SaluGenecists Science Blog

Mid-February is a cruel time. Dirty snow in the midwest, sideways rain in the Pacific northwest, even overcast skies in LA. No wonder every third person in my orbit seems to be suffering with a lingering cold at the present time.

One of the persistent pieces of mythology in the integrative medicine world is the belief that dietary sugar is a potent immunosuppressant. This citation usually presented as proof of this theory is a small and uncontrolled study (n=10) from 1973. In this study, the 10 volunteers were fed 100 grams of sugar, then phagocytosis index and blood sugar were monitored over a 5 hr period. At the one to two hours post-prandial measurements, phagocytosis had diminished by about 30-40% in each of the four simple sugar groups, but only by about 10% in subjects fed 100 grams of sugar from starch.

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Yet another large-scale epidemiological trial has failed to see a correlation between multivitamin use and either cancer or cardiovascular prevention. What should we clinicians make of these data?

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The CDC is now recommending routine shingles vaccination for people over the age of 60. It appears that the vaccine reduces incidence of shingles by 50%, and reduces the incidence of post-herpetic neuralgia in people who do develop shingles. The most common adverse effects are local reaction and headache.

Since the vaccine is relatively new, there are still some questions about it. First, it isn’t established whether the vaccine is effective in younger people who have had shingles (although it is effective in 60-year-olds who have a history of shingles). Second, the duration of the response beyond four years is not known. The latter is particularly important because the efficacy of the vaccine appears to dwindle with age.

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This morning, the American Heart Association (AHA) released a scientific advisory that for the first time recommends a range of omega-6 fatty acid consumption as part of a cardiovascular preventive strategy. Unlike similar AHA recommendations supporting omega-3 fatty acids from fish, these new guidelines don’t distinguish between animal and plant sources of these fatty acids.

Surprisingly, these guidelines are not based on a single intervention trial that was designed to assess the conclusion - that higher intakes of omega-6 fatty acids are better than lower intakes with respect to cardiovascular risk. Similarly, none of the trials listed support the conflation of linolenic acid and arachidonic acid as a single clinical entity. As such, it is hard to conclude that the data currently support such a sweeping recommendation.

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This year has been a particularly cold winter, and it seems like a new respiratory infection sweeps the population every couple weeks. Good diet, sleep, and exercise habits help to reduce the risk of infection, but every once in a while, it hits you anyway.

Here’s an easy tip for helping to shake a cold more quickly: rinse your nasal passages with saline. This is pretty easy to do, and is a good adjunct treatment in URI or sinus infection.

This news item is sure to get the chattering classes to chattering away. Because this conversation is no place for a reasoned debate, I’m going to steer away from it for now.

Instead, I’d like to remind our readers that the most effective treatments for autism to date have been behavioral therapies (although not all groups are convinced of significant benefit). The CDC has a program aimed at early diagnosis and intervention both for parents and providers.

I have been very disappointed in the CAM community response to autism. If we actually do have effective treatments, I call on my colleagues to publish them through a peer review process. If we have experimental treatments, we should bill them as such. If we don’t act responsibly, we’ll abdicate our role as trusted advisors to people who have a bigger platform or who have conflicts of interest.

Wow.

It doesn’t take a rocket scientist (just a medical device company scientist) to see why this fight is on. The manufacturers are well aware that when they sponsor research, they define the parameters. This helps to maintain a situation where company sponsored research is much more likely to show a clinical benefit from a treatment. 

This debate may have implications for CAM providers, as well. Although I’ve not seen any data to support this, I suspect that federally sponsored research is more likely to include diet and lifestyle treatment arms as comparison. The DASH Diet Trial and the Diabetes Prevention Trial Type 2 are examples of trials sponsored by federal agencies that showed clinically relevant benefits from diet and lifestyle therapies.

