According to Michael Murray, ND, "A deficiency of virtually any single nutrient can significantly impair immunity. Throughout the world, nutrient deficiency is by far the most common cause of poor immune function. This fact is by no means limited to people whose diets are restricted by poverty. In America, many people are overfed but undernourished. They choose foods that have a lot of calories but little real nutritional value. Every week I see people in my practice who are suffering from poor immune function. They benefit tremendously by following these simple guidelines:
Eat a diet that is rich in a variety of vegetables (especially the green leafy ones), fresh fruits, whole grains, beans, nuts, and seeds. These plant foods are rich in essential nutrients and immune-boosting chemicals. See Plant foods with high anti-cancer Salvestrols1 content
Cut out the sweet stuff. Sugar makes your white blood cells sluggish. Studies show that eating 100 g of sugar (about 3.5 ounces) reduce the effectiveness of a type of white blood cell known as a neutrophil, which engulfs and destroys bacteria, by as much as 40 % within 2 hours after ingestion. Since neutrophils account for about 60 to 70 % of your white blood cells, interfering with them can seriously impair your immune function.
Decrease the intake of saturated fats and cholesterol. A diet high in saturated fat suppresses immunity. Many of my patients initially presenting with high levels of cholesterol and triglycerides also report more frequent colds and flu. When cholesterol and triglyceride levels are normalized, proper immune function is restored.
Eat sufficient but not excessive amount of protein. Adequate protein intake is critical in the making of white blood cells, antibodies, and chemical messengers such as interferon. You also need protein to make antioxidant enzymes such as glutathione, which is found in abundance in white blood cells. Elevated glutathione levels are associated with better immune function. Patients with low immune function can benefit from eating more protein from fish, lean poultry, and lean cuts of meats. I have seen many vegetarians who are suffering from low immunity solely as a result of not consuming enough protein. In these patients, I recommend either soy protein isolate if they eat absolutely no animal products, or whey protein if they eat dairy. An additional 40 to 50 g per day for one month will boost protein stores back to normal. After the month is up, I would still recommend 20 g of either choice daily.
Take a high-potency vitamin and mineral supplement. Doing so will increase your intake of the key nutrients for immune function. Not long ago, a study of adults found that those who took multiple vitamin and mineral supplement had a 50 % decrease in the number of days of illness due to infection compared with the group that took a placebo (dummy pill). Those taking the supplement also showed improvement on eight out of twelve objective measures of immune function. Pretty good results for such little effort!
Now let's discuss the practical steps you can take to improve immune function. The first goal is to take a look at your lifestyle to see if there are any factors that may be interfering with your body's ability to fend off illness. Among the most likely culprits:
Chronic or severe stress
Too much simple sugar in diet
Dysbiosis -- overgrowth of unfriendly organisms, especially yeast (candida), in the bowel
Excessive consumption of alcohol
Exposure to environmental toxins
Lack of exercise
Once you've identified any harmful influences, of course, the next step is to do what you can to correct them.
One essential nutrient that most people are missing is UV light from the sun which is central to healing, happiness and vitality. See Sun Yoga & Its Healing Aspects
1 Salvestrols are inert nutrients in fruits and vegetables.
-Salvestrols in our diet are depleted by pesticides used in modern farming methods.
-Salvestrols are converted into toxins by CYP1B1 found only in cancers.
-Salvestrols cannot affect the normal cells since these cells do not have CYP1B1
-Salvestrols are mainly present in unprocessed organic food. Food manufacturing and processing remove Salvestrols to make product taste sweeter, as most Salvestrols have a sharp or bitter taste.
In the body, salvestrols can be chemically transformed into chemical entities that can induce cell death. Interestingly, the activation of salvestrols is dependent on a particular enzyme found exclusively in cancerous cells. This gives salvestrols the ability to be highly selective about the cells they kill: while they can be the kiss of death to cancerous cells, they leave healthy cells untouched.