The Sunshine Vitamin May Reduce Stress
~ November 1999 No.86 ~
Recent experimental results with rats may provide even more reason to start your day off with a glass of sunshine. University of Alabama scientists have found that, when rats consume high levels of vitamin C (200 mg / day), their levels of cortisol are reduced. Because many citrus fruits are a good source of vitamin C, it is often referred to as "the sunshine vitamin".
Cortisol, a hormone produced by the adrenal glands, is released in times of stress. The adrenal glands located on top of the kidneys produce a wide variety of hormones such as estrogen, progesterone, steroids, cortisol, and cortisone, and chemicals such as adrenalin (epinephrine), norepinephrine, and dopamine. Cortisol plays an important role in the function of almost every part of the body. Corticosteroid medications have 2 main actions in the body. They reduce inflammation and decrease the activity of the immune system. But if you are under a lot of stress, your cortisol levels are probably high.
Vitamin C is usually consumed because of its anti-oxidant properties and has become popular as part of the ACE combination (vitamin A, vitamin C and vitamin E) consumed by many seniors. Vitamin C also received publicity when Nobel Prize laureate Linus Pauling ( in chemistry) claimed that mega-doses of vitamin C could prevent or reduce the effects of the common cold.
As with many other studies, the levels that were given to the rats in the US studies to affect cortisol levels were very high compared to what is generally accepted as adequate levels. Rats normally need about 60 mg /day in their diet. If the results are true and can be applied to humans it would mean that to get the same effects, humans would have to eat several grams of vitamin C per day. Levels this high were what Pauling was advocating to fight colds. Even if not totally correct, it may mean that the levels of vitamin C that we normally consume may be low, and that we could be helping our immune system by upping our intake of the sunshine vitamin.
|Food||content (1 cup or 248 g portion)|
|orange juice:||86 mg|
|apple juice:||2.2 mg|
|cranberry juice:||90 mg|
|grapefruit juice:||77 mg|
|prune juice:||10 mg|
|grape juice:||0.3 mg|
|tomato juice:||44 mg|
|all juices canned or bottled, unsweetened and no salt added; no vitamin C added|
|USDA Agriculture Research Service -Nutrient Data Laboratory|