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The Longevity Diet: Carbs Aren't The Enemy

We have all met people who look curiously years or even decades younger than they actually are; Dr. Valter Longo explains his theory regarding why that is—and, in particular, how food can impact the difference between your chronological age (the number of years you have been alive) and biological age (the age at which your body functions and appears to be).

The director of the Longevity Institute at the University of Southern California and the Program on Longevity and Cancer at IFOM in Milan, Longo has devoted his career to researching aging, disease and how to optimize health and longevity through nutrition.

His international bestseller, “The Longevity Diet” proposes that sticking to a plant-based pescatarian diet and implementing periodic fasting-mimicking techniques—nutritional programs that cause effects on metabolism and cellular function similar to those caused by water-only fasting—a few times a year is the best recipe for living longer, living better and even looking better. “What you put into your body—nutrition—makes a major difference,” he says. “We think a plant-based pescatarian diet, which is associated with longevity, can likely affect the look of the face and skin.” Below, his advice on how to have a long life, age gracefully, and even have a little dessert every night.

A Q&A with Valter Longo, PhD

Q: Preliminary research has shown that fasting can promote cell rejuvenation and longevity—do the benefits also show up on skin?

A: While we do not yet have direct evidence, it would make sense that if there is a little bit of cleanup going on everywhere, it’s also happening in the skin. Most cells in our system are going to respond in a similarly. Some organs and systems are affected more quickly—for example, changes in the white blood cells may happen more rapidly than changes in the skin, but it makes sense that changes in the skin would follow. We are now doing molecular studies to test that.

Q: How are skin age and overall age-linked? Are we able to slow down skin aging and overall aging?

A: If someone is chronologically 80 years old, but when you measure markers in their blood, their biological age is actually 95, in my experience, their skin and face look older than 80. If the face looks older, our hypothesis is that most likely, the rest of the body is older, their cells and systems are functioning older and that person most likely has an increased mortality rate. The face—the look of skin and wrinkles—seems to be very reflective of the aging status of the entire body; the slower you age, the better your face is going to look. And we think a plant-based pescatarian diet, which is associated with longevity, can likely affect the face and skin’s look.

After Gwyneth did the fast-mimicking diet in the documentary “The goop Lab”, her biological age was reduced by 1.7 years. So theoretically, if someone were to do a fast-mimicking diet a couple of times a year for a few years, the skin could reflect that rejuvenation process by aging more slowly. This may explain the anecdotal comments we’re hearing from a lot of people about how their skin looks younger.

Q: How significant can the discrepancy be between someone’s biological age and chronological age?

A: It would be almost impossible to see a 100-year-old person whom you couldn’t tell was around 100. You might guess she was 83 or 110, but her older age would be reflected very, very well in her skin. Of course, from 83 to 110 is a range of 27 years, so that means someone could be 20 to 30 years biologically younger than their chronological age. That’s not very common, but certainly, it is possible. It’s why some people die of age-related diseases at 57, and some people never get age-related diseases and die at 110.  A study a few years ago was done on a number of 38-year-olds to determine their biological ages. It turned out their biological ages ranged from under 30 years old to over 60. That discrepancy in years is most likely dictated by a combination of good genes, diet and exercise.

Q: What are the most important factors that influence aging and the way the physical signs of aging show up in skin?

A: Nutrition and genes play the most important roles. If you are born with “supergenes,” you may always be ahead of the curve in terms of your biological age: When you are 50, you might look 40; when you are 40, you might look 32; when you are 30, people might think you are 24. So yes, some people are genetically predisposed to looking younger than they are and aging more slowly. These are usually the families where you see many members making it to 90 or older. Where you live isn’t always an important factor. People in New York tend to have pretty long lives. So this idea that you need to live on a hill in the countryside in the middle of nowhere to live long—it definitely helps to be there, but it’s not everything. And exercise is important.

Q: You’ve done studies on how exercise can decrease mortality. Can it also benefit skin?

A: Exercise is important, but it’s a distant second after nutrition in terms of affecting aging. I would say 70 to 80% of how we age is nutrition, and then 20 to 30% is exercise, so most likely, the same is true for skin aging. Exercise causes the body to undergo stress, and that stress is usually associated with at least a small rejuvenation process—not as big of a rejuvenation process as we get from fasting, though. There is a lot of evidence that exercise can increase stem cells.

