Nutrition and Behaviour
15th February 2017
Lecture 4: Fatty acids, aggression, anti-social behaviour and depression
Fatty acids, aggression and anti-social behaviour
So far, have talked about the brain being an organ that is made up of fatty tissue and that the essential fatty acids
are important for brain development, which need to be taken up via diet.
There are two stages:
1: The original construction of the brain.
2: There is the possibility of there being a continuous turnover in terms of molecules, possible that having gone
through childhood and brain development, what is consumed afterwards on a day-to-day basis may influence
further brain development because of the idea of turnover.
There are a lot of epidemiological studies on the relationship between fatty acid intake and aggression/anti-social
behaviour.
,The data is astonishingly strong in terms of a correlation between fatty acids and aggression.
The graph above:
World Health Organisation (1995)
World health statistics annual.
Negative correlation of -0.63, significance level of p< .0006, included 26 countries, very powerful relationship.
Between the apparent level of consumption of seafood and the number of homicides per 100,000.
Can see clearly that as the amount of seafood consumed increases, homicide rates decrease.
Coming back to this image on the left, presenting the relationship between omega-3 and omega-6 essential fatty
acids.
The omega-3 fatty acids are what people talk about more in terms of brain functioning and development.
The point is that these fatty acids share the use of enzymes, therefore in competition with each other.
, A lot of the consumption of the essential fatty acids is based around cooking oils and the oils added to processed
foods.
The majority of the oils listed contain a much higher percentage of omega-6, with a lot not even containing any
omega-3.
The only major source of omega-3 seems to be fish oil. Flaxseed allegedly contains a higher percentage of omega-3
than omega-6. However, misleading as most of the body cannot metabolise the flaxseed oil, cannot deal effectively
with it in order to obtain the omega-3.
Lichtenstein et al. (2006):
Dietary recommendations
The Nutrition Committee of the American Heart Association has recommended that no more than 30 percent of a
person's daily calories come from fat.
Of that, less than 7 percent of total calories should be from saturated fatty acids, and less than 1 percent should be
from trans-fatty acids.
Simopoulos (2002):
The suggestion was that when humans evolved, they evolved on a diet with a ratio of omega-6 and omega-3
essential fatty acids at approximately 1:1. How was this found out? Probably estimated? Accurate? Cannot falsify?
Now, in Western diets, the ratio is 15-16.7:1
This is caused by a deficiency in obtaining omega-3 fatty acids but also as a result of there being an excess amount of
omega-6 consumed, resulting in competition for the enzymes.
A high omega-6 : omega-3 ratio, promotes cardiovascular disease, cancer, and inflammatory and autoimmune
diseases.
Arguments for reduced LA/omega-6 intakes are based on the assumption that because CHD has an inflammatory
component (Libby, 2006) and because the omega-6 fatty acid, AA, is the substrate for the synthesis of a variety of
pro-inflammatory molecules, reducing LA intakes should reduce tissue AA content, which should reduce the
inflammatory potential and therefore lower the risk for CHD.
15th February 2017
Lecture 4: Fatty acids, aggression, anti-social behaviour and depression
Fatty acids, aggression and anti-social behaviour
So far, have talked about the brain being an organ that is made up of fatty tissue and that the essential fatty acids
are important for brain development, which need to be taken up via diet.
There are two stages:
1: The original construction of the brain.
2: There is the possibility of there being a continuous turnover in terms of molecules, possible that having gone
through childhood and brain development, what is consumed afterwards on a day-to-day basis may influence
further brain development because of the idea of turnover.
There are a lot of epidemiological studies on the relationship between fatty acid intake and aggression/anti-social
behaviour.
,The data is astonishingly strong in terms of a correlation between fatty acids and aggression.
The graph above:
World Health Organisation (1995)
World health statistics annual.
Negative correlation of -0.63, significance level of p< .0006, included 26 countries, very powerful relationship.
Between the apparent level of consumption of seafood and the number of homicides per 100,000.
Can see clearly that as the amount of seafood consumed increases, homicide rates decrease.
Coming back to this image on the left, presenting the relationship between omega-3 and omega-6 essential fatty
acids.
The omega-3 fatty acids are what people talk about more in terms of brain functioning and development.
The point is that these fatty acids share the use of enzymes, therefore in competition with each other.
, A lot of the consumption of the essential fatty acids is based around cooking oils and the oils added to processed
foods.
The majority of the oils listed contain a much higher percentage of omega-6, with a lot not even containing any
omega-3.
The only major source of omega-3 seems to be fish oil. Flaxseed allegedly contains a higher percentage of omega-3
than omega-6. However, misleading as most of the body cannot metabolise the flaxseed oil, cannot deal effectively
with it in order to obtain the omega-3.
Lichtenstein et al. (2006):
Dietary recommendations
The Nutrition Committee of the American Heart Association has recommended that no more than 30 percent of a
person's daily calories come from fat.
Of that, less than 7 percent of total calories should be from saturated fatty acids, and less than 1 percent should be
from trans-fatty acids.
Simopoulos (2002):
The suggestion was that when humans evolved, they evolved on a diet with a ratio of omega-6 and omega-3
essential fatty acids at approximately 1:1. How was this found out? Probably estimated? Accurate? Cannot falsify?
Now, in Western diets, the ratio is 15-16.7:1
This is caused by a deficiency in obtaining omega-3 fatty acids but also as a result of there being an excess amount of
omega-6 consumed, resulting in competition for the enzymes.
A high omega-6 : omega-3 ratio, promotes cardiovascular disease, cancer, and inflammatory and autoimmune
diseases.
Arguments for reduced LA/omega-6 intakes are based on the assumption that because CHD has an inflammatory
component (Libby, 2006) and because the omega-6 fatty acid, AA, is the substrate for the synthesis of a variety of
pro-inflammatory molecules, reducing LA intakes should reduce tissue AA content, which should reduce the
inflammatory potential and therefore lower the risk for CHD.
