You sit down to finish a report, open your laptop, and just... stare. The words won't come. You re-read the same sentence three times and still can't figure out where you were going with it. Sound familiar? That's brain fog — and plenty of people are talking about it.
Brain fog isn't a medical diagnosis. It's an umbrella term for cognitive symptoms like poor concentration, slow thinking, forgetfulness, and mental fatigue. Researchers are interested in what drives it — and whether certain nutrients might play a part.
The honest answer is: probably multiple things at once. Disrupted sleep, chronic low-grade stress, a diet heavy in ultra-processed food, and long stretches of screen time may all chip away at cognitive clarity. For many people working long hours, the late-night teh tarik run doesn't help either — caffeine late at night can get in the way of good sleep.
Some younger PMEBs in Singapore describe the feeling online as "running on empty" even after a full night's sleep. Older generations tend to attribute it to ageing and move on. Some researchers are exploring whether nutrient gaps play a role, though research here is still limited.
Omega-3s — particularly DHA — are a core structural component of brain cell membranes. When your diet is low in oily fish and high in takeaway meals, your DHA levels may drop. Some research has found an association between lower omega-3 status and poorer cognitive performance, but results are mixed and more study is needed. Many hawker centre staples aren't major sources of long-chain omega-3s, which come mainly from fish.
Magnesium plays a role in hundreds of enzymatic reactions in the body, including ones involved in nerve function and energy production. Early research suggests it may also play a part in sleep, though the evidence is still developing. True deficiency is uncommon in healthy people, but many people don't get the recommended amount from food. Sleep and focus problems have many possible causes, so if they persist it's worth talking to a doctor.
B12 is essential for nerve function and the production of myelin — the protective sheath around nerve fibres that helps signals travel quickly. When B12 is truly deficient, symptoms can include fatigue, poor memory, and confusion. For people with normal levels, supplements haven't shown a clear benefit for thinking. Low B12 is a known risk for people who eat little or no animal foods, which can include those choosing plant-forward diets.
Despite living in a tropical country with year-round sunshine, spending most days indoors in air-conditioned offices and malls can limit how much sun you actually get, so low vitamin D is possible. Vitamin D receptors exist in brain areas involved in memory and thinking, and some observational research has linked lower vitamin D levels to cognitive decline and low mood. It isn't clear that low vitamin D is the cause.
Zinc is involved in signalling between brain cells — the chemical messaging system your brain uses to communicate. It also helps antioxidant enzymes that deal with oxidative stress, which researchers study in relation to cognitive ageing. Zinc deficiency has been linked to changes in thinking and mood, especially in older adults, but research on mild shortfalls and everyday focus is limited.
It's important to be realistic. Evidence that supplements boost thinking in healthy, well-nourished people is limited. The most plausible benefit is in people whose levels of a specific nutrient are genuinely low, and a doctor can help work out whether that applies to you.
The lifestyle piece matters just as much. Some research has linked physical inactivity, poor sleep, and social isolation to cognitive decline. No supplement substitutes for those basics.
Before reaching for a stack of capsules, it's worth talking to a GP about whether a blood test makes sense. They can advise which levels, such as B12, vitamin D, or iron, are worth checking. That gives you a real baseline instead of guessing.
If your diet is heavy on char kway teow and light on vegetables, legumes, and oily fish — the gap is likely dietary first, supplement second. Work with what you eat before adding what you swallow.
This article is for general informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional before starting any supplement. Individual needs vary based on health status, diet, and existing conditions.
Ask Elaine how this applies to your goals and routine — free, no pressure.