Monday, September 1, 2008

Vegetable Oil and Homicide

One of the major dietary changes that has accompanied the downward slide of American health is the replacement of animal fats with industrially processed vegetable oils. Soybean oil, corn oil, cottonseed oil and other industrial creations have replaced milk and meat fat in our diet, while total fat consumption has remained relatively constant. The result is that we're eating a lot more polyunsaturated fat than we were just 30 years ago, most of it linoleic acid (omega-6). Corn oil may taste so bad it inspires you to violence, but its insidiousness goes beyond the flavor. Take a look:

This figure is from a paper that Dr. Joe Hibbeln sent me recently, of which he is the first author. This followed an interesting e-mail conversation with Robert Brown, author of Omega Six: the Devil's Fat. He put me in touch with Dr. Hibbeln and Dr. William Lands (NIH, NIAAA), both of whom warn of the dangers of excessive linoleic acid consumption from modern vegetable oils. Dr. Lands has been researching the relationship between dietary fat and inflammation since the 1970s, and has been a critic of modern vegetable oils for just as long. Both Dr. Hibbeln and Dr. Lands were very generous in sending me a number of their papers. The figure above shows the homicide rate vs. linoleic acid consumption of five countries over the course of 40 years. Each point represents one year in one country. The U.S. has the distinction of being in the upper right.

I asked Dr. Hibbeln how he selected the five countries, and he told me the selection criteria were 1) available homicide and linoleic acid consumption statistics, 2) "first world" countries, and 3) countries representing a diversity of linoleic acid intakes. I'm satisfied that there was probably not a significant selection bias.

What's interesting about the graph is that not only does the homicide rate track with linoleic acid consumption across countries, but it also tracks within countries over time. For example, here is the same graph of the US alone:

And here is the UK, which doesn't suffer as much from the confounding factor of firearm availability:

I don't think we can draw any solid conclusions from this, but it is worth noting that epidemiological associations don't get much better. In the next few posts, I'll explore the data from intervention trials that support the hypothesis that excessive omega-6 consumption, and insufficient omega-3 consumption, cause serious problems for psychiatric and physical health.


Gyan said...

I agree about excess omega-6 but the jury is still out on omega-3.

A lot of populations consume very little omega-3. Great many people eat no fish and yet have normal eyes and brain.
Probably the equired intake of omega-3 is very small and excess omega-6 disturbs the omega-3 metabolism as well.
SO it is not lack of omega-3 per se but just excess of omega-6.

Gyan said...

Interestingly, the mentioned book links excess omega-6 to increased homosexualisation in the womb.

Ross said...

Hi Stephan,

I found this post very thought provoking. The correlations look remarkably strong, but I'll admit that I'm skeptical of the idea that seed oil is causing violence. Keeping an open mind to that possibility, here are some thoughts/questions I have...

Are there any studies in humans or lab animals where linoleic acid was administered in a controlled manner, and aggression was measured? If experimental studies confirm this, it would give a strong rationale for changing some of the dogma on nutritional recommendations.

If processed seed oils are a cheaper energy source than animal fats (are they?) then linoleic acid intake might just be a marker of economic hardship. In which case there would be very little surprise that it correlates with homicide or violent crime. I would be curious what the correlation coefficients are between linoleic acid and unemployment rate, rate of inflation, or GDP. Do the authors address this in the paper?

The authors of this study estimated linoleic acid intake based on "disappearance data" for seed oils, so they would have omitted contributions from other sources. Is linoleic acid found in significant quantities in any other foods besides seed oils? If so the correlation of violence / seed oil still stands, but linoleic acid might not be what is driving it. This point would be important in guiding follow-up randomized trial experiments. Which chemical do you administer? Or just go with seed oils in general? Has this latter experiment ever been done?

In the abstract they report homicide mortality rate, "adjusted for age." What does this mean?

Robert Andrew Brown said...

Stephan -

Thank you very much for this excellent and provoking post.


