CLAIM:
Set of daily lifestyle habits - including drinking water first thing in the morning, eating fermented foods, engaging in “metabolic walking,” consuming cruciferous vegetables, and maintaining proper sleep- can significantly reduce cancer risk after the age of 50.
FACT:
Current research does not support the claim that these daily habits can directly prevent cancer after 50. While physical activity, diet, sleep, and overall lifestyle are linked to better health and may influence cancer risk, most evidence is associational, inconsistent, or based on early-stage studies, not definitive prevention. These habits are beneficial, but they are not proven standalone cancer-prevention solutions.
In a viral YouTube video posted by the channel ‘Bio Bites’, which has over 1.3 lakh subscribers, a set of health claims linking simple daily habits to cancer prevention after the age of 50 is gaining widespread attention online. The video features Dr William Li, a physician and researcher known for his work on the connection between food and disease, who presents what he describes as “the most important four minutes of health information” viewers may hear.
In the video, Dr Li opens with a strong assertion, saying, “Hey, stop what you're doing right now because what I'm about to share with you could be the most important four minutes of health information you'll hear this year.” He claims that many doctors, including oncologists, are not informing patients over 50 about these findings, “not because they don’t know, but because it doesn’t come in a pill bottle.”
Drawing on what he says are over 25 years of his own research, Dr Li claims that his findings are “confirmed by a landmark 2022 study from Harvard’s T.H. Chan School of Public Health,” which followed more than 1,16,000 adults over 28 years. According to him, this research shows that a specific category of daily lifestyle habits can reduce overall cancer risk by up to 61% in people over the age of 50.
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He then outlines five key habits, ranked from “helpful to absolutely transformational,” beginning with what he calls “cold water hydration.” He advises drinking 16–20 ounces of cold or room-temperature water first thing in the morning, before food or coffee, linking hydration to lymphatic function, inflammation control, and cellular processes like autophagy. He also claims that pairing hydration with light movement can “compound the cellular cleansing effect by up to 40%.”
The second habit he highlights is the regular consumption of fermented foods such as yogurt, kefir, kimchi, sauerkraut, and miso. Citing research, he says these foods improve gut microbiome diversity and reduce inflammatory markers, adding that compounds like butyrate can signal precancerous cells to die. He recommends one to two daily servings and suggests combining them with prebiotic-rich foods like garlic or slightly underripe bananas.
Dr Li then discusses “metabolic walking” as the third habit, describing it as 30–45 minutes of moderate-intensity walking that elevates heart rate. He links this to reduced glucose availability for cancer cells and improved oxygenation, citing studies that associate regular physical activity with lower risks of several cancers. He also connects walking to improved mitochondrial function, particularly in older adults.
The fourth habit focuses on sulforaphane, a compound found in cruciferous vegetables such as broccoli, cabbage, and Brussels sprouts. He explains that sulforaphane activates protective genes involved in detoxification and DNA repair, claiming it may reduce the risk of several cancers. He also emphasises specific preparation methods, such as chopping vegetables and allowing them to sit before cooking, to maximise the compound’s effectiveness.
Finally, he identifies sleep as the most important factor, referring to it as “oncological sleep architecture.” He explains that deep sleep supports the glymphatic system and melatonin production, which he describes as critical for cancer defence. He cites studies linking poor sleep and disrupted circadian rhythms to increased cancer risk, recommending consistent sleep schedules, dark environments, and adequate duration.
The video has gained massive traction, with over 30.6 lakh views, 1.21 lakh likes, and more than 7,300 comments, indicating that these claims have resonated widely and sparked significant public interest.
What research says?
#Claim 1: Cold water, hydration prevents cancer
Fact: Dr Li suggests that drinking water, especially first thing in the morning, can help reduce cancer risk by improving lymphatic function, lowering inflammation, and supporting cellular processes like autophagy.
Current research shows that while adequate hydration is important for overall health, there is no clear or consistent scientific evidence that drinking water, cold or otherwise, directly prevents cancer or significantly reduces cancer risk, as claimed.
A large-scale study from the Netherlands Cohort Study (N = 120,852), which followed participants for over 13 years, specifically examined whether fluid intake affects colorectal cancer risk. The researchers found that “multivariate analyses showed no dose-response relationship of total fluid intake… with the risk of overall colorectal, proximal, and distal colon cancer.” The study concluded that “total fluid intake was not associated with colorectal cancer risk in either men or women,” directly contradicting claims that higher water intake reduces such risks.
Similarly, while some studies suggest a limited association in specific contexts, the evidence remains inconclusive. A 2015 study examining fluid intake and bladder cancer risk in women found only a “suggestive inverse association” between higher fluid intake and overall bladder cancer risk. The researchers noted that while there may be some reduction, particularly among heavy smokers, the findings were not strong enough to establish a clear protective effect.
Research on other cancers shows mixed and limited evidence. A 2020 case–control study on breast cancer reported that women diagnosed with breast cancer consumed less water than controls, noting that “low water and liquids intake… may be related to the younger age of our subjects.” However, the authors emphasised that this was an observational finding and that “the effect of age… should be investigated,” indicating that causation cannot be established.
More recent large-scale data also does not firmly support the claim. A 2022 analysis using data from over 35,000 adults in the NHANES cohort found that while higher water intake was associated with lower overall mortality, the relationship with cancer-specific outcomes was more complex. The study reported that “beverage and food water intakes… were associated with decreased malignant neoplasms/cancer mortality risk,” but also identified a “U-shaped dose–response relationship” and found no consistent association across all measures of water intake.
#Claim 2: Diet, fermented foods help prevent cancer and destroy precancerous cells
Fact: Dr Li suggests that regularly consuming fermented foods can reduce cancer risk by improving gut health, lowering inflammation, and triggering the death of precancerous cells.
Existing research indicates that while fermented foods may support gut health and influence immune responses, there is no conclusive human evidence that they directly prevent cancer or eliminate precancerous cells. Many of the claims rely on