Eat Cod to Lose More Weight

BUS30079Five servings of cod per week led to loss of an extra 3.7 pounds (1.7 kg) over eight weeks, according to a 2009 research report.

European researchers noted that cod consumption in a prior study enhanced weight loss. They wondered if that result could be reproduced, and whether the effect was “dose dependent.” In other words, would those eating more cod lose more weight than those eating less?

They studied 125 subjects between the ages of 20 and 40, with body mass index between 27.5 and 32.5. The abstract doesn’t mention sex of the participants. They were all placed on calorie-restricted diets with identical percentages of protein, fat, and carbohydrate, and were followed for eight weeks. Researchers divided the subjects into three groups:

  1. One group was given 150 g (a little over 5 ounces) of cod three times weekly
  2. Another group was given 150 g cod five times weekly
  3. The third group was given no seafood

Average weight loss overall was 11 pounds (5 kg). The more cod consumed, the greater the weight loss. Those eating five servings a week averaged 3.7 pounds (1.7 kg) more than the group not eating seafood.

It’s unclear whether other types of fish would produce similar results.

These results support the prominent role of fish in the Ketogenic Mediterranean Diet.

Steve Parker, M.D.

Reference: Ramel, A., et al. Consumption of cod and weight loss in young overweight and obese adults on an energy reduced diet for 8-weeks. Nutrition, Metabolism and Cardiovascular Diseases, 19 (2009): 690-696.

Drink Vinegar and Lose 2-4 Pounds Effortlessly

CB052540Japanese researchers a couple years ago documented that daily vinegar reduces body weight, fat mass, and triglycerides in overweight Japanese adults.

Beverages containing vinegar are commonly consumed in Japan. The main component—4 to 8%— of vinegar is acetic acid. Vinegar can lower cholesterol levels, lower blood pressure, and limit increases in blood sugar after meals.

Japanese researchers studied the effects of vinegar on 175 overweight—body mass index between 25 and 30—subjects aged 25 to 60. Men totaled 111; women 64. Average weight 74.4 kg (164 pounds). They were divided into three groups that received either a placebo drink, 15 ml apple vinegar (750 mg of acetic acid), or 30 ml apple vinegar (1,500 mg acetic acid). Placebo and vinegar were mixed into 500 ml of a beverage, half of which was drunk twice daily after breakfast and supper for 12 weeks. Changes in body fat were measured with CT technology. Subjects were told to eat and exercise as usual.

Results

By the end of the 12 weeks, weight had decreased by 1-2 kg (2.2 to 4.4 pounds) in the vinegar drinkers, with 30 ml of vinegar a bit more effective. CT scanning showed that the lost weight was fat mass rather than muscle or water. Triglyceride levels in the vinegar groups fell by about 20%. The placebo drinkers saw no changes.

Four weeks after the intervention ended, subjects were retested: values had returned to their baseline, pre-study levels.

The scientists report that the acetic acid in vinegar inhibits production of fat and may stimulate burning of fat as fuel. Although vinegar contains many other ingredients, they think the acetic acid is responsible for the observed changes.

My Comments

It’s possible that apple vinegar components other than acetic acid led to the weight loss and lowered triglyceride levels. Further study could clarify this.

Remember that weight lossed was regained after the vinegar was discontinued. Would you want to drink the vinegar indefinitely to maintain a loss of 2-4 pounds? Probably not, unless you like vinegar. But adding 12 weeks of vinegar to your weight-loss program might be worth it if you’re just preparing for a school reunion or the start of swimsuit season.

These results may or may not be applicable to non-Japanese races.

This study supports the use of vinaigrette as a salad or vegetable dressing in people trying to lose weight with diets such as the Ketogenic Mediterranean Diet or Advanced Mediterranean Diet. Vinaigrettes are combinations of olive oil and vinegar, often with various spices added. If you eat a salad twice a day, it would be easy to add 15 ml (1 tbsp) of vinegar to your diet daily.

With a little imagination, you could come up with other ways to add 15–30 ml (1–2 tbsp) of vinegar to your diet.

Update May 17, 2012:  After posting this, I ran across on article on the Apple Cider Vinegar Diet at Life123.

Steve Parker, M.D.

Reference: Kondo, Toomoo, et al. Vinegar intake reduces body weight, body fat mass, and serum triglyceride levels in obese Japanese subjects. Bioscience, Biotechnology, and Biochemistry, 73 (2009): 1,837-1,843.

Video Demonstrating HIIT

Gretchen Reynolds is the Phys Ed blogger at the New York Times.  She posted a five-minute demonstration of high intensity interval training on a stationary bicycle.  It’s narrated by Martin Gibala of McMaster University.

No mention of Tabata.

