WARNING!
This is an older article that may not reflect Dr. Mercola’s current view on this topic. Use our search engine to find Dr. Mercola’s latest position on any health topic.
By Dr. Mercola
Allergies are your body's reaction to a protein (allergen) and are a sign your immune system is working overtime. According to the Allergy and Asthma Foundation of America,1 nasal allergies affect nearly 50 million people in the U.S., and that number is growing. As many as 30 percent of adults and 40 percent of children suffer from allergic diseases, including asthma.
These conditions are the fifth leading chronic disease in the U.S. and the third chronic disease in children under 18. In 2010, Americans with allergic rhinitis spent nearly $17.5 billion on health care related to the condition, lost more than 6 million work and school days and had nearly 16 million doctor visits.2
During the second encounter with an allergen, your body is ready to react, sending a powerful cocktail of histamine, leukotrienes and prostaglandins to protect your body. They trigger a cascade of symptoms associated with allergies, such as sneezing, sore throat, runny nose and itchy, watery eyes. Histamine may also cause your airways to constrict, triggering an asthma response or hives.
Pollen is one common allergen that triggers this reaction, but other protein molecules may as well, including mold spores, dust mites, pet dander, cockroaches and cleaning and personal care products. The activation of this allergic response may be related to your dietary intake and your gut microbiome. Recent research has identified a higher risk of allergies and asthma in children born to mothers who ate high amounts of sugar during their pregnancy.3
Sugar During Pregnancy Increases Your Child's Risk of Allergies
Researchers at Queen Mary University of London evaluated survey data from nearly 9,000 mother-child pairs in the ongoing Avon Longitudinal Study of Parents and Children, tracking the health of families with children born between April 1, 1991, and December 31, 1992.4 Lead author Annabelle Bedard, Ph.D., commented on what triggered the researchers to evaluate the association between sugar and allergies:5
"The dramatic 'epidemic' of asthma and allergies in the West in the last 50 years is still largely unexplained — one potential culprit is a change in diet. Intake of free sugar and high fructose corn syrup has increased substantially over this period. We know that the prenatal period may be crucial for determining risk of asthma and allergies in childhood and recent trials have confirmed that maternal diet in pregnancy is important."
Using self-reported estimates of sugar intake from questionnaires, the researchers calculated the amount of sugar the mothers ate during their pregnancy and compared this against the number of children diagnosed with allergies or asthma by age 7. Sixty-two percent of the children did not have allergic reactions, 22 percent had common allergies and 12 percent had asthma.
As a comparison, 10 percent of children in the U.S. were diagnosed with asthma in 2010, six years prior to this analysis.6 When the children were grouped into those with the lowest sugar intake during pregnancy (less than 34 grams or 7 teaspoons) and those with the greatest (over 82 grams or 16 teaspoons) the researchers discovered that children whose mothers ate the highest amounts had a 38 percent increased risk of allergies and a 73 percent higher risk of becoming allergic to two or more allergens.7
Women who ate high amounts of sugar were also twice as likely to have children who developed allergic asthma.8 Co-author Seif Shaheen, Ph.D., said:9
"We cannot say on the basis of these observations that high intake of sugar by mothers in pregnancy is definitely causing allergy and allergic asthma in their offspring. However, given the extremely high consumption of sugar in the West, we will certainly be investigating this hypothesis further with some urgency."
Impact of Asthma on Your Community
Asthma is a chronic lung disease that inflames the lining of your lung tissue and narrows the airways. The inflammation in your lung tissue is sensitive to environmental stimuli, also called triggers, which differ from person to person.10 Allergy triggers include dust mites, cockroaches, mold, pet dander and pollen.11
However, you may develop an asthma exacerbation from triggers other than allergic proteins. For instance, strong irritants, such as chemical sprays, perfumes and tobacco smoke or scented products may irritate your lung tissue and narrow your airways. Other triggers include cold weather, exercise, upper respiratory infections, food sensitivities and stress.
In the featured study, researchers found children whose mothers ate high amounts of sugar while pregnant developed asthma triggered by allergens and not by fragrances, cold weather, exercise, infections or food sensitivities. In the past 30 years, the incidence of asthma has increased worldwide. While the condition is generally accepted as costly, some countries do not consider it a health care priority.12
The total cost of treatment and lost work and school to society is difficult to estimate, due in part to different definitions and characterizations of the conditions and different assessments of the socioeconomic impact on society. Although variable from country to country, an average cost per patient in Europe is $1,900, while in the U.S. the cost hovers near $3,100.13
Vitamin D During Pregnancy Helps Reduce Asthma Risk
Low vitamin D levels in children who have asthma may increase the number of severe exacerbations they suffer, including the need for a trip to the hospital.14 A previous study, which followed over 1,000 children for nearly four years, found vitamin D insufficiency was linked to a 50 percent increased risk of a severe asthmatic attack necessitating a visit to the emergency room or hospitalization.
A more recent study15 published in the Journal of Allergy and Clinical Immunology also links low vitamin D levels in pregnant women to a higher risk of asthma in their children.16 This study supports similar findings from Harvard Medical School,17 in which vitamin D intake in over 1,100 mothers from the Northeastern U.S. was assessed. Children from mothers whose intake was higher during pregnancy had a decreased risk of recurrent wheezing by age 3, whether the vitamin D was from diet or a supplement.
The Journal of Allergy and Clinical Immunology study evaluated the effect of using an oral supplement of vitamin D3 during the second and third trimester of pregnancy at nearly 4,000 IUs higher than the recommended daily intake of 400 IUs.18 After birth, researchers took a sample of the cord blood, testing the newborn's innate immune system response known to provide the baby with long-term protection against environmental pathogens.
