Laura Manning is a Clinical Dietitian at The Susan and Leonard Feinstein Inflammatory Bowel Disease Clinical Center at Mount Sinai. Today, she is discussing the basics of lactose intolerance.
According to the 2020 Dietary Guidelines for Americans, it is recommended that adults consume 3 servings of low fat or fat free dairy products daily as part of a healthy diet.[i] Dairy products consist of milk, yogurt, cheese and kefir and supply the primary source of calcium for Americans. Calcium is associated with improved bone health and is especially important to consume during childhood and adolescence, as bone mass is being built at this time.[ii] In adults, dairy intake is associated with lower blood pressure[iii] and a reduced risk of cardiovascular disease[iv] and type 2 diabetes. [v],[vi]
One 8-ounce glass of milk from cows, sheep and goats consists of carbohydrates (12g of lactose) for energy, protein (6-8g of casein) for growth, fat for brain health, and the all-important calcium for bone development. The fat content can vary widely as there are a variety of milk choices on the market; from milk that contains zero fat (skim) to milk with a full fat content (whole). Additionally, dairy milk is comprised of phosphorous, potassium, magnesium, vitamins A, D, B12, niacin and riboflavin. It is a widely consumed beverage and supplies us with important nutrients across the lifespan.
Fact: Most people are born with the innate ability to digest dairy, as lactose is found in breast milk. However, the ability to digest dairy milk may become more and more difficult as we get older. It is estimated that about 30 million Americans are lactose intolerant by the age of 20.[vii]
WHAT CAUSES LACTOSE INTOLERANCE?
We typically digest milk with an enzyme (lactase) found in our small intestine. Lactase cleaves the sugar from milk into glucose and galactose to make it more digestible. This product is then absorbed into the bloodstream to be used for energy. However, some people may not produce adequate amounts of the lactase enzyme and, as a result, may experience symptoms such as gas, bloating and diarrhea soon after consuming milk products. Low enzyme levels cause the lactose to remain intact as it travels to the colon, where it attracts bacteria and begins to ferment. The uncomfortable symptoms associated with an intolerance are a result of this fermentation process.
TYPES OF LACTOSE INTOLERANCE
Primary lactose intolerance is the most common food intolerance in the world and is more prevalent among certain cultures. It is the most common form of the disorder and is often found in people of African, Asian, Hispanic, Mediterranean and southern European descent. Secondary lactose intolerance may arise due to an injury, surgery or illness where inflammation or changes in the small intestinal structures occur. Crohn’s and Celiac disease are the two most common intestinal diseases associated with having lower levels of lactase production. This is a very frequent topic that I discuss with patients at the IBD Center at Mount Sinai. Lactose intolerance can also present during a Crohn’s or Ulcerative Colitis flare.
There is a small subset of people who may have intolerance to casein, the protein component in milk. Of the 6-8 grams of casein in milk, 2-3 grams are known as beta casein and come in two forms, known as A1 and A2. Most cows contain an even distribution of A1 and A2, but before milk became industrialized, most cows were producing A2. A2 milk may be an easier to tolerate form of milk and you will see it beginning to pop up in the dairy aisle.
YES, THERE ARE LACTOSE-FREE CHEESES!
If you have lactose intolerance, it does not mean that you should avoid all dairy products. This is a common misconception and can lead people to miss out on the important nutrients that dairy products provide. There are varying levels of lactose in dairy products, ranging from 12 grams in a glass of cow’s milk to 1 gram in a serving of aged cheddar cheese. Most people with lactose intolerance can tolerate up to 12g of lactose in one sitting, and approximately 18g of lactose if spread throughout the day.[i] However, some individuals may need the help of an added enzyme to assist with their digestion. Over-the-counter enzyme pills and chewables consumed at the time of meal will help break down the lactose, making it more enjoyable to eat without all of the gas and bloating that typically accompanies digestion. It may even be possible to train the body to tolerate lactose if given small amounts over a period of time.[ii] Additionally, having lactose-containing dairy as part of a meal, rather than on an empty stomach, will further help aid in the digestion process.[iii]
On a Low FODMAP diet, lactose is one of the fermentable sugars that should be lessened in the elimination phase of the diet. You are able to consume dairy products on the Low FODMAP diet, but the lactose content should be small. Take a look at the Nutrition Facts label. The lactose will be considered ‘low’ if there are 4 grams of carbohydrate or less per serving. Just be sure, keep it to the serving size indicated and have one single serving per meal. Low lactose cheeses permitted with this diet include aged cheeses such as cheddar, Swiss and Parmesan. Greek yogurt is low lactose as well, but try stick to the unflavored/original yogurts and add fruits for natural sweetness. You’ll be happy to know that butter is almost completely lactose free! You can also select dairy products that contain the lactase enzyme in them. Dairy can be challenging to tolerate for many people, but following a few guidelines on food choice and quantity allows you to keep it in your diet and reap all the nutritional benefits dairy has to offer.
Resources that can help you:
Mount Sinai Make an appointment at the Feinstein IBD Clinical Center here or contact the office at 212.241.8100.
Epicured For exceptional low FODMAP, IBD-friendly prepared meals delivered right to your door, visit our menu.
DISCLAIMER: Mount Sinai is an investor in Epicured. This material is for informational purposes only, and Mount Sinai makes no representation or guarantee as to any results or experience with Epicured. You should consult with your physician before using a dietary program such as Epicured. Mount Sinai employees do not receive material benefit from endorsing or recommending Epicured.
Laura Manning is not employed by Epicured. Laura is a full-time employee of the Mount Sinai Health System and receives no compensation, monetary or otherwise, from Epicured.
 Dietary Guidelines for Americans 2015-2020. Recommended amount of dairy to be consumed daily for Americans 9 years and older. www.choosemyplate.gov. accessed June 8, 2018.
 Weaver CM, et al. The National Osteoporosis Foundation’s position statement on peak bone mass development and lifestyle factors: a systematic review and implementation recommendations. Osteoporosis Int. Published online Feb 8, 2016.
 Machin DR, Park W, Alkatan M, Mouton M, Tanaka H. Effects of non-fat dairy products added to the routine diet on vascular function: a randomized controlled crossover trial. Nutr Metab Cardiovacs Dis. 2015;25(4):364-369.
 Dalmeijier, GW, et al. Dairy intake and coronary heart disease or stroke: A population-based cohort study. Int J Cardiol 2013;167:925-929.
 Margolis, KL, et al. A Diet High in Low Fat Dairy Products lowers diabetes risk in in post menopausal women. J Nutr 2011;141:1969-1974.
 Sluijs I, et al. The amount and type of dairy product intake and incident of type 2 diabetes: results from the EPIC-InterAct Study. Am J Clin Nutr 2012;96:382-390.
 Lactose intolerance. Statistics accessed from the web June 6th, 2018. U.S. National Library of Medicine. https://grh.nlm.nih.gov/condition/lactose-intolerance#statistics.
 Corgneau M, Scher J, et al. Recent advances on lactose intolerance: Tolerance thresholds and currently available answers. Crit Rev Food Sci Nutr. 2017;57(15):3344-3356.
 Pribila BA, Hertzler SR, Martin BR, Weaver CM, Savaiano DA. Improved lactose digestion and intolerance among African-American adolescent girls fed a dairy rich diet. J Am Diet Assoc. 2000; 100(5):524-8.
 Shaukat A, Levitt MD, et al. Systemic Review: Effective management strategies for lactose intolerance. Annals Int Med. 2010; 152(12):797-803.