The evidence for the importance of vitamin D for health continues to stack up yet there has still been no consensus as to how much should be recommended for optimal health and disease prevention. Many people in the UK do not get enough vitamin D and have insufficient/deficient blood levels. There is some agreement that blood levels of vitamin D ought to be around 40-50 nmol/l and that for most people a minimum 2000iu vitamin D daily would be needed to maintain those levels. Some researchers call for higher doses of around 5000iu to be recommended.
Recently (1) a paper has been published, written by, Anthony Norman, a leading international expert in vitamin D. The paper proposes worldwide policy changes regarding people’s vitamin D daily intake amount in order to maximise the vitamin’s contribution to reducing the frequency of many diseases, including childhood rickets, adult osteomalacia, cancer, autoimmune type-1 diabetes, hypertension, cardiovascular disease, obesity and muscle weakness (2). The paper discusses the fact that at present about half of elderly North Americans and Western Europeans and probably also of the rest of the world are not receiving enough vitamin D to even maintain healthy bones let alone contribute to optimal health. Besides the intestines and bone vitamin D generates biological responses in the immune system, heart, muscle and brain. In the paper the authors state “Responsible medicine demands that worldwide vitamin D nutritional guidelines reflect current scientific knowledge about vitamin D’s spectrum of activities”.
In a press release Anthony Norman said “It is high time that worldwide vitamin D nutritional policy, now at a crossroads, reflects current scientific knowledge about the vitamin’s many benefits and develops a sound vision for the future.” “Worldwide public health is best served by a recommendation of higher daily intakes of vitamin D,” “Currently, more than half the world’s population gets insufficient amounts of this vitamin”.
In their review paper (1) the authors note that if the daily dietary intake of vitamin D was increased by 600-1000 IU in all adults above their present supply, it would bring beneficial effects on bone health in the elderly and on all major human diseases e.g., cancer, cardiovascular, metabolic and immune diseases. The researchers add, however, that if the vitamin D dietary intake were increased to 2000 IU per day and even more for subgroups of the world population with the poorest vitamin D status, it could favourably impact multiple sclerosis, type-1 diabetes, tuberculosis, metabolic syndrome, cardiovascular risk factors and most cancers (1,2).
As I have said in all of my posts on vitamin D if you rarely get out into the sunlight you may wish to consider taking a vitamin D supplement. Only small amounts of vitamin D are found in food sources such as oily fish (mackerel, salmon and sardines) and egg yolks. Vitamin D supplements may be particularly useful during the autumn and winter months and for individuals who have darker skins or who don’t go outside regularly. For most people over 18 a supplement containing up to 2000 iu/day can be considered. Too much Vitamin D can cause serious health problems so always check with your medical doctor before taking a high dose (above 2000iu daily) so that blood levels of the vitamin can be monitored. When looking for vitamin D supplements two forms are generally available. Cholecalciferol, known as vitamin D3, and ergocalciferol or vitamin D2. Cholecalciferol is generally taken to be the more potent, easily absorbed and preferred form of vitamin D
(1)Norman AW & Bouillon R. 2010. Vitamin D nutritional policy needs a vision for the future. Proceedings of the Society for Experimental Biology and Medicine. Minireview. First published on 28 July 2010. doi:10.1258/ebm.2010.010014
(2)Press release. University of California – Riverside (2010, August 9). Biochemist proposes worldwide policy change to step up daily vitamin D intake. ScienceDaily. Retrieved August 13, 2010, from http://www.sciencedaily.com /releases/2010/08/100809133325.htm
Written by Ani Kowal
Folate (the naturally occurring form of folic acid), a B vitamin, is one that I have written a lot about, it has been linked to heart health, mood, pregnancy outcomes and much more. In July I wrote about the B vitamins, folate and vitamin B12, being linked to heart disease .
