Eat your ice cream for a long, healthy life? This doctor says so

Oncologist and bioethicist Zeke Emanuel takes a back-to-basics approach to maintain good health in his new book, including tips like allowing yourself to enjoy ice cream. WeBond Creations/Getty Images hide caption

If you're hankering for a cool treat on a hot day, nothing screams summer like ice cream.

And a physician renowned for shaping U.S. healthcare policy has a message: Go ahead and enjoy it.

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Zeke Emanuel is an oncologist and bioethicist who served as an advisor to the Obama administration, helping shape the Affordable Care Act. He believes in a system that invests in prevention, one that aims to keep people healthy. So when he released his book, literally titled Eat Your Ice Cream: Six Simple Rules For A Long And Healthy Life , I asked him what motivated him.

"Mostly anger at the wellness industrial complex," Emanuel told me. He says the wellness industry is selling people all kinds of things that are expensive and clinically unproven, pointing to the latest peptide trend, whole body scans and "all sorts of supplements" marketed as anti-aging elixirs.

Emanuel takes a back-to-basics approach, based on evidence, to maintain good health in his book .

And though the title is a bit tongue-in-cheek, he points to evidence that people who are in the habit of eating ice cream have a lower risk of metabolic disease , despite the fact that it has lots of sugar and fat. Researchers have dubbed this the "ice cream paradox." There's data from 2015 that suggests "that ice cream is actually pretty good at preventing development of type two diabetes, and dairy in general is good at preventing type two diabetes," Emanuel says.

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Dairy contains whey protein that may benefit glucose regulation which may partially explain the association, though the research doesn't nail down cause and effect. Emanuel is also big on consuming more fiber and fermented foods, pointing to the need to feed the bacteria in our guts.

"Evolution would have gotten rid of them if they weren't there for a reason," Emanuel says. "And so treating them well, through eating more fermented foods, whether it's yogurt or cottage cheese or hard cheeses like gruyere or kimchi or sauerkraut, good things for us."

Prioritize sleep and stay active

Emanuel's other recommendations for increasing your chances of a long, healthy life track with a huge body of evidence on the importance of daily habits, including exercise, social connections and sufficient sleep. A new study published this month in the Annals of Internal Medicine finds people who skimp on sleep for just six weeks start to gain weight , in part because lack of sleep throws off hunger hormones.

"We know that biologically sleep is important. We know that it's important to clear out the brain's, to basically empty the garbage, as it were. We know it's important to consolidate long-term memories. We know it's important for DNA to repair. So there's a lot of very important elements," Emanuel says.

Bottom line: Sleep, he says, should not be shortchanged.

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Emanuel's most controversial advice: Do not retire. He points out that work provides a structure and a schedule, "so you get up and you go. It also provides a mental challenge and a social environment," Emanuel says. So, you've got to think through how you'll find structure, purpose and a social circle if you plan to leave a job that provides these elements.

He says that unless you consciously recreate this sense of purpose, you could increase your risk of cognitive decline . There are endless hobbies and volunteer opportunities to take up instead. Research from UC Davis shows people who report a higher sense of purpose in life are 28% less likely to develop cognitive impairment.

"There are lots of organizations that need help, and you have skills, and you can get to know people," Emanuel says, pointing to everything from volunteering at a school or food bank to signing up for a class or joining a club — all good ways to meet people.

People who may want to meet up, he suggests, could also get ice cream.

"I enjoy it, that's for sure," Emanuel says. Chocolate hazelnut is his flavor of the summer. But of course, everything should be taken in moderation.

Here's a take on his six simple rules:

1. Don't be a schmuck! Avoid self-destructive risks. "Smoking is obviously not good for you. Vaping is also not good for you," he says. Emanuel recommends limiting alcohol to 3 or 4 drinks a week, avoiding distracted driving, and he says it's probably a "schmuck move" to climb Mt. Everest, pointing to high risk of harm or death.

2. Talk to people . Strike up conversations. "My standard when I get into an Uber is to ask the person, where are you from?" Emanuel says. If you initiate a conversation, people will likely respond. "People actually like to interact. We're social beings. We're programmed to interact. And so you just need to take the initiative." Casual interactions are meaningful and can promote positive feelings.

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3. Expand your mind. Emanuel says he realizes most people eventually retire, but take steps to maintain lifelong learning and stay curious. Finding ways to stay engaged and having a strong sense of purpose can reduce the risk of cognitive decline.

4. Eat your ice cream. A balanced diet matters, and people should eat to nourish and enjoy. Making simple shifts such as limiting soda and sugary drinks and snacks while focusing on healthy meals and having a treat at the end of the day. Everything in moderation.

5. Move it! Regular movement is important, including aerobic exercise that gets your heart rate up, as well as strength training. Walking after a meal is a great way to stabilize blood sugar and can help offset the harms of sitting.

6. Sleep like a baby. Sleep is fundamental to good health, and people who give short-shrifts to sleep are more likely to gain weight and be more sedentary. Sleep aides don't work well, so practice good sleep hygiene, including setting a regular bedtime and optimizing your bedroom for sleep.