“Fingernails can be a direct reflection of our age,” Dr. Shari Lipner, a dermatologist at Weill Cornell Medicine and NewYork-Presbyterian, tells Fortune. “As we get older, our nails generally become thinner and weaker, with an increase in ridges. Nails may also lose their luster.”

The rate of nail growth decreases by about 50% throughout someone’s life. David Sinclair, a geneticist and author of “Lifespan: Why We Age – and Why We Don’t Have To,” said on a 2022 podcast that, “the rate of your nail growth is a really good indicator of how you are aging or not aging. And so, every time I have to cut my nails I’m thinking, ‘How long ago did I cut my nails?'”

How nails change with age

As you age, blood circulation slows, and keratin—a protein that aids nail and hair growth—decreases. Along with slower growth, there are also physical changes. 

“As we get older, nails tend to become more brittle, develop ridges, or change slightly in thickness,” Dr. Danilo Del Campo, a dermatologist in Chicago tells Fortune. 

However, he says that it’s important to “distinguish normal age-related changes from potential signs of an underlying health issue.” Particular changes are worth looking out for, and can be signs of a more serious intervention—especially as older adults are more at risk for a host of chronic conditions. 

More significant discoloration may indicate osteoporosis, a disease defined by bone loss that affects older adults and is more common in women. When a nail bed looks swollen and thicker, it is called clubbing and can be a sign of heart or lung issues, such as lung cancer. Whitish or pale discoloration could be a sign of liver disease or anemia, Del Campo says. 

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“If someone notices sudden thinning, dark streaks, or separation from the nail bed, it could indicate something more concerning and should be evaluated,” he says. “Not every nail change is a red flag, but if something is persistent or unusual, it’s always best to check in with a board-certified dermatologist.” 

How to improve nail health 

Nail changes are a normal part of aging, and there’s no practical way to measure growth. But here’s how to keep them in the best shape and monitor any unusual changes. First, you can pay closer attention to the appearance of your nails when you cut them for any clues of an internal health problem, Dr. Mona Sadeghpour, a dermatologist in Pennsylvania, tells Fortune. And as with keeping other bodily functions intact, diet and hydration are key for nail health. 

“I don’t think there is any good science or evidence yet that improving nail growth can change our aging trajectory, but the reverse can be true,” says Sadeghpour. “Practices that improve our overall health and decrease inflammation such as healthy and well-balanced nutrition, exercise, and adequate hydration can improve our longevity as well as our nail health.”

Here are 6 tips for healthy nails, according to dermatologists: 

1. A diet rich in protein, biotin, iron, and omega-3s (which all already contribute to a nutritious diet and support immune, brain, and organ function) helps with nail growth and strength, Del Campo says. Eating whole foods, like fish, legumes, and beans, is the best way to ensure an adequate portion of these nutrients. 
2. One of the most common supplement for nail and hair growth is biotin (vitamin B7 or vitamin H), but it’s essential to speak with your doctor before trying because there’s limited evidence on efficacy. Dr. Carmen Castilla, a board-certified dermatologist based in New York City, previously told Vogue that “there is no strong scientific evidence to support the idea that biotin supplementation improves hair or nail growth in individuals who are not biotin deficient.”
3. Stay hydrated 
4. Avoid extensive nail filing
5. Limit the use of acetone-based removers
6. Limit UV exposure. If you come in contact with UV light, The Skin Cancer Foundation recommends using broad-spectrum sunscreen on your hands 20 minutes before exposure

For more on healthy aging: 

• Ageism in health care is a $63 billion problem. An expert offers 8 ways to combat it
• Actress Halle Berry is ready for her ‘second act,’ as she becomes a major player in the $17 billion menopause market 
• New health benefit of omega-3s: Study shows the supplement may slow down the aging process