-Steve

Mediterranean Diet Linked to Lower Stomach Cancer Risk

The Mediterranean diet is associated with a 33% reduction in stomach cancer, according to a study published in the American Journal of Clinical Nutrition.

Stomach cancer (aka gastric cancer) is uncommon in the U.S. Most cases are advanced and incurable at the time of diagnosis. So prevention is ideal.

European investigators studied 485,000 people over the course of nine years, during which 449 cases of stomach cancer were found. Surveys determined how closely the food consumption of study participants tracked nine key components of the Mediterranean diet. Compared with people who had low adherence to the Mediterranean diet, those with high adherence had 33% less risk of developing stomach cancer.

The Mediterranean diet has long been associated with a lower risk of cancer: specifically, cancers of the breast, colon, prostate, and uterus. We can add stomach cancer to the list now.

Steve Parker, M.D.

Reference: Buckland, Genevieve, et al. Adherence to a Mediterranean diet and risk of gastric adenocarcinoma within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort study. American Journal of Clinical Nutrition, December 9, 2009, epub ahead of print. doi: 10.3945/ajcn.2009.28209

Book Review: The Blue Zones

Here’s my review of The Blue Zones: Lessons for Living Longer From the People Who’ve Lived the Longest, a 2008 book by Dan Buettner. I give the book four stars on Amazon.com’s five-star system (“I like it”).

The publisher donated three copies of The Blue Zones as give-aways, which I gave away to my blog readers.

♦ ♦ ♦

The lifestyle principles advocated in The Blue Zones would indeed help the average person in the developed world live a longer and healthier life. The book is a much-needed antidote to rampant longevity quackery. Dan Buettner’s idea behind the book was “discovering the world’s best practices in health and longevity and putting them to work in our lives.” He succeeds.

Mr. Buettner assembled a multidisciplinary team of advisors and researchers to help him with a very difficult subject. Do people living to 100, scattered over several continents, share any characteristics? Do those commonalities lead to health and longevity?

They studied four longevity hot spots (Blue Zones):

  • Okinawa islands (Japan)
  • Barbagia region of Sardinia (an island off the Italian mainland)
  • Loma Linda, California (a large cluster of Seventh Day Adventists)
  • the Nicoya Peninsula (Costa Rica).

Research focused on people who lived to be 100.

Until recently, two of the Blue Zones—the Nicoyan Peninsula and Sardinia—were quite isolated, with relatively little influence from the outside world.

Mr. Buettner et al identify nine key traits that are associated with longevity and health in these cultures. Of course, association is not causation, which Mr. Buettner readily admits. He draws more conclusions from the data than would many (most?) longevity scientists. Scientists can wait for more data, but the rest of us have to decide and act based on what we know today. Here are the “Power Nine”:

  1. regular low-intensity physical activity
  2. hari hachi bu (eat until only 80% full—from Okinawa)
  3. eat more plants and less meat than typical Western cultures
  4. judicious alcohol, favoring dark red wine
  5. have a clear purpose for being alive (a reason to get up in the morning, that makes a difference)
  6. keep stress under control
  7. participate in a spiritual community
  8. make family a priority
  9. be part of a tribe (social support system) that “shares Blue Zone values”

Of these, I would say the available research best supports numbers 1, 4, 7, 8, and the social support system.

I doubt that hari hachi bu (eat until you’re only 80% full) will work for us in the U.S. It’s never been tested rigorously. The idea is to avoid obesity.

The author believes that average lifespan could be increased by a decade via compliance with the Power Nine. And these would be good, relatively healthy years. Not an extra 10 years living in a nursing home.

Appropriately and early on, Mr. Buettner addresses the issue of genetics by mentioning a single study of Danish twins that convinces him longevity is only 25% deterimined by genetic heritage. Environment and lifestyle choices determine the other 75%. I believe he underestimates the effect of genetics.

Over half the population of the Nicoya Peninsula Blue Zone are of Chorotega Indian descent, not from Spanish Conquistadores. Would a Danish twin study have much to say about Chorotega Indians’ longevity? We don’t know, but I’m skeptical. Also, the Sardinians and Okinawans would seem to have centuries of a degree of inbreeding, too, according to Buettner’s own documentation.

Do the Adventists tend to marry and breed with each other (like Mormons), thereby concentrating longevity genes? You won’t find the question addressed in the book.

Because I think genetics plays a larger role in longevity than 25%, I’d estimate that the healthy lifestyle choices in this book might prolong life by six or seven years instead of 10. But I’m splitting hairs. I don’t have any better evidence than Mr. Buettner, just a hunch plus years of experience treating diseased and dying patients.

