Scientists Won a Nobel Prize for This — 12 Anti Aging Foods That Help Your Cells Protect Their DNA

In 2015, three scientists won the Nobel Prize in Chemistry for showing how your cells repair their own DNA. Every day, thousands of small changes happen to the DNA in each of your cells, and a set of repair kits finds them and fixes them, all day long, for as long as you live. Those repair kits slow down a little with age. In blood cells from 135 healthy people, the kit that fixes sun damage worked about 0.6% less well with each year of age, from 20 to 60. Here are 12 everyday foods that help your cells protect their DNA. In small human trials, people who ate or drank four of them ended up with less DNA damage in their blood cells. One is a juice tested against a dummy juice. Number two is a leaf most people only see as a garnish. And number one is a drink where scientists watched a repair enzyme from the Nobel kit become more active. Number 12. Number 12 is the red bell pepper. One medium red pepper, raw, gives you about 152 milligrams of vitamin C. The daily amount is 90 milligrams for men and 75 for women, so one pepper covers more than a full day. It also brings some beta-carotene, the orange pigment you'll hear a lot about in this video, and a little folate. First, how I'll rate these foods. Four of them were tested in small human trials that measured DNA damage in blood cells, and for each one, I'll tell you how many people took part and for how long. The other eight are here as some of the richest everyday sources of the nutrients your repair kits rely on, measured by USDA. Those eight haven't been tested on their own. Here's why vitamin C makes the list. In a study of 340 healthy adults by researchers in Oslo and Prague, people with more vitamin C in their blood had a stronger repair kit for sun damage, the kit Aziz Sancar mapped. That's a link from one study, which can't show the vitamin C was the cause. Red peppers are sweeter than green ones, because they're the same pepper left on the plant to ripen. Eat them raw to keep the most vitamin C, since heat breaks some of it down. Slice them into strips for dipping in the chickpea spread from number 8, or roast them with the chickpeas for a crunchy tray. Choose peppers that feel firm and heavy, with shiny, tight skin. They keep in the fridge for about a week, and you can freeze the strips for cooking. Evidence level. A USDA source of vitamin C, with a link from one study of 340 people. Number 11 is butternut squash. One cup of baked butternut cubes gives you about 9 milligrams of beta carotene. Plus, a second orange pigment called alpha-carotene. Your body turns both into vitamin A, and that one cup covers more than a full day of it. Those are the same two pigments found in the carrot juice from number three's trial. And in that study of 340 adults, people with more alpha-carotene in their blood also had a stronger sun damage repair kit. Again, a link and not proof. It's squash season right now, and a whole butternut keeps for a month or more in a cool, So, you can buy a few at once. The skin is tough, so microwave the whole squash for two or three minutes to soften it, then peel it, scoop out the seeds, and cut it into cubes. Roast the cubes at 400 degrees Fahrenheit for about 25 to 30 minutes, until the edges brown. Mash them with a pat of butter and a pinch of cinnamon, or stir them into the lentil soup at number 5. Evidence level. A USDA source, and a rich one for both orange pigments. Number 10 is the sweet potato. One medium sweet potato, baked in its skin, gives you about 13 milligrams of beta-carotene, the most of any food on this list. That's more than a full day of vitamin A in one potato. You may be wondering whether that much is too much. MedlinePlus, from the US National Library of Medicine, says large amounts of beta-carotene won't make you seriously ill. Very large amounts can turn the skin a little yellow-orange, and that goes away when you eat less. Number six is a different story, and I'll explain why when we get there. Scrub it, prick it with a fork, and bake it at 400 degrees Fahrenheit for 45 minutes 10 minutes to an hour until it's soft all the way through. Put a baking sheet underneath, because the sugars drip and caramelize. Split it open and add a little butter and cinnamon, or top it with the black-eyed peas from number 7. Store them in a cool, dark cupboard, not the fridge, where they can turn hard in the middle. Evidence level. A USDA source, with the most beta-carotene per serving on this list. Number nine is beets. One cup of boiled beet slices gives you about 136 micrograms of folate. The daily amount is 400 micrograms, so that's about a third of a day. Folate is one of the building blocks your cells use to make new DNA letters. And I'll show you exactly how it works before number 6. Beets are the first of five folate foods on this list, and the next two bring two to almost