It is about both excess Omega 6 and lack of 3. Excess 6 is the bigger issue.

Intake requirement of the vegetable `mother` Omega 6 fat is around 1% of energy. Western actual intake is 10-13%, so we are seriously overloading with Omega 6.

Vegetable `mother` Omega 3 fat intake is falling as we take it out of the food chain to achieve longer shelf life. Omega 3 is more reactive than Omega 6 so is lost first in processing of vegetable oils. We are breeding Omega 3 out of grain crops.

Long chain animal based Omega 3s are falling. DHA in breast milk has fallen by 50% in 15 years.

Homosexualisation - I link the Omega 6 pathways and not Omega 6 per se with Homosexualisation in the womb. Omega 6 ultimately controls hormone and steroid production by controlling at least some of the enzymes in the cholesterol pathways.

Intervention in the hormone pathways at a critical time with common drugs administered in human pregnancy to delay or induce birth has been shown to unequivocally alter brain structure and gender behaviour in rats. No observational work has been conducted in humans.

I have raised the issue with various groups including the Church of England seeking support to call for trials. To my surprise it seems the issue is so sensitive nobody actually wishes to address it.

My question is do we have the right however innocently to risk altering the given gender identity of an unborn infant. A potential brain gender alteration mechanism has been identified in rats due to administration of commonly used drugs to delay or induce birth. Do we not have an obligation to determine if the same mechanism is applicable in humans?

This is a global issue. If brain gender is being altered by human intervention (And I guess it may well be) it raises some profound issues.


Why is Omega 6 key, and arguably a master controller of many processes in the body including behavioural responses?

Omega 6 links the body to the fecundity of the earth through the chemical and structural processes it controls in the body. The body cannot make Omega 6 (or Omega 3). Omega six in the human diet in nature is found in plants in low maintenance quantities. It is only found in high quantity in seeds nuts and related plant reproductive material. Plant reproductive material is scarce and seasonal, and reflects the fecundity of nature.

It would make sense to initiate breeding related behaviour and processes when there was sufficient food to support a successful pregnancy. Breeding behaviour would include aggression, acquisitiveness, impulsiveness etc.

Omega 6 moderates behaviour through the control of hormones and neurosteroids like testosterone and serotonin. Low serotonin and high testosterone equate to uncontrolled aggression.

Vegetable oils, and animals products raised on high grain feed are the primary sources of Omega 6 in the modern human diet. They are also cheap and commonly used in processed foods. In Nature high Omega 6 diet sources seeds nuts etc above a maintenance dose are scarce and seasonal.

I am a non specialist who came to the subject of excess Omega 6 and lack of Omega 3, and its impact on human health and behaviour by accident, whilst looking at breast cancer. Once you begin to understand the subject and read round it for me it is unquestionable that Excess Omega 6 and a lack of 3 is at the root of many western health conditions, behavioural issues, and loss of cognitive and related functions in old age.

The real experts in the neurological field include Professors Lands and Hibbeln. Professor Lands has been in the field for 50 years and warning of the impact of excess Omega 6 for 30 years

Thanks for your interest

Robert Brown

Author - Omega Six The Devils Fat

brian said...

While I agree there is much concern over the amount of omega-6 consumption, I have a question regarding the figures.

The title indicates apparent consumption. I didn't go through the paper(s) but this may raise a question of accuracy.

Taubes and others have consistently said that food availability and consumption are two very different things. For example, the most recent info regarding food consumption in the US is from food available in the market place. The consumed data is arrived at via controlling for production, exports and waste. In this manner, the estimation of consumption can be woefully inaccurate.

The consumption of processed oils is frought with even more error as the amount of waste is impossible to estimate.

While I agree with the premise and these results show some rather interesting relationships, the question I would as is are the data actual consumption or food availability?


Methuselah said...

Stephan, Robert - one of the most interesting posts I've read in weeks. Might even buy the book.