There has been a lot of research interest in the links between B vitamins and risk of cardiovascular disease (stroke and heart disease) over the last decade. The rationale behind this is that there is evidence to suggest that elevated homocysteine levels are a risk factor for heart disease and low levels of the B vitamins B6, folate and B12 are linked to raised homocysteine levels. For more information on homocysteine please click here
A recently published study(1) has found that folate may also be linked to cholesterol levels (another potential risk factor for heart disease). The study looked at data for blood vitamin B12 and folate levels in over 1700 individuals. They found that higher folate levels were associated with lower levels of low density lipoprotein cholesterol (LDL-cholesterol, the so called ‘bad’ cholesterol which has been linked to an increased risk of heart disease). They also found that higher levels of folate were linked to higher levels of ‘good’ cholesterol, high density lipoprotein cholesterol (HDL-cholesterol). The study authors also compared the individuals of the highest with those of the lowest levels of folate. They found that individuals with the highest folate had higher levels of HDL-cholesterol, lower levels of LDL-cholesterol and a lower LDL-C: HDL-C- ratio, this is indicative of a favourable cholesterol profile. In this study Vitamin B12 was not associated with the cholesterol profile.
The study authors call for more research to further investigate the link between folate and cholesterol levels. The current study only provides a potential link, it does not prove that low folate levels are linked to raised LDL cholesterol levels. The study does provide further evidence to suggest that there may also be a link between cholesterol and homocysteine levels, other studies have also suggested such a link. These are very complex interactions and further research to elucidate links could provide really useful information on how diet can be used to reduce the risks of heart disease.
At the present time there is no conclusive evidence to suggest that B vitamins can reduce the risk of heart disease and supplements cannot be recommended as a preventative measure. Having a good level of B vitamins in the diet is, however, important for health. Vitamin B6 is found in foods like potatoes, bananas, beans and chickpeas, avocados, fish and poultry. Vitamin B12 is found mainly in meat, fish and poultry. Eggs and cheese also contain B12 as does brewer’s yeast. Folic acid is found in beans, green vegetables and wholegrains.
Supplements should never be seen as an alternative to a healthy diet and it is wise to check with you doctor before starting any new supplement regiment. If you are thinking about taking a vitamin B supplement I would always suggest a broad spectrum supplement that supplies adequate, but not megadose, levels of all of the B vitamins (not single nutrient supplements), these vitamins work best together as a team
(1)Semmler A et al. 2010. Plasma folate levels are associated with the lipoprotein profile: a retrospective database analysis. Nutrition Journal. 9:31E-pub prior to print. doi:10.1186/1475-2891-9-31 Published 28 July 2010
Following a traditional Mediterranean Diet has been linked to good health in numerous association studies. Although there are many reasons why this kind of eating could be good for health, e.g. it is rich in antioxidants and nutrients that play a role in disease prevention, the studies only show potential links and do not conclusively prove that following this kind of eating pattern is good for health. Recently a study (1) has been published which begins to help elucidate one of the reasons why a Mediterranean diet might be useful for health.
The study(1) looked at how a Mediterranean diet and olive oil might impact the way our genes function and how that might be effecting health. The study scientists looked specifically at genes related to heart health. The study was small, involving 90 healthy individuals aged between 20 and 50 and lasted 3 months. The participants were split into three groups:
Group 1) Were given a traditional Mediterranean diet to follow including the use of good quality virgin olive oil that was high in polyphenols (active plant chemicals)
Group 2) Were asked to follow a traditional Mediterranean diet but using a ‘washed’ virgin olive oil which was very low in polyphenols
Group 3) Were asked to follow their normal diet and acted as a control group.
The researchers took blood samples from the participants and checked them for various health-related factors in a laboratory e.g. inflammatory status and various genetic changes. They found that group 1, who were following a traditional Mediterranean diet with a good quality virgin olive oil rich in polyphenols, had ‘down-regulation’ [positive changes] of various genes related to atherosclerosis (hardening of the arteries associated with poor heart health). Additionally, the olive oil polyphenols made a significant impact on the expression of genetic changes influencing coronary heart disease. Results also showed that the consumption of virgin olive oil in conjunction with a Mediterranean diet can positively impact lipid and DNA oxidation, insulin resistance, inflammation, carcinogenesis, and tumour suppression.
In a press release (2) one of the researchers involved in the study said “Knowing which genes can be modulated by diet in a healthy way can help people select healthy diets,” “It is also a first step for future nutritional therapies with selected foods.” The editor of the scientific journal publishing the study said (2) “This study is ground breaking because it shows that olive oil and a Mediterranean diet affect our bodies in a far more significant way than previously believed” “Not only does this research offer more support for encouraging people to change their eating habits, it is an important first step toward identifying drug targets that affect how our genes express themselves.”
