I recently came across this video, in which low-carb diet advocate Dr. Michael Eades defends his nutritional recommendations at the Ancestral Health Symposium of 2011. He starts out by responding to those who essentially ask him “why, if carbohydrates are unhealthy, are the people of (insert healthy, carb eating culture here) so healthy.”
In regards to this question, he could have just said “correlation does not imply causation, bitches”, popped his collar, and walked off stage. Had he done this, I’d have left it alone (and been very amused), but he chose to give a lengthy counter argument. As a result, I decided to give a brief counter argument to his counter argument.
First, he brings up Pablo Picasso, Claude Monet, and Winston Churchill. The reason for this is simple; they were all smokers and they all lived to be quite old (91, 86, and 90 respectively). Eades uses them to explain that even in the presence of something harmful (cigarette smoke), these men lived a long time. Dr. Eades goes on to choose the Japanese and their rice-loving ways as his healthy carb-eating culture of example (apparently he is often asked about them). He brings up the fact that the Japanese are heavy smokers, yet have a fairly long life expectancy. His point is that citing Japanese consumption of carbs is not proof of the innocence of carbs, just as citing their cigarette smoking is not proof of the innocence of cigarettes. He eventually implies that for all we know, if the Japanese ate less carbs they might actually live longer.
I think he leaves out some important specifics that would ultimately make his argument much weaker.
When we talk about chronic cigarette smoking, lung cancer is often a result. This is hardly under debate. When Eades brings up the smoking habits of Picasso, Monet, and Churchill, he fails to mention that Monet died from lung cancer. Using this, the percentage of deaths from lung cancer in Dr. Eades’ example men is 33.3%. Compare this to the rate of lung cancer in the general population at about 2.1% and it becomes clear that the effect of smoking in those 3 men was not completely avoided (1,2). Even the rate of lung cancer in male smokers is lower at 17.2% (3).
If you have 10 people who all live to be 120 years old, but 1 guy shoots himself in the head at the age of 50, the average person still lives to be 113. That’s a pretty impressive life expectancy, but it doesn’t make shooting yourself in the head any less deadly.
Now that we’re looking at lung cancer rates instead of overall life expectancy, let’s take a look at Japan. The Japanese do appear to smoke at a fairly high rate, yet death from lung cancer is fairly low when compared to smoking rates and lung cancer death in other countries. However, if we look at gender differences in the country, observations become a bit easier. Dr. Eades points out that more men than women smoke and indeed, about 36% of men compared to about 10% of women are smokers(4). Here we have two graphs plotting lung cancer rates among males and females in Japan (5):
These two graphs illustrate an important trend. The number of deaths per year from lung cancer is much higher in males than females (about 50,000 versus about 20,000 annually). So what we find is that about 3.6 times more males than females smoke and, in a crazy twist of fate, males die from lung cancer at a rate of about 2.5 times that of females. Clearly, the Japanese are not protected from the dangers of smoking, it’s just hard to tell because Japan is a place where people live longer and smokers die from lung cancer proportionally less than smokers in other countries.
Now let’s take a look at carbohydrates consumption in Japan. Most would agree cigarette smoking causes lung cancer and observations of the Japanese seem to support this. Alright, what do carbohydrates do? According to Dr. Michael Eades “We now know why we get fat. Excess insulin drives fat into the fat cells increasing the fat cell mass, ultimately leading to the state we call obesity” and “We make too much insulin because we eat too many carbohydrates, especially sugar and other refined carbohydrates” (6) With that in mind, it’s not surprising people bring up Japan. The Japanese are by no stretch of the imagination eating a low carbohydrate diet as their diet features a lot of rice, soba (buckwheat), ramen (noodle soup), and udon (thick noodles). Despite all this, Japan has the lowest rates of obesity in the 1st world (along with South Korea) at about 3.2% (7). This is probably why Japan gets brought up when people proclaim carbohydrates to be fattening.
Whether or not Mr. Eades chooses to respond to this question about Japan isn’t of great concern to me. Epidemiology is fascinating, but it doesn’t gives us proof of much, just a basis for ideas. It doesn’t hurt when theories are consistent with what we observe, but Eades is right in pointing out that many interlinking factors often make such observations difficult. Still, if he does come up with explanations for the observations of Japan, I’m curious to hear them.
By example, the French paradox is the observation that the French consume a lot of saturated fat, yet have low levels of coronary heart disease. Many nutritionists are quick to explain this by citing all the beneficial (magical, life giving, etc.) compounds in red wine (which the French love) and y’know, that’s probably why the French don’t drop dead from heart attacks every five seconds. Personally, I don’t think saturated fat increases risk of coronary heart disease and thus the French paradox isn’t a paradox at all. I also don’t think carbohydrates increase risk of obesity, but Dr. Micheal Eades does. I wonder what his explanations for this “Japanese paradox” are.
(1) World Health Report (2004)
(3) Villeneuve PJ, Mao Y. Lifetime probability of developing lung cancer, by smoking status, Canada. Can J Public Health. 1994 Nov-Dec;85(6):385-8. PubMed PMID: 7895211.
(7) OECD Factbook: Economic, Environmental and Social Statistics. Organization for Economic Co-operation and Development (2005)