By Forrest H. Nielsen
Recently, the word inflammation has gotten a sinister reputation in nutrition.
The reason is that inflammation is thought to be a major risk factor for
some ailments that prevent everyday well-being and often are life-threatening.
These ailments are called chronic diseases because they take time to develop.
They include heart and blood vessel disease, diabetes, osteoporosis, arthritis,
and Alzheimer's disease.
Human survival, however, depends upon inflammation. Inflammation
is the body's immediate response to infection or injury. It
results in redness, swelling, heat and pain. This response happens
because blood flow increases and blood vessels change to allow infection
fighting blood cells and large molecules to move from the blood stream
into tissue that needs healing. The cells and molecules kill
bacteria and remove damaged tissue through inducing the formation of a
reactive form of oxygen. The cellular and molecular response also
signals for biochemical changes that cause unwanted cells to destruct.
Inflammation and reactive oxygen are designed to work best under certain
conditions. These conditions are a well-nourished person with
a mild to moderate injury or infection over a short period of time.
The inflammatory response shows its bad side when it is roused in the
body without the need to fight an acute injury or infection. This
results in inflammation that usually is prolonged and does not develop
typically, and thus is called low-grade or chronic inflammation.
Chronic inflammation can induce the excessive formation of reactive oxygen
that attacks healthy tissue, which is called oxidative stress.
Chronic inflammation is mainly triggered by improper nutrition, particularly
deficient intakes of nutrients regulating the inflammatory response and
excessive calorie intake leading to obesity. Because excessive reactive
oxygen damages tissue, chronic inflammation also can be triggered by dietary
practices that cause oxidative stress. These practices include, for
example, high intakes of simple sugars such as fructose and sucrose and
low intakes of anti-oxidant nutrients such as vitamin C and zinc.
Both animal and human studies have shown that obesity is associated with
chronic inflammation. Compared to fat tissue from lean people,
fat from obese people contains more cells that produce activators of the
inflammatory response. In addition, the blood of obese people
usually contains more of the different molecules involved in the inflammatory
response than blood in lean people. As a result, chronic inflammation
is considered a reason that obesity, which affects over 35% of the population,
is a major risk factor for chronic diseases such as heart disease and diabetes.
An example of a nutrient deficiency that may be responsible for some low-grade
inflammation is magnesium deficiency. Animal-model experiments
show that magnesium has a regulatory role in inflammation and magnesium
deficiency results in inflammation and oxidative stress. Both
decreased magnesium intakes and blood magnesium levels have been associated
with an increased marker of chronic inflammation in people of all ages.
Numerous studies have shown that a low magnesium status occurs often in
people with diseases that have a chronic inflammation component, including
heart disease, diabetes, high blood pressure, and osteoporosis.
The idea that a low magnesium status has a role in low-grade inflammation
and chronic disease may not be unusual because a recent nutrition survey
indicated that about 60% of adults in the United States do not consume
the estimated average requirement for magnesium. Even less adults
meet the recommended dietary allowance or RDA for magnesium of 310-320
milligrams per day for women and 400-420 milligrams per day for men.
Not all people who are obese or magnesium deficient exhibit low-grade
inflammation and oxidative stress. Animal experiments suggest
that this happens because other nutritional factors can prevent or lessen
the inflammation or oxidative stress. Among the food components with
anti-inflammatory or anti-oxidant action are omega-3 fatty acids, coenzyme
Q10, vitamin C, vitamin E, and plant chemicals in foods such as blueberries,
cherries, grape seed, and green tea. Low intakes of omega-3 fatty
acids, vitamin C and vitamin E may make inflammation or oxidative stress
worse.
This also means that a combination of a low magnesium status and obesity
would be more likely to result in chronic inflammation and oxidative stress
and increasing the risk of chronic disease than either one alone.
All chronic diseases apparently have two components: chronic
inflammation and oxidative stress. They occur together because one
induces the other. However, taking a specific anti-inflammatory
agent may not prevent all the changes induced by oxidative stress that
lead to increased risk for chronic disease. Likewise, taking a specific
anti-oxidant supplement may not prevent all changes caused by chronic inflammation.
Examples of this are studies showing that estrogen therapy, which is anti-inflammatory,
did not prevent heart disease; neither did supplemental vitamin E, which
is an anti-oxidant. This indicates that the best way
to prevent chronic inflammation and oxidative stress that increases the
risk for heart disease is to maintain a proper body weight and eat a diet
that provides essential nutrients in adequate amounts and rich in foods
that have anti-inflammatory and anti-oxidant actions.