SaluGenecists Science Blog

The American Association for Cancer Research (AACR) guidelines presented the past weekend made a sweeping recommendation that medical oncologists should avoid prescribing nutritional supplements. This is an important issue, as studies have found that the majority of cancer survivors are using nutritional supplements, and a large subset are not informing their oncologist about supplement use.

Ultimately, I believe that this type of pseudo-Cartesian dualism (pharmaceutical and OTC medications OK, supplements not OK) is not a helpful philosophy. True, there appear to be many supplements that are potentially counter-productive or potential scams. But not all of them.

(more…)

A new recommendation was issued by the American Urological Association suggesting baseline PSA testing at age 40. This is a big change from previous recommendations, which recommended baseline screening at age 50, unless risk factors were present.

This new recommendation seems odd in a couple of ways. First, prostate cancer in younger men is quite rare. Only about 57 Amercian men in 100000 under the age of 65 will be diagnosed with prostate cancer this year. Almost none of these men will be younger than age 55. Prostate cancer prevalence in the younger than 50 set is so rare, it appears that the ACS doesn’t even keep stats to monitor.

Second, PSA screening in large populations over the age of 50 affects prostate cancer mortality barely, if at all. Two new studies earlier this year demonstrated this finding emphatically. Given that the efficacy of PSA screening has never been so controversial, expanding screening efforts seems a little counterintuitive (and a lot expensive).

One of the potential drawbacks seen with large-scale PSA screening, and one that the recent clinical trials weren’t designed to assess, is that increased diagnosis leads to increased expensive and potentially dangerous treatment. At the risk of seeming impolitic, the members of the American Urological Association might stand to profit from this increased treatment.

To be fair, the AUA appears to be making the assertion that the baseline PSA in younger men is a strong predictor of future risk, and that this piece of information can be used to target more aggressive screening procedures appropriately. Note that the more conservative United States Preventive Task Force has concluded that the use of PSA screening in men under the age of 75 is based on insufficient evidence.

There is a rich and deep mythology in the internet world about acid and alkaline forming foods. Like many other health mythologies, this one takes a seed of truth and grows it into an elaborate pseudoscience.

(more…)

This is in response to a reader question. The question was complex, so I’m going to try to tackle it in two parts. Here’s the first.

The most popular dietary intervention for the prevention of herpes outbreaks (either oral or genital) is a low arginine diet. Arginine (Arg) is an amino acid, found in pretty much all foods at varying levels. Although this is a popular intervention in the community, medical research has yet to assess the effect of this strategy, making its use anecdotal.

Lysine (Lys) is another amino acid, and it tends generally to antagonize Arg in physiological processes, and specifically related to herpes virus growth. Researchers have used lysine supplements to try to suppress herpes outbreaks, although sometimes with marginal or no effect. Note that the treatment appeared much more effective when gram doses were given multiple times per day.

Here’s a list of arginine content of foods. I would recommend trying to reduce items with both a ratio of Lys / Arg of less than one and at least 200 mg Arg per serving. In particular, nuts (including peanuts) tend to be the highest arginine foods. The protein content of the fruits and vegetables on this list is not significant enough to matter in this intervention, and we don’t want to restrict those essentially health-promoting foods.

It is still unknown how low arginine diets could potentially reduce herpes outbreaks. This might have something to do with it, but it is awfully preliminary. It has been pretty conclusively shown that arginine is necessary for the growth of the virus, and that Arg-deficient media suppress growth.

I would be remiss if I didn’t note that arginine is also very important to healthy immune function, including immunity against viruses. There is even some new evidence that high amounts of Arg could suppress herpes virus growth, although it isn’t clear whether this finding is relevant to human nutrition.

For active outbreaks, by the way, I have used topical lemon balm extracts as treatment. Not a lot of research here, either, but it is a simple and non-toxic herbal application. It really needs to be applied as early as possible in the prodrome stage.

