Fish Oil Supplements Are a Waste for Many

Salmon is one the the cold-water fatty fish loaded with omega-3 fatty acids

Salmon is one the the cold-water fatty fish loaded with omega-3 fatty acids

Many of us eating fish or taking fish oil supplements, hoping that they will prevent heart attacks and the associated premature death. As it turns out, they may do neither.

I’ve been sitting on this research report a few years, waiting until I had time to dig into it. That time never came. The full report is free online (thanks, British Medical Journal!). I scanned the full paper to learn that nearly all the studies in this meta-analysis used fish oil supplements, not the cold-water fatty fish the I recommend my patients eat twice a week.

Here’s the abstract:

Objective: To review systematically the evidence for an effect of long chain and shorter chain omega 3 fatty acids on total mortality, cardiovascular events, and cancer.

Data sources: Electronic databases searched to February 2002; authors contacted and bibliographies of randomised controlled trials (RCTs) checked to locate studies.

Review methods Review of RCTs of omega 3 intake for 3 6 months in adults (with or without risk factors for cardiovascular disease) with data on a relevant outcome. Cohort studies that estimated omega 3 intake and related this to clinical outcome during at least 6 months were also included. Application of inclusion criteria, data extraction, and quality assessments were performed independently in duplicate.

Results: Of 15 159 titles and abstracts assessed, 48 RCTs (36 913 participants) and 41 cohort studies were analysed. The trial results were inconsistent. The pooled estimate showed no strong evidence of reduced risk of total mortality (relative risk 0.87, 95% confidence interval 0.73 to 1.03) or combined cardiovascular events (0.95, 0.82 to 1.12) in participants taking additional omega 3 fats. The few studies at low risk of bias were more consistent, but they showed no effect of omega 3 on total mortality (0.98, 0.70 to 1.36) or cardiovascular events (1.09, 0.87 to 1.37). When data from the subgroup of studies of long chain omega 3 fats were analysed separately, total mortality (0.86, 0.70 to 1.04; 138 events) and cardiovascular events (0.93, 0.79 to 1.11) were not clearly reduced. Neither RCTs nor cohort studies suggested increased risk of cancer with a higher intake of omega 3 (trials: 1.07, 0.88 to 1.30; cohort studies: 1.02, 0.87 to 1.19), but clinically important harm could not be excluded.

Conclusion: Long chain and shorter chain omega 3 fats do not have a clear effect on total mortality, combined cardiovascular events, or cancer.

If you’re taking fish oil supplements on your doctor’s advice, don’t stop without consulting her. The study at hand doesn’t address whether eating cold-water fatty fish twice a week prevents heart attacks and premature death. 

Steve Parker, M.D.

Reference: Hooper, Lee et al. Risks and benefits of omega 3 fats for mortality, cardiovascular disease, and cancer: systematic review. BMJ  2006;332:752-760 (1 April), doi:10.1136/bmj.38755.366331.2F (published 24 March 2006).

Very-Low-Carb Diet Beats Medium-Carb ADA Diet in Type 2 Diabetes

Compared to a traditional American Diabetes Association diet, a very-low-carbohydrate ketogenic diet was more effective at controlling type 2 diabetes and prediabetes, according to University of California San Francisco researchers.

The debate about the best diet for people with diabetes will continue to rage, however. You’ll even find some studies supporting vegetarian diets. I’m still waiting for published results of the Frassetto group’s paleo diet trial.

Some non-starchy low-carb vegetables

Some non-starchy low-carb vegetables

Details

Thirty-four overweight and obese type 2 diabetics (30) and prediabetics (4) were randomly assigned to one of the two diets:

  1. MCCR: American Diabetes Association-compliant medium-carbohydrate, low-fat, calorie-resticted carb-counting diet. The goals were about 165 grams of net carbs daily, counting
    carbohydrates, an effort to lose weight by eating 500 calories/day less than needed for maintenance, and 45–50% of total calories from carbohydrate. Protein gram intake was to remain same as baseline. (Note that most Americans eat 250–300 grams of carb daily.)
  2. LCK: A very-low-carbohydrate, high-fat, non-calorie-restricted diet aiming for nutritional ketosis. It was Atkins-style, under 50 grams of net carbs daily (suggested range of 20–50 g). Carbs were mostly from non-starchy low-glycemic-index vegetables. Protein gram intake was to remain same as baseline.

