Thursday, May 7, 2009

Anti-inflammatory diet

Lifestyle and Supplement Considerations Sanford H. Levy, MD

The epidemiological (population) data thus far indicates that those who get sickest from Swine flu and those who succumb to it are
predominantly 20-40 years old. Twenty to forty year olds are the same group which most frequently succumbed during the brief SARS
epidemic, as well as the Spanish flu pandemic of 1918-1919.

A theory to explain why young, healthy individuals are more likely to succumb to these viruses is that it the cause of death is not
the virus itself, but rather an immune response to a foreign virus which leads to excess inflammation and what is labeled as
'systemic inflammatory response syndrome.' If this theory is correct, and I believe it is, it follows logically that an
anti-inflammatory diet may protect against death from Swine flu.

Many Westerners eat a diet considered pro-inflammatory. This is considered a part of the reason for the rising incidence of many
chronic conditions, including diabetes, high blood pressure, chronic kidney disease, coronary heart disease.

The general principles of an anti-inflammatory diet are to eat whole foods rather than processed food and 'fast food,' and to eat a
wide variety of fruits, vegetables, nuts and seeds, and whole grains. With regard to carbohydrate intake, one should maximize
dietary fiber intake, and minimize intake of high glycemic index foods and minimize intake of refined grains. With regard to fat
intake, one should avoid all trans fats, limit intake of saturated fat, consume plentiful amounts of mono-unsaturated fat, and
plentiful amounts of foods with omega 3 fats. Good sources of monounsaturated fat include olive oil (preferably extra-virgin) and a
variety of nuts and seeds. Fatty fish, such as salmon, sardines, mackerel, herring, tunafish, and trout are rich dietary sources of
omega 3 fat.

With regard to protein intake, fatty fish, nuts and seeds, and legumes are all excellent sources of protein, and also excellent
sources of either omega 3 fat, monounsaturated fat, and/or fiber, all mentioned above as important elements of the anti-inflammatory
diet. Intake of poultry and red meat should be limited, or restricted to pasture fed poultry and cows. Pasture fed animals graze on
the grass, whereas most animals (including organic meat and poultry) are fed an unnatural diet consisting mostly of corn and soy.
Corn and soy are omega 6 fatty acids, found not only in meat but also in many processed foods. Optimal health is dependent upon a
balanced intake of omega 3 and omega 6 fatty acids, and the Standard American Diet (SAD) contains far too much omega 6 fatty acids
and far too little omega 3 fatty acids, and this likely contributes to a pro-inflammatory state in the body. Pasture fed meat
contains higher quantities of omega 3 fatty acids and lower quantities of omega 6 fatty acids, compared to 'ordinary' meat. Bison is
rich in omega 3 fat, as bison cannot be raised in close quarters like cows, and thus all bison are pasture fed (some bison are
topped off with corn and soy just prior to slaughter, as this practice creates meat more similar to cow meat and thus more palatable
to many Westerners).

A superb summary of the anti-inflammatory diet can be found in Appendix A of the book Healthy Aging, by Andrew Weil, MD (2005). A
more detailed narrative on healthy nutrition is posted on my web site, www.sanfordlevymd.com.

Based on the theory that an overactive immune response to certain viruses such as Swine flu triggers excess inflammation which can
lead to death, the dietary supplements most likely to be beneficial are those that reduce inflammation and those that modulate
immune response rather than stimulating it (a caveat is that an individual with a suppressed immune system due to AIDS or
prescription corticosteroids would probably benefit from immune stimulating supplements).

The primary anti-inflammatory supplement is fish oil, and specifically the EPA in the fish oil. Barry Sears, PhD, author of The
Anti-Inflammation Zone, states in this book that healthy adults should consume 2.5 grams of EPA + DHA in supplement form daily. I
believe that a healthy individual eating an anti-inflammatory diet needs only 1 gram per day of EPA +DHA, derived from either food
or fish oil supplementation. Flax oil is an omega 3 oil, but the molecule is 18 carbon atoms in length, and must be converted to
EPA, 20 carbon atoms in length, in order to have an anti-inflammatory effect. Published studies indicate that only 5-20% of alpha
linoleic acid in flax is converted in the human body to EPA, and thus flax does not have nearly the same anti-inflammatory effect as
fish oil. The percentage of alpha linoleic acid in flax which is converted to EPA will vary from person to person, and an
understanding of the biochemical pathways in the body leads to the conclusion that a person eating an anti-inflammatory diet will
convert a greater percentage of alpha linoleic acid to EPA than the person eating a pro-inflammatory diet.

Supplements which likely modulate immune system function include probiotics, vitamin D, zinc, and selenium. While all of these
supplements can boost immune system function, it is my understanding of the mechanism of action of each that these supplements will
likely normalize the immune response in an individual who is experiencing an overactive response.