6 foods to eat and 2 to avoid for healthier skin, according to a doctor

• Healthy and vibrant skin starts with good nutrition, according to a doctor.
• Individual nutritional needs vary, but many people could benefit from more magnesium, zinc, and fiber.

Don't rely on expensive lotions for a glowing, youthful appearance — eating the right nutrients for your unique needs can help your skin look its best, according to a doctor.

"We spend so much time, energy, and money smearing stuff on our face in hopes of getting nutrients into the skin, but it's the blood flow that's bringing in the essential nutrients," Dr. Mark Tager, author of "Feed Your Skin Right: Your Personalized Nutrition Plan for Radiant Beauty," told Insider.

He said it's difficult to provide a one-size-fits-all approach to nutrition, since individual needs vary based on factors like age, genetics, lifestyle, medications, and more.

"There is no other person on the planet with skin that is exactly like yours. There are recommendations that experts will give you that are general but some have to be specific," he said. "It's a dance of multiple nutrients in the body coming together."

However, a few basic principles and food groups can help you get started with finding the ideal diet for your best skin, hair, and nail health.

Eat more fresh fruits and vegetables

One of the simplest ways to begin eating for healthier skin, is to incorporate more fresh produce into your diet, which offers a wealth of vitamins and minerals that you may be lacking, according to Tager.

For instance, citrus and other fruits are packed with vitamin C, which is crucial for healing and protecting cells.

Dark, leafy greens are rich in iron, folate, vitamin C, magnesium, and more. Together, they can help maintain healthy levels of compounds like collagen that provide structure and elasticity to the skin, Tager said.

"Vitamin C, along with iron, is needed in good amounts to create collagen," Tager said. "One of the issues with vitamin C is that it is easy oxidized and rendered impotent, so the emphasis needs to be on 'fresh.'"

Fruits and vegetables are also rich in fiber, a nutrient that feeds beneficial bacteria in the human digestive system which produce compounds that help protect the skin, Tager said.

Magnesium-rich foods like beans and grains help prevent dryness

Tager said that while you may not be medically deficient in certain nutrients, you might not be getting the optimal amount.

Many people don't get enough magnesium, a crucial mineral for more than 300 chemical reactions in the body, Tager said.

Eating more whole grains and legumes can provide magnesium for better cell repair and maintenance to protect the skin from becoming dry and damaged.

"One of the things you want for a vibrant appearance is a healthy skin barrier," Tager said.

While you can get more magnesium and other nutrients via supplements, focusing on whole foods can be a more effective approach for overall health, according to Tager.

"There's no way to out-supplement a crappy diet so everything has to begin with nutrition," he said.

Seafood and nuts are a good sources of zinc for clearer skin

Tager said another common compound lacking in a typical diet is zinc, a mineral that helps reduce inflammation in conditions like acne.

Fish like sardines, herring, and anchovies, and nuts like cashews and almonds are rich in zinc.

Seafood, nuts, and seeds can also be good sources of healthy fat called omega 3, which helps keep your skin healthy.

Minimize processed foods and sugary drinks

One of the worst food groups for healthy skin is also something most of us eat daily, according to Tager.

"The biggest culprit we have is processed food," he said.

The combination of added sugars, unhealthy fats, and other preservatives in many processed foods may accelerate the development of fine lines in the skin and worsen inflammation, he said.

"Inflammation in the skin is often reflected in the breakdown of structural elements that keep the skin healthy and beautiful," Tager said.

Sodas and other sweetened beverages can be particularly harmful, because they're high in added sugar and can take the place of plain water, making it harder to stay hydrated, according to Tager.

He said it can be challenging, time-consuming, and expensive to eat more nutritious whole foods, but taking small steps can make a big difference over time in how you look and feel.

"It's easy to take a supplement, but it's hard to cut down on sugar and reduce your dependence on processed foods," Tager said. "We're all going to eat processed food at some time, so it's really balance and minimization."