Baseline participant characteristics:

  • average weight 100 kg (220 lb)
  • 25 of 34 were women
  • average age 60
  • none were on insulin; a quarter were on no diabetes drugs at all
  • most were obese and had high blood pressure
  • average hemoglobin A1c was about 6.8%
  • seven out of 10 were white

Participants followed their diets for three months and attended 13 two-hour weekly classes. Very few dropped out of the study.

Results

Average hemoglobin dropped 0.6% in the LCK group compared to no change in the MCCR cohort.

A hemoglobin A1c drop of 0.5% or greater is considered clinically significant. Nine in the LCK group achieved this, compared to four in the MCCR.

The LCK group lost an average of 5.5 kg (12 lb) compared to 2.6 kg (6 lb) in the MCCR. The difference was not statistically significant, but close (p = 0.09)

44% in the LCK group were able to stop one or more diabetes drugs, compared to only 11 % in the other group

31% in the LCK cohort were able to drop their sulfonylurea, compared to only 5% in the MCCR group.

By food recall surveys, both groups reported lower total daily caloric intake compared to baseline. The low-carbers ended up with 58% of total calories being from fat, a number achieved by reducing carbohydrates and total calories and keeping protein the same. They didn’t seem to increase their total fat gram intake;

The low-carbers apparently reduced daily carbs to an average of 58 grams (the goal was 20-50 grams).

There were no differences between both groups in terms of C-reactive protein (CRP), lipids, insulin levels, or insulin resistance (HOMA2-IR). Both groups reduced their CRP, a measure of inflammation.

LCK dieters apparently didn’t suffer at all from the “induction flu” seen with many ketogenic diets. They reported less heartburn, less aches and pains, but more constipation.

Hypoglycemia was not a problem.

If I recall correctly, the MCCR group’s baseline carb grams were around 225 g.

Bottom Line

Very-low-carb diets help control type 2 diabetes, help with weight loss, and reduce the need for diabetes drugs. An absolute drop of 0.6% in hemoglobin A1c doesn’t sound like much, translating to blood sugars lower by only 15–20 mg/dl (0.8–1 mmol/l). But remember the comparator diet in this study was already mildy to moderately carbohydrate-restricted. At least half of the type 2 diabetics I meet still tell my they don’t watch their carb intake, which usually means they’re eating around 250–300 grams a day. If they cut down to 58 grams, they most likely will see more than a 0.6% drop in hemoglobin A1c after switching to a very-low-carb diet.

If you’re developing a new diabetes drug that drops hemoglobin A1c by 0.6%, you’ll get FDA approval for effectiveness.

This is a small study, so it may not be reproducible in larger clinical trials and other patient populations. Results are consistent with several other similar studies I’ve seen, however.

Steve Parker, M.D.

Reference: Saslow, Laura, et al (including Stephen Phinney). A Randomized Pilot Trial of a Moderate Carbohydrate Diet Compared to a Very Low Carbohydrate Diet in Overweight or Obese Individuals with Type 2 Diabetes Mellitus or PrediabetesPLoS One. 2014; 9(4): e91027. Published online Apr 9, 2014. doi: 10.1371/journal.pone.0091027     PMCID: PMC3981696

PS: When I use “average” above, “mean” is often a more accurate word, but I don’t want to have to explain the differences at this time.

PPS: Carbsane Evelyn analyzed this study in greater detail that I did and came to different conclusions. Worth a read if you have an extra 15 minutes.

Guest Post: The Three Bears of Blood Sugar

Paul Cathcart has diabetes; type 1 I’m guessing. He contacted me by email and wanted to share a chapter out of his book, Persona Non Grata With Diabetes: A Self-Portrait of the Diabetic Condition. The only modification I’ve made is to translate mmol/l to mg/dl for my U.S. readers. Here ’tis.

♦♦♦

The Three Bears of Blood Sugar

How do I make myself better?

Fat bear: too much insulin. Skinny bear: sugar too high. Just right bear: healthy, happy diabetic.

Let’s for a moment, forget the experts and let us concentrate on me the diabetic instead.Like the cave man my body does not expect to eat every day. My body by default, collects and stores energy till it seeps through my diabetic veins, peaking my sugar levels, disrupting my salt levels, polluting my blood into acidic syrup; and after fifteen years, making me cry out for help: all anyone could tell me was to have more insulin.