Exercise is important for overall health, which affects skin health. If you do 150 minutes a week of exercise and devote 10% of that time to more-strenuous exercise, that seems to be a very good recipe for doing well. It’s associated with greater than a 30% decrease in mortality. So, a big effect. Interestingly, if you do more exercise than that and go up to 300 minutes, there does not seem to be that much more of a benefit. That’s based on a large study.

Another important component is moving. Walking or climbing stairs should be in addition to—and not instead of—the 150 minutes a week of exercise. I do between 12,000 and 15,000 steps a day. Walk everywhere. Always take the stairs. The people who live to 110 and 117, almost all of them, this is how they operate. People always say, “Let me go to a restaurant or coffee shop that’s close by.” Do the opposite. Pick a place that is farther away so that you have to walk forty minutes to go get a coffee and come back. I do this twice a day. That’s a really good habit.

Q: How effective is skincare in helping with the physical signs of aging?

A: The skin and body are very sophisticated, and to regulate the way they age, you need to do that from the very center of control, which seems to be the growth hormone receptor pathway. Putting cream on your skin can help, but it’s the same idea as trying to make a symphony better by making just the cello play louder.  Treat skin from the inside with things we know will be beneficial to your entire system, including the skin. The only thing I use on my skin is a natural moisturizer that does not have any inflammatory components or harmful chemicals. Dry skin is a problem and can start an inflammatory process, so moisturizer can be important.

Q: Many people are surprised by your approach to carbohydrates: You eat bread and pasta almost every day. What is a healthy way to incorporate carbohydrates into our diet that’s not harmful to the body and how the skin looks?

A: People forget that our number one fuel is sugar. Our brain works on sugar. But a problem emerges when you eat too much of it and keep producing insulin; you become insulin resistant, and then sugar intake can cause all kinds of problems. Most people in the U.S. are not eating the right amount of carbohydrates. Over 70% are overweight or obese and could benefit from eating fewer sugars and starches—so less bread, pasta and potatoes. If you tend to gain weight or are overweight, the best way to return to a healthy weight is to reduce starches and sugar.

But if you look at the people who live longest around the world, the data shows that it’s actually better to have an 80% carbohydrate diet than to have a low-carbohydrate diet. This again is meta-analysis—the studies of many studies. The ideal is a 60% carbohydrate diet.

Eating organic, if you can, is very important. People confuse what a healthy level of carbohydrates, sugars and starches is. I eat pasta and bread almost every day, yet I maintain my weight and BMI (body mass index, a measurement derived from a person’s weight and height that’s used to diagnose healthy body fat ratio). That is what the centenarians of Okinawa and the centenarians of Italy do—they eat lots of carbohydrates, and most of them stay within a healthy BMI range.

Q: What is a healthy amount of carbs to eat daily?

A: The ratio of different foods on your plate is what really matters. I’ll have two ounces of pasta once a day, with, say, ten ounces of chickpeas, and five to seven ounces of mixed vegetables with lots of olive oil and some Parmesan cheese. That’s a typical dish for me and something that I eat six or seven times a week in different formats, different vegetables, different legumes. That’s a very healthy type of meal.

What’s very unhealthy and something that 80% of Americans do is have a big dish of rice, a big dish of pasta, a big ball of bread. At a restaurant, they will give you a big basket of bread and then a big dish of pasta right after. We have to change that mentality. When you eat a big serving of bread or other simple forms of carbohydrates, it gets into the bloodstream very quickly, almost as quickly as it would if you ate spoonfuls of straight-up sugar. The glycemic index of pasta is lower, so pasta gets into your blood a little bit slower. But when you eat a lot of vegetables, you’re getting nutrients, fiber and all the right components. You feel full longer, for four or five hours. Without the vegetables, a big bowl of rice on its own causes you to feel hungry an hour later and have high levels of insulin in your bloodstream.

Q: Do you ever eat dessert?

A: Every night: 85% dark chocolate. If I am a guest somewhere and they’re serving cake, I may have some. But once you start eating well, I think you appreciate how healthy food tastes—complex food, good vegetables, good legumes, good olive oil—way more than you appreciate the junk.

Valter Longo, PhD, is the Edna Jones Professor in Gerontology and Professor in Biological Science at USC. He is the director of the USC Longevity Institute and of the Program of Longevity and Cancer at IFOM in Milan, and he is also the author of The Longevity Diet.


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