A leading supplement researcher says she doesn't take any — because she's getting what she needs from her vegan diet

• A leading supplement researcher says she doesn't take supplements.
• The longevity doctor says you should understand what's going on in your body before popping pills.

Dr. Andrea Maier is serious about supplements. The co-director of the Centre for Healthy Longevity at the National University of Singapore is conducting research studying both the label claims of supplements (are they legit?) and the people taking them (do they work?).

Maier isn't categorically against using supplements. She's founded two new longevity clinics in Singapore, one public and one private, both dedicated to slowing down biological aging and decline. Her patient regimens sometimes include supplements.

But she says that if you really want to know which supplements to take, you should start by getting to know more about your body.

"Before you buy any supplements, the first step is you need to know what your genome is," Maier told Business Insider. "This is very personal, but it should be driven by the biology of your body and it should be driven also by the physiology, which you can measure."

Maier practices what she preaches. She keeps close tabs on her own health, and the regular tests and checks she performs on herself suggest she doesn't need supplements.

Though she has taken supplements in the past, she says that for now she's focusing on getting the nutrients, vitamins, and minerals that her body needs from food.

Maier prefers getting her vitamins from whole foods

"My supplement strategy? I have nothing, sorry!" she said. "At the moment at least, no, there's nothing on my kitchen table. There's only good vegan food on it, every day."

In recent years, Maier said she used "a couple" of different prebiotic and probiotic supplements to nurture her gut microbiome, after taking antibiotics. But today, she relies on whole, nutritious foods like nuts and legumes to get what her body needs.

"You need lots of deep knowledge of your body, and about the material you are eating, and how you eat, and how you prepare it," she said.

Many supplements aren't what they say they are, and don't do what they claim

Maier's own research has shown that the label claim of a supplement often doesn't accurately reflect what's inside the bottle. Even if what you're taking really is what you think it is, there are other issues that can make supplements ineffective, including your own biology and other drugs you're taking.

"We are exposing our body to so many supplements we might not need," she said.

The equation grows more complicated when people start adding multiple supplements into their regimens, she said. It's still relatively unknown which supplements counteract others, or whether there are any serious negative health effects of combining different supplements.

"What we do in chemistry has effects, and has side effects," Maier said.

That's why in her clinics she employs a cautious approach, adding only one new supplement into people's routines at a time, then waiting at least three months to see what effect each new compound has had, if any.

Maier knows most people want a quicker answer for their problems, and that most Americans are shopping in the roughly $10 billion supplement aisle because they want to have something that will help them feel both more empowered and less anxious about their health.

The thinking is often 'Oh, this bottle looks nice, and let's do it!' she said, admitting she herself has fallen into this trap before.

But she wishes that people would spring for diagnostic tests instead of playing a guessing game with pill bottles.

The 3 tests Maier recommends before taking supplements

In her private Chi Longevity clinic in Singapore, Maier encourages patients to take a set of at least five different kinds of diagnostic tests and health measurements to assess which supplements they may need.

The first is a basic DNA spit test, geared toward helping patients discover their genetic risk for common chronic health issues. The second measurement is a blood-based biological age test (Maier actually conducts four different kinds of age tests with patients' blood, knowing one test can't tell you everything about your biological age.) It's also a good idea, she says, to have your poop analyzed, studying the health and diversity of your microbiome — the bacteria and other microorganisms in your gut.

Then there are the more standard health measurements like weight, blood pressure, and pulse. Finally, a person's physical activity, sleep, and diet are all assessed. All of this goes into Maier's clinical decision-making about whether to try a certain supplement on a specific patient.

"Do not just take things," she said. "This is the most important advice, and unfortunately, we are not yet there."