Arsenic in Brown and White Rice

I recently added more rice into my diet and wanted to understand the nutritional value of switching from white to brown rice. Then I recalled hearing about the potential risk of more arsenic so I dug into the research.

This 2016 risk assessment from the FDA provided baseline numbers of the amount of arsenic in rice and rice products as well as a quantitative estimate of lung and bladder cancer risk from long-term exposure of these products.

We found that average concentrations of inorganic arsenic – the more toxic form of arsenic – were as follows:

• 92 parts per billion (ppb) in white rice

• 154 ppb in brown rice

• 104 ppb in infants’ dry white-rice cereal

• 119 ppb in infants’ dry brown-rice cereal

The primary culprit of damage is inorganic arsenic in foods, which I learned in not a traditional heavy metal but a "toxic metalloid". The good news is this means inorganic arsenic doesn't bioaccumulate the same way other heavy metals do. The risk however is still continuous exposure over a long period of time which can damage DNA, the skin, and the vascular system.

Dr. Michael Greger also provides a good summary and insights in his video

Which Rice Has Less Arsenic: Black, Brown, Red, White or Wild?Evaluating differences in rice, we can observe:

• brown rice contains more arsenic than white rice

• long grain contains more than shorter grains, though this may be due more to where these grains are grown

• arsenic accumulates in the rice bran, which is why brown rice contain so much more arsenic

• many of the varieties of colored rice were worse than white rice for the reason above

• children under 6 should almost definitely avoid rice AND rice products, with regulations in the EU now adding more conservative limits on the amount of acceptable arsenic in rice products for infants

One bit of good news is brown rice MAY make the arsenic less bio-available as shown in this population study. As Dr. Greger says:

So, if you test the urine of thousands of Americans who don’t eat rice at all, they’re still peeing out about eight micrograms of toxic, carcinogenic arsenic a day. It’s in the air; it’s in the water; there’s a little bit in nearly all foods. But, eat just one food—a cup or more of white rice a day—and your exposure shoots up 65%.

Okay. But, what about those who eat a cup or more a day of brown rice, which technically contains even more arsenic? Your exposure shoots up the same 65%. No difference between the urine arsenic levels of white rice-eaters compared to brown rice-eaters. Now, this was not an interventional study, where they feed people the same amount of rice to see what happened, which would have been ideal. This was a population study. So, maybe the reason the levels are the same is that white rice-eaters eat more rice than brown rice-eaters. So, that’s why they ended up with the same levels? We don’t know, but it should help to put the minds of brown rice-eaters at rest.

So what is the risk? This analysis from the EPA used a Bayesian approach to estimate the dose response of inorganic arsenic exposure from water. It found a linear relationship of more arsenic exposure with bladder and lung cancer. If we extrapolate the EPA's 2025 upper-bound estimate: one daily cup of brown rice for life adds up to 0.42 percentage points of bladder or lung cancer risk (+5.5% relative to a 7.6% baseline); white adds 0.25 (+3%). At three cups: 1.45 (+19%) for brown and 0.8 (+10%) for white.

A more direct causal study would need to prove out this relationship, but this definitely took me aback. For rice staple cultures, three cups of rice daily is pretty normal. These upper bound figures begin to look similar to increased risk of cancer from a daily beer or alcoholic drink.

Unfortunately rinsing rice does little to remove arsenic, especially in brown rice. But researchers did find a parboil method could dramatically reduce the amount of arsenic, removing 54% & 73% iAs from brown & white rice. This is a specific method that requires a lot water that is then tossed out but it does retain a lot of the same nutrients.

My takeaway? We are exposed to arsenic across a number of ways; through our air, water, and food. The increased cancer risks are linear from continued exposure, which means the amount of arsenic consumption scales with risk. If I was a regulatory body in a country where rice is a staple food, I would set significantly stricter regulations to evaluate and limit the amounts in rice and rice products.

Personally, it doesn't seem worth eating rice regularly, especially brown rice. I'll probably try to have less than 3 to 4 servings a week and mix in other grains. I'd be especially careful with infants and rice products that may concentrate the arsenic levels.

Research Reveals a Surprising Anti-Alzheimer’s Effect of Eggs

A recent study looked at links between different environmental exposures and Alzheimer’s risk, based on a sample of around 500,000 people in the UK. Oddly, consuming eggs had one of the strongest protective effects out of everything covered in the study. But is this just an odd result, or does something as simple as eating eggs really have a protective effect?