A traditional Mediterranean style of eating includes plentiful amounts of vegetables, fruits, nuts/seeds, olive oil, legumes (beans and peas), wholegrains, fish (including oily fish such as salmon, trout, sardines and mackerel) and low-fat dairy products. When looking at low fat yoghurts be aware and check the labels, often these can be loaded with added sugar. Opt for natural yoghurts, with nothing added – fruit can be added for some natural sweetness and added nutritional benefit. This kind of eating pattern is ‘nutrient dense’ – the food is packed with lots of vitamins, minerals, fibre and flavonoids (members of the polyphenol family, plant chemicals), much of the food is not high in calories (not energy dense) but is high in nutrition, a great way of eating for health and weight control reasons.
(1)V. Konstantinidou et al. 2010. In vivo nutrigenomic effects of virgin olive oil polyphenols within the frame of the Mediterranean diet: a randomized controlled trial. The FASEB Journal. 24(7):2546-57. DOI: 10.1096/fj.09-148452
(2)Federation of American Societies for Experimental Biology (2010, June 30). Virgin olive oil and a Mediterranean diet fight heart disease by changing how our genes function. ScienceDaily. Retrieved July 2, 2010, from http://www.sciencedaily.com /releases/2010/06/100630111035.htm
Written by Ani Kowal
Last year I mentioned a couple of studies which found a link between folate and age-related hearing loss. Now, a newly published study in the American Journal Of Clinical Nutrition (1) has found that fish consumption and long chain omega 3 fatty acids, EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), which are found in oily fish such as salmon, mackerel, sardines and trout, may protect against age-related hearing loss (known as presbycusis).
The study scientists (1) wanted to determine the association between dietary intakes of fish and long chain omega 3 fatty acids and the risk of age related hearing loss. They used a population of individuals from a study known as ‘The Blue Mountains Hearing Study’ and collected data via a specially designed food frequency questionnaire in order to estimate fish and omega 3 intakes. In almost 3000 participants, aged 50 or over, age related hearing loss was measured. It was found that there was an inverse association between total long chain omega 3 fatty acid intake and prevalence of hearing loss i.e. those individuals with the highest intakes of long chain omega 3 fatty acids had the lowest prevalence of hearing loss. The scientists also found that individuals who ate 2 or more servings of fish a week had a significantly reduced risk, 42% reduced risk, of developing age related hearing loss when compared to individuals who ate less than one serving a fish per week.
The researchers conclude “There was an inverse association between higher intakes of long-chain n–3 PUFAs [Polyunsaturated Fatty Acids] and regular weekly consumption of fish and hearing loss. Dietary intervention with n–3 PUFAs could prevent or delay the development of age-related hearing loss” (1)
In another recent study (2) researchers looked at blood plasma levels of long chain omega 3 fatty acids to see if there was an association with age-related hearing loss. The study included 720 men and women aged between 50 and 70 years old and lasted 3 years. It was found that individuals with the highest levels of blood plasma long chain omega 3 fatty acids has less hearing loss in the low frequencies (but not high frequencies) over three years than individuals with the lowest levels of omega 3 fatty acids. The association held firm even after the researchers adjusted for potential confounding factors such as baseline mean hearing thresholds, age, sex, level of education and alcohol consumption. The researchers conclude that “This study is the first to show an inverse association between plasma very long-chain n-3 PUFAs and age-related hearing loss. These results are encouraging, but require confirmation from future studies”.
