"High doses of fish oil reduced the size and concentration of several lipoprotein subclasses in type II diabetes patients while lowering patients� insulin sensitivity according to study published in the European Journal of Clinical Nutrition (ePub, ahead of print, Feb. 2007, DOI: 10.1038/sj.ejcn.1602703)."
You read correctly. Fish oil does appear to negatively impact insulin sensitivity - to some degree. There are a bunch of PUBMED studies that point to such an effect. Whether the cardiovascular benefits of fish oil outweigh the effects on insulin sensitivity is the question.
Background: Insulin resistance is a condition in which the amount of insulin released is inadequate to produce a normal glucose response from fat, muscle and liver cells. Its prevalence is increasing, affecting approximately 25% of the UK population (Diabetes UK, 2006) and with it the risk of developing type 2 diabetes and cardiovascular disease (CVD). One of the major contributing factors to insulin resistance is obesity, the incidence of which is also on the rise in the UK (Zaninotto et al.,2006). Medication and lifestyle changes can be implemented to improve insulin sensitivity but whilst the use of fish oils to improve cardiovascular risk is well documented (Erkkila et al., 2003) its effect on insulin sensitivity are less well known.
The aim of the study was to determine the effects of 60 days of fish oil supplementation on insulin sensitivity, plasma glucose and insulin levels as assessed by an oral glucose tolerance test (OGTT), total serum cholesterol levels and serum triglyceride (TG) levels.
Method: Subjects (n = 5) from Surrey, UK, were selected based on BMI (>/=25 kg m(-2)) and waist circumference (>37 inches for men and >31 inches for women) and current oily fish consumption (no fish oil supplements and <2 portions of oily fish per week). Selected subjects self-reported to be otherwise mentally and physically healthy.
This was a single-blind intervention study with all subjects being placed on fish oil supplements [n-3 Polyunsaturated fatty acid (PUFA) (100%); 440 mg Docosahexaenoic acid (DHA), 660 mg Eicosapentaenoic acid (EPA)] for 60 days. An oral glucose tolerance test (OGTT) over 120 min was completed to assess fasting plasma insulin and glucose levels and glucose response over time. Fasting serum triglycerides (TG's) and total cholesterol were also measured from baseline blood samples and blood pressure and anthropometric measurements taken before and after supplementation with the fish oils. Dietary intake was assessed and subjects' insulin sensitivity and b-cell function assessed using the homeostatic model assessment (HOMA). Data was analysed using SPSS (v14) with non-parametric statistics, performed due to the small sample size.
Results: Following supplementation there was a significant decrease in diastolic blood pressure (Z = -2.03; P = 0.042), but no other significant changes in anthropometric measurements (Table 1).
There was an increase in insulin sensitivity following supplementation as demonstrated by a reduction in the plasma glucose response during the OGTT, and a mean reduction in serum TG's and total cholesterol, although these were not statistically significant (Table 1).
Discussion: Supplementation with fish oils over 60 days improves a number of biomarkers used to assess risk of CVD in overweight individuals. Whilst only changes in diastolic BP were statistically significant, clinically significant reductions in all other biomarkers with positive implications for CVD risk and mortality were found.
There were however a number of limitations, such as the small samples size, screening method, original glucose tolerance and insulin sensitivity of the subjects and the lack of a control group, that reduced the strength of these findings.
Future, high dose, long-term, double-blind intervention studies controlling for these limitations would therefore be recommended.
Conclusion: The findings of this pilot study show that the intake of high dose fish oil supplements over 60 days can help to reduce the risk of CHD and mortality in overweight individuals.
References Diabetes UK. (2006) Guide to Diabetes [Online]. Available at https://www.diabetes.org.uk/Gdide-to-...lin_resistance. Diabetes UK (accessed on December 2006). Erkkila, A., Lehto, S., Pvorala, K. & Uusitupa, M. (2003) n-3 fatty acids and 5 year risk of death and cardiovascular disease events in patients with coronary artery disease. Am. J. Clin. Nutr.78, 65-71. Zaninotto, P., Wardle, H., Stamatakis, E., Mindell, J. & Head, J. (2006) Forecasting obesity to 2010; Prepared for the Department of Health: Joint Health Surveys Unit (National Centre for Social Research and Department of Epidemiology and Public Health at the Royal Free and University College Medical School).
it is a very small study, though. 5 people. but still...
While fish oil may help reduce the risk of heart disease are we not missing the heart of the problem?
