There is a metabolic difference between simple and complex carbohydrates. The simple ones become glucose soon after they are eaten. The complex ones take longer to turn into sugar and are less apt to spike insulin and cause energy crashes down the line. But that isn’t the only difference between the two.

Almost forty years ago scientists had an interest in the relationship of diet to health, specifically of sugar intake to immunity. But their curiosity went past simple sugar to include carbohydrates other than glucose. The cells that are the backbone of the immune system are supposed to kill, swallow, and dispose of alien bodies, including bacteria, viruses and cancer cells. Scientists at Loma Linda University in California examined the activity of neutrophilic phagocytes (cells that dissolve the enemy) after subjects ingested glucose, fructose, sucrose, honey, or orange juice and found that “…all significantly decreased the capacity of neutrophils to engulf bacteria…” (Sanchez, Reeser, et al. 1973). Looking more closely, the researchers also discovered that the greatest effects occurred within the first two hours after eating, but “…the effects last for at least 5 hours.” (Ibid.) If there is any promise, it’s that the effects can be undone by fasting from added sugars for the next two or three days.

At the start of the twentieth century, Americans consumed only about five pounds of sugar a year. By the fifties, that had grown to almost 110 pounds a year, and to more than 152 by the year 2000. Corn sweeteners account for 85 of those pounds. America’s sweet tooth increased 39% between 1950 and 2000 as the use of corn sweetener octupled.

Although the statistics above are decades old, its message is contemporary. High-fructose corn syrup has become the bad boy of the anti-sugar crusade. HFCS began replacing sugar in soft drinks in the 1980’s, after it was portrayed by marketers as a healthful replacement for demon sugar. It didn’t hurt the industry that it cost less, either. The biological effects of sugar and HFCS are the same, however. Neither has any food value — no vitamins, protein, minerals, antioxidants, or fiber — but they do displace the more nutritious elements of one’s diet, and we tend to consume more than we need to maintain our weight, so we gain.

Even though the number of calories from the glucose in a slice of bread or other starch is the same as that from table sugar (half fructose and half glucose), they are metabolized differently and have different effects on the body. While fructose is metabolized by the liver, glucose is metabolized by every cell in the body. When fructose reaches the liver, especially in liquid form (as in soda), it overwhelms the organ and is almost immediately converted to fat. (Taubes. 2011)

Innate immunity is that which occurs as part of your natural makeup and defends you against infection by other organisms. Short-term hyperglycemia, which might come from a pint of vanilla, has been found to affect all the major components of the innate immune system and to impair its ability to combat infection. Reduced neutrophil activity, but not necessarily reduced neutrophil numbers, is one of several reactions to high sugar intake. (Turina. 2005) Way back in the early 1900’s, researchers noted a relationship between glucose levels and infection frequency among diabetes sufferers, but it wasn’t until the 1940’s that scientists found that diabetics’ white cells were sluggish. (Challem. 1997) More recent study has corroborated the diabetes-infection connection, agreeing that neutrophil phagocytosis is impaired when glucose control is less than adequate. (Lin. 2006) Impaired immune activity is not limited to those with diabetes. As soon as glucose goes up, immune function goes down.

Some people think they’re doing themselves a favor by using artificial sweeteners. Once the brain is fooled into thinking a sweet has been swallowed, it directs the pancreas to make insulin to carry the “sugar” to the cells for energy. After the insulin finds out it’s been cheated of real sugar, it tells the body to eat in order to get some, and that creates artificial hunger, which causes weight increase from overeating. Even environmental scientists have a concern with fake sweeteners in that they appear in the public’s drinking water after use. You can guess how that works. (Mawhinney. 2011)

Mineral deficiencies, especially prevalent in a fast-food world, contribute to immune dysfunction by inhibiting all aspects of the system, from immune cell adherence to antibody activity. Paramount among minerals is magnesium, which is part of both the innate and acquired immune responses. (Tam. 2003) Epidemiological studies have connected magnesium intake to decreased incidence of respiratory infections (PDR. 2000). But sugar pushes magnesium — and other minerals — out of the body. (Milne. 2000) This will compromise not only immune function, but also bone integrity. (Tjäderhane. 1998). Mix a sweet alcohol cocktail and find the whammy doubled. (Fuchs. 2002).

