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Nov 02 2010
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From the Source, Over the Counter, Stop Press

Update on High Fructose Corn Syrup

High-fructose corn syrup, a disaccharide (sugar) derivative from the mountains of corn produced in the mid-west has been used extensively in thousands of food products as a cheap and effective sweetener.

It has been the topic of much debate and ridicule, taking the blame for everything from cavities to obesity.  I touched on HFCS a few months ago, and came to the conclusion that it’s not appreciably different from other sugars typically used:

The assertion that high fructose corn syrup is single-handedly responsible for the negative health impacts we are seeing appears to be ill-founded.  It is very clear, however, that with increasing intake of calories in the form of added sweeteners like HFCS, particularly in beverages, there is an increase in weight gain.

Now, I’m all for eating my words, and a recent study, covered by Marion Nestle (no relation to the food conglomerate) over at Food Politics notes that what’s on the package might not be what is inside the package.

A recent analysis tested the sugar content of a number of soft drinks to assess the levels of various individual components.  Bottles of twenty-three soft drinks (like Coke, Pepsi, Sprite etc.) and four syrups were included in the analysis.

Quick summary of results from the publication Fact Sheet:

- There is 18 percent more fructose in the HFCS used by soda companies than estimated.

- Several major brands appear to be produced with HFCS that is 65 percent fructose.

- The mean fructose content in the HFCS used was 59 percent.

What this means is that these beverages contain way more fructose than: 1) they advertise; and 2) they are allowed.  More fructose = more “lipogenic” or “fat producing” sugars being consumed that one may realize.

However, the study had a number of major flaws, outlined in Marion Nestle’s post, and deserves caution. It will be interesting to see how this gets whipped up and whether other labs will reproduce the results.

Regardless of whether a Coke has 55% fructose (what is typically in HFCS) or 59% fructose, it’s not a health beverage!

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Oct 26 2010
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From the Source

Merits of the Mediterranean Diet

What is a fad diet?

The term conjures images of short-term starvation, compulsive calorie counting, and ‘lite’ salad dressings, focussed on shedding a few pounds of flab in the short term. Fads rise quickly, as their merits decay away just as fast.

But I’ve always been one to think of a “diet” as the foods we eat everyday; not a short-term departure from our fodder.  There is one of these non-fad diets that has become a recurring headline (warningly like a fad diet), and more and more scientific research is revealing the positive health benefits of the Mediterranean Diet.

Since the ’60′s, the Mediterranean Diet has been drawing attention for the purported health benefits, and scientific investigation has been consistently expounding the nutritional and health value of this diet.

Proponents call it a “life-style”, characterized by:

  • Getting plenty of exercise
  • Eating primarily plant-based foods, such as fruits and vegetables, whole grains, legumes and nuts
  • Replacing butter with healthy fats such as olive oil and canola oil
  • Using herbs and spices instead of salt to flavor foods
  • Limiting red meat to no more than a few times a month
  • Eating fish and poultry at least twice a week
  • Drinking red wine in moderation (optional)  (Source: MayoClinic)

An updated meta-analysis, published this week in the American Journal of Clinical Nutrition, has reiterated the positives of this diet.  This study by Sofi et al. added another seven studies to their previous analysis published in 2008.

This meta-analysis of prospective, cohort studies included 18 trials including over 2 million subjects with follow-up times ranging from 4 to 20 years.  The analysis was interesting because it used a scale of “adherence” to the diet and its effects on outcomes including: overall mortality, mortality and/or incidence from cardio- and cerebrovascular diseases, mortality and/or incidence from cancer, and incidence of neuro-degenerative diseases.

Results

The results corroborated the findings of the previous meta-analysis, reporting that with increasing adherence to the Mediterranean diet, as measured through Food Frequency Questionnaires or other survey methodologies, risk of all-cause mortality decreased.

A two-point increase in adherence was related to a ~10% decrease in cardiovascular death (CI: 0.87-0.93; p<0.00001) and a ~6% reduction in death due to cancer and other neoplastic diseases (CI: 0.94-0.96; p<0.0001).  The authors also noted a 13% reduction in neurodegenerative conditions with increasing adherence to the diet.

Reservations

I’ve got a few “hold-it-right-there” reservations.  First of all, the only thing that can be shown here is an association between morbidity and mortality and the Mediterranean diet, and this is because the analysis only included prospective cohort trials, not randomized, controlled interventions, and thus cannot show causation.  With so many different components to the diet, which might be contributing most significantly to the health benefits?

