6.3) Food Tolerances
Your genetic makeup is unique. Your body may not be able to properly break down, absorb and utilize all of the foods you are putting into it. By identifying your predisposition and food intolerances, you can avoid consuming nutrients that are not ideal for your genetic type.
Avoid foods that slow your body down, causing an imbalance in your system. Help your body to run at its highest efficiency. Give yourself more energy to do the things you love, increasing your mental and physical wellbeing. You can increase your health and wellness by eating for your body type.
Question: What is the difference between food intolerances/sensitivities and food allergies?
Answer: Food intolerances arise if the body is unable to digest a certain food — it is related to digestion. Allergies are an abnormal reaction by the immune system following consumption of a certain food — it is an immune response issue rather than a digestive issue.
If you have genetic variations in an area, it is an indicator of where you are more likely to have issues over time. But it does not automatically mean that you have an issue.
For example, your DNA test may show that you have lactose variations which may contribute to a problem digesting the lactose in milk. However, this does not mean that you are allergic to milk. If the body builds up a response to the lactose, then you may develop a sensitivity over time.
Conversely, you can acquire a food intolerance based on gut health and other factors.
Next, we will discuss:
- Ability to process alcohol.
- Sensitivity to caffeine and salt.
- Gluten and lactose tolerance.
6.3.1 Alcohol
How well your body metabolizes alcohol
Alcohol consumption is a common element of many social situations. However, for some people with variations in these genes, alcohol consumption can be very unpleasant. This is due to their inability to clear the acetaldehyde produced by the metabolism of alcohol. Symptoms include flushing of the skin, accelerated heart rate, shortness of breath, throbbing headache, mental confusion, and blurred vision. This is known as “alcohol flush” in which certain individuals, have their face, neck and sometimes shoulders turn red after drinking alcohol. The discomfort with drinking alcohol leads to very low rates of alcohol dependency. The variation appears in 8% of the global population and up to 40% of the Asian population.
Diseases associated with this genetic variation include: esophageal, colorectal, gastrointestinal, lung and liver cancer, coronary artery disease, hypertension and others.
Regardless of your genetic type, consuming too much alcohol can have serious side effects.
If you have a variation in this panel, you may want to consider the following to improve your health:
- Decrease or eliminate alcohol from your diet.
- If you drink, be sure to have someone watching out for you. Be aware that the alcohol will stay in your body much longer tha others and leave you feeling much worse.
- Monitor your health for diseases related to this variation.
An example of a gene that has been associated with how well your body metabolizes alcohol is:
ALDH2: The aldehyde dehydrogenase (ALDH) gene family, mediates acetaldehyde clearance, a step-in alcohol metabolism. Variations is associated with high alcohol sensitivity, facial flushing and severe hangovers.
6.3.2 Caffeine
How well your body processes caffeine
Caffeine is a stimulant present in coffee and some teas, carbonated beverages and energy drinks. Caffeine is metabolized in the liver, and the resulting metabolites travel to other organs and affect their function. For example, caffeine metabolites bind to receptors in the brain, causing arousal and interacting with neurotransmitters. This leads to caffeine’s signature effect of warding off drowsiness and increasing alertness.
Research into caffeine’s impact on long-term health has provided both positive and negative results. These include an increased risk of bladder cancer with excessive coffee consumption (> 5 cups/day), and a decreased overall risk of cancer, cardiovascular disease, and type 2 diabetes with moderate consumption (2 cups/day).
Short term negative effects include dehydration, diarrhea, hypertension, sleep and anxiety disorders. Short term positive effects include improved cognitive function.
Carriers of variations in this panel metabolize caffeine at a slower rate and, as a result, may experience greater stimulation effects.
Regardless of your genetic type, consuming more than 400mg of caffeine a day can have detrimental side effects.
If you have variations in this panel, you may want to consider the following to improve your health:
- Lower caffeine intake to one serving per day.
- If experiencing stress and anxiety, cut caffeine out of your diet.
An example of gene that has been associated with processing caffeine is:
CYP1A2: Involved in the metabolism and clearance of caffeine. Impacts the rate of caffeine metabolism.
6.3.3 Gluten
Your normal risk for gluten sensitivity
Gluten sensitivity is a physical condition in the gut. Gluten is a protein found in wheat, barley, and rye. Individuals who suffer from gluten sensitivity may experience symptoms including chronic fatigue, neurological disorders, depression, nutrient deficiencies, anemia, nausea, skin rashes, acne, bloating, diarrhea, constipation, muscular issues, headaches, dental decay, bone/joint pain and more.
Only about 15-20% of the population has a genetic risk for gluten sensitivity, however, many more people have become gluten sensitive. This is in part due to the Standard American Diet. It has been suggested that sugar, refined flour, alcohol, antibiotics, environmental toxins, and other allergens can contribute to imbalanced intestinal flora and can lead to gluten-sensitivity.
This test cannot rule out wheat allergy or other issues with digestion such as irritable bowel syndrome.
