Below, four things to know about dairy and how it relates to our skin.

We know that our hormones can impact our skin – the spots that can appear at certain points in our menstrual cycle provide monthly anecdotal evidence of this. What we eat (and, of course, how we live) can affect our hormones, too. “Cow’s milk and dairy products contain casein and whey protein, which are thought to raise levels of a certain hormone (insulin-like growth factor-1, or IGF-1) which is linked with increased production of sebum, the oily substance produced by our skin, which is, in turn, linked with acne development,” says Rossi. “Some studies have shown that people with acne have higher levels of the IGF-1 hormone.” A link has been drawn between a high sugar, dairy and carb diet and increased incidence of acne in the western world, but as Rossi points out, a clinical trial is yet to have shown that dairy alone causes skin issues.

Dairy alone isn’t the only foodstuff that can impact our hormones – other foods, when combined with dairy products (like milk) can leave them out of whack, too. “Milk, combined with other processed foods and sugar, disrupts insulin levels, pushing other hormones out of balance; because when we digest milk we break down the proteins it contains, turning them into hormones that are very similar to insulin,” Thomas says. The higher our insulin levels, the more susceptible we are to infection, and the more inflammation our bodies suffer – cue more breakouts and angry skin. “Inflammatory skin conditions include, most commonly, acne, eczema, and rosacea,” says Thomas. “If the inflammation is present in the body as a long-term issue, it will eventually reach the skin, which results in a breakdown of collagen, faster appearance of fine lines and compromised skin health.”

Read more: Are You Following The Right Skincare Regime For Your Age?

“Lactoses in milk need enzymes to break them down,” says Rossi. “About 65 per cent of people lose these enzymes when they pass infancy. When we’re older, the body develops an intolerance or allergy to the lactose, which triggers an inflammatory reaction within the body.” Of course, some of us are more intolerant than others, and if you suffer from any symptoms – like bloating, nausea or flatulence – Rossi recommends trying her three-step Record, Restrict, Retintroduce assessment (found in her book Eat Yourself Healthy) to find out if you could have a food intolerance safely and effectively.

If you’re considering quitting all dairy in pursuit of better skin, know that not all cow produce is created equal. A 2019 study found that there was some association between overall milk consumption and acne, particularly for those consuming a lot of it. “Interestingly, the relationship of acne with different types of milk – whole, semi-skimmed or low fat and skimmed – varied, with skimmed milk having the highest [negative] impact on the skin,” says Rossi. Fermented dairy, on the other hand, has not been found to increase the risk of acne, so consider things like yoghurt and (hallelujah!) cheese, your friends, rather than enemies. “Furthermore, fermented dairy, such as kefir and live yoghurt, has been linked with better heart and bone health, plus improved digestion and weight management,” she points out. So perhaps, as with all good things in life, it’s about opting for moderation and balance, rather than total dairy abstinence.