How much SPF is too much?

 

Dr. Aparna Santhanam
Dermatologist and Cosmetologist
Mumbai, India

Dermatologist and cosmetologist, Dr. Aparna Santhanam, has decades of experience in skin health and wellness. The Mumbai-based expert tells us about the effects of the sun’s rays — long-wave ultraviolet A (UVA) and short-wave ultraviolet B (UVB); and what all those SPF number and PA plusses on our sunscreen bottles really mean.

When it comes to choosing sunscreen, is more SPF better?

Dr. Aparna Santhanam The perceptions people have of sunscreen are both right and wrong.Everybody’s looking at SPF — sun protection factor. What SPF protects you against is UVB, which are the rays that tan your skin. The lowest SPF is 15. If applied correctly for optimum efficacy, an SPF15 sunscreen will provide about 92% protection from UVB for a period of four hours.

If SPF15 covers 92%, why do we need to go any higher?

Dr. Aparna If you double your SPF from 15 to 30, your skin protection may only improve marginally from 92% to 94%. Countries like the US don’t allow brands to put anything more than SPF50 on their products, because anything more is just a marketing tool, rather than giving you more protection.

But that still means the higher the SPF the better the sunscreen, yes?

Dr. Aparna The more SPF there is, the thicker the product. In Asia, where it’s humid a lot of the time, we wash our face, apply moisturizer, and then sunscreen, and then makeup — that’s a lot of products to put on the skin. It’s too much sometimes.

So how much SPF should we apply?

Dr. Aparna Some Asians, like Indians, are naturally blessed with more melanin. As far as UVB is concerned, you don’t need anything very high. SPF30 should be sufficient for daily use. 

We haven’t considered UVA at all. UVA is related to aging because it can penetrate deeper into the skin’s layers, damaging collagen. What you need is a broad-spectrum sunscreen to cover both UVB and UVA. For the latter, you’ll need to look out for a PA grade on your sunscreen bottle. It simply stands for protection grade of UVA rays, and the strength of each grade is indicated by the number of plusses —  PA+, PA++ and PA+++.

So what PA grade should we choose?

Dr. Aparna PA++ is enough. 

My opinion is, for a daily-use sunscreen, SPF30 and PA++ are sufficient for Asian populations.