If you have variations in this panel, you may want to consider the following to improve your health:
- Reduce or eliminate gluten from your diet if you are experiencing digestive issues.
- Avoid foods made from wheat, rye, bran, enriched flour, bulgur, and barley. This includes some cereals, breads, pastas, croutons, crackers, cakes, cookies, beer, and other grain-based alcohol.
- Refer to Your Genetic Profile at the back of your report: Greatest Gluten Sensitivity Risk HLA-DQ 2.5 indicates the greatest risk, whereas Gluten Sensitivity Risk HLA-DQ 8 and 2.2 indicate lesser risk.
- If you have symptoms, talk to your healthcare professional about being tested for gluten intolerance and celiac disease.
An example of a gene that has been associated with risk for gluten sensitivity is:
HLA: Most relevant genetic factor for non-celiac gluten sensitivity and celiac disease, accounting for 40 to 50% of the genetic variance occurring in people with the disease. Variation is associated with an increased risk for autoimmune destruction of the small intestine resulting in gluten sensitivity.
Gluten intolerance and celiac disease
Celiac disease is a physical condition created in your gut in response to the presence of gluten. Gluten is a protein found in wheat, barley, and rye. Individuals experience celiac disease when undigested gluten in the intestine is treated by the body like a foreign invader, it irritates the gut and flattens the microvilli along the small intestine wall. Without those microvilli, there is less surface area to absorb the nutrients from food. This leads sufferers to experience symptoms of malabsorption, including chronic fatigue, neurological disorders, nutrient deficiencies, anemia, nausea, skin rashes, depression and more.
Celiac disease is one of the most common genetic disorders in the West with 1% prevalence in the population. Western dietary practices (i.e., the Standard American Diet heavy in fast food and light in fresh foods and vegetables) creates added environmental risks for celiac disease. The systems by which celiac disease is triggered are not fully understood. It has been suggested that sugar, alcohol, antibiotics, environmental toxins, and other allergens can contribute to imbalanced intestinal flora and can lead to gluten-intolerance. While many individuals have genetic predisposition to celiac disease it appears that the clinical presentation only occurs when there is sufficient gluten in the diet and an autoimmune trigger is presented. For example, if you contracted rotavirus or other digestive system infections in your early childhood this could increase the chances of getting celiac disease.
Interestingly, there is increased prevalence of celiac disease amongst women compared to men with a male to female ratio of 1:3. The population with diabetes, autoimmune disorder, or relatives of celiac disease individuals have even higher risk for the development of celiac disease.
Genetic testing can be used to rule out celiac disease with over 95% certainty. If you do not have genetic risk, you are unlikely to have flattened microvilli associated with celiac disease. The HLA gene is the most relevant genetic factor for celiac disease. Variations in these genes are associated with an increased risk for autoimmune destruction of the small intestine resulting in sensitivity to gluten and have been associated with gluten intolerance. It is possible to have gluten intolerance and not have celiac disease, this is known as non-celiac gluten intolerance. Both celiac and non-celiac gluten intolerance have the same genetic risk factors.
Monsuur, A.J, De Bakker, P.I, Zhernakova, A, Pinto, D, Verduijn, W, Romanos, J, . . . Wijmenga, C. (2008). Effective detection of human leukocyte antigen risk alleles in celiac disease using tag single nucleotide polymorphisms. PloS One, 3(5), E2270.
Question: If my test shows that I am 70% red in the gluten category does that mean that I have celiac disease?
Answer: The simple answer is, no. This test cannot diagnose celiac disease. If you have genetic risk in this category and have symptoms of celiac disease you should visit your health care provider.
Alternatively, you could be 100% green in the gluten category and still have sensitivity to gluten products. This points to another cause for sensitivity. You can become sensitive to foods due to health reasons including gut biome issues such as irritable bowel syndrome (IBS) or a wheat allergy.
6.3.4 Lactose
How well your body digests lactose from dairy products
Lactose intolerance means the body does not easily digest lactose, a type of natural sugar found in milk and dairy products. Individuals need lactase, an enzyme that is produced in the small intestine, to break down lactose. Individuals with variations of this gene should watch for bloating, cramping, nausea, and diarrhea when consuming dairy products.
This gene’s lactase-regulating mechanism is naturally turned off by the age of four. The test cannot tell you if you have an allergy to milk which is caused by an allergic reaction to the protein in milk. Non-genetic factors such as the composition of your gut bacteria can also determine your level of lactose tolerance. The “on” allele is rare in Asian and African populations. However, there may be other genetic factors that allow lactose to be digested for these groups.
If you have variations in this panel, you may want to consider the following to improve your health:
- If you are experiencing symptoms of lactose intolerance aim for remission of symptoms by avoiding milk and dairy products.
- Consider dairy alternatives such as rice, soy, coconut, and almond milk products.
- Read food labels to avoid ingredients such as whey, casein, curds, milk by-products, dry milk solids and non-fat dry milk powder. Vegan products are dairy free.
