Fish, Fish Oils and Cardiovascular Disease

Years ago the scientific researcher responsible for the promotion of fish oils as an antioxidant and protector against vascular disease recommended we all eat two fleshy fish meals of cold water fish a week. He continued to endorse this dietary addition and included canned tuna fish and canned salmon in the types of fish that produced this positive effect.

Over the years I heard him lecture at a large annual medical conference held in Broward County and he fretted about the growth of the supplement industry encouraging taking fish oils rather than eating fish. He worried about the warnings against eating all fish to women of child bearing age because of the fear of heavy metal contamination and knew that the fish oils and omega 3 Fatty Acids played a developmental role in a growing fetus and child.

I then attended lectures, in particular one sponsored by the Cleveland Clinic, during which they promoted Krill oil as the chosen form of fish oil supplements because it remained liquid and viscous at body temperature of 98.6 while others solidified. I listened to this debate only to hear the father of the science speak again and this time advocate that one or two fleshy fish meals a month was adequate to obtain the protective effect of Omega 3 Fatty acids. He felt that the supplements did not actually provide a protective effect as eating real fish did. Since I love to eat fresh fish I had no problem with this message but others are not comfortable buying and preparing fish at home or eating it at a restaurant. Supplements to them were the answer.

Steve Kopecky, M.D. examined the question in an article published in JAMA Cardiology this week. He looked at 77,917 high risk individuals already diagnosed with coronary artery disease and vascular disease who were taking supplements to prevent a second event. His study concluded that taking these omega 3 supplements had no effect on the prevention of recurrent cardiovascular events. The study did not discuss primary prevention for those who have not yet had a vascular illness or event.

Once again it seems that eating fish in moderation, like most anything, is the best choice. I will continue to eat my fresh fish meals one or two times per week, not necessarily for the health benefit but because I enjoy eating fresh fish.

I advise those worried about preventing primary or secondary heart and vascular disease to find a form of fish they can enjoy if they want this benefit. If you really wish to reduce your risk of a cardiovascular event; I suggest you stop smoking, control your blood pressure and lipid profile, stay active and eat those fresh fish meals.

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Fish Oils in Osteoarthritis – Low Dose vs. High Dose

Using the common sense approach that if a little bit is good then more is better in the treatment of “rheumatism” Catherine Hill, M.D., of the University of Adelaide in Australia and colleagues looked at the effect of taking low dose fish oil supplements versus high dose fish oil supplements. When one looks at the adult population of Australia, one third of them take fish oil supplements and had within a month of this study. The typical dose is one ml of fish oil per day. Experts say the dose for anti-inflammatory effect for arthritis is considerably higher at 2.7 gram or 10 ml per day. Dr Hill’s theory was that high dose fish oil for symptomatic and structural outcomes in people with knee osteoarthritis was better.

She enrolled 202 symptomatic patients in a double blind study. High dose group patients received 4.5 g EPA/HPA per day. The low dose group were given a blended of fish oil containing 0.45 g EPA /DHA per day in combination with Sunola oil. Both supplements were flavored with citrus oil.

All patients received a baseline MRI of the knee at inception of the study and at two years. The patients mean age was 61 years and body mass index was 29kg/meter squared. Both groups showed x-ray evidence of arthritis in the knee at inception and both groups were allowed to take non-steroidal anti-inflammatory medications and acetaminophen for arthritic pain during the course of the study.

At two years there was no difference in the MRI findings or cartilage volume loss between the high dose and low dose groups. Each group took similar amounts of NSAIDs and acetaminophen for pain on a regular basis. The high dose had no benefit over the low dose.

The researchers concluded that there was no benefit in their study to high dose versus low dose fish oil supplementation for arthritis. They reasoned that since patients in the study were permitted to take additional fish oils on their own during the study this may have altered the findings. The researchers additionally had little control over how much fish the participants ate.