Insulin makes me fat; it’s a foreign synthesised chemical hormone injected into my body to process sugar, storing the excess energy as fat. The more insulin I take the more my body resists. The more my body resists the more it blocks and backs up, creating insulin pockets. These pockets then randomly infuse with my system as a massively unexpected dose, leaving me in one hell of a hypo, and my body burning off fat and muscle producing sugar to fight it. And there I go, straight back up into the high blood sugar numbers tail spin again.

Carbohydrates make me fat; my body cannot digest them in a timely fashion with the insulin. They cause spikes in my blood sugar, which peak and trough out of phase from my five hours analogue insulin timeline. They don’t really catch up and round off, Dose Adjustment For Normal Eating (D.A.F.N.E) style, but slowly degrade the quality of my blood, and clog my organs forcing my body to react in the early morning trying desperately to process them with dawn sugars; and there it is back up to “18.0” again when I went to bed with sugar of “7.2.” [18 mmol/l = 324 mg/dl; 7.2 mmol/l = 130 mg/dl]

High sugar makes me skinny, unable to properly digest food, hold water or heal; my body melting into a puddle of acidic sugar as it did prior to first being diagnosed with diabetes. Easy to slip back in and out of when combining too much insulin, in meeting with the requirements of feeding off the wrong kinds of food for energy, topped up by too much sugar in chasing the tail of excessive insulin.

These very same ups and downs are what aggravate my temper, tire my soul and over time negate my character. Far simpler to digest protein and green leaf vegetables; easy, slow burning energy matching a, small quantity, five hours insulin timeline: synchronising my body while negating fluctuations. I’m far less likely to build up pockets of insulin under the skin, avoiding numerous side effects at later stages. It’s metabolic meditation. We are all just flowers really; I can feel myself begin to wilt after only a few days of uneven blood sugar, then after only two of even levels I feel uplifted as though the sun has come up. It’s really ninety percent diet, ten percent insulin, to be in control.

—Paul Cathcart

Taken from, ‘Persona Non Grata with Diabetes.’
http://www.pngwd.com/the_three_bears.html

Website for Paul’s book

New Kitchen Gadget: Vitamix

Our first creation with the Vitamix

Our first creation with the Vitamix

Grok couldn’t grok it. The noise would scare him.

I call it a mixer; my wife calls it a food processor. We’ll be blending up a storm and reporting at my various blogs. My wife’s been thinking about getting a contraption like this for months. She got excited and bit the bullet when she saw a live demonstration at Costco a few months ago.

Almost immediately out of the box, my wife threw in a couple handfuls of ice, couple handfuls of frozen strawberries, and one and a half bananas. I thought this would be a fruit smoothie, but with the very thick consistency, “Italian ice” might be a better term.

One of our goals is to sneak more fiber, vegetables, and fruit into our kids diets. (Shhhh….don’t tell!)

It's a little noisy, but easily bearable

It’s a bit noisy, but easily bearable

$500 (USD) at Costco, so not cheap. It seems well-made and has a good SEVEN-year warranty!

$500 (USD) at Costco, so not cheap. It seems well-made and has a good SEVEN-year warranty!

Pollution May Be Causing T2 Diabetes and Obesity

It sounds like Jerome Ruzzin is convinced that’s the case. I put some thought into it last August and was skeptical—still am, but I’m keeping an open mind. Mr. Ruzzin has a review article published in 2012 at BMC Public Health (“Public health concern behind the exposure to persistent organic pollutants and the risk of metabolic diseases”). Here’s his summary:

The global prevalence of metabolic diseases like obesity and type 2 diabetes, and its colossal economic and social costs represent a major public health issue for our societies. There is now solid evidence demonstrating the contribution of POPs [persistent organic pollutants], at environmental levels, to metabolic disorders. Thus, human exposure to POPs might have, for decades, been sufficient and enough to participate to the epidemics of obesity and type 2 diabetes. Based on recent studies, the fundaments of current risk assessment of POPs, like “concept of additive effects” or “dioxins and dl-PCBs induced similar biological effects through AhR”, appear unlikely to predict the risk of metabolic diseases. Furthermore, POP regulation in food products should be harmonized and re-evaluated to better protect consumers. Neglecting the novel and emerging knowledge about the link between POPs and metabolic diseases will have significant health impacts for the general population and the next generations.

Read the whole enchilada.