It is not yet known how the omega 3 fatty acids might be acting but these fats are highly active molecules and could be working via a number of different mechanisms in the body e.g. through their anti-inflammatory actions. Both of these studies are interesting and point toward a potential use for omega 3 fatty acids to delay, or prevent against, age related hearing loss. However, the studies do only show an association and do not prove that omega 3 fatty acids can prevent age related hearing loss. Further studies would be needed before any recommendations could be made for the use of long chain omega 3 fatty acids for the prevention of age-related hearing loss. As you will know from my numerous past blog posts, omega 3 fatty acids are vital to health for a vast number of reasons and including oily fish weekly as part of a healthy balanced diet would certainly seem sensible. Sadly many people in the UK do not regularly consume oily fish. On average, adults in the UK are eating 1/3 of a portion of oily fish per week, with 70% of adults eating no oily fish at all. The Government advises that individuals aim to eat at least two portions of fish a week, one of which should be oily (3). Supplements can never be viewed as an alternative to a healthy diet but if you do not regularly eat fish you might want to consider talking to your GP or nurse about taking a fish oil supplement. For vegetarians and vegans a flaxseed oil supplement could be considered (to provide the short chain omega 3 fat alpha-linoleic acid). Also, there are now a few companies who make vegetarian and vegan EPA and DHA from algal sources, a very exciting development and well worth investigating if you wish to take an omega 3 supplement.
(1)Bamini Gopinath B et al. 2010. Consumption of omega-3 fatty acids and fish and risk of age-related hearing loss. American Journal of Clinical Nutrition. 92: 416-421
(2)Dullemeijer C et al. Plasma very long-chain n-3 polyunsaturated fatty acids and age-related hearing loss in older adults. J Nutr Health Aging. 14(5):347-51.
(3) (4)British Nutrition Foundation. http://www.britishnutrition.org.uk/home.asp?siteId=43§ionId=593&subSectionId=322&parentSection=299&which=1
Written by Ani Kowal
Age related macular degeneration (AMD) is the most common cause of blindness in people over the age of 50 in the UK. The condition is one that I have written about many times previously. The exact causes of AMD are unknown although free radical damage, where unstable oxygen molecules damage the eye cells, is strongly implicated. Tobacco smoke and sun exposure can increase the level of free radicals in the body and both are a risk for AMD. High blood pressure and diabetes are also risk factors as these conditions can limit blood flow to the eyes. There is no cure for AMD, but certain treatments may prevent or delay serious vision loss. Please read my previous posts for nutrition related ideas for keeping eyes healthy.
Antioxidants such as vitamin C, E, carotenes, zinc, lutein and zeaxanthin have all been implicated in keeping eyes healthy and slowing the progression of AMD. There has also been evidence to suggest that fish oil might be helpful in prevention of the condition
A recently published study (1) has concluded that the “data support a protective effect of fish/shellfish intake against advanced AMD”. The study researchers wanted to determine the relationship between fish and shellfish consumption and AMD status. Over 2500 people aged between 65 and 84 were included in the study. A specific food frequency questionnaire was used to estimate weekly fish/shellfish consumption for each participant and AMD status was determined from photographic analysis. The scientists then investigated the links between weekly fish/shellfish intake and risk of AMD.
15% of the participants were found to have early- or intermediate-stage AMD, while just under 3% were in the advanced stage of the disease (1). Overall, there was no clear relationship between participants’ reported fish intake and the risk of AMD. However, there was a connection between higher intake of omega-3-rich fish and the risk of advanced AMD, those with advanced AMD were significantly less likely to consume fish/shellfish high in omega-3 fatty acids. Individuals who ate one or more servings of oily fish (e.g. salmon, trout, mackerel and sardines) each week were 60% less likely to have advanced AMD than those who averaged less than a serving per week. This statistic took into account known risk factors for AMD such as sex, race and smoking habits.
The results (1) are interesting but do not prove that eating oily fish cuts the risk of developing the advanced stages of AMD. However, the study results do add to previous evidence that fish eaters tend to have lower rates of AMD than people who infrequently eat fish. The results also add to the increasing evidence that omega 3 fatty acids, found in oily fish, may be important for eye health and prevention of AMD and AMD disease progression. More research is certainly necessary before any firm conclusions or recommendations can be made.
Long chain omega 3 fatty acids from oily fish do seem to be particularly important for health and including oily fish as a regular part of the weekly diet would seem sensible. Sadly many people in the UK do not regularly consume oily fish. On average, adults in the UK are eating 1/3 of a portion of oily fish per week, with 70% of adults eating no oily fish at all. The Government advises that individuals aim to eat at least two portions of fish every week, one of which should be oily (2). It is not yet recommended that omega 3 supplements be taken specifically for protection against AMD, however if you do not regularly eat oily fish you may wish to talk to your doctor about the possibility of taking a fish oil supplement. Vegetarians and vegans can take a flaxseed oil supplement (which provides short chain omega 3 fatty acids) or look into buying EPA/DHA supplements produced from algae, these supplements are becoming increasingly available.