This is one more to add to the list of substances we are poisoning ourselves with. I have been preoccupied with refined sugar and starchy carbohydrates and the psychological (as well as physiological) effects these have on us, so for me the indictment of Omega 6 completes a terrifying picture of a food industry that could scarcely do more to upset the natural balance of our minds and bodies.

Pay Now Live Later

Debs said...

This is intriguing. Reading the study, my initial reaction is that it would be worth investigating whether high linoleate diets increase violence on an individual level, but that I share Ross's skepticism about these data.

First, unless I missed something in the study, they didn't show that those who consume linoleic acid are necessarily those more prone to violence, just that a society with a higher linoleate intake is a more homicidal society. It might be more convincing if the data were linked to individuals.

Second, consumption of cheap vegetable oils goes hand in hand with other detrimental changes in a society: increased poverty and economic stress stands out, as does poorer diet overall -- more fast food, cheap food, processed food, packaged food.

The authors do acknowledge this. They write, "Greater linoleic acid consumption is not proposed here as a sole determinant factor for greater homicide mortality, but as a readily modifiable potential risk factor." They mention other potential factors for increased violence in a society.

What convinces me that it might be worth looking into is that they cite some studies showing that linoleates have an effect on aggressive behavior, in animals and human beings. Although, at least one of those studies focused on soybean oil. What if it's not (just) the linoleic acid, but the phytoestrogen in soybeans? There are also a few studies that show an association between intake of phytoestrogen and increased aggression.

I do think diet plays an enormous role in mental health and wellness, and that the problem is partly about detrimental things we're eating and partly about protective things we're not eating. Maybe if linoleic acid is one small contributing factor to decreased mental health and increased violence, it's worth investigating. Besides, there are other health benefits to booting vegetable oil --- and all the foods it appears in -- from our diets, so it wouldn't hurt for it to gain more bad stigma. It also wouldn't hurt if the government didn't subsidize corn and soy production, leaving bad vegetable oils the most affordable option for some.

Food Is Love

Stephan Guyenet said...

Ross and Debs,

I wouldn't even have posted this if I didn't have intervention trials and animal data to back it up. I'll be going through that in subsequent posts; the homicide connection is just the 'hook'.

Brian and Ross,

The data are based on estimates of food consumption that come from food sales. So yes it's a proxy for consumption, not a direct measure. That is a limitation that's important to keep in mind of course. But with any type of epi study, all you're doing is making a hypothesis. Then you have to back it up with controlled trials. Stay tuned.

Gyan said...

Seed oils are certainly cheaper than animal fats but it is hard to imagine people in US not buying butter because it is expensive,.

Stephan Guyenet said...


It's partly a matter of price but it's also a misplaced attempt at being healthy. We've been hearing the message to reduce saturated animal fats and replace them with unsaturated seed oils for decades. You can see it in the food consumption statistics.

It also reflects the fact that processed foods go with what's cheapest, which is seed oils at this time.

Anonymous said...


Interesting. I was just thinking the other day of how wheat and other grains have shaped modern society, by which I mean its philosophy, values, politics.

From my libertarian/anarchist perspective, the chief fundamental antagonism in modern society is that of individualism vs. collectivism. It's reported that the reason hunter-gatherers lived in small groups of around 30 is because things become too complex much beyond that. I speculate that in groups of about 30 or less, each adult individual of sound mind and body has a real potential of influencing the rest of the group, so life is much more harmonious. We're social beings, but that has limitations that were evolutionarily established over millions of years.

I thought this was all wildly speculative, so have not written about it. Now this post, and I have to wonder again.

Here's what comes immediately to mind, and you can find it on page 7 of Nutrition and Physical Degeneration, by Weston A. Price:

"Thinking is as biologic as is digestion, and brain embryonic defects are as biologic as are club feet."

I think it's pretty certain that agriculture is behind the human creation of the nation state (it could never be sustained otherwise). It always mystifies me why so many people who understand these important health issues, from gains to concentrated sugars to concentrated vegetable and seed oils want to turn to the state to solve the problem.