Eggs Consistently Reduce Alzheimer’s Risk in Studies

Based on available research, it really does seem like egg consumption is associated with a reduced risk of Alzheimer's and cognitive decline. Firstly, the UK-based study had a huge sample size, so it’s pretty compelling on its own, suggesting a 76% increase in risk for people who never ate eggs.

But that is far from the only result:

• A 2024 study followed 1,024 older adults over 6.7 years on average, and analysed their risk based on their egg consumption at baseline. The results showed that consuming more than one egg per week was associated with a reduced risk of Alzheimer’s, 47% lower than people who ate less than one egg per week.

• A 2026 study used a large cohort of Seventh-day Adventists in the US, looking at a sample of 39,498 people (who were aged 65 or older during follow-up) over an average of 15.3 years. Risks decreased with greater egg consumption. For instance, there was a 17% reduction in risk for people who ate eggs once a month to once a week, and a 27% reduction for people who ate eggs five or more times a week, compared to people who never or rarely consumed eggs.

• A meta-analysis looking at 13 longitudinal and 8 cross-sectional studies on egg consumption found that consuming 1 egg per day was associated with a 9% decrease in the risk of cognitive decline. More precisely, the benefits peaked at 50 to 60 g of egg per day.

Why Are Eggs Good for Your Brain?

As well as containing omega-3 fatty acids, lutein, tryptophan, vitamin B12 and other potentially beneficial ingredients, many authors point to choline as a key factor. This essential nutrient is a precursor to acetylcholine, which is crucial for memory and synaptic function. Choline levels in the body have been independently linked to changes in cognitive function with aging and Alzheimer’s disease – so there are also other options if you don’t like eggs!

Patrick Jane lie detection through pulse-sensing

Patrick is "The Mentalist", who helps police solve murders.

The show aired between 2008-2015, and I just started watching it after seeing a few reels/clips on social media.

A logician rivalling Sherlock, plus the mentalism of course.

One skill Patrick frequently showcases is detecting lies by sensing changes in someone's pulse.

Obviously, the show takes (giant) liberties with Patrick's "skills". So I'm not expecting everything Patrick does to be "evidence-based".

But pulse-sensing seems believable to some degree, and I wanted to see what actual science may exist.

If you think about it, what Patrick is doing is basically administering a polygraph test (using his own natural devices). Of course, a polygraph test senses much more than a person's pulse or heart rate.

In any case, as a starting point, it seems instructive to ask "do polygraph tests work" (as lie detectors)?

That's exactly what this 2025 study examines.

It's a fascinating research paper. What the researchers did:

Dow, Jeu, and Watkins present the first published empirical analysis of polygraph reliability. Starting with the universe of cases where an individual was convicted and was subsequently exonerated on the basis of DNA evidence ... the Authors take advantage of a natural experiment that results from the conviction of individuals subsequently determined with near certainty to be innocent. By ascertaining which cases of the wrongfully convicted individuals included a polygraph examination, and by studying how those examinations were interpreted, then, because the individuals are now known to be innocent, the Authors were able to determine the reliability of these polygraph results (which were obtained before the actual innocence of the subjects was known).

And their conclusion?

polygraphs yield unreliable conclusions in approximately 50 to 65 percent of all cases-worse than a coin flip. This failure rate represents a reason for caution in all contexts where polygraph examinations are routinely used, including criminal investigations.

The study gives a few case studies:

Corey Batchelor insisted he had nothing to do with either the robbery or murder of Lula Mae Woods, who was found dead in 1989 in Chicago, Illinois. During their interrogation, police told Batchelor he had failed a polygraph exam. Confronted with this bogus claim, Batchelor confessed to a murder he did not commit. He served twenty-seven years before being exonerated.

Justin Black suffered a similar fate. In 2007, he was charged in West Virginia with the 2002 murder of Deanna Crawford. After maintaining his innocence from the outset, including during a polygraph examination, Black confessed to the crime after being told he had failed the exam. He served eleven years for a crime he did not commit before being officially exonerated in 2021.

In Nebraska, James Dean began to wonder whether he really might have been an accessory to the murder of Helen Wilson. Informed he had failed a polygraph and would face the electric chair if he did not come clean, Dean confessed to participating in a crime he had nothing to do with. He served five years before being exonerated in 2009.

Even a confession doesn't prove guilt.

So, all in all, not so good for Patrick Jane -- even if he could read pulses as good as a polygraph!

Claim: AI is “Much Better Informed Than Any Doctor in the Country”

Verdict: False and misleading

“You may have a medical record that is a thousand pages long. You have six minutes with a doctor today. He is not gonna be able to review it, but the AI can and it can distill it. It can give you a second opinion that is much better informed than any doctor in the country.”

