Can Carbs Age Your Skin Prematurely? Dr. Longo on Food, Longevity, and Skin

While we don’t yet have direct evidence, it would make sense that if there’s a little bit of a cleanup going on everywhere, it’s also happening in the skin. Most cells in our system are going to respond in a similar way. 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 skin would follow. We’re now doing molecular studies to test that.

If someone is chronologically eighty years old, but when you measure markers in their blood, their biological age is actually ninety-five, in my experience, their skin and face look older than eighty. 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 look of the face and skin.

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.

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’s 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. There was a study a few years ago that 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.

Nutrition and genes play the most important roles. If you’re born with “supergenes,” you may always be ahead of the curve in terms of your biological age: When you’re fifty, you might look forty; when you’re forty, you might look thirty-two; when you’re thirty, people might think you’re twenty-four. 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 ninety 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 in order to live long—it definitely helps to be there, but it’s not everything. And exercise is important.

Exercise is important, but it’s a distant second after nutrition in terms of affecting aging. I would say 70 to 80 percent of how we age is nutrition, and then 20 to 30 percent 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’s 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 percent of that time to more-strenuous exercise, that seems to be a very good recipe for doing well. It’s associated with greater than 30 percent decrease in mortality. So a big effect. Interestingly, if you do more exercise than that and go up to 300 minutes, there doesn’t 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’s 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.

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. The cello is maybe the nicest instrument in the orchestra, but making it louder will not all of a sudden make the symphony sound better. Treat skin from the inside with things we know are going to be beneficial to your entire system, including the skin. The only thing I use on my skin is natural moisturizer that doesn’t have any inflammatory components or harmful chemicals. Dry skin is a problem and can start an inflammatory process, so moisturizer can be important.

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 United States are not eating the right amount of carbohydrates. Over 70 percent are overweight or obese and could benefit from eating fewer sugars and starches—so less bread, pasta, 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 percent carbohydrate diet than to have a low-carbohydrate diet. This again is meta-analysis—the studies of many studies. The ideal is a 60 percent 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’s 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.

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 percent of Americans do is have a big dish of rice, a big dish of pasta, a big ball of bread. At a restaurant, they’ll 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.

Every night: 85 percent dark chocolate. If I’m 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.