To my mind, it's like turning to the mafia to deal with the problem of theft. They'll deal with it alright, by setting up a monopoly on theft. Sound familiar?

Stephan Guyenet said...


I absolutely agree that the brain is an organ like any other. It's perfectly normal that nutrition would affect how if functions, just like it does for the other organs.

Well I'm with you that relying on the state to solve our health problems isn't wise at this point. I hope that will change though. Blogs like this aren't going to change the course of American food habits, so as long as the government is giving poor diet advice, most people are going to be out of luck. I hope that once the consensus of what constitutes a healthy diet changes, the gov't will change its education programs and things will get better on a larger scale. Only time will tell.

Pasi said...

In this research from Finland You can see same kind of results: violent deaths increases in intervention group when they are advised to eat healthy foods. (Deaths from coronary heart disease increased too...)

Mortality in participants and non-participants of a multifactorial prevention study of cardiovascular diseases: a 28 year follow up of the Helsinki Businessmen Study.

Stephan Guyenet said...


Thanks for the information. One of the things that's often been noted in trials that try to decrease heart disease deaths by replacing saturated fat with unsaturated fat, is that even if heart attacks decrease, often total mortality remains unchanged or even increases. It's often due to increases in cancer and violent deaths. It could be due to the increase in linoleic acid.

Binko Barnes said...

Gyan, it's not just fish that supplies omega-3. Beef raised on grass or pork raised on natural forage is also high in omega-3. You commented that many societies eat little fish. But what do they eat instead? Often it's goat or lamb that is raised entirely on grass.

In the USA most people eat little fish and what fish they do eat tend to be from fish farms. Instead they eat primarily feed lot beef in which omega-3 has almost completely disappeared.

My belief is that the single most important rule for great dietary health would be to eat no grains nor anything made from grains nor any animal fed primarily on grains.

Stephan Guyenet said...


Sounds like a great rule. I think it's helpful to point out that fish oils have a lot more n-3 than land mammals though, so they are better suited to supplementing if you have a higher than optimal n-6 intake.

But I agree 100% that fish oils aren't essential for good health.

Anonymous said...

Binko, I think the biggest problems are the omega-6 oils, hydrogenated oils, all kinds of flour (including whole grain), and refined sugars in the diet. To even mention grain-fed meats on the same page as all those other foods is hyperbole. Eat grass fed if you can afford it and if you like the taste, but don't say it is vastly better, because many people have gotten very healthy by eating grain-fed meat while avoiding PUFA oils, trans fats, processed sugars, and refined white flour (or rancid whole grain flour). You damage your credibility by comparing grain-fed meat to eating grains. Where is the evidence that grain-fed meat is bad that removes vegetable oils, wheat, sugar, and high fructose corn syrup from the equation? Thanks.

Dana Seilhan said...

I think we're eating bad fats but I've also gotten curious recently about the role of the fat-solubles. Another commenter here mentioned Weston Price. I need to get his book, but he apparently talked about fat-solubles a lot.

I realized the other day that although nutritional labels for plant foods mention their vitamin A content, no plant food actually contains vitamin A. That number you see on a label for baby carrots that tells you you're getting surplus daily value for vitamin A is actually telling you how much A you'd get if you converted all the beta carotene in your carrot serving.

Well, many people can't do a complete conversion of beta carotene, and some people can't convert it at all.

Yet the government allows food companies to tell us we're eating vitamin A, and most of us believe we are. But where are we getting "vitamin A"? From plant sources, primarily.

Even people who eat meat may not be getting enough. How many of us eat liver anymore? I know I sure don't.

Then they're telling us now that we're not getting enough vitamin D. Who knows whether we're getting enough E, and we can make our own K, but not if our bacterial flora is messed up--and for many of us, it is.

We may be looking at more here than mere fat intake.

Stephan Guyenet said...


Absolutely! I've written about the fat-soluble vitamins extensively in later posts, particularly K2.