three times as much. Wash them, leave the skins on, and boil them whole for 30 to 45 minutes. Or wrap them in foil and roast them at 400 degrees Fahrenheit for about an hour. Once they cool a little, the skins rub right off with a paper towel. Slice them over the watercress from number two. Where the sweet beets and the peppery leaves balance each other. Ready cooked beets in vacuum packs are a handy shortcut. Beets are also one of the easiest crops in the garden, and they keep for weeks in the fridge. One harmless surprise? Beets can turn your urine or stool pink or red for a day. It's just the pigment, and it's nothing to worry about. Evidence level? A USDA source of folate, and the sweetest one here. Number eight is chickpeas, also called garbanzo beans. One cup of cooked chickpeas gives you about 282 micrograms of folate, more than 70% of a day. Canned chickpeas are the easy way. Rinse them in a sieve first to wash off some of the salt. For roasted chickpeas, pat them dry, toss them with a little oil and salt, and roast them at 400 degrees Fahrenheit, 200 Celsius, for 25 to 30 minutes, shaking the pan halfway, until they're crisp. Add strips of red pepper from number 12 for the last 10 minutes. For a soft spread, blend a can of chickpeas with a few spoonfuls of water, a pinch of salt, and some cumin. Spread it on toast, or use it as a dip for carrot sticks. If whole chickpeas are hard on your teeth, the spread is the soft way to have them. Evidence level? A rich USDA source of folate, one of the two nutrients from a human trial I'll show you before number six. Chickpeas themselves haven't been tested. Number seven is Black Eyed Peas. One cup of cooked black-eyed peas gives you about 356 micrograms of folate, nearly 90% of a day, in one bowl. In the American South, they're a New Year's Day tradition, eaten for good luck in the year ahead. They're also a heat-loving garden crop that does well where summers are hot. Unlike most dry beans, black-eyed peas don't need soaking. Rinse them and simmer them in fresh water for about 45 minutes to an hour until they're tender. Canned ones are ready in a few minutes. Warm them with a pat of butter, a pinch of salt, and diced red pepper, or spoon them over a baked sweet potato from Number 10. They cook up soft and creamy, so they're easy to chew. Cook a big pot and freeze them in one-cup portions. If beans give you gas, start with a few spoonfuls and build up over a couple of weeks. Evidence level? A rich USDA source of folate, the second richest on this list. Next comes the food with the strongest building blocks of all, and the one that needs the most care. First, let's open those repair kits. Before number six, let's look inside those repair kits, and at what food can and can't do for them. The Nobel Prize went to three scientists, and each one mapped a different kit. Tomas Lindahl found the kit for everyday wear. The DNA letters slowly wear down, a bit like letters fading on an old sign. And this kit finds a worn letter, cuts it out, and puts in a fresh one. Aziz Sancar mapped the kit that fixes sun damage. Cutting out a damaged stretch and rebuilding it. And Paul Modrich showed how cells fix copying mistakes. Your body copies DNA several million times a day as it makes new cells, and his kit cuts the mistakes left behind about a thousand-fold. Scientists now list damage to DNA as the first of 12 hallmarks of aging, in a major 2023 review in the journal Cell. That's why keeping these kits supplied matters more as the years go by. Food can't build these kits for you. It can help in two ways. In some trials, a food lowered the amount of damage the kits had to fix. And your cells need building blocks to make new letters, and two of the main ones are folate and vitamin B12. Here's how folate fits in. Your cells need it to make one of the four DNA letters, the T. Researchers at UC Berkeley showed that when folate runs very low, a wrong letter slips into its place. The DNA breaks during repair and, giving folate, reverses it. Then, two trials from the same lab in Australia, both double-blind. In young adults aged 18-32, folate and vitamin B12, first in a breakfast cereal and then in tablets, lowered chromosome damage by about a quarter in those who started with more damage, while those who started with less saw no change. In men aged 50-70, folic acid on its own raised folate in the blood four-fold over four months, And their chromosome damage stayed the same. In both trials, the damage followed vitamin B12 more closely than folate. In three trials that simply added more fruit and vegetables in general, for a few weeks, repair activity stayed the same. So for every food here, I'll tell you exactly what its own research found. So the best food for those building blocks brings both folate and B12 at once. That's number six. Number six is beef liver. A small two-ounce portion of braised beef liver gives you about 144 micrograms