These four Blue Zones do share a mostly plant-based diet of natural foods with minimal processing. Two of the populations—the Okinawans and Costa Ricans—didn’t seem to have any choice. Heavy meat consumption just wasn’t an option available to them. Rather than promoting a low-meat plant-based diet, it might be more accurate to conclude that “you don’t have to eat a lot of meat, chicken, or fish to live a long healthy life.”

In other words, it may not matter how much meat you eat as long as you eat the healthy optimal level of fruits, vegetables, and whole grains. It’s a critical difference not addressed in this book except among the Adventists.

Even if you could live an extra two years as a vegan, I’m sure many people would choose to eat meat anyway. By the way, this book conflates vegan, lacto-vegetarian, lacto-ovo vegetarian, near-vegetarian, and vegetarian into one: vegetarian. They are not necessarily the same. It’s a common problem when considering the health aspects of vegetarianism.

By the same token, plenty of my patients have told me they don’t like any kind of exercise and they won’t do it, even if it would give them an extra two years of life. What many don’t realize is that from a functional standpoint, regular exercise makes their bodies perform as if they were ten years younger. There’s a huge difference between the ages of 80 and 70 in terms of functional abilities.

Why read the book now that you have the Power Nine? To convince you to change your unhealthy ways, and indispensible instruction on how to do so.

Steve Parker, M.D.

Disclosure: The publisher’s representative did not pay me for this review, nor ask for a favorable review. They offered me a review copy and three give-aways, and I accepted. I figure the cost of the books to the publisher was $16 USD total.

Fish With Omega-3 Fatty Acids Reduce Risk of Blindness

Age-related macular degeneration is the leading cause of blindness in Americans over 65. Impaired vision precedes blindness. A recent study linked consumption of omega-3 fatty acids with 30% lower risk of developing macular degeneration. Believe me, it’s a lot better to prevent it than try to treat it once present.

(I have a couple older relatives with macular degeneration, so I pay close attention to the scientific literature.)

What’s the best source of omega-3 fatty acids? Our friend, the fish. Especially cold-water fatty fish such as tuna, trout, sardines, herring, mackerel, halibut, and sea bass. A few plants are also decent sources, but our bodies don’t utilize those omega-3 fatty acids as well as they do from fish.

Note that both the Advanced Mediterranean Diet and Ketogenic Mediterranean Diet feature fish.

Steve Parker, M.D.

Reference: SanGiovanni, J.P., et al. Long-chain polyunsaturated fatty acid intake and 12-y incidence of neovascular age-related macular degeneration and central geographic atrophy: AREDS report 30, a prospective cohort study from the Age-Related Eye Disease Study. American Journal of Clinical Nutrition, 90 (2009): 1,601-1,607. First published October 7, 2009. doi:10.3945/ajcn.2009.27594

Medical Costs of Obesity, Yearly, Per Person: $1,723

The direct yearly medical cost of being obese in the U.S. is $1,723 per obese person, according to a 2009 report in Obesity Reviews. Being overweight is a relative bargain at $266.

These numbers translate into $114 billion yearly, or five to 10 percent of total healthcare spending.

Not included in the numbers are costs such as lost productivity due to obesity-related illness and replacement or repair of items that wear out or break due to excessive amounts of physical stress. Not to mention pain and suffering.

Are you overweight or obese? Find out with an online body mass index calculator.

Want to do anything about it? See my “Prepare for Weight Loss” series.

Steve Parker, M.D.

Reference: Tsai, A.G., et al. Direct Medical Cost of Obesity in the U.S.A. Obesity Reviews, online January 6, 2009. doi: 10.1111/j.1467-789x.2009.00708.x

Can You Hari Hachi Bu?

I loved the sound of this phrase – hari hachi bu – even before I knew what it meant.

“Hari hachi bu” comes from the Japanese islands of Okinawa. It refers to eating a meal until you’re only 80% full, then stop eating. It’s a method to control weight.

Okinawa, remember, is one of the longevity hot spots in Dan Buettner’s Blue Zones.

But would it really work for many in Western culture? Probably not. We don’t have the discipline to stick with it long-term. Maybe for a day.

One of the currently popular dieting gimmicks is to eat every 3-4 hours while awake. The rationale is, “you need the energy.” If you eat 5-6 meals a day, you’re not cutting back on total calories even if you eat only until 80% full.

As long as you’re eating a fair amount of carbohydrates, you can store plenty of energy as glucose in glycogen – in your liver and muscles – to easily live without eating for at least 8-12 hours. So, there’s no “need” to eat every 3-4 hours. If there were, we would have gone extinct years ago. At rest, you’re getting about 60% of your energy supplied by metabolism of fats, not carbohydrates. Most people can live without all food, but not water, for about two months.