Why does the body develop a problem in handling sugar/glucose in the first place? But first let me digress a bit and ask why is an alcoholic, an alcoholic? Aside from psychological reasons isn�t it obvious that the person is drinking too much alcohol. In a similar manner could it not be said the reason a person has diabetes is because they are consuming why too much sugar? Is a peanut butter and jelly sandwich with a super sized soda and a Twinkie the ideal lunch? Or a breakfast cereal that is nothing more then a sugar coated sugar to which you add milk and more sugar does this represent a healthy start for the morning?
Now even thought the body is extremely durable and has many ways of dealing with excesses still at some point its ability to cope will be exceeded. It is then that whatever the weakest point is, heart, kidneys, eyes, etc. they will start to break down.
If one is an alcoholic the first thing they told is to stop drinking alcohol. So why is a diabetic is told to take a pill or shot of insulin rather then change their eating habits?
With diabetes I, the pancreas cannot produce insulin. Won't matter what you eat at that point. You have to take insulin.
But even with diabetes II, I don't think it is that simple. I think some people are genetically predisposed to problems with even slight excess.
My mother always cooked very healthy meals, but my brother developed diabetes I at 13, my father developed diabetes type II in later life... and here I am, middleaged, and no problems with blood sugar.
I definitely think there is a link between lowfiber carbs and blood sugar problems in people with a predisposition to blood sugar problems. And add lack of exercise to that.
I remember a friend of my mothers that said her husband would walk every night for over an hour... said he didn't feel good unless he did. Eventually, years later, they found out he had diabetes II.. and I guess this was keeping him ok. He listened to what his body was telling him. But I think it irked her a bit that he would take that walk, no matter what.. until she found out about the diabetes. :P
I agree with you on diabetes 1 no change in diet is going to “fix” a broken pancreas.
However with type 2 I believe there is a generic predisposition but that it is more cultural then physical. Those families that tend to live on raw sugar and carbohydrates are more likely to have a problem then those that consume only moderate amounts.
Before the 1900’s it was rare for someone to be diabetic. But then most everyone was eating fresh natural foods. However by the beginning of the 1900’s the industrial revolution was in full swing and with it came the need to make foods stay fresh longer. Natural cooking oils were replaced with man made oils that would not turn rancid. They could sit on store shelves for months and look as clean and clear as the day they were made the only problem they provided no nutritional value. Grains became easily refined so that everyone could now have “white bread” of course in the refining process much of the nutritional value of the wheat is lost and all that is left is a carbohydrate that when eaten quickly turns to sugar.
Many farm fields were over planted and thus became striped of basic minerals resulting in crops that were also deficient in these minerals. When these crops were then feed to cattle the cattle also became deficient in these minerals thus our meats are not as nutritious as they once were. Milk is pasteurized to kill all the “bad bugs” and make it stay fresh longer of course this also kills many of the “good bugs” and with skin milk then everything else of value is striped out leaving you with basally a colored sugar water.
So while we have plenty of food to eat the food that we are eating is high in sugar content and not much else. During this time period the amount of sugar that the average person ate per year has grown from a few pounds to about 150 pounds per year. Is it surprising that our bodies are having a hard time dealing with all this so called good food?
Mad Scientist... I agree that the changes you describe in the diet of the average American have definitely attributed to the rapid rise in diabetes II.
But.. I also think that there is the factor of decreasing insulin sensitivity as people age. And some people will have this happen sooner than others.. again, sometimes as the result of genetics.
I have a friend that I spent a lot of time with when my son was little, because her son was about the same age and they played together a lot. So, we ate at each others houses all the time. She and her husband had a garden, she was very aware of eating healthy.. and she ended up with diabetes II. which really surprised me. But... she has been able to totally control it by going on a very controlled diet, and increasing her exercise.
so.. I don't think it is just diet with some people.
but I do agree with you that when you overload your diet with refined carbohydrates and sugar.. yes, you will probably end up with blood sugar problems. Which is why we are seeing it in young people nowadays.
I think that the cause of diabetes in type 11 is multifaceted.
But is is of much interest to me that some people who use MMS have reduced their insulin injection needs and some have even thrown their syringes away.
So in light of this evidence perhaps the causes are more than diet alone, genetics alone or any combination there of. Perhaps there is a microbe factor involved brought on by poor diet or genetics that cannot defend the organism sufficiently, or some combination there of.
__________________ "The nurse should be cheerful, orderly, punctual, patient, full of faith, - receptive to Truth and Love" Mary Baker Eddy