Zinc has been touted for its ability to shorten the duration of the common cold. Like magnesium, zinc levels decrease with age, and even tiny deficiencies can have a large effect on immune health, particularly in the function of the thymus gland, which makes the T-cells of the immune system. Zinc supplementation improves immune response in both the young and the old. (Haase. 2009) (Bogden. 2004) (Bondestam. 1985) All the microminerals, in fact, are needed in minute amounts for optimal growth and development…and physiology. Low intakes suppress immune function by affecting T-cell and antibody response. Thus begins a cycle whereby infection prevents uptake of the minerals that could prevent infection in the first place. Adequate intakes of selenium, zinc, copper, iron plus vitamins B6, folate, C, D, A, and E have been found to counteract potential damage by reactive oxygen species and to enhance immune function. (Wintergest. 2007)

Who would have viewed something as sweet as sugar as being so hostile to its host? It likes to let itself in, but has the nasty character of pushing everything else out.

Albert Sanchez, J. L. Reeser, H. S. Lau, P. Y. Yahiku, et al. Role of sugars in human neutrophilic phagocytosis. American Journal of Clinical Nutrition, Nov 1973; Vol 26, 1180–1184

Profiling Food Consumption in America. USDA http://www.usda.gov/factbook/chapter2.pdf

Taubes G. “Is Sugar Toxic?” in New York times Magazine, 13 April, 2011

Turina M, Fry DE, Polk HC Jr. Acute hyperglycemia and the innate immune system: clinical, cellular, and molecular aspects. Crit Care Med. 2005 Jul;33(7):1624–33.

Challem J and Heumer RP. The Natural health Guide to Beating the Supergerms. 1997. Simon and Schuster Inc. New York. Pp. 124–125

Lin JC, Siu LK, Fung CP, Tsou HH, Wang JJ, Chen CT, Wang SC, Chang FY. Impaired phagocytosis of capsular serotypes K1 or K2 Klebsiella pneumoniae in type 2 diabetes mellitus patients with poor glycemic control. J Clin Endocrinol Metab. 2006 Aug;91(8):3084–7.

Mawhinney DB, Young RB, Vanderford BJ, Borch T, Snyder SA. Artificial sweetener sucralose in U.S. drinking water systems. Environ Sci Technol. 2011 Oct 15;45(20):8716–22.

Tam M, Gómez S, González-Gross M, Marcos A. Possible roles of magnesium on the immune system. Eur J Clin Nutr. 2003 Oct;57(10):1193–7.

PDR: Physicians’ Desk reference for Herbal Medicines. Magnesium. 2nd edition. Mintvale NJ: Medical Economics Company; 2000: 5340540

Milne David B, PhD and Forrest H. Nielsen, PhD. The Interaction Between Dietary Fructose and Magnesium Adversely Affects Macromineral Homeostasis in Men. J Am Coll Nutr February 2000 vol. 19 no. 1 31–37

Tjäderhane Leo, and Markku Larmas. A High Sucrose Diet Decreases the Mechanical Strength of Bones in Growing Rats. J. Nutr. October 1, 1998 vol. 128 no. 10 1807–1810

Fuchs, Nan Kathryn Ph.D. Magnesium: A Key to Calcium Absorption. The Magnesium Web Site on November 22, 2002. http://www.mgwater.com/calmagab.shtml

Haase H, Rink L. The immune system and the impact of zinc during aging.. Immun Ageing. 2009 Jun 12;6:9.

Bogden JD.. Influence of zinc on immunity in the elderly.. J Nutr Health Aging. 2004;8(1):48–54.

Bondestam M, Foucard T, Gebre-Medhin M. Subclinical trace element deficiency in children with undue susceptibility to infections. Acta Paediatr Scand. 1985 Jul;74(4):515–20.

Wintergerst ES, Maggini S, Hornig DH. Contribution of selected vitamins and trace elements to immune function. Ann Nutr Metab. 2007;51(4):301–23. Epub 2007 Aug 28.

Smolders I, Loo JV, Sarre S, Ebinger G, Michotte Y. Effects of dietary sucrose on hippocampal serotonin release: a microdialysis study in the freely-moving rat. Br J Nutr. 2001 Aug;86(2):151–5.

Jack Challem, Burton Berkson, M.D., Ph.D., Melissa Diane Smith Glucose and Immunity http://www.diabeteslibrary.org/View.aspx?url=Article638 Accessed 11/2011

Van Oss CJ. Influence of glucose levels on the in vitro phagocytosis of bacteria by human neutrophils. Infect Immun. 1971 Jul;4(1):54–9.

Bernstein J, Alpert S, et al Depression of lymphocyte transformation following oral glucose ingestion. Am J Clin Nutr. 1977; 30: 613

Robert A. Good, Ellen Lorenz. Nutrition and cellular immunity. International Journal of Immunopharmacology. Vol 14, Iss 3, Apr 1992, Pp. 361–366