Tag Archives: omega-3 fatty acids

Fish Oil Supplements Are a Waste for Many

Posted on September 15, 2014 | 9 comments
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 are 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).

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Posted in Heart Disease, Longevity

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Minimize Mercury and Maximize Health With These Fish

Posted on April 17, 2014 | Comments Off on Minimize Mercury and Maximize Health With These Fish
paleo diet, low-carb, Steve Parker MD

This hunter-gatherer snagged himself a brown trout

The Environmental Working Group has a fresh article reviewing the risk of mercury poisoning from seafood consumption. I’m not familiar with EWG. I’m trying not to hold it against them that Dr. Mark Hyman is on the board of directors.

Anyway, the EWG has some advice for you if you worry about mercury toxicity from fish. I try to stay up to date on the issue since I’m convinced that consumption of cold-water fatty fish twice a week is good for your health, in general. If the mercury doesn’t kill you.

Here are some quotes from the EWG article:

…EWG has compiled a list of “moderate mercury” species that would pose a mercury risk for pregnant woman and children who eat fish regularly. This list is more comprehensive than the 2004 EPA/FDA advisory, which warned that women of childbearing age and young children, who are most susceptible to the damage done by mercury, should eat only six ounces a week of albacore tuna and should avoid four other high-mercury species – swordfish, tilefish, king mackerel and shark.

EWG rightly points out that much of the “seafood” consumed in the U.S. really doesn’t provide much of the healthful omega-3 fatty acids.

Among popular seafood species, salmon stands out as an excellent choice.  Four to eight ounces of salmon weekly, depending on the species, can provide 100 percent of the recommended amount of omega-3s. Some types of farmed salmon present significant environmental health concerns. EWG recommends that people choose wild salmon instead.

EWG’s analysis highlights several other affordable and sustainably produced species, including anchovies, sardines, farmed trout, and mussels.  Just four to eight ounces of these species weekly would meet recommended omega-3 requirements for pregnant women and people with heart disease.

***

Americans eat more than 400 million pounds of canned imported tuna because it is affordable and can be stored for a long time. Canned tuna is the second most popular seafood in the U.S., after shrimp.  An average American eats an average of 2.5 pounds of tuna every year (NOAA 2012).  Albacore tuna, also called “white” tuna, contains significant amounts of omega-3s, but tests indicate that it also contains significant amounts of mercury. “Light” tuna is usually skipjack tuna but can also contain yellowfin tuna. Skipjack and yellowfin have lower mercury levels than albacore, but fewer omega-3s.

As Jim Gaffigan asked, “Has anyone even bothered to ask why the tuna are eating mercury?”

In 30 years of practicing medicine, including 12 years right on the U.S. Gulf Coast, I’ve never seen a case of mercury toxicity. Maybe I’ve missed it. Maybe it’s quite rare.

Read the whole enchilada.

Steve Parker, M.D.

h/t Conner Middelmann-Whitney

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What Is The Only Australian Plant Crop That Has Ever Been Commercially Developed as a Food?

Posted on December 23, 2013 | Comments Off on What Is The Only Australian Plant Crop That Has Ever Been Commercially Developed as a Food?

David Mendosa says the answer is the macadamia nut.

Paleobetic diet

Macadamia nuts

From a paleo perspective, a great thing about the macadamia nut is that it’s one of the few nuts with a good omega-6/omega-3 fatty acid ratio. In other words, it’s high in omega-3 and low in 6. This may have important cardiovascular health implications. Macadamias are one of the nuts I recommend on my Paleobetic Diet.

David writes:

The first Australian macadamia plantation didn’t begin until the 1880s. And not until 1954 with the introduction of mechanised processing did commercial production became viable. Nowadays about 90 percent of the the world’s macadamia nut production comes from Hawaii, where it has become its third most important crop, according to The Wellness Encyclopedia of Food and Nutrition, University of California at Berkeley (1992).

Read the rest, where you’ll learn that macadamia nuts are the highest of all nuts in calories, gram for gram.

Paleobetic diet

Macadamia nuts on the tree

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Recipe: Waldorfian Salad

Posted on December 5, 2013 | 3 comments
paleobetic diet, low-carb diet

One cup of Waldorfian salad. I doubled the cinnamon in this batch, so yours won’t look quite like this.

Today’s meal is inspired by the classic Waldorf salad, made famous by New York’s Waldorf Hotel over a century ago. The hotel today is called the Waldorf-Astoria.

The primary ingredients are apples, walnuts, and celery.