- Increase alternative calcium-rich foods in your diet such as spinach, salmon, sardines, dark green leafy vegetables and almonds.
- Talk to your healthcare professional about calcium supplements.
An example of a gene that has been associated with risk for lactose intolerance is:
MCM6: Helps control the activity of a nearby lactase gene. It determines whether the lactase gene is turned on or off. This gene provides instructions for making the enzyme lactase, which is responsible for breaking down lactose.
Genetic vs acquired lactose intolerance. Why genetic testing can tell you something that other tests cannot.
Steve struggled with abdominal bloating and pain. He went to his doctor for a blood test that showed high lactose intolerance. However, when he did his DNA + Diet genetic test, it showed that he was not genetically prone to lactose intolerance.
Steve’s genetic test indicates he does not have genetic lactose intolerance as he does not have an inherited genetic marker.
However, Steve’s blood test indicates he has acquired lactose intolerance. This can be caused by gastroenteritis, celiac disease, Crohn’s disease, ulcerative colitis, chemotherapy, or long courses of antibiotics. It is possible to develop acquired lactose intolerance later in life, even without another condition to trigger it.
Many people will develop some level of lactose intolerance over time. It is estimated that up to 70% of the world’s population has some level of lactose intolerance by the time they reach adult age.
This is a case where an individual who did not have genetic risk for a condition, lactose intolerance, developed the condition due to environmental conditions. The genetic test is useful because it lets Steve know that his lactose intolerance may be a result of poor digestive health rather than a genetic predisposition. By taking steps to improve his digestive health Steve may be able to enjoy dairy products again, without paying for it later!
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Genetic lactose intolerance: Is common and involves reduced lactase production with age. With good gut health, many people with genetic lactose intolerance, may be able to consume a small amount of lactose each day. For others it may be a hidden factor for inflammation and weight gain over time.
Acquired lactose intolerance: Is caused by inflammation in the gut caused by IBS or other gut conditions. This is also very common.
6.3.5 Salt
How well you metabolize salt
Salt is made up of sodium and chloride and found in high quantities in pre-packaged and fast foods. An increased intake of sodium can lead to high blood pressure which has many negative health effects.
Left untreated, high blood pressure can lead to damage to the heart and coronary arteries, including heart attack, heart disease, congestive heart failure, aortic dissection and atherosclerosis (fatty buildups in the arteries that cause them to harden), stroke, kidney damage, vision loss, erectile dysfunction, memory loss, fluid in the lungs, angina, and peripheral artery disease.
The salt sensitivity of blood pressure differs between individuals. Individuals with variations in this panel are prone to blood pressure that is more sensitive to salt intake.
If you have variations in this panel, you may want to consider the following to improve your health:
- If you have high blood pressure, consider limiting your salt intake to a maximum of 1 teaspoon total per day, which is equivalent to 2.2 grams of sodium per day. Depending on your level of athletic activity this recommendation can vary.
- Exercise regularly to decrease the effect that sodium has on your blood pressure.
- Consult your healthcare professional to take preventative measures.
Some examples of genes that have been associated with salt metabolism are:
ACE: Produces the angiotensin I converting enzyme that balances electrolytes and regulates blood pressure. Variations are associated with hypertension, salt sensitivity, and cardiovascular risk due to a decrease in excretion of lithium, sodium, and uric acid and an enhanced rate of sodium reabsorption.
AGT: Involved in constriction of blood vessels and increased blood pressure in response to exercise. Variations are associated with susceptibility to hypertension.
6.3.6 Sugar Craving
Your ability to resist sugar cravings and sweet foods
Sugar cravings can be intense. While it may not be harmful to give in once in a while, persistently elevated sugar levels in the blood can lead to type 2 diabetes and cardiovascular diseases.
Variations in these genes have been linked to increased sugar cravings and a higher consumption of sweet products. If you have a predisposition to crave sweet foods, you should be careful when giving into these tendencies. They can lead to addictive type behaviors, with potentially cascading health effects, including increased weight.
If you have a mutation in this panel, you may want to consider the following to improve your health:
- Regulate your simple sugar and caloric intake to ensure a proper macronutrient balance.
- Replace high sugar foods and drinks with healthier options such as fruit.
- Increase your fibre intake to help balance your blood sugar with foods such as nuts, beans and legumes.
- Maintain adequate magnesium intake with pumpkin seeds, spinach and chard, avocado, banana, yogurt or kefir.
- Ensure you drink enough water as sugar cravings often arise from dehydration.
- Participate in relaxing exercises to regulate cortisol levels and decrease stress.
Some examples of genes that have been associated with sugar cravings are:
ADRA2A: Plays a critical role in regulating neurotransmitter release in the central and sympathetic nervous systems. Variations are associated with an increase in cortisol, a stress hormone that stimulates individuals to eat foods high in sugar.
SLC2A2: Encodes GLUT2, a high capacity glucose transporter. Variations are associated with the tendency to increase consumption of sugars and food intake regulation.