One of the criticisms I hear pretty frequently about nutrition science is that frequently changing recommendations are indicative of the ignorance of scientists (if this is your point of view, try watching the video I posted yesterday). Unfortunately, the Archives of Internal Medicine isn’t helping here.

A new review article in today’s Archives looks at the strength of association between different dietary factors and heart disease risk.  Their conclusions are many, but two important ones that will be sure to be widely quoted are that high glycemic index foods (like sugar) are strongly associated with heart disease and that meat intake is not associated strongly enough to make a recommendation.

It seems like just weeks ago that the Archives printed an article and an editorial that suggested that people with high intakes of meat had increased mortality risk. So what are we supposed to make of this?

The methodology of the newer study was first developed to conclusively show that smoking is associated with lung cancer, so it will be hard to critique the report on these grounds. I will, however, note a couple of things. First, the range of meat intake (as well as saturated fat intake, which usually moves in parallel with meat) is not terribly large in most of these studies. It’s not like we’re comparing vegetarians to non-vegetarians, just the highest intakes against average and moderate. Also, this study is not concluding that there isn’t an assocation, just that the evidence isn’t that strong at the given time.

I wonder if the Indian study published in March would have been available to the reviewers would it have helped push meat intake up into a higher evidence bracket? I suspect given the half million people surveyed and the number of confounding variables corrected for, it may have.

Either way, I think perhaps the most important message from the new Archives review is that the Mediterranean diet strategy is probably the best studied dietary prevention strategy against cardiovascular disease. That, and donuts are really bad for you.

Nice to see that skeptics make videos. My favorite part is the distinction between “I can’t explain my experience” and “you can’t explain my experience” — that is absolutely critical to understanding why anecdote is not compelling medical evidence.

Thanks to Andrew Sullivan at the Atlantic for the original post.

I was reading an insightful brochure from the Breast Cancer Fund on the falling age of puberty in American girls (order for yourself here), and it reminded me that in 1996, the U.S. established through the Environmental Protection Agency an Endocrine Disruptor Program. The mandate for this group was to study environmental chemicals to determine levels of risk and make appropriate recommendations for risk reduction.

Here we are in 2009, and the best that can be said is that the group has decided which 73 chemicals deserve further study. Like many other EPA programs during the last few years, this one has taken some heat for being a little industry-friendly. It has also endured criticism from animal rights groups based on some of the testing models.

Missed deadlines, litigation, insufficient funding…this is the story of a country that is not taking a potential public health crisis very seriously. It should only take a couple of years at a modestly funded lab to determine which, if any, of these chemicals has the potential to be behind the observed changes in wildlife populations and in human reproductive health. So c’mon, let’s get to it already.

As promised here is part two of my post from two days ago. This post is responding to the article linked here. Since I’m going to go through it in some detail, it might be helpful to pop it open now (3 second pause). This is gonna be a long one, so you might want to grab a snack.

(more…)

Here’s an interesting article. Prolonged sauna, exercise, diets high in antioxidants, laxative herbs - this is a pretty standard, if aggressive CAM detoxification protocol. With all of the financial investment made by the state, it would be really helpful if they kept some data to measure the outcome, so we don’t need the standard “well, we don’t know if this works disclaimer” in the future.

It’s sort of bracing to see Scientology take credit for the development of the protocol. Versions of this approach have kicked around the U.S. since at least the early 20th century, and around Europe for somewhat longer. While I have read that time travel is a tenet of Scientology, it seems hard to believe that they would have invented something that predates them by more than half a century.

A colleague of mine brought a 2006 article to my attention tonight. It looks like I have been called onto the carpet for the whole world to see over my yearly lecture on how saturated fats are potentially linked to diabetes risk. Never one to shirk a good scientific debate, let’s indulge in a two-part response.

For today, I’m going to start with the high level overview. Next time, we’ll dive into the specifics of the author’s critique of your humble blogger.

(more…)