The original salad was made with mayonnaise, which I’m leaving out since I don’t yet have a paleo-compliant formula. They’re out there, however. Do you have a favorite?

paleobetic diet

Good source of omega-3 fatty acids

Instead of mayonnaise, we use a dressing—a vinaigrette—made with walnut oil. Walnut oil is attractive in part because it is rich in omega-3 fatty acids: 1.77 grams per tbsp (15 ml). Compared with Paleolithic diets, modern Western diets are too low in omega-3s and too high in omega-6s. You can use your left-over walnut oil the way you’d use olive oil.

paleobetic diet, low-carb diet, ketogenic diet

I made my dressing in this BPA-laden plastic container

In composing the Paleobetic Diet, my biggest challenge is breakfast. I’m fine eating eggs almost daily, but that may not be your cup ‘o tea. Most of us in America are accustomed to grain-based options like cold cereal, porridge, bagels, donuts, pancakes, granola, and toast. Plus yogurt. Those aren’t paleo, and they have too many carbohydrates for many diabetics. I came up with Waldorfian salad as a low-carb paleo-style breakfast, reminiscent of Brian’s Berry Breakfast.

This recipe makes two large servings of 2 cups (480 ml) each. Small or sedentary folks may well be satisfied with a 1- or 1.5-cup serving.

paleobetic diet, low-carb diet, ketogenic diet

Apples are the primary source of carbohydrates in this recipe.

Ingredients:

2 apples, raw, medium size, skin on, diced (I used Red Delicious; consider Granny Smith, Fuji, or Gala)

3 celery stalks, 8-inches long (20 cm), diced

1 cup (240 ml) walnuts, broken by hand into small chunks (Option for ? more flavor: toast in a skillet over medium-high heat for 7-10 minutes or in oven (350 F or 175 C) on baking sheet for 10 minutes

1/4 tsp (1.2 ml) black pepper, ground

1/4 tsp (1.2 ml) salt

1.5 tbsp (22 ml) walnut oil

1 tbsp (15 ml) cider vinegar

1/2 tsp (2.5 ml) cinnamon

1/4 tsp (1.2 ml) nutmeg

Instructions:

First make a dressing with the bottom six ingredients. I put mine in a small container with a lid, then shook vigorously. Or you can put them in a small bowel and whisk them.

paleobetic diet, low-carb diet, ketogenic diet

Walnut pieces

Place the walnuts, apples and celery in a bowel, add the dressing and toss thoroughly. You’re done.

Serve as is, or chill first in the refrigerator. Maybe it was my imagination, but I thought it tasted better after it sat on the counter for 10 minutes. Consider serving on a bed of lettuce (1-2 oz), but if you do, increase your digestible carb count by 1-2 grams.

If you want more calories or protein than this recipe provides, chicken or steak should go well with Waldorfian salad and won’t increase your carb grams.

Number of Servings: 2 (2 cups each)

Nutritional Analysis:

73% fat

21% carbohydrate

6% protein

500 calories

27.5 g carbohydrate

7.6 g fiber

20 g digestible carbohydrate

341 mg sodium

529 mg potassium

Prominent features: High in copper and manganese, low in sodium. This is vegetarian (so much for the paleo diet being meat-centric). On a 2,000 calorie diet, this provides only 15% of the Recommended Dietary Allowance for protein, so you’ll want to eat more protein at some point during the day.

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Posted in Nuts, Recipes

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Right Diet Preserves Brain Function and Size

Posted on April 12, 2012 | 1 comment

mp9004223691.jpgThe journal Neurology reports that the proper diet seems to help prevent age-related brain shrinkage and cognitive decline.

From the press release:

People with diets high in several vitamins or in omega 3 fatty acids are less likely to have the brain shrinkage associated with Alzheimer’s disease than people whose diets are not high in those nutrients, according to a new study published in the December 28, 2011, online issue of Neurology, the medical journal of the American Academy of Neurology.

Those with diets high in omega 3 fatty acids and in vitamins C, D, E and the B vitamins also had higher scores on mental thinking tests than people with diets low in those nutrients. These omega 3 fatty acids and vitamin D are primarily found in fish. The B vitamins and antioxidants C and E are primarily found in fruits and vegetables.

So the dietary pattern linked to preservation of brain size and function in this study is: high omega-3 fatty acids and vitamins B, C, D, and E. I don’t know if study participants were getting these nutrients from supplements or from food or a combination. (I haven’t read the full article.)

To find foods high in the aforementioned nutrients, you can use NutritionData’s Nutrient Search Tool.

Note that the time-honored Mediterranean diet is also associated with lower rates of dementia and slower rate of age-related mental decline.

I previously reported that a supplement cocktail of three B vitamins slowed the rate of brain shrinkage.

Steve Parker, M.D.

Reference: Bowman, G.L., et al. Nutrient biomarker patterns, cognitive function, and MRI measures of brain aging. Neurology. doi: 10.1212/WNL.0b013e3182436598

h/t to Randall Parker at FuturePundit

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