Also, no biomarkers of nutritional status were collected and thus it was only through analysis of food frequency questionnaires and dietary diaries that data was collected. We have no idea what the actual biological health of these participants was!

From my experience, these methodologies are acceptable (and indispensable) for public health research, but have a decent level of error.  When dealing with small risk reduction values like those reported here, reporting bias could potentially diminish these positive results.

However, the huge sample size included in this meta-analysis, one of the largest I have seen outside of other massive prospective cohorts like the Nurses Health Study, provides strength to the findings.

The Big Take Home

Interest in the Mediterranean Diet has been on the rise in recent years

Something that is not clear at all is how this translates into clinical practice.  It is not feasible to expect that patients might be willing and able to dramatically switch their dietary practices, for a slight reduction in disease risk.

The results of this analysis appear to support the benefits on a population scale, but beyond providing kindling for the “eat more fruits and vegetables, less red meat, and more olive oil” camp, it’s hard to make concrete recommendations to individuals.

Continue reading →

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Aug 13 2010
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From the Source, Myth Buster, Nutrition in Practice

Omega-3s – The Verdict!

SPECIAL ISSUE: OMEGA-3 WEEK ON THE FODDER FILE

PART 4 OF 4: OMEGA-3 – THE VERDICT

It’s been an exciting week on the Fodder File.  I’ve learned a lot, and I hope you have too. So now it’s time for the Verdict!

This is basically where the evidence stands:

Heart Health:  Excellent. For people at high risk.

Brain Health: Very Good. For normal development of brain and eyes.  Sketchy for added benefits.

Planet Health: Strong. Omega-3 recommendations are detrimental to planet health.

It’s up to you… Based on what you have read, you decide:

You can review the Omega-3 posts by clicking on the icons below:

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Aug 12 2010
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From the Source, Myth Buster, Nutrition in Practice

Omega-3s and Planet Health

SPECIAL ISSUE: OMEGA-3 WEEK ON THE FODDER FILE

PART 3 OF 4: PLANET HEALTH

Environmental sustainability is a big issue, and the field of nutrition and health should not be exempt from responsible practice.

With health benefits being significant for cardiovascular disease and possible in cognitive and visual performance, there is certainly evidence to support increasing intakes of fish for the long-chain omega-3 fats in some people.

However, 35% of the world’s fish stocks have collapsed, and we’ve plateaued  on how much fish we’re bringing in. If we are to take recommendations for health seriously, and every Canadian (North American? Human?) increased their intake of fish by 2-3 fold, the consequences would be catastrophic.

State of fish stocks. Taken from Jenkins et al.

So wild fish are out of the question.  What about farmed fish, you ask?

Well, aquaculture is primarily fixated on carnivorous fish like salmon and sea bass.  The diet for these fish?  Fishmeal and fish oils from smaller fish – the source of omega-3s.  It directly perpetuates the problem.  Check out this gem from Naylor et al.:

“It takes 2.5–5 kg of feed fish to make 1 kg of farmed carnivorous fish.”

In addition to the potential detrimental effects increased recommendations could have on the state of the worlds ocean critters, there are socio-economic and health concerns at the human level.  As Brunner notes:

“Overfishing undermines food security by reducing the supply of a vital source of dietary protein, particularly in the coastal regions of less economically developed countries. … These dynamics are likely to increase health inequalities within and between populations.”

But the main question that hasn’t been answered yet, is why we need to get omega-3 from fish at all?  Well, you’re right.  Omega-3 fats are found in many plant sources including flax, canola oil and soy beans.  But the critical thing is that not all omega-3s are equal.

Omega-3s are a family of fats, with short, medium and long-chain members.  Plants are rich in the medium-chain ALA omega-3.  But the health benefits that we see come from the long-chain DHA and EPA, which are only found in marine sources.

But there may be hope.  The long-chain DHA accumulates up the food chain in the ocean.  The primary producers of DHA are microalgae, consumed by krill (tiny crustaceans), then by larger and larger fish.  There are efforts underway to grow and purify DHA from algae, which would satisfy ethical (and vegetarian) demands.

Health recommendations have serious impacts on the planet.  We cannot neglect to consider this when wrapped-up in the righteous guise of human health.  After all, human health is planet health.  We cannot separate the two.

So what’s the take-home message?