In reviewing the data it seems to indicate that fish oil played a minor role in slowing down arthritis in the knee joint. Low dosage had as good of an effect as high dosage but the studies lack of a true control group who did not take fish oil at all made the conclusions hard to accept.

I will suggest to my patients that they continue to eat two fleshy fish meals per week to get their fish oils for arthritis and cardiovascular protection, rather than purchasing and taking low dose or high dose fish oil supplements.

American Diabetes Association: Fish Oils Do Not Reduce Cardiovascular Event Risk

The American College of Cardiology now recommends that individuals take “fish oil” supplements in pill form to prevent coronary artery and vascular disease. The scientist who discovered that fish oils may have beneficial effects has publically come out and let it be known that he feels differently on the subject. While he once advocated eating two fleshy cold water fish meals a week to gain some degree of protection, he has most recently reduced that requirement to two meals a month. He has additionally scolded the nutritional supplement community for the promotion of fish oils in pill form when it can be safely and effectively obtained by eating a few cans of tuna fish or salmon per month.

Recently, at the annual meeting of the American Diabetes Association, Jackie Bosch, MSc, from McMaster University and Hamilton Health Sciences in Hamilton, Ontario presented data that suggested that fish oils did not reduce cardiovascular deaths or events.  The data was abstracted from the ongoing ORIGIN (Outcome Reduction with Initial Glargine Intervention) study of 12,536 patients with type 2 diabetes, impaired fasting glucose levels or impaired glucose tolerance. These study participants were composed of 65% men with a mean study age of 64 years who were followed for over six years. The study group received one gram daily of n-3-fatty acids.

The data showed that fish oils did not make a difference in the number of fatal or non-fatal heart attacks, fatal and non-fatal strokes, hospitalizations for heart failure, revascularization procedure numbers, and loss of a limb or digit due to poor circulation for any cardiovascular cause. The study additionally showed that the use of a long-acting insulin Glargine had no detrimental or beneficial effects on cardiovascular disease.  The story was covered and summarized in the online periodical of the University of Pennsylvania Medical School, MedPage.  Interestingly, the placebo group received one gram per day of olive oil.

Clearly this is another indictment against taking pills instead of acquiring nutrients in a well prepared balanced diet that includes cold water fleshy fish weekly.  Upon reading the study, I wondered if the use of olive oil by the placebo group was cardio-protective and fish oils were just no more cardio-protective than olive oil?  Once again, further research is needed. While the research is ongoing, eating cold water fleshy fish once a week as part of a nutritionally sound, well prepared diet rather than taking fish oil pills seems to make sense.

Fish Oils Fail To Stave Off Mental Decline

Dietary supplementation with Omega-3 fatty acids did not prevent cognitive decline in older individuals according to a study which reviewed the subject in the online magazine MedPage, a publication of the University of Pennsylvania School of Medicine.  By the year 2040, more than 80 million people will be affected with dementia. There has been increasing interest in identifying dietary factors that could help diminish these numbers.

The study was performed by Emma Sydenham, MSc of the London School of Hygiene and Tropical Medicine in response to some previous observational studies that suggested that consuming high levels of polyunsaturated fatty acids may reduce the likelihood of cognitive decline with aging. Some evidence does exist that fatty acids play an important role in brain health through the maintenance of neuronal functioning while acting as mediators of inflammation and oxidative stress.

Sydenham and associates looked back at three major studies designed primarily to assess the efficacy of Omega-3 fatty acids in preventing cardiovascular disease.  Cognitive function was assessed by various methods in all three well-designed studies.  All three studies indicated that Omega-3 fatty acids played no role in preventing cognitive decline.

Sydenham’s team suggested that more research is needed in this area. I believe this study emphasizes the wisdom of eating a balanced diet prepared in a way to retain the nutrients – inclusive of several portions of cold water fleshy fish per week.

In general, if you provide your body with the nutrients it needs by consuming appropriately prepared healthy portions, your body will extract what it needs.