The samples from babies whose mothers had taken the higher supplemental dose of 4,400 IUs of vitamin D3 responded with a healthier innate cytokine response and greater IL-17A production after T lymphocyte stimulation. The researchers believe this would likely lead to improved respiratory health as the child grows, since past research has linked a strong immune response with a reduction in asthma.
The lead researcher, Catherine Hawrylowicz, Ph.D., professor of immune regulation in allergic disease at King's College London, commented on the importance of the results as it relates to both the health of future children and the importance of investigating further links between vitamin D and immunity:19
"The majority of all asthma cases are diagnosed in early childhood implying that the origin of the disease stems in fetal and early life. Studies to date that have investigated links between vitamin D and immunity in the baby have been observational.
For the first time, we have shown that higher vitamin D levels in pregnancy can effectively alter the immune response of the newborn baby, which could help to protect the child from developing asthma. Future studies should look at the long-term impact on the immunity of the infant."
Impact of Sugar on Your Body
Sugar is 50 times more potent than total calories in explaining the rising rates of diabetes worldwide, explains Dr. Robert Lustig in this short video. While both glucose and fructose are sweet, they are two different molecules.
Research demonstrates not only the detrimental effect sugar has on your developing baby and their future health, but also on your own health. Despite the American Heart Association's seal of approval on products that meet or exceed their own recommended daily limit on sugar, there is no nutritional reason to eat foods with added sugar.
In fact, the opposite is true. Diets high in net carbohydrates and added sweeteners may do far more than spike your blood glucose and insulin levels. Sugar will overload and damage your liver. High levels of sugar in your body will also trigger metabolic syndrome, a combination of weight gain, abdominal obesity, rising cholesterol levels and elevated triglycerides.
Eating a diet rich in net carbohydrates and excess sugars has also been linked to hypertension. As your insulin and leptin levels rise in response to sugars, your blood pressure also rises. Your body uses magnesium to fully relax your blood vessels, but your body is unable to store magnesium as you become resistant to insulin from a diet rich in sugar. When your body doesn't have enough magnesium to relax your blood vessels, your blood pressure also rises.
Eating high amounts of sugar is also linked to brain-related health issues, such as depression, learning disorders, memory problems and food addiction. Sugars trigger the reward center in your brain, leading to cravings that may rival cocaine addiction in some individuals.20 However, not all sugars have identical effects. For instance, fructose may activate your brain to increase your interest in food, while glucose triggers your brain's satiation signal.
Your Gut Microbiome and Allergies
High sugar intake also affects the growth of bacteria in your gut. In an evaluation of data from market research firm Euromonitor, researchers found people in the U.S. ate more sugar per person than any other country evaluated.21 The average person in the U.S. consumes more than 126 grams of sugar each day, nearly twice the amount consumed by 54 monitored countries and twice the amount recommended by the World Health Organization.
Researchers have demonstrated that diets rich in sugar will alter your gut microbiome,22,23 likely since your beneficial bacteria thrive on fiber and pathogenic bacteria thrive on sugar. Increasing the amount of sugar to the diet of mice transplanted with human fecal material demonstrated the gut microbiome would change dramatically within 24 hours of adding sugar to their diet.24
Scientists have found infants who go on to develop allergies start with early-life abnormalities in their gut microbiome and microbial function.25 While research continues to find links between healthy gut microbiota and a reduction in allergic response in adults and children, the evidence to date suggests that your gut microbiome is a significant target in the prevention and management of allergic asthma.26
In a recent scientific review, scientists found an association between immune-regulated epigenetic imprinting from mother to child during pregnancy that may support the immune system of the growing child after birth.27
However, if your gut microbiome is altered from high intake of sugar and net carbohydrates, this may alter your body's ability to support the growing immune system of your child. In yet another study, doctors were able to associate altered intestinal microbiota with the development of asthma and allergies in children, suggesting the mother's immune system may also play a role.28
Break Free From Sugar
Research supports making a break from processed foods and added sugars in your diet to optimize your health and the health of your children. While sugar is an additive that can be challenging to reduce or eliminate from your diet, the benefits to your overall health, energy level and brain function may become rapidly evident, helping to motivate your efforts.
If you currently eat a lot of sugar, there's a good chance you're struggling with sugar addiction. If so, I highly recommend trying an energy psychology technique called Turbo Tapping. It has helped many "soda addicts" kick their sweet habit, and it should work for any type of sweet craving you may have.
As you begin eliminating sugar from your diet, be sure to avoid most processed foods, as added sugar can be found in nearly 74 percent of processed foods under more than 60 different names.29 If you're already fighting diabetes, heart disease, high blood pressure or are overweight, you would be wise to limit your total fructose and sugar intake to 15 grams per day until your condition has normalized.
For all others, I recommend limiting your total fructose to 25 grams or less per day. As you move toward limiting your sugar intake, here are several tips to help reduce cravings and help you on your journey to good health:
• Exercise: Anyone who exercises intensely on a regular basis will know a significant amount of cardiovascular exercise is one of the best "cures" for food cravings. It always amazes me how my appetite, especially for sweets, dramatically decreases after a good workout. I believe the mechanism is related to the dramatic reduction in insulin levels that occurs after exercise.
• Organic, black coffee: Coffee is a potent opioid receptor antagonist, and contains compounds such as cafestol — found plentifully in both caffeinated and decaffeinated coffee — which can bind to your opioid receptors, occupy them and essentially block your addiction to other opioid-releasing food.30,31 This may profoundly reduce the addictive power of other substances, such as sugar.
• Sour taste: Simply tasting something sour, such as cultured vegetables, helps reduce sweet cravings, too. This is doubly beneficial, as fermented vegetables also promote gut health. You can also try adding lemon or lime juice to your water.