Fish stocks are dwindling. Increasing recommendations for optimal heart and brain health would instantly outstrip the available supply of fatty fish, so we had better be damn sure that the science is solid if we’re going to go down that road (or river).  The old adage of being up a brown creek without a paddle comes to mind.  There may be other potential sources of the beneficial DHA in algae (but that’s missing the other heart-healthy long-chain omega-3, EPA).  This is going to be a tough call.

STAY TUNED FOR PART 4 OF 4 TOMORROW – THE VERDICT!

See PART 1 – HEART HEALTH HERE

See PART 2 – BRAIN HEALTH HERE

References after the jump. Continue reading →

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Aug 11 2010
2 Comments
From the Source, Myth Buster, Nutrition in Practice

Omega-3s for Brain Health

SPECIAL ISSUE: OMEGA-3 WEEK ON THE FODDER FILE (Rebroadcast)

PART 2 OF 4: BRAIN HEALTH

At the age of 20, the average male has got 175,000 km of myelinated neurons in his brain, enough to go around the world almost 4.5 times!  By the age of 80, that male will have lost almost half his myelinated neurons (92,700 km).

To be honest, I was very surprised when I read those facts.  But it serves to highlight the importance of caring for our brains.

Our brain is mostly fat – 60% actually.  And a major component necessary for proper brain development and function is the long-chain omega-3 fatty acid, docosahexaenoic acid, or DHA.  This is especially important during fetal and childhood brain development.

DHA is also essential for building rod cells in the retina (responsible for night-vision). It’s indispensable for normal function, but will we super-charge our brains and eyes with taking fish oil capsules?

Well, the data appears to have a checkered history.  I can’t list the whole body of literature here, but it’s less consistent than the heart-health data.  A couple of big reviews by the Cochrane Collaboration, the gold-standard for meta-analyses of multiple studies, found DHA-supplemented formulas didn’t do much for pre-term infants:

“no clear long-term benefits were demonstrated for infants receiving formula supplemented with [long-chain omega-3s].”

The story for infants born at term fed with DHA-supplemented formula is a little hazier:

“[Results] have not shown beneficial effects of [long-chain omega-3] supplementation of formula milk on the physical, visual and neurodevelopmental outcomes of infants born at term.”

However, it goes on to say that there are some conflicting results that show benefits of DHA-supplementation, which deserve more study.

Other recent research has shown that chidren with ADHD may benefit from fish-oil supplementation (~1g/day), and consumption of high amounts of fish could translate into better grades for kids (that from a Swedish study).  Hmmm…

On the other end of the age spectrum, patients with Alzheimers Disease are looking to long-chain omega-3s from marine sources for help.  But the scientific research is lacking.

Epidemiological studies (population-based) suggest that people who eat fish once-per week have a 60% reduced chance of developing Alzheimers:

“Participants who consumed fish once per week or more had 60% less risk of Alzheimer disease compared with those who rarely or never ate fish (relative risk, 0.4; 95% confidence interval, 0.2-0.9).”

Follow-up clinical trials have been a little more cryptic.  Fish/omega-3 intake appears to potentially play a protective effect if consumed regularly before advanced stages of Alzheimers, but once those advanced stages are reached, there’s no benefit.  More research needs to be done in this field in particular.

I can’t paint the whole picture here, but long-chain omega-3s from marine sources have also been implicated in playing a beneficial role in other mental conditions like major depression, psychosis, and anxiety disorders.

So what’s the take-home message?

Well, there is absolutely no doubt that we need DHA and other omega-3s (including shorter chain ALA, which can be converted to DHA in the body, though to a limited extent) for normal brain and eye health. Pregnant and lactating women might benefit their future child by taking an omega-3 capsule to boost DHA levels, but you should talk to your to doctor about this!  For the general population, taking a fish-oil supplement will not hurt (adverse reactions are limited to very high intakes of >3-4 g/day), and it might even benefit you in the long run when considering brain and neural conditions like Alzheimers.  There’s still a whack-load of more research that needs to be done to convince me of the miraculous brain-effects that omega-3s have been purported to play, but those might come in time.  I’m certainly open to it.

STAY TUNED FOR PART 3 OF 4 TOMORROW: OMEGA-3S AND PLANET HEALTH

SEE PART 1 (HEART HEALTH) HERE.

(Omega-3 Week originally broadcast in March 2010)

References after the jump.

Continue reading →

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