of folate, more than a third of a day, and about 40 micrograms of vitamin B12. The daily amount of B12 is 2.4 micrograms, so that small portion covers it more than 16 times over. It's the only food on this list with plenty of both building blocks from those Australian trials. Here's the care I promised. Liver is also very rich in ready-made vitamin A, about six times a man's daily amount in those two ounces. That's different from the beta-carotene in orange vegetables, so a sensible way to enjoy liver is a small portion, about two ounces, once a week. Skip it if you take a vitamin A supplement. Two ounces is about two-thirds the size of a deck of cards. Cut the liver into thin slices and pan-fry them in butter for about two minutes a side until they're browned outside and cooked through. Overcooked liver turns tough, so take it off the heat as soon as it's done. Serve it beside the mashed butternut squash from number 11, whose sweetness softens liver's strong taste. Liver freezes well, so buy a pound, cut it into 2-ounce portions, and freeze them one by one. Evidence level? The richest USDA source of both folate and B12 on this list. The two nutrients from the Australian trials, which used cereal and tablets, not liver. Number 5 is lentils. One cup of cooked lentils gives you about 358 micrograms of folate, 90% of a day, the most per serving on this list. Researchers in Houston measured repairability in blood cells from 559 adults using the same sun damage kit from the start of this video. The third who ate the least folate had about 18% lower repairability than the third who ate the most, a link from one study that can't show folate was the cause. And, in a British trial, 12 weeks of folic acid pills cut the number of wrong letters in people's DNA, with mixed results on the other repair measures. Lentils are the quickest dry pulses of all. They need no soaking. Brown or green lentils cook in about 20 to 25 minutes, and red lentils in about 15, when they melt into a thick, soft soup. Simmer a cup of red lentils with diced carrots and sweet potato in about four cups of water or vegetable stock with a pinch of cumin and salt until everything is soft. That's three foods from this list in one bowl, and it's soft enough for anyone. Dry lentils keep for a year or more in a closed jar. Evidence level. The richest USDA source of folate here, with a link from one study of 559 adults. From here on, every food was tested in a human trial of its own. Number four is purple grape juice, the deep purple kind. In a trial in Korea, 40 adults with blood pressure above 130 over 90 were split into two groups for eight weeks. One group drank purple grape juice every day. The other drank a dummy juice. And neither the volunteers nor the researchers knew who had which. In the grape juice group, DNA damage in blood cells fell by 26%, while the dummy juice group had no change, in a small trial that measured damage, not disease. The amount was large, about one and a half cups a day for a 155-pound person. A cup of grape juice has about 150 calories, all from fruit sugar, so if you watch your blood sugar, have a small glass with a meal rather than on its own. Whole purple grapes are a natural swap, though the trial tested the juice. Look for 100% juice with no added sugar, made from purple grapes, since white grape juice is a different drink. Evidence level, a small human trial, with a dummy juice for comparison. Number three is carrots. In a study in Germany, 23 healthy men aged 27 to 40 drank a little under a cup and a half of carrot juice a day for two weeks. And their blood cells showed less oxidative DNA damage, the wear and tear kind, in a small study with no comparison group. That's the everyday wear Thomas Lindahl's kit fixes. In a separate small British study, cooked carrots made one step of the repair kit more active, while the amount of damage stayed the same. That glass of juice held about 22 milligrams of beta-carotene. One medium raw carrot has about 5, so the juice packed in what you'd get from more than 4 carrots. You don't need a juicer. Cooked carrots release more of their beta-carotene than raw ones, especially with a little fat, so roast them with a pat of butter, or simmer them in the lentil soup. Store-bought carrot juice is fine too, in a small glass. Carrot sticks with the chickpea spread from number eight make an easy snack. Keep carrots in the fridge with their green tops cut off, and they stay crisp for weeks. Evidence level. A small human trial in men, with no comparison group. Two to go! Number two has the largest food trial in this video, and number one comes with three trials of its own. Number two is watercress, the leaf most people only see as a garnish. In a trial in the UK, 60 adults ate about 85 grams of raw watercress a day for 8 weeks, and each person also spent 8 weeks on their usual diet for comparison. Their blood cells showed 17% less DNA damage overall and about 24% less oxidative damage, with the biggest effect in smokers. The volunteers were fairly young, with an average age of 33, and the trial was funded by watercress growers. 