The cold-water fatty fish I so often recommend to my patients could be hurting them. They are major reservoirs of food-based POPs.

Steve Parker, M.D.

Should “Low-Carb” Be the Default Diet for Diabetes?

Yes….according to a manifesto to be published soon in Nutrition. The abstract:

The inability of current recommendations to control the epidemic of diabetes, the specific failure of the prevailing low-fat diets to improve obesity, cardiovascular risk or general health and the persistent reports of some serious side effects of commonly prescribed diabetic medications, in combination with the continued success of low-carbohydrate diets in the treatment of diabetes and metabolic syndrome without significant side effects, point to the need for a reappraisal of dietary guidelines.

The benefits of carbohydrate restriction in diabetes are immediate and well-documented. Concerns about the efficacy and safety are long-term and conjectural rather than data-driven. Dietary carbohydrate restriction reliably reduces high blood glucose, does not require weight loss (although is still best for weight loss) and leads to the reduction or elimination of medication and has never shown side effects comparable to those seen in many drugs.

diabetic diet, low-carb diet, paleobetic diet

Low-Carb Brian burger and bacon Brussels sprouts (in the Paleobetic Diet)

The lead author is Richard Feinman. Others include Lynda Frassetto, Eric Westman, Jeff Volek, Richard Bernstein, Annika Dahlqvist, Ann Childers, and Jay Wortman, to name a few. Some of them disclose that they have accepted money from the Veronica and Robert C. Atkins Foundation. That doesn’t bother me.

I’m familiar with most of the supporting literature they cite, having read it over the last decade.

Read the whole enchilada.

Steve Parker, M.D.

PS: The linked article is preliminary and may undergo minor revision over the coming months.

Do Processed Red Meats Reduce Lifespan?

They were linked to higher risk of death in this Swedish study. Regular non-processed red meats had no association with shorter life, however. 

 

 

Dr. Richard Feinman Doubts Red Meat Causes T2 Diabetes

This looks healthful to me, despite the red meat

This looks healthful to me, despite the red meat

At least one recent study implicated red meat consumption as a cause of type 2 diabetes. Dr. Richard Feinman at his blog takes a close look at the 2013 study and points out the great difficulty in making the leap from red meat to diabetes. I think Dr. Feinman’s point is best made by his graph about half way through the post, showing steadily decreasing red meat consumption as T2 diabetes takes off over the last four decades. (I assume all the figures are based on U.S. data.)

For the opposing viewpoint, read the original study (linked at Dr. F’s blog) or search at Fanatic Cook.

Do I worry that red meat causes diabetes? Not much. I await definitive research.

Steve Parker, M.D.

Dr. Briffa on Carbohydrate Restriction for Diabetics

Diabetes UK is a prominent charity in Britain. It recommends that diabetics eat generous servings of carbohydrates: 5–14 daily servings of lower-glycemic-index items. Dr. Briffa strongly disagrees:

I can categorically state here that when individuals with diabetes cut back on carbohydrates, they almost always see significant improvement in their blood sugar control. They usually lose weight, and see improvements in markers of disease too. I’m most certainly not the only person to have noticed this. Just yesterday I met a most wonderful general practitioner who has come to the low-carb approach quite late in his career, but has used it to utterly transform the health of his patients. He showed me a variety of graphs from several patients pre- and post-adoption of a lower carbohydrate diet. He relayed a few stunning anecdotes too of people who believe eating a lower-carb diet has given them their health and their lives back.

***

I won’t mince my words and state here that I believe these recommendations [of Diabetes UK] are utterly mad. My experience tells me they will generally just entrench diabetics in their condition and the need for medical care. Compared to a lower-carbohydrate diet, the regime advocated by Diabetes UK stands to worsen blood sugar control and increase the need for medication and risk of complications. If Diabetes UK is serious about helping diabetics, I suggest it starts by ceasing to recommend a diet that, in my view, is utterly unsuitable for diabetics.

 

QOTD: J. Stanton on Weight Loss and Exercise

Let me be clear. Exercise is not important because it burns calories! Exercise without calorie restriction is a remarkably ineffective weight loss intervention, because it usually makes us hungry enough to replace the calories we burn. Exercise is important because it restores your ability to oxidize fat—both when fasting and after meals. And we can tie this in with mitochondrial dysfunction by noting that exercise is proven to increase mitochondrial volume.

J. Stanton