– RFK Jr.

VP Vance speaks at MAHA Summit with HHS Sec. Kennedy

Speaking at the MAHA Summit in Washington, last week RFK Jr. claimed that AI is “much better informed than any doctor in the country.” While RFK Jr. did mention some undeniable advantages – quickly reading long medical histories, for instance – how does the overall claim stack up?

What Do Doctors Think?

Major medical organisations, including the American Medical Association, pushed back RFK Jr.’s statement, stressing the value of physicians’ years of training and experience. The statement emphasises the benefit of using the technology responsibly, as a tool to help doctors, guided by the “humanity of clinical practice.”

What Does the Evidence Say?

There are some studies showing a benefit of AI systems over human doctors, including one oft-cited meta-analysis result on empathy. This study typifies an issue with much of the research in the area. Of 15 studies included in the study, 13 showed higher empathy ratings for AI, compared to human doctors. However, the interactions studied were only through text. This severely limits applicability to real-world situations, where most medical evaluations are face-to-face.

Another meta-analysis compared diagnostic capabilities of AI with human doctors, based on 83 studies. The results showed that AI performed roughly as well as physicians overall, or non-expert physicians. However, it was worse than expert physicians.

A controlled study touched on the “second opinion” aspect of RFK Jr.’s claim, looking at whether LLMs can help members of the public choose accurate diagnoses and treatments. Generally, this study found that the LLM did better alone than it did assisting a human. When assisting non-experts – who may not communicate clearly – it does no better than participants findings their own online sources. 

The Final Verdict

LLMs may play many valid roles in healthcare both now and in the future, but they certainly are not better informed than any doctor in the US. Nor is it a particularly useful option for non-experts seeking medical advice.

Getting an Infection during the period of "Morning Sickness", poses Higher Risks of Congenital Heart Disease?

One of the most unexpected parts of the conversation was Jimmy Carr’s discussion of morning sickness. 🫣

It sent me down a rabbit hole because there is an interesting evolutionary theory behind why morning sickness tends to occur during this particular period of pregnancy.

The Maternal and Embryo Protection Hypothesis, an evolutionary theory about morning sickness, where:

1. Organogenesis: Morning sickness typically peaks between weeks 6 and 14 of pregnancy. When the embryo’s major organs (including the heart, brain, and limbs) are forming and are most vulnerable to damage from toxins or pathogens.

2. The "Shield" Effect: Because pregnancy naturally suppresses a woman's immune system (to prevent her body from rejecting the fetus), she becomes more sensitive to foodborne pathogens. Evolutionary biologists believe nausea and vomiting evolved to force mothers to avoid or expel potentially toxic or bacteria-laden foods during this window.

3. The Shift: Once the organs are fully formed (around the second trimester) and the baby enters the growth-only phase, morning sickness usually stops for most women.

EVIDENCE for Infection & Congenital Heart Disease ﮩ٨ـﮩﮩ٨ـ🫀ﮩ٨ـﮩﮩ٨ـ

A link from two meta-analyses, between First Trimester Maternal Infections and Fetal Congenital Heart Defects has been found, especially in regards to rubella virus, coxsackievirus, respiratory infections, and influenza.

⚠️ Though there is an important distinction here to make:

This does NOT mean that morning sickness itself is linked to congenital heart defects.

But the same period of pregnancy in which morning sickness may have evolved to reduce exposure to potentially harmful substances is also a period when the developing embryo is particularly vulnerable to certain environmental insults, including infections.

Season 17, Episode 61: Why Crystal Healing is More Harmful than Helpful

Hey StarTalkians! Episode 61 of season 17 was a rare, chemistry-focused episode featuring guest Kate Biberdorf, along with Neil and Negin. Early in the discussion, they start discussing crystals, and Neil asks for a chemist’s blessing about a point he often makes:

The Chemistry of Life with Kate the Chemist - StarTalk Radio

(from 11:30)

Kate is (understandably) a little wary of criticising crystal healing to avoid offending her friends, but for a few reasons, it’s worth making the point a little more clearly than they did in the podcast.

Testing Crystal Healing

There have been surprisingly few tests of the claims of crystal healing. However, psychology professor Chris French, working with Lynn Williams and (later) Hayley O’ Donnell, conducted two widely-cited but never fully-published tests.  

