Beta Carotene Increases the Activitiy of Natural Killer (NK) Cells

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Beta Carotene Increases the Activitiy of

Natural Killer (NK) Cells

JoAnn Guest

Jan 04, 2004 19:37 PST

 

Beta-Carotene

 

 

As we age, disease worms its way into our lives. Arthritis,

cardiovascular problems, longer-lasting colds, even cancer—they seem

to sneak up on us at a certain age, doing their best to ruin the

quality of our lives, just when we should be enjoying a bountiful

retirement.

 

In the past, people accepted this as one of the evils of growing

old; in other words, that age beget disease.

 

Today, we know that this is not true, and that many of the health

problems traditionally associated with aging have more

to do with the immune system than aging.

 

Supplementation

 

Writing in the June, 1996, issue of The American Journal of Clinical

Nutrition, authors Kelley and Bendich note that " . . .several

recent,

well controlled human intervention studies found that clinically

important immune responses were improved when amounts of vitamin C,

vitamin E, or beta carotene higher than the recommended dietary

allowance (RDA) were consumed in healthy populations. "

 

Beta carotene has long been known to be an immune booster, and

recent

studies support this contention.

 

The same authors as quoted above go on to say that, " Beta carotene

supplementation appears to be beneficial for individuals with

compromised immune systems, and does not overstimulate the immune

responses of healthy adults . . . "

 

Beta carotene may be particular helpful for the immune system of the

elderly. According to Richard Passwater, Ph.D., in his book, Beta

Carotene and Other Carotenoids, beta carotene supplementation has

been

shown to enhance some, but not all, aspects of cell-mediated

immunity in

healthy older men.

 

 

 

Michelle Santos, et al, writing in the November 1996 issue of The

American Journal of Clinical Nutrition, notes that beta carotene may

increase the activity of natural killer cells.

 

This is an important point, as natural killer (NK) cell activity has

been postulated to be an immunologic link between beta carotene and

cancer prevention.

 

 

The article states that, " Our results show that long-term beta

carotene

supplementation enhances NK cell activity in elderly men, which may

be

beneficial for viral and tumoral surveillance. "

 

 

 

The link between Beta Carotene and Reduced Cancer Risks

 

Last year, Harvard Medical School released research that indicates

that

beta carotene can sharply reduce the risk of prostate cancer in men

with

low beta carotene blood levels.

 

(Cancer Weekly Plus, June 9, 1997). In this research, the diets,

lifestyles, and health of more than 22,000 male doctors were

observed.

 

Half of the doctors were given 50 mg (80,000 IU) of beta carotene

every

other day.

 

The findings indicated that physicians with low levels of beta

carotene

were one-third more likely to develop prostate cancer.

 

The doctors who supplemented with beta carotene were 36 percent less

likely to develop

prostate cancer than those who ate few beta carotene-rich fruits and

vegetables and did not take beta carotene supplements.

 

The link between cancer and beta carotene is also mentioned in more

recent research. An article in the American Journal of Clinical

Nutrition (August 1997) notes that epidemiological studies reveal

that

people with high intakes of beta carotene or high blood

concentrations

of this nutrient have a reduced risk of various diseases, including

cancer and heart disease.

 

The authors note that this is a credible hypothesis, because

 

1) increased consumption of beta carotene is strongly associated

with

reduced risk of cancer;

 

2) beta carotene is a dietary antioxidant and antioxidants inhibit

early

stages of carcinogenesis, and

 

3) beta carotene 'reduces' cancer in experimental animal models.

 

It appears that this hypothesis is on the right track, as doctors

may

have discovered why beta carotene 'fights' cancer.

 

Apparently, beta carotene stimulates a molecule that helps the

immune

system target and destroy cancer cells.

 

It increases the number of receptors on white blood cells for a

molecule

known as major histocompatibility complex II (MHC II).

 

MHC II is integral in helping monocytes, a type of white blood cell,

direct killer T cells to cancerous cells (Cancer Weekly Plus, Jan 6,

1997).

 

In other words, beta carotene is integral in 'directing' the immune

system

to kill cancer cells.

 

The link between Beta Carotene and Rheumatoid arthritis

 

Rheumatoid arthritis (RA) is another problem linked to aging, and it

occurs when the immune system turns on itself.

 

This results in inflammation, which in turn triggers the release of

chemicals into the joint lining. This in turn results in joint

damage

that makes it hard to manipulate areas such as the knuckles and

knees.

 

Arthritis experts have known for years that free radicals (harmful

renegade molecules) are present in the fluid of the joint lining,

and

that they increase in joints inflamed by RA.

 

Related research has shown that patients with RA have lower blood

levels of beta carotene than patients without RA.

 

Now, The Tufts University Health & Nutrition Letter, (Sep. 1997,

Vol. 15

No. 7) reports that a Johns Hopkins University study suggests that a

low

level of beta carotene in the blood may actually increase a person's

risk of developing RA.

 

Surveys show that among those without this condition, the pre-

disease

beta-carotene blood levels were 29 percent higher.

 

What does all this mean? Beta carotene is important for all of us to

get, especially the elderly.

 

Studies have shown that extracts reduce prostate inflammation, which

in

turn reduces prostate size.

_________________

JoAnn Guest

mrsjo-

DietaryTi-

http://www.geocities.com/mrsjoguest