Before the can start getting health costs under control in America, we’re going to have to get to a place where we don’t hear the word “rationing” as a threat in the way we heard “communist” as a threat in the 1950s. The fact is that we already do ration care in America, and we always will. This is why I haven’t had a PSA test yet - because under age 50, it isn’t a cost effective screening test in the population. The more information we have, particularly when it is not biased by industry input, the smarter we can be about rationing care.

So here is the original article I was reacting to with the multi-post blurt.

So as not to lose the forest for the trees, I actually agree with a major point that this article makes - that refined carb intake is a big driver, maybe the key driver, for the increase in obesity over the past couple decades. But here’s the thing: it is not necessary to throw 50 years of science around fats under the bus to make a point about carbohydrates. To read this article, you’d think that there was no experimental data to prove any of the beliefs about saturated fat, but that’s just flat-out misleading (note: this is not meant to be a representative cross-section, just a few of the more recent examples of the physiological effects of fats that have crossed my desk).

The original article reminds me a bit of the Peter Duesberg / AIDS hypothesis from the 1990s (does this theory still have adherents? I haven’t heard about it in a long time). It is an important thing to do to poke holes in existing medical theories, because that’s how we continually expand our body of knowledge. But the existence of gaps in our understanding of the prevailing theory is not a positive argument in favor of another theory. When we pretend it is, that’s how we get to bizarre leaps of logic like “AZT causes AIDS.”

To recap:

• saturated fat pretty clearly causes some short-term detrimental metabolic changes
• epidemiology suggests that these short-term changes may lead to increased risks long-term, but some data don’t agree with this
• extra calories, whether from fats or carbs are associated with obesity
• during the rapid increase in obesity in the US, fat intake didn’t increase or decrease, and carb intake went way up
• to a certain extent, calories are calories, but there appear to be effects with saturated fat that don’t exist with other macronutrients

Then there’s the Women’s Health Initiative (WHI)… In this trial, a group of nearly post-menopausal women were either counseled about a low fat and high fiber dietary intervention or left to eat their current diet, then followed for 6 years. Data analysis at the end of the 6 year period did not show a significant difference between cardiovascular outcomes, and only fairly minor improvements in blood pressure and cholesterol.

This study is sometimes presented as damning evidence that strategies aimed at reducing saturated fat and cholesterol are not effective in preventing heart disease. Maybe, but for a clinical trial to be definitive, the recommendation needs to be followed to a reasonable extent. In the WHI, the diet group was counseled to eat 20% of calories from fat. Instead, their fat intake was 29% of calories - a drop from baseline, but nowhere near the goal. Similarly, fiber intake only increased by a gram and a half over baseline. Although self-reported calorie intake dropped in both groups (treatment and controls) by over 200 hundred calories, only marginal weight changes were noted, suggesting that self-reporting bias may have been pretty active in this trial.

Of course, if you are going to take on the low saturated fat / high fiber diet as cardiovascular prevention, it would probably be pretty helpful to ignore some of the other important clinical trials in this field.

Here’s the next data point against my as yet unidentified debate subject. We’ll probably have a couple more of these before I show you who I’m building a case against.

The rate of obesity has very clearly been increasing in the US. In the NHANES survery between 1976 and 1980, 15.0% of the adult population was obese. It was up to 32.9% by 2003-4.

As discussed yesterday, almost certainly the most striking concurrent dietary trend was an increase in calorie consumtion of more than 100 calories per day. At 3500 calories per pound weight gain, this is about a pound per month weight gain over the mid-70s diet.

Obesity isn’t just a diet related issue. Over the same period that weights went up, exercise levels appear to have gone down. Although national mean incomes have gone up markedly, some economists believe that the lower and middle classes have suffered for an extended period. Being poor is an independent predictor of obesity risk in the U.S.

To claim that the increase in obesity risk has somehow followed from a shift of the American diet toward a low-fat strategy, you have to at least acknowlege these other factors. Especially as the number of fat calories consumed by Americans has only increased over time.

Any guess yet where this is going?