French, writing in The Skeptic, explains that the test involved one real quartz crystal and one identical-looking one made of glass. In the first test, 80 participants held one of these crystals for five minutes, before reporting if they felt any of six “mildly anomalous” sensations. Half of them also read a brief primer on crystals beforehand. The results were clear: it made no difference whether participants were holding a real crystal – most of them felt one of the sensations either way. This was more likely if they were primed.

A second test was conducted a couple of years later with better blinding, and the result was basically the same, except priming didn’t make a difference this time.

There is one published test looking at crystal healing. This worked in a similar way: 138 participants were randomly assigned either a true crystal or a similar-looking placebo, and were instructed to keep it for two weeks. They completed two surveys to track anxiety symptoms before and after intervention. They were also classified as either believers in crystals or non-believers.  

The study again found that there was no apparent difference between the real and fake crystal. Regardless of which they got, believers generally felt improvements while non-believers didn’t. The authors concluded that this was likely due to conditioning and the placebo effect.

The Harm of Crystals

A common counter-argument is that crystals are ultimately harmless. However, aside from the risks of crystal healing being used for serious health problems, the industry exploits workers in low-income countries such as Madagascar, including child labour, low pay and dangerous working conditions. For consumers, crystals are “safe,” but the industry is certainly not.  

New Stem Cell Therapy for Parkinson's 💉

I had a senior recently return from this year's BioJapan forum, essentially a bio-industry partnering event, and he shared with us some interesting cases/studies/products being developed. Given that iPSC technology, which won the 2012 Nobel Prize, was first developed in Japan, this was no surprise.

Japan remains at the forefront of regenerative medicine. This year, Japan authorized the world's first two commercial induced pluripotent stem cell (iPSC)-based cell therapies:

One of them is for Parkinson's Disease, where allogeneic iPSC-derived dopaminergic neural progenitor cells are transplanted into the brain to restore dopamine generation.

This comes as a surprise for us who have tinkered with iPSC: 🤔❓

1. They are injecting the progenitor cells, not the final derived product > basically injecting Tomato instead of Ketchup situation

2. It is not personalised therapy > iPSC was always presumed to eventually have great breakthroughs with personalised cells. Thank goodness because the price of ¥55,306,737 is already steep.

💉 Injections to the putamen/striatum, report improvements in motor skills at the end of their 2 year trial. This is also the first clinical trial using iPSC cells confirming that iPS-cell-derived progenitors can survive without forming tumours and produce neurons in the putamen of patients with Parkinson's.

Nevertheless, I'm excited to see what comes next: 🚶 During this 7-year window, Sumitomo Pharma is required to conduct mandatory Phase IV post-marketing surveillance and collect additional safety and efficacy data before full, permanent approval can be considered.

Microplastics from Keurig K-cups or Capsule machines

I know that a leading factor for microplastic leaching is heat, especially hot water, interacting with plastic. So I dug into what we know about plastic K-cups and microplastics. Effectively there is no research on the topic that I could turn up, which is pretty surprising. The closest study I could find was this 2025 study on beverage products from the UK. This study was linked to by a number of articles like this from microplastics app or Do Coffee Pods Release Microplastics? What the Research Actually Says that cited ~43 microplastic particles (MP) per liter. These article findings fed into AI results like Claude and Gemini, but I found the takeaways provided were incorrect.

The main finding from the study:

Hot coffee prepared in 3 domestic machines (Table SI-3) showed considerable variation in MP levels, with the oldest model (8 years old with water tank made of PET) releasing higher MPs concentrations (17 ± 2 MPs per cup) compared to newer machines (1 and 0.5 years old with ABS water tank releasing 10 ± 2 MPs per cup and 7 ± 2 MPs per cup, respectively). This is consistent with existing research indicating that material degradation over time leads to increased MP shedding (Luo et al., 2022). The higher MP concentrations in coffee prepared using the older coffee machine may be due to wear and tear of the plastic water tank and other materials, a trend also observed in other products like water bottles (Schymanski et al., 2018).

This ended up being one of the largest amounts of microplastics found compared to the other beverages except for Hot Tea. The other comparisons being iced coffee, iced tea, soft drinks, energy drinks, and juices. The problem with this study being repeated for Kcups is a few fold:

• The 43 MP figure was for the Hot Coffee category overall which included other sources like hot coffee from large chains served in takeaway cups, hot coffee made in sachets served in glass cups, and coffee made from capsules.

