed foods. 



By contrast certain types of fat, especially the long chain omega 3 fatty acids (EPA and DHA) from marine sources have been linked to a reduced risk of heart disease.  Many studies have also found that there is not enough evidence to link heart disease to saturated fat or total fat intakes (e.g.1).  I feel quite strongly that the push to eat ultra low fat diets over the last 50 years has impacted negatively on our health (and mood) since it has often led to diets rich in carbohydrates, especially refined carbohydrates.  Look at a low fat yoghurt for instance, the natural fat is removed and, often, replaced with copious quantities of sugar.  Low fat products in general are often full of sugars.  Actually I think the low fat campaigns have been a BIG FAT LIE.



This month in the American Journal of Clinical Nutrition fat is mentioned in a number of studies (e.g. 2,3,4,5).  In a commentary (2) authors point out that “An independent association of saturated fat intake with CVD [cardiovascular disease] risk has not been consistently shown in prospective epidemiologic studies”, the authors also point out that if saturated fat is removed from the diet and then replaced with a higher carbohydrate intake, particularly a higher intake of refined carbohydrates, this is associated with an increased risk of heart disease – specifically a high carbohydrate diet is associated with increasing problems such as insulin resistance, increased triglycerides (blood fats associated with heart disease), increased levels of a particularly destructive type of cholesterol known as small dense LDL cholesterol.  The authors also note that high carbohydrate diets are also linked to a reduced level of HDL ‘good’ cholesterol (2).  They conclude that “there are few epidemiologic or clinical trial data to support a benefit of replacing saturated fat with carbohydrate” and “dietary efforts to improve the increasing burden of CVD risk associated with atherogenic dyslipidemia [blood fat disorder linked to health problems] should primarily emphasize the limitation of refined carbohydrate intakes and a reduction in excess adiposity [body fat]”.



A research paper (3) looking at data on saturated fat and cardiovascular disease (which includes coronary heart disease and stroke) evaluated 21 scientific studies which in total involved over 340,000 individuals followed for 5-23 years showed that “there is no significant evidence for concluding that dietary saturated fat is associated with an increased risk of CHD [coronary heart disease] or CVD [cardiovascular disease]”.



Two other studies in the March issue of the American Journal of Clinical Nutrition (4,5) looked at the positive health benefits of the long chain omega 3 fatty acids, EPA and DHA, found in oily fish such as mackerel, trout, salmon and sardines.  In the first study (4) scientists show that supplementation with these fatty acids are beneficial in improving blood vessel function in individuals with type 2 diabetes.  In the second study (5) high intakes of EPA and DHA were associated with greatly reducing chronic disease risk. 
 


I am not advocating eating a diet that is packed with saturated fat, not in the slightest, personally I feel that the take home message from studies such as these is that a healthy diet, based around natural unprocessed and unrefined foods, is crucially important to prevent disease risk.  Any health-full diet will be rich in plant foods such as vegetables, fruits, beans and pulses, nuts and seeds and will include unprocessed meats and fish (especially oily fish), wholegrain unprocessed and unrefined carbohydrates.  Particularly I feel that omega 3 fats are important to health.  In a press release (6) the lead author of a study looking into heart disease and diet (7) said: “This isn’t just hype; we now have tremendous and compelling evidence from very large studies, some dating back 20 and 30 years, that demonstrate the protective benefits of omega-3 fish oil in multiple aspects of preventive cardiology“.  I also feel that refined carbohydrates are generally unnecessary and quite probably damaging to health when eaten regularly and consistently.



If you do not regularly, at least twice a week, eat oily fish then it would certainly be worth taking a fish oil supplement in order to provide your body with the essential omega 3 fatty acids.  For vegetarians and vegans a flaxseed oil supplement will provide the short chain omega 3 fatty acid, alpha linolenic acid.  Unfortunately the body is not very good at converting this into the long chain EPA and DHA forms that are crucial for health.  New vegetarian and vegan EPA and DHA supplements, made from algae, are becoming increasingly available and are worth looking in to.


 


(1)Mente A et al.  2009. A Systematic Review of the Evidence Supporting a Causal Link Between Dietary Factors and Coronary Heart Disease.  Arch Intern Med. 169(7):659-669.
(2) Patty W Siri-Tarino PW et al.  2010.  Saturated fat, carbohydrate, and cardiovascular disease.  American Journal of Clinical Nutrition.  91: 502-509
(3) Patty W Siri-Tarino PW et al.  2010.   Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease.   American Journal of Clinical Nutrition.  91: 535-546
(4)Stirban A et al.  2010.  Effects of n–3 fatty acids on macro- and microvascular function in subjects with type 2 diabetes mellitus.  American Journal of Clinical Nutrition.  91:808-813
(5)Makhoul Z et al.  2010.  Associations of very high intakes of eicosapentaenoic and docosahexaenoic acids with biomarkers of chronic disease risk among Yup’ik Eskimos.  American Journal of Clinical Nutrition.  91:777-785
(6)
http://www.sciencedaily.com/releases/2009/08/090803173250.htm.  American College of Cardiology (2009, August 3). Mounting Evidence Of Fish Oil’s Heart Health Benefits. ScienceDaily. Retrieved August 4, 2009, from http://www.sciencedaily.com¬ /releases/2009/08/090803173250.htm
(7)Lavie CJ et al.  2009.  Omega-3 Polyunsaturated Fatty Acids and Cardiovascular Diseases.  J Am Coll Cardiol, 2009; 54:585-594

Written by Ani Kowal

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