Antioxidants and Respiratory Track Infections
The Ongoing Vitamin Debate
There is a lot of debate as to the health benefits of supplemental vitamins. To my knowledge, there is no hard scientific evidence that taking vitamins will improve your athletic performance, although there are people out there that will swear to the contrary. However, there is a lot of evidence that vitamin supplements, especially antioxidants, might be really good for your overall health. Since healthier athletes are able to train and compete with more consistency I will go out on a limb and say that taking vitamins, at safe prescribed levels, will help you stay healthy and get more benefit from your training. There is a long list of more important things you need to do to support your training but I will leave those for other discussions. Right now, we’re talking antioxidant vitamins.
In recent years, there has been a good deal of research into the potentially harmful effects of oxidative metabolism (aerobic fuel production) on the body, at the cellular level, and how this affects the body’s immune system. Although there is no conclusive evidence, some companion studies have suggested that the regular intake of antioxidant nutrients (vitamin C, vitamin E, and beta-carotene) might help reduce the overall oxidative stress on the body from training and competition and assist in the recovery process. There has also been some promising research into antioxidant supplementation and the potential support of the immune system in controlling a persistent health problem for endurance athletes, the common cold.
One very interesting piece of research was a 1995 study on a group of ultra-marathon runners competing in the 90-kilometer, Comrades Marathon, in Cape Town, South Africa. Researchers from the University of Witwaterserand and the University of Cape Town, in South Africa, studied the effects of three separate, pre-event, protocols of antioxidant vitamin supplementation on a control group of 172 competitors and a comparable number of sedentary (non competing) individuals.
The marathon runners and their vitamin protocols were divided up as follows:
** 43 runners ingested 500 mg of vitamin C daily
** 45 runners took 500 mg of vitamin C plus 400 IU (international units) of vitamin E daily
** 37 runners supplemented their diets with 300 mg of vitamin C, 300 IU of vitamin E, and 18 mg of beta-carotene (a chemical which the human body readily converts to vitamin A).
** 47 additional runners took in only a placebo (a inactive substance designed to look like the vitamins taken by the other groups).
The individuals from the sedentary control groups took in similar amounts of vitamin supplements or placebo. All test subjects were instructed to eat normally during the study and the researchers did not take dietary habits into consideration.
The 344 test subjects were monitored for upper respiratory tract infections for 14 days after the marathon. Compared to sedentary individuals, the runners did have more respiratory tract infections during the two weeks after the competition. This was a 54-mile marathon after all and the demands on the human body during training and competition would tend to suppress the immune system and increase the risk of illness and infection.
After 14 days only 16%-20% of the runners receiving vitamin C alone or the combination of C, E, and beta-carotene showed signs of respiratory system infection, compared with 40% of the runners who were given the placebo. The level of respiratory infections in the sedentary control individuals were lower overall than the runners, which helps support the notion that antioxidant supplementation can have a positive effect on general health.
The research data suggests that the intake of supplemental antioxidants may lower the endurance athletes’ risks of respiratory tract infections during and after periods of extreme physical exertion. Researchers speculated that the antioxidants might help to stabilize and strengthen cell membranes in the athletes’ respiratory systems, thereby making the cells less vulnerable to viral attack. It was also suggested that the vitamin supplements helps boost the immune system in its fight against the infections.
Does exercise increase your protection against illness and disease?
Other research, in the United States, has focused on the positive effects of increased levels of exercise and physical activity on lowering the risks of major illness and disease, namely, lung cancer.
A 28-year lung cancer study by Harvard investigators, Ralph Paffenbarger and l. M. Lee involved 17,755 men (average age, 47) observed between 1962 and 1990. The activity levels of the study subjects were measured using annual questionnaires. The subjects were classified into 3 categories:
Inactive (expending fewer than 1000 calories/week during exercise)
Moderately Active (burning between 1000-2500 calories/week during exercise)
Highly Active (using more than 2500 calories/week during exercise)
Other factors which were believed to increase the risk of lung cancer; smoking, age, and body mass (% body fat) were measured statistically as the study developed keeping physical activity as the key factor in comparison during the study.
A total of 354 lung cancer cases occurred during term of the study. Analysis of the data revealed that physical activity was linked with an appreciably lower risk of lung cancer, especially in men who were Highly Active throughout the 28-year study. The incidence of lung cancer in the Highly Active group was about 50% of that in the group of Inactive men. The men that reported Moderate Activity levels also had a lower incidence of lung cancer than the Inactive group at a rate of about half, or about 25%, of that of the Highly Active group.
Although not directly, the study does “hint” at the positive effects of antioxidant vitamins on controlling respiratory tract infections in the more athletic individuals. Unfortunately, dietary records were not kept as part of the study but it can be speculated that the more active and athletic individuals eat a more balance diet, likely higher in antioxidant nutrients, than the less active or inactive groups. Newer research is suggesting that antioxidants may be associated with lower frequencies of several types of cancers and combined with physical activity, could have been a contributing factor in the Harvard study.
Unfortunately, the time period of the research (between 1962 and 1990) was before antioxidant supplementation became a widespread practice, so the true influence of antioxidant nutrients cannot be firmly established.
Maybe, could, possible, potential effect. These uncertain terms do not lend themselves to establishing that antioxidant nutrients are helpful in preventing cancer but anyone in their right mind understands that being active and eating a good diet will keep you healthier, give you a stronger immune system and help you fight off a host of illnesses and diseases. That’s a no brainer.
How can exercise protect the lungs from cancerous growths? The actual mechanism is unknown, but it is clear that regular physical activity stimulates the immune system and makes healthier athletes. A fully functioning immune system will do a better job of attacking small clusters of cancer cells before they have a chance to develop into full-blown tumors. The research is there to support that notion that active people live healthier lives and experience a lower incidence of major, life threatening diseases.
In Conclusion
The connection between exercise and a reduced risk of lung cancer is great news. It is even better news that antioxidant supplementation has been proven to support better immune function in endurance athletes. It can difficult sometimes to get the nutritional support you need from you diet, especially when you are in a hard training cycle or traveling for extended periods of time. I believe it is a good idea to have a little nutritional insurance in these cases. However, too much of a good thing can be harmful so do not exceed the recommended daily doses of any vitamin you are taking.