For more information about AMD please visit Macular Disease Society website. The Macular Disease Society aims to build confidence and independence for those with central vision impairment. They are the only UK charity dedicated to helping people with macular degeneration and offer information, a helpline, counselling and emotional support among other resources.
(1)Bonnielin K. Swenor KB et al. 2010. The Impact of Fish and Shellfish Consumption on Age-Related Macular Degeneration. Opthalmology. E-Pub. doi:10.1016/j.ophtha.2010.03.058
(2) British Nutrition Foundation. http://www.britishnutrition.org.uk/home.asp?siteId=43§ionId=593&subSectionId=322&parentSection=299&which=1
Written by Ani Kowal
Previous evidence has suggested that probiotics (‘friendly’ gut bacteria) given to pregnant women at risk of having children with atopic dermatitis (a type of eczema), and then their infants, seems to reduce the incidence of eczema in the children. A recently published study in the British Journal of Dermatology (1) took place to examine whether probiotic supplements given to non-select pregnant women (not just those at risk of having a child with eczema) could prevent eczema in the child’s first two years.
In the study (1) women received a probiotic milk or placebo (milk which did not contain probiotics) from 36 weeks of pregnancy to three months postnatally during breastfeeding (all the mothers breastfed their children). The probiotic milk contained the probiotic strains Lactobacillus rhamnosus GG, Lactobacillus acidophilus La-5 and Bifidobacterium animalis subsp. lactis Bb-12. Children with an itchy rash for more than four weeks were assessed for eczema. After two years of age, all the children were assessed for various conditions such as atopic dermatitis, asthma and allergic rhinoconjunctivitis. The results showed that children of the women who drank the probiotic milk during and after their pregnancy had a 40% reduced incidence of eczema.
“The results showed that probiotic bacteria reduced the incidence of eczema in children up to age two years by 40 percent. And the kids in ‘probiotics group’ who did have eczema, had less severe cases,” explains Christian Kvikne Dotterud, a student in the Medical Student Research Programme at the Department of Community Medicine at NTNU (2).
The study was conducted by researchers at the Norwegian University of Science and Technology (NTNU), Norwegian University of Science and Technology, it is part of a larger research project at the university called the Prevention of Allergy Among Children in Trondheim, or PACT, an ongoing population-based intervention study in Norway focused on childhood allergy (2).
One of the study researchers said (2) “Our study is the first to show that certain probiotic bacteria given to the mother during pregnancy and breast-feeding prevents eczema,”. Previous studies have shown that probiotics taken by pregnant mothers and then by their children may prevent eczema, but this is the first study to show a preventative effect when the mother alone consumed the probiotics. It is thought that the probiotic bacteria, taken by the mothers, affects the composition of breast milk in a positive way.
The researchers of this study used a variety of strains of probiotics. In the press release they say “There is reason to believe that it is beneficial for your health to consume a variety of bacterial strains with documented efficacy, rather than unilateral influence of only one bacterial strain”. One of the strains of bacteria used in the probiotic milk drink was LGG ®, (Lactobacillus rhamnosus GG) which is currently the probiotic bacteria that are most extensively studied and researched in terms of human health in the world. It has been shown that LGG ® contributes to good gut function and a stronger defense against unwanted bacteria and viruses in the stomach. At present there are more than 500 published articles on LGG ® in international journals and more than 30 doctoral theses have been completed on LGG’s ® effect on health. More than 40 countries in different parts of the world market products with LGG ® (2). The probiotic milk also a contained a strain of Bifidobacteria, which have also been used in numerous research studies.
Evidence is continually accumulating for the use of probiotics (and prebiotics) for health. It is important to talk to your doctor or midwife before beginning any supplement regimen during pregnancy or when breastfeeding.