Plenty of people have said, “I’m going to lose weight by cutting back on food intake.” I don’t have scientific data to back it up, but I’d bet that a food diary works better.

A simple weight-loss or management plan that would work better for Western world inhabitants would be:

Don’t eat anything man-made.

So off limits are bread, rolls, soft drinks, table sugar, high fructose corn syrup, pancakes, pizza, potato chips, Pringles, pies, cookies, cake, casseroles, cannolis, Doritos, Ding-Dongs, Snickers, etc. I’d complicate it just a bit by also avoiding naturally starchy foods like potatoes and corn.

For those who don’t like the negativity of “don’t eat that,” here’s the positive spin:

Eat only natural, minimally processed food.

In other words, eat fresh fruit, fresh vegetables, eggs, meat, chicken, fish, olive oil, nuts, etc. These are God-made foods, not man-made.

Steve Parker, M.D.

Take Vitamin D With Largest Meal to Increase Blood Level

The Healthy Librarian at the Happy Healthy Long Life blog wrote about a small scientific study documenting an incredibly easy way to increase blood levels of vitamin D in people taking supplemental vitamin D:

Take the supplement with the largest meal of the day

Subjects of this research were taking vitamin D supplements—often a very high dose—for medical reasons, yet blood levels remained unacceptably low. Blood levels of vitamin D (25-hydroxyvitamin D) rose by 50% simply by taking the same dose with the largest daily meal.

Other people, including young healthy adults, may or may not respond the same way. Do you know?

As for me, I’ll be sure to take my vitamin D supplement with my largest meal.

Steve Parker, M.D.

Disclaimer: All matters regarding your health require supervision by a personal physician or other appropriate health professional familiar with your current health status. Always consult your personal physician before making any dietary, nutritional supplement, or exercise changes.

Response to Weight-Loss Diet May Depend on Genes

Dieters with particular genetic make-up respond better or worse to specific types of weight-loss diets, suggest researchers who presented data at the 2010 Cardiovascular Disease Epidemiology and Prevention /Nutrition, Physical Activity, and Metabolism conference. Findings are preliminary, but may explain the common phenomenon of two people going on the same diet, but only one achieving good results.

I’ll bet you can imagine several other explanations.

Several years ago, the “A to Z” study compared the weight loss of 311 overweight women on one of four diets: Atkins (low-carb), Ornish (very low fat, vegetarian), Learn (low-fat), and Zone (moderate carb restriction, high protein, moderate fat). Atkins was a bit better than the other diets, in terms of long-term (one year) weight loss. But within each diet group, some women lost 40–50 pounds (18–23 kg), whereas others gained over 10 pounds (4.5 kg).

Stanford University researchers obtained DNA from 138 of the 311 women and noted the occurence of three genes—ABP2, ADRB2, and PPAR-gamma—that had previously been shown to predict weight loss via diet-gene interactions. For example, a particular mix of these genes predict better weight loss with a low-fat diet; a different mix predicts more loss with a low-carb diet.

Women who had been randomly assigned to one of the A to Z diets tended to lose much more weight if they happened to have the gene mix appropriate for that diet (compared to those on the same diet with the wrong gene mix). The difference, for example, might be loss of 12 pounds versus two pounds.

The lead researcher, Dr. Mindy P. Nelson, told TheHeart.Org that the proportion in the general population genetically predisposed to the low-fat versus low-carb approach is about 50:50.

Take-Home Points

These results, again, are preliminary; additional testing is necessary for confirmation. If they had been able to test the DNA of the other 178 women in the A to Z study, the results could have been either stronger or shown no diet-gene interaction. The study hasn’t even been published in a peer-reviewed journal yet.

Men may or may not be subject to similar diet-gene interaction.

With a little effort, you’ll be able to find the aforementioned genetic test available via the Internet. It’s under $100 (U.S.). The company sends you a kit to swab the inside of your cheek, then you mail your DNA to them.

Other peope just try a particular diet first and see if it works over 4–6 weeks. Successful long-term weight loss is like smoking cessation—most smokers try 5–7 different times or methods before hitting on one that works for them.

Regular readers here know that I advocate, for weight loss, both a reduced-calorie, balanced Mediterranean diet (Advanced Mediterranean Diet) and a very low-carb diet (Ketogenic Mediterranean Diet). Regardless of genetics, experience has taught me that there’s no single weight-loss program that works for everyone across-the-board.

This potential diet-gene interaction could be a major finding that will stop the arguing about which is the single best way to lose excess fat. Many paths may lead to the mountaintop.

Steve Parker, M.D.

Reference: O’Riordan, Michael. Dieting by DNA? Popular diets work best by genotype, reseach shows. HeartWire by TheHeart.Org, March 8, 2010.