podcast
Chasing Life
All over the world, there are people who are living extraordinary lives, full of happiness and health – and with hardly any heart disease, cancer or diabetes. Dr. Sanjay Gupta has been on a decades-long mission to understand how they do it, and how we can all learn from them. Scientists now believe we can even reverse the symptoms of Alzheimer’s dementia, and in fact grow sharper and more resilient as we age. Sanjay is a dad – of three teenage daughters, he is a doctor - who operates on the brain, and he is a reporter with more than two decades of experience - who travels the earth to uncover and bring you the secrets of the happiest and healthiest people on the planet – so that you too, can Chase Life.
Should We Be Drinking Cow’s Milk?
Chasing Life
Dec 16, 2025
“Drink your milk,” we are told as children. CNN Chief Medical Correspondent Dr. Sanjay Gupta examines our practice of continuing to drinking cow’s milk as we grow up. Plus, how to get the best sleep if you work the night shift.
Producer & Medical Writer: Andrea Kane
Showrunner: Amanda Sealy
Senior Producer: Dan Bloom
Technical Director: Dan Dzula
Executive Producer: Steve Lickteig
Episode Transcript
Dr Sanjay Gupta
00:00:05
Hey there, and welcome to Paging Dr. Gupta. Thank you so much for joining us today. This is the place where I get to take a deep dive into some of your health questions, address some of you concerns, and hopefully get you some answers that are backed by the best available evidence. Kyra is with us. Who do we have first?
Kyra
00:00:25
So today's first question is actually coming from one of our younger listeners. His name is David, and he wants to know about a very popular childhood drink and whether you should still be having it as you age.
David from FLA
00:00:41
Hello, this is David, age 14, calling from Florida. And my question is, is milk from cows good to drink? Because my dad, I remember he told me that drinking milk from cow is basically like drinking baby milk. Not really good for teenagers or adults. And I was wondering, like, we don't drink milk from other animals, so why are we drinking from a cow? Thank you so much, and thank you for having me on the show.
Dr Sanjay Gupta
00:01:12
Okay, David, age 14, thank you for calling in. You know what? We're gonna milk this question for all it's worth, hopefully give you a lot of useful information. We'll do it right after this short break.
Dr Sanjay Gupta
00:01:35
Welcome back to Paging Dr. Gupta. We are talking about cow's milk. Why? Because David wants to know whether people should be drinking something that is specifically meant to nourish a calf.
Dr Sanjay Gupta
00:01:48
It's true that we are probably one of the only species that drinks the milk of other species and that does so beyond infancy. And to learn why that's the case, let's go back in time.
00:02:02
Research has shown that humans have been drinking milk or eating some sort of dairy product like cheese or yogurt. For guess how long? At least 6,000 years. These early milk adapters were likely farmers who lived alongside their livestock.
00:02:20
And the advantages of drinking milk back then was that, look, milk was a good source of calories and nutrients when you obviously couldn't go to a grocery store. Milk may have also been providing antibodies against certain infections like anthrax. Milk may also have been a source of clean hydration. Keep in mind that milk is about 87 to 90 percent water, clean water, depending on fat content.
00:02:45
And if you fast forward to today, milk is still a good source of certain nutrients. Calcium, of course you know that one. What about protein? Vitamin B2, vitamin B12, phosphorus, potassium. And if your buying milk from the store, it's often fortified with vitamins A and D.
00:03:03
Now, as far as the health benefits of drinking milk, a lot of the study findings and the data are confusing. And sometimes contradictory. So for example, milk contains nutrients like calcium. I just mentioned that. That's important for bone health and this may protect against bone loss and fractures later in life, but research hasn't definitively shown that to be the case. Okay, so conceptually it makes sense, but the research hasn't definitively show this.
00:03:31
'Also research is mixed when it comes to the impact of milk on heart disease. The biggest headline in those studies seems to be that it depends on the type of milk used in the study, low-fat or whole, and what other food milk is being compared to or has been swapped out with.