(1) C. K. Dotterud CK et al. 2010. Probiotics in pregnant women to prevent allergic disease: a randomised, double-blind trial. British Journal of Dermatology E-Pub prior to print. 10.1111/j.1365-2133.2010.09889.x
(2)Press release. Norwegian University of Science and Technology. http://www.ntnu.edu/probiotic-use-in-pregnancy
Written by Ani Kowal
A few years ago I wrote about various studies which showed that diet could be useful in preventing against the development of cataract . In that post I mentioned the importance of lutein, zeaxanthin, antioxidants such as vitamin C and E and also omega 3 fatty acids. Now a new study (1) has found that women who have a healthful diet, rich in a variety of minerals and vitamins might have a lower risk of developing cataracts.
Cataracts are cloudy areas that develop in the lens of the eye, the cloudiness reduces the amount of light transmitted to the retina and this causes poor vision. In the UK about 1 in 3 people over the age of 65 develop a cataract, which gradually forms over many years. Initially vision may only be very mildly affected and this may not progress, however, in some individuals the vision will get worse over time.
The study (1) involved over 1800 women aged between 55-86 who took part in a study known as the “Carotenoids in Age-Related Eye Disease” study. The daily diets of the women were assessed using a specific food frequency questionnaire and the prevalence of nuclear cataract was determined 4-7 years later. The diets were also assessed to see how closely they reflected the 1990 dietary guidelines for Americans and the 1992 food guide pyramid. The authors of the study wanted to see if there were any associations between healthy diet scores and prevalence of nuclear cataract in women (1).
The researchers found (1) that having a high Healthy Eating Index score was the strongest modifiable predictor of low prevalence of nuclear cataract. Foods that contributed to higher diet scores were intakes at or above recommended levels for vegetables, fruits, grains, milk, meat (or beans, fish or eggs) and below recommended levels for fat, saturated fat, cholesterol and sodium. Women with the top 20% of healthy eating scores were found to have a 37% lower risk of developing cataracts than those in the bottom fifth. Higher prevalence of nuclear cataract was also associated with other modifiable factors such as smoking and marked obesity.
The authors conclude that “These data add to the body of evidence suggesting that eating foods rich in a variety of vitamins and minerals may contribute to postponing the occurrence of the most common type of cataract in the United States”. They also write that “Lifestyle improvements that include healthy diets, smoking cessation, and avoiding obesity may substantively lower the need for and economic burden of cataract surgery in aging American women.”
This study (1) is an association study and does not prove that a healthy diet can protect against cataract. However, it does pave the way for further studies and adds to previous evidence which shows that what we eat, and our lifestyles, can impact our eyesight. For more information on diet and eye health please read my previous posts covering the topic
(1)Julie A. Mares JA et al. CAREDS Group. 2010. Healthy Diets and the Subsequent Prevalence of Nuclear Cataract in Women. Arch Ophthalmol. 128 (6): 738-749
Written by Ani Kowal
A recent study (1) has found that women who take fish oil supplements seem to have a reduced risk of developing breast cancer
The VITAL (VITamins And Lifestyle) study (1) involved a cohort of over 35,000 women aged 50-76 years old. They completed a comprehensive 24-page questionnaire at the start of the study (2000), as part of this questionnaire they were asked about their recency (current versus past), frequency (days/week), and duration (years) of specialty supplement use. The women were followed for around 7 years. In that time over 850 cases of invasive breast cancers were noted and the researchers of the study performed analysis on the data to see if there was any association between supplement use and breast cancer risk.
The results showed that current use of fish oil was associated with reduced risk of breast cancer. Ten-year average use of fish oil was also suggestive of reduced risk (though the results were not statistically significant). These results held for ductal but not lobular cancers (1). Specifically, those women who said they regularly used fish oil supplements were about one-third less likely than non-users to develop breast cancer over the next six years. The lower risk was seen even when a number of known and suspected risk factors for breast cancer were taken into account e.g. including older age, obesity, heavy drinking and sedentary lifestyle. The other specialty supplements which were studied were not associated with breast cancer risk. Specifically, use of supplements sometimes taken for menopausal symptoms (black cohosh, dong quai, soy, or St. John’s wort) were not associated with risk (1).