• The capsules weren't specifically specified as Kcup, this being a UK study, these are more likely nespresso pods. I'll email the paper author to see if I can get the exact types as its not listed in the study and attach what I hear in the comments

• When comparing the capsule results to other Hot Coffee sources, the capsules didn't perform worse overall when you scale the figures above to MP/liter. The authors suggested differences came from degradation of the water tank rather than the capsules themselves. But because we don't know if these were Kcups, we can't be sure this neutral outcome means the pods are the same.

• Some of the articles I listed said the results showed Polypropylene (PP) in the microplastic results which is the primary material for Kcups. However, the authors said this is probably from leaching from the takeaway cup lids in the Hot Coffee category, which is a repeated result from other studies.

• This study only tested for MP sizes greater than 10μm and excludes cellulose, organic microplastic. This makes these results less comparable to prior studies that may have found more microplastics.

TLDR; There's no studies I've found showing Kcup generated microplastics, the amount generated is unknown. Further articles claiming results are likely incorrect or misleading. The biological impacts of microplastics remain debated with unclear risk thresholds for consumption. But I'll leave what the UK study says about impacts below.

Microplastic (MP) ingestion raises health concerns due to their potential to cross biological barriers and accumulate in tissues. Studies suggest that MPs can physically damage gut cells, alter the gut microbiota, and trigger inflammatory responses, which may lead to immune dysregulation and metabolic disturbances (Cox et al., 2019; Deng et al., 2017). MPs can also act as carriers for hazardous chemicals, including heavy metals and endocrine-disrupting compounds such as bisphenol-A, which may leach into the body upon ingestion and disrupt hormonal functions, affecting processes like reproduction and metabolism (Gallo et al., 2020; Hahladakis et al., 2018). The degree of impact is influenced by MP size, shape, and polymer type, with evidence from studies conducted on polystyrene, polyethylene, and polypropylene MPs suggesting that smaller particles and fragment-shaped MPs are more prone to tissue penetration and chemical release upon ingestion (Banaei et al., 2023). The cumulative effect of MPs and associated chemicals in human tissues highlights the importance of establishing standards to limit MP exposure in food and beverages, given the potential for long-term health risks (Schwabl et al., 2019).

Season 17, Episode 58: Why Does String Theory Have So Many Dimensions?

Hey StarTalkians! Episode 58 of season 17 was another Cosmic Queries edition, with guest and string theorist Professor Lara Andersson, Neil and Jordan. Many of the questions concerned the – seemingly excessive – number of dimensions in string theory. This one really gets to the heart of the matter:

Quantum Anomalies with Lara Anderson - StarTalk Radio

(from 30:30)

Professor Andersson explains it very well in layman’s terms. Truthfully, it’s difficult to convey without a lot of mathematics, but here, I’ll try to address the core issue in a little more detail.

Why Does String Theory Have Extra Dimensions?

String theory is an attempt to unify all four fundamental forces – thus creating a “theory of everything.” When you’re doing this, it’s probably wise to not make any assumptions about the number of dimensions there are. After all, it’s possible that we aren’t aware of all of them.

So you can develop the ideas of string theory in a “dimension agnostic” way, just putting d in place of anything dependent on the number of dimensions.

Working this way, you eventually run into an issue. Any such theory would have to be invariant under a transformation called a Weyl transformation, but this can be broken by quantum mechanical effects. In order to form a consistent theory with these “Weyl anomalies,” they have to cancel out.

That’s when d comes back. It was found that with d = 26 (in the case of bosonic – force-related – string theory) or d = 10 (in the case of fermionic – matter related – superstring theory), you can ensure the cancellation. In this way, the dimensions kind of just come out of the theory, if it is to work at all.

How Many Extra Dimensions?

It depends on the specific theory. Five different variants of string theory quickly developed, which physicists found connections between by rescaling so-called “coupling constants” which appear in each. In 1995, Ed Witten realized that these five theories were just special cases of “M theory” – the mother of all string theories.

In M theory, there are 11 dimensions. This is therefore the best answer to how many dimensions are present in string theory.

So... Where Are They?  

As explained on the podcast, the complete lack of these dimensions in our experience is explained by “compactification.” This is questionable, from a philosophical perspective, but does fix the problem of “where are the extra dimensions?”.

Childcare : what the science says

The article reviews research on childcare, arguing that its effects depend on a child’s age, hours in care, and family environment. It highlights research associating long hours of daycare at younger ages with later behavioral difficulties and poorer social skills, while noting differences by socioeconomic status.

This article seems to suggest that starting daycare later (after 2.5) is better. Also potentially more pronounced benefits of daycare for lower socio-economic status families/households. Would love to understand whether this evidence suggested in this article is reflective of the larger literature and people's thoughts in general.