00:03:49
Now when it comes to lowering the risk of developing type 2 diabetes, consuming dairy does appear to help, but it looks like the primary benefit probably comes from consuming fermented dairy products, like yogurt, rather than drinking milk.
00:04:04
Now there are some reasons why you might not want to drink milk. Some are health related. Others may be more philosophical. Milk, especially whole milk, is relatively high in saturated fat. We need some saturated fat in our diet, but if you're drinking a lot of whole milk you may be getting more than you need.
00:04:21
'Some people have true allergies to milk. Some people become lactose intolerant, meaning they stop making an enzyme called lactase, which helps our bodies digest milk. That happens to many people as they get older. Other people may be vegan, so they don't consume any animal product at all. Either for health reasons or because they think it is cruel to animals or because of the environmental impact of raising dairy-producing animals.
00:04:46
'And on top of all of that, nowadays, there are plenty of plant-based alternatives to cow's milk: soy milk, almond milk, rice milk, oat milk, coconut milk. And for those people who are lactose intolerant who want cow's milk, there is lactose-free cow milk. Now, many of those alternatives are fortified to add in the nutrients that are not going to be naturally occurring in those products, such as vitamin A and D and vitamin B12 and calcium and protein.
00:05:17
So that's a lot of preamble, David. What it comes down to for you is personal preference and what you and your parents feel is best for your health. I will tell you the most recent dietary guidelines for Americans recommends individuals consume two to three cups of dairy products or its equivalent per day, depending on age, gender, and level of physical activity.
00:05:39
One cup of dairy products could be one cup of cow's milk, yes, also one cup yogurt, one and a half ounces of natural cheese, two ounces of processed cheese, or one cup of fortified soy milk.
00:05:53
And finally, David, you might be surprised to learn that cow's milk isn't the only animal milk that humans consume. Some people consume milk from buffaloes, and goats, and sheep and even yaks and camels, especially in other parts of the world.
00:06:08
So David, thank you so much for calling in, just 14 years old, I love it. Coming up after the break, how can people who do shift work stay healthy despite keeping hours that are not conducive to getting the best sleep?
Dr Sanjay Gupta
00:06:28
There's that beeping sound. I know it well. Time for another question. Who do we have next?
Kyra
00:06:34
Alright, so our next listener question is actually coming from someone who's a little worried that her job might be messing with her sleep.
Felana
00:06:42
My name is Felana. I'm 45 years old. I was calling because recently you did a podcast about sleep and how important it is to be on a natural circadian rhythm. I'm a medical lab technician and my husband is a critical ICU nurse and we both work night shifts. I'm always reading articles about how unhealthy it is to work night. But some of us have no choice. And also in the medical field, there has to be some coverage during the night hours. Can you give any advice for night shift workers on how to maintain sleep and stay healthy? Thank you.
Dr Sanjay Gupta
00:07:26
Okay, thanks for calling in, Felana. And you are right. It seems that everyday researchers are discovering additional benefits to sleeping well. Not just sleeping, but sleeping well, and they've also been discovering new risks associated with the lack of sleep.
00:07:43
So let's start there. Sleep deprivation can be caused by many situations, including stress and depression and eating or exercise habits, a health condition like sleep apnea, pain — chronic pain— and also shift work to the point of this conversation.
00:08:00
According to a CDC survey, in case you're curious, an estimated 30.7 million Americans work irregular, rotating hours. It's a lot. One analysis published in 2025 found an estimated 21 million employed U.S. Adults worked overnight hours between 1 and 5 a.m.
00:08:20
So that's a little bit of background and a little of context to remind you that this is pretty common, Felana, you're not alone. Working during normal sleeping hours, and sleeping during normal waking hours. That can desynchronize your circadian rhythm. That should be no surprise. That's the internal clock in your brain that sort of acts as a conductor for all your bodily functions. It affects alertness, but also bodily functions like the release of hormones, regulation of body temperature, and digestion.