The authors conclude that (1) “Fish oil may be inversely associated with breast cancer risk” but they stress that “Fish oil is a potential candidate for chemoprevention studies. Until that time, it is not recommended for individual use for breast cancer prevention”
The study was just an observational association study, it does not prove that fish oil supplements prevent against breast cancer. As the authors mention, further studies and specific trials would be necessary before any conclusion drawn or recommendations made. In a press release (2) one of the study authors states ”Without confirming studies specifically addressing this,” “we should not draw any conclusions about a causal relationship.” Currently there is a trial underway in America which is looking at whether fish oil and vitamin D supplements affect the risk of cancer, heart disease and stroke in older men and women. The results won’t be known for a number of years yet.
Fish oil contains long chain omega 3 fatty acids which are important to health for a number of reasons and also linked to the prevention of various diseases such as heart disease. Eating oily fish such as trout, salmon, mackerel and sardines at least twice weekly is a good way of ensuring adequate amounts of these essential fats in the diet. It is plausible that fish oil could to linked to reduced breast cancer risk via its anti-inflammatory effects in the body, but further research would be necessary to find out any specific preventative actions in the body
(1)Brasky TM et al. 2010. Specialty Supplements and Breast Cancer Risk in the VITamins And Lifestyle (VITAL) Cohort. Cancer Epidemiol Biomarkers Prev; 19(7); 1696–708. doi: 10.1158/1055-9965.EPI-10-0318
(2)Press release. American Association for Cancer Research (2010, July 8). Fish oil may reduce risk of breast cancer. ScienceDaily. Retrieved July 9, 2010, from http://www.sciencedaily.com /releases/2010/07/100708071349.htm
Written by Ani Kowal
Oily fish, such as salmon, trout, mackerel and sardines, and fish oil supplements provide the body with the long chain omega 3 fatty acids (EPA and DHA) that are so important for health and which I write about so frequently. In adults there is indication that fish oil is important for heart health, it can help to lower blood pressure and seems to have beneficial effects on cholesterol levels.
A newly published study (1) has found that fish oil supplements might be useful for lowering blood pressure in overweight teenage children. This could be important for heart health in later life.
The study researchers wanted to investigate whether fish oil affects cardiovascular (heart) risk factors during the time of adolescent growth spurt (1). The study was small, involving 78 teenage boys, aged 13-25, who were slightly overweight. The boys were given either fish oil, which provided 1.5g of long chain omega 3 fatty acids daily, or vegetable oil (the control group) for 16 weeks. Neither group knew whether they were taking the fish oil or the vegetable oil since the oils were ‘hidden’ in bread.
After 16 weeks (1) the group eating the fish oil infused bread had higher concentrations of the long chain omega 3 fatty acids EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) in their red blood cells than the group eating the vegetable oil bread, indicating that the fish oil was being well absorbed and incorporated into the body. The systolic blood pressure was around 3.8mm Hg lower and diastolic blood pressure was around 2.6 mm Hg lower in the fish oil group compared with the control group. The changes in red blood cell EPA content were inversely correlated with the changes in systolic and diastolic blood pressure i.e. the higher the EPA content in the blood the greater the reduction in blood pressure.
Systolic blood pressure, represented by the top number in a blood pressure reading, is the measure of the phase of the heartbeat when the heart contracts and pumps blood into the arteries. Diastolic blood pressure, represented by the bottom number in a blood pressure reading, is the measure of the phase of the heartbeat when the heart muscle relaxes and allows the chambers to fill with blood.
The findings are significant since, in adults a drop in blood pressure of 3 mm Hg corresponds to at least a 15% reduction in the risk of stroke. In addition to this, blood pressure has been shown to track into adulthood: children and teenagers with higher blood pressure seem more likely to suffer from high blood pressure later in life. High blood pressure is a risk factor for stroke and heart disease. More research is certainly needed before any recommendations can be made for fish oil supplementation for heart protection in children however, research showing the benefits of omega 3 fatty acids for health is vast and ever growing. It would seem sensible to introduce young children to the taste of oily fish early in life and to make oily fish a regular (twice weekly) part of the diet, especially since here in the UK many individuals do not include fish as a regular part of their weekly diet. If you want to consider a fish oil supplement for yourself or your children it would be worth checking with a medical doctor prior to starting a new regimen.
