Glass Skin Diet: What to Eat

Carrots, pumpkin and peppers

Carotenoids are the yellow, orange and red pigments in foods such as carrots, pumpkin, spinach and red peppers. When you eat them, some build up in your skin and change how golden it looks.

In a crossover trial, 30 women ate 7 daily servings of high- or low-carotenoid fruit and vegetables for 4 weeks. On the high-carotenoid produce, skin yellowness rose in sun-exposed and covered skin, with no change in lightness or redness (Pezdirc et al., 2016).

Asian surveys point the same way. In 716 Japanese women, a higher intake of green and yellow vegetables went with a lower wrinkle score (Nagata et al., 2010). In 108 Korean adults, skin carotenoid scores rose with fruit and vegetable intake (r = 0.40) (Ahn et al., 2023). A 2026 analysis in adults with obesity found the same kind of link between the skin score and reported fruit and vegetable intake (r = 0.33) (Jilcott Pitts et al., 2026).

In 714 volunteers, South Koreans living in Korea had higher skin carotenoids than Germans and than Koreans living in Germany (Jung et al., 2014). The authors concluded that a healthy diet alone does not give a high antioxidant status unless stress falls too.

Ground flaxseed or flax oil

Four small trials have tested oils rich in ALA, the plant omega-3. The biggest gave 120 Japanese women aged 45 to 65 oil blends with 0.97 to 2.13 g of ALA a day, or a placebo, for 12 weeks (Ando et al., 2025). Water loss through the skin, the main outcome, didn't change. Hydration rose in a secondary analysis. Three of the four authors work for an edible-oil company.

A 2026 trial gave 60 adults 2.5 g a day of a manufactured linseed (flax) oil, carrying 0.9 g of ALA, or a sunflower oil placebo, for 8 weeks. Cheek hydration rose compared with placebo, while water loss didn't differ (Fukagawa et al., 2026).

Two older trials gave flax oil capsules. Water loss fell by about 10% within 6 weeks on 2.2 g of oil fats a day (De Spirt et al., 2009). In the other, 13 women per group took flax oil for 12 weeks, and their water loss, roughness and scaling fell while hydration rose (Neukam et al., 2011).

How to eat it: a tablespoon of ground flaxseed weighs 7 g, and 1 to 2 tablespoons a day is the usual suggestion (Kunutsor et al., 2025). Buy it ground. Full hydration notes live on our foods for hydrated skin page.

Green tea or matcha

Among 244 Japanese women aged 30 to 60, those who drank more green tea had lower scores for UV-related dark spots on facial scans (Fukushima et al., 2020). Coffee showed a stronger link. One author works for Nestlé Japan, and a survey cannot prove cause.

Trials have used strong extracts, not a normal mug. In 60 women, a drink with 1402 mg of green tea catechins a day for 12 weeks improved elasticity, roughness and water balance (Heinrich et al., 2011). Three cups of brewed green tea give about 405 mg of catechins, so that drink held roughly ten cups' worth (Khokhar and Magnusdottir, 2002).

Our suggestion of 2 to 3 cups a day is a pleasant extra, not that extract. We found no skin trial of ordinary brewed tea or of matcha for glass skin. Skip bottled teas with added sugar.

Sugary drinks

In 84 healthy Korean adults aged 19 to 37, a dietary pattern high in cereals, potatoes and starch, saccharides and fish and shellfish went with lower skin hydration (Lim et al., 2019). After the researchers split the foods, hydration was not linked to fish and shellfish. It showed a decreasing tendency across saccharide intake (p for trend = 0.040). That is one snapshot, not a trial of cutting fizzy drinks. More on sugar and acne.

Kimchi

No study we found has tested kimchi itself on skin. The closest used candy made with broken-down cells of a bacterium taken from kimchi. A significant increase in hydration in the experimental candy-administered group as compared with the control candy-administered group was observed on the face after 4 and 8 weeks (Kim et al., 2015).

A 2026 study of 74 healthy Korean adults found hydration was higher in people with more varied gut bacteria. Latilactobacillus and Weissella, which are abundant in kimchi, were identified as key genera potentially involved (Kim et al., 2026). That is a link, not a kimchi trial. Adults who ate no kimchi on a surveyed day rose from 11.7% in 2010 to 22.7% in 2024 (Zhao et al., 2026).

Fermented milk drinks

In a 4-week Japanese trial, 40 healthy adult women drank a probiotic fermented milk or a plain, unfermented milk each day. The trial was carried out in Tokyo between October and December 2009, a season of particularly low humidity. After intake, hydration of the outer skin fell in the plain-milk group and stayed higher with the fermented drink (Kano et al., 2013). Staff from the drink's maker co-wrote the paper.

A 2022 review recognised an overall 66 randomised trials of oral products for skin moisture. No benefits regarding water content and water loss were observed for lactic acid bacteria or Lactobacillus fermented foods (Sun et al., 2022). So one small branded drink is not a shortcut.

Soy foods

The newest food-adjacent trial used a powder, not a meal. 44 postmenopausal women took a soy protein isolate with added isoflavones or casein for 6 months. Average wrinkle severity decreased in the soy group at week 16 and week 24 by 5.9% and 7.1%. Compared with baseline, skin hydration in the soy group increased by 39% and 68% on the left and right cheeks at 24 weeks (Rizzo et al., 2023).

That does not mean tofu will do the same. An earlier Japanese trial had 60 women drink soy milk or fermented soy milk twice a day for 8 weeks. Both groups' skin scores improved compared with before the trial, and the two drinks did not differ. There was no soy-free group (Nagino et al., 2018).

What food cannot do

Glass skin is a Korean beauty term for skin so smooth, even and hydrated that it looks almost see-through, like glass. Food can nudge water and colour. It cannot create the polished surface.

In an Australian trial of 903 adults younger than 55, skin ageing from baseline to the end of the trial was 24% less in the daily sunscreen group than in the discretionary sunscreen group (Hughes et al., 2013). Beta-carotene pills had no overall effect on skin ageing. For people who already drink enough, topical emollients improve barrier function and the look and feel of dry skin (Popkin et al., 2010). Work out your skin type before you buy a stack of serums, and see foods for glowing skin if colour is the goal more than dew.