Discover: Nutrition

Lactose is a sugar found in milk. Your genes reveal your body’s ability to produce an enzyme called lactase which is essential for the digestion of lactose. Other factors can also affect your lactose tolerance (such as cow’s milk protein allergy or stomach disease or injury) but understanding your DNA can help you tweak your diet if you experience unpleasant symptoms.

Lactose Digestion

Lactose Digestion And The MCM6 Gene

Lactose is a type of simple carbohydrate (sugar) found in milk. It is broken down by an enzyme called lactase, which is produced in the small intestine. In most human populations, the production of the lactase enzyme naturally decreases with age. When not enough lactase is produced, the body presents a reduced ability to digest lactose. Undigested lactose can cause such symptoms as bloating and diarrhea which are associated with lactose intolerance. Unlike lactase deficiency, where no lactase is being produced, individuals with decreased lactase production are still able to produce some of the lactase enzyme. This means that they can often tolerate some dairy in their diet like cheese and small amounts of milk and yogurt.

The MCM6 gene (also called LCT) helps to regulate the production of the lactase enzyme. When the rs4988235 variation is present in the MCM6 gene the natural decrease in lactase activity is not observed. This results in the ability to maintain high lactase levels throughout life and is referred to as lactase persistence. The maintained ability to digest lactose is an evolutionary effect linked to the development of dairy farming. In fact, lactase persistence is more frequent in populations where cattle and dairy farming have been a common practice for centuries, like Europeans, and much less common in populations of Asian or African descent.

MCM6- Positive Impact

MCM6- Neutral Impact

MCM6- Negative Impact

What this Means

Women 50+ y/o: It’s hypothesized that women with osteoporosis have low Vitamin D levels due to their inability to digest milk (especially with low exposure to sunlight).

Women 19-50 y/o: Pregnant women with this result who consume more than 1.5 cups of milk per day are at higher risk of birth complications because a high consumption of lactose may lead to gastrointestinal changes that results in nutrient malabsorption.

People with lactose intolerance can consume up to 250ml (one glass) of milk each day if it is had in small amounts throughout the day with other foods.

This result is very common in individuals of Asian and African descent but less common in Europeans.

Under 18yo: Taking lactase supplements or a very low lactose diet reduces insulin resistance by almost two times. Children with this result tend to have higher insulin resistance when obese (which could lead to Type 2 Diabetes).

How to Empower Yourself

To get the equivalent Calcium of one serving of dairy from non-dairy substitutes, reach for 100 grams of almonds with the skin, or tuna fish (in water), or canned pink salmon.

Also, about 100g of firm tofu can provide enough Calcium to fulfill your daily needs (but check the food label when you choose as Calcium levels in tofu vary).

Women 19-50 y/o

If you are pregnant, make sure you have less than 1.5 cups of milk per day to keep your baby healthy.

Consider consulting an Accredited Practicing Dietitian to help you adjust your diet.

Under 18 y/o: If you have diabetes or pre-diabetes, taking lactase supplements or having very low lactose in your diet can improve your insulin resistance.