85 grams is about two and a half cups chopped, roughly one supermarket bag. Watercress has a fresh peppery bite. Pile it on buttered toast, slice the beets from number nine over a big handful, or stir it into hot lentil soup just before serving, where it wilts in seconds. Rinse it well, then keep it in the fridge standing in a jar of water, like a bunch of flowers, with a bag loosely over the top. Watercress grows naturally in shallow running water. At home, you can grow it in a pot standing in a tray of water, changed every day or two. Watercress is rich in vitamin K, so if you take warfarin, keep your greens steady and talk to your doctor before adding a daily bowl. Evidence level. A human trial in 60 adults. The largest food trial in this video, funded by growers. And number one is green tea. Researchers at one lab, at Hong Kong Polytechnic University, ran three small trials of green tea. Eighteen adults drank two cups a day for four weeks, compared with water, and their blood cells showed more than 20% less oxidative DNA damage, while a urine test of DNA damage across the whole body stayed the same. In the second, 16 people drank a single cup, and within an hour, their blood cells showed about 30% less DNA damage, and a repair enzyme was more active. That enzyme starts the repair kit Tomas Lindahl discovered, the kit for everyday wear. After a week of two cups a day, it was still more active. In the third, 43 adults with type 2 diabetes drank two cups a day for 12 weeks, and compared with water, they had about 15% less DNA damage and about 50% more activity from that same repair enzyme. The trials are small, they all come from one lab, and the researchers say larger studies are needed to confirm it. That makes green tea the one food in this video where scientists watched a part of the Nobel repair kit itself become more active in people, and a 2023 review of about 90 human trials of this kind named green tea among the foods with the clearest protection. Green and black tea come from the same plant, and these trials used green tea. The trials used two ordinary cups a day, about five ounces each, a fairly light brew. Use water that's hot but not boiling. About 175 degrees Fahrenheit or let boiled water stand for a couple of minutes, then steep it for two to three minutes. Boiling water and long steeping make it bitter. Loose leaves and tea bags both work. Green tea has some caffeine, so have your cups earlier in the day if caffeine keeps you up. The trials used regular green tea, so decaf hasn't been tested. Evidence level. Three small human trials from one lab. And the only food here where a repair enzyme was measured directly. Here's how these fit into one ordinary day. a cup of green tea and toast with butter and a handful of watercress. a bowl of red lentil soup with carrots and sweet potato. Carrot sticks with the chickpea spread and your second cup of green tea. Black-eyed peas with diced red pepper, roasted butternut squash on the side, and a small glass of purple grape juice. That day brings more than 600 micrograms of folate, well past a full day, plus both cups of green tea from the trials and three orange vegetables. From food, that's fine. The caution about folate is for folic acid pills, where more than 1,000 micrograms a day needs a doctor's advice. Once a week, a small piece of liver adds the B12. If you'd like one place to start this week, make it two cups of green tea a day. And if you take prescription medicine, mention big diet changes to your doctor or pharmacist. Here's the whole list in one go. Number 12, red bell pepper. Number 11, butternut squash. Number 10, sweet potato. Number 9, beets. Number 8, chickpeas. Number 7, black-eyed peas. Number 6, beef liver, a small portion once a week. Number 5, lentils. Number 4, purple grape juice. Number 3, carrots. Number 2, watercress. And number 1, green tea. The top four were tested in small human trials, and each one went with less DNA damage in blood cells. The other eight bring the vitamin C, orange pigments, folate, and B12 your cells use measured by USDA. Remember those repair kits. Every day, in every cell, they find thousands of small changes and fix them, for as long as you live. Give them the building blocks they use and a few foods from the trials, and you're helping your cells protect the DNA they've carried all your life. The full list, with every study I mentioned, is in the description. If you take warfarin or a vitamin A supplement, check with your doctor before adding watercress every day or liver each week. Tell me in the comments which one you'll try first. My guess is lentil soup, and I hope a few of you give watercress a chance too. Until next time, take care of yourself from the inside out.