00:08:52
'Chronic sleep deprivation has been linked to dementia, heart disease, type 2 diabetes, obesity, certain cancers, and a weakened immune system. Short-term sleep deprivation can cause irritability and forgetfulness and brain fog, drowsy driving, which is really problematic, obviously, resulting in accidents, can also result in impaired cognition and lead to workplace accidents and other injuries. So, when you look at all those harmful effects, they are often true for shift workers.
Matthew Weaver
00:09:24
'Most individuals are never able to adapt fully to the night shift and this leads to a wide array of adverse health outcomes. Most prominently, worse metabolic outcomes like obesity, diabetes and metabolic syndrome, but also cardiovascular disease and hypertension. They tend to have an increase in inflammatory markers that persists and mental health also tends to be worse with decrements to depression, mood, self-esteem, and general well-being.
Dr Sanjay Gupta
00:09:51
That was Matthew Weaver, an epidemiologist at Mass General Brigham in the Division of Sleep and Circadian Disorders. He's also an instructor in medicine at Harvard Medical School. He basically says the people who do shift work, yes, are probably getting less sleep and also poorer sleep quality.
Matthew Weaver
00:10:11
Sleep during the day tends to be shorter. It's more difficult to initiate. It's more fragmented. There are more awakenings during it. And the composition of that sleep tends to comprised more of light sleep rather than deep sleep or REM, so it feels also less restorative.
Dr Sanjay Gupta
00:10:28
So why is that? It's probably because the part of our brain, the hypothalamus, that controls our circadian rhythm has a direct connection to specialized cells in our eyes that respond to our exposure to light. So that is probably the first place to start, to tackle lighting.
Matthew Weaver
00:10:45
Light is the most powerful resetting for our circadian rhythms. Light immediately and completely suppresses melatonin and it delays circadian rhythm. And the amount of that delay is dependent on the timing, duration and intensity of that light. We need to think about all the key sleep hygiene principles and optimize them to be able to sleep during the day. So you need to be to create an environment for sleep during day that's very dark, cool and quiet. You need to avoid light and other alerting signals in the time immediately preceding your sleep. And this can be challenging if you need to be awake and alert for work and then commute home safely.
Dr Sanjay Gupta
00:11:21
Weaver also said that sleep regularity is as important a component of healthy sleep as duration and quality. Let me repeat that. Sleep regularity, going to bed and waking up around the same time is probably as important a component to healthy sleep as how long you're sleeping and the quality of the sleep. And for that reason, it is recommended that shift workers keep a consistent sleep schedule even on weekends.
00:11:46
'So that's the second point. First point being lighting. Second point being consistent sleep schedule, even on weekends. Look, I think most people realize that many shift workers can't do this, either because they wish to spend time with family and friends, or because their work schedule itself is not always consistent. And in those cases, you might try a compromise sleep schedule so your body can enjoy some hours of sleep, the same time at least, every 24-hour period, on both work and rest days.
Matthew Weaver
00:12:16
So maintaining what we call core or anchor sleep for rotating shift workers can be quite helpful. This is a time of day of several hours that you know you'll always be able to sleep, ideally at least four hours. And then around that time, as your commitments change from day to day, supplementing that sleep with another bout of four hours if possible. Just maintaining that core sleep and then trying to supplement up to get at least seven hours of total sleep on each day.
Dr Sanjay Gupta
00:12:44
Felana, I hope that helps with you. I know it's not easy. The National Institute for Occupational Safety and Health also has some tips for nurses on shift work on their website and we will link to it in our show notes.
00:12:57
If I can say on a personal note, I just want to thank you and your husband for all you do to take care of others in the wee hours of the night when so many of us are asleep, you're caring for other people, and you should make sure to take of yourselves as well.
00:13:13
'That's our show for today. Thanks for listening, and as always, a big thanks to so many of you who have shared your questions, comments, and concerns. You're the reason this show works, and I love that you're a part of the conversation. So if there's something health-related you've been wondering about, share it with us. Record a voice memo, email it to asksanjay@cnn.com, or give us a call, 470-396-0832. We'll be back with a new episode of Chasing Life on Friday.