(1)Pedersen MH et al. Effects of Fish Oil Supplementation on Markers of the Metabolic Syndrome. The Journal of Pediatrics. E-pub prior to print online May 17, 2010. doi:10.1016/j.jpeds.2010.04.001
Written by Ani Kowal
Statins are commonly prescribed as cholesterol lowering agents and many individuals take them in the belief that they will reduce their risk of heart disease. Statins are considered by some as among the most successful drugs of all time and have been credited with preventing millions of heart attacks and strokes. However, there are many people who prefer not to take statins due to potential side-effects which include possible liver and kidney problems and a possible increased risk of cancer.
A recently published study (1) by British researchers calls into question the expanded use of statins such in patients who do not have heart disease but may develop it. The study was a meta-analysis, which reviews all previous published scientific evidence, which found scant evidence that statins saved lives in the short term in groups without heart disease.
The authors of the study wrote that (1) “There is little evidence that statins reduce the risk of dying from any cause in individuals without heart disease,” “This, along with harms caused by statins in some subgroups, have called into question the benefit of statins in primary prevention [prevention of the development of heart disease].” They conclude that “The results of the trial do not support the use of statin treatment for primary prevention of cardiovascular diseases and raise troubling questions concerning the role of commercial sponsors”
Previously I have written about a few natural ways to reduce cholesterol and also about the possible cholesterol reducing effects of artichoke leaf extract
One of the studies (2) I mentioned stated that:
“Lifestyle changes combined with ingestion of red yeast rice and fish oil reduced LDL-Cholesterol in proportions similar to standard therapy with simvastatin. Pending confirmation in larger trials, this multifactorial, alternative approach to lipid lowering has promise for a subset of patients unwilling or unable to take statins”
Recently (3,4,5) further studies have found that red yeast rice might be useful in patients who have either a statin intolerance or who, for other reasons, have chosen not to take statins. A small study this year (3) looked at the use of red yeast rice versus pravastatin medication in patients who were unable to tolerate other statins because of myalgia (muscle pain). Individuals were assigned to red yeast rice supplement 2,400 mg twice daily or pravastatin 20 mg twice daily for 12 weeks and all subjects were enrolled in a 12-week therapeutic lifestyle change program. The results showed that red yeast rice was tolerated as well as pravastatin and achieved a comparable reduction (of around 30%) of low-density lipoprotein cholesterol (‘bad’ cholesterol) in a population previously intolerant to statins. The other two studies also found that re yeast rice decreased LDL cholesterol levels and may be considered a treatment option in patients intolerant to statin therapy.
The studies were small and so firm conclusions over the use of this supplement cannot be drawn. However, evidence for many alternatives to statins are coming to light and, in conjunction with lifestyle changes which include increased daily activity and exercise, cannot be discounted. Chinese red yeast rice is a dietary supplement which contains a variety of components such as monacolins, unsaturated fatty acids, and phytosterols which may be capable of lowering low-density lipoprotein (LDL) cholesterol.
If you decide to try any supplement for cholesterol lowering I would encourage you to check with your medical doctor prior to beginning the regimen. If you are already taking any medications for heart disease, cholesterol or any condition it is crucial to check with your prescribing doctor before taking a supplement.
(1)de Lorgeril M et al. 2010. Cholesterol Lowering, Cardiovascular Diseases, and the Rosuvastatin-JUPITER Controversy. A Critical Reappraisal. Arch Intern Med. 170(12):1032-1036.
(2) Becker DJ et al. 2008. Simvastatin vs Therapeutic Lifestyle Changes and Supplements: Randomized Primary Prevention Trial. Mayo Clin Proc. 83:758-764
(3) Halbert SC et al. 2010. Tolerability of red yeast rice (2,400 mg twice daily) versus pravastatin (20 mg twice daily) in patients with previous statin intolerance. Am J Cardiol. 105(2):198-204.
(4) Venero CV et al. 2010. Lipid-lowering efficacy of red yeast rice in a population intolerant to statins. Am J Cardiol. 105(5):664-6.
(5) Becker DJ et al. 2010. Red yeast rice for dyslipidemia in statin-intolerant patients: a randomized trial. Ann Intern Med. 150(12):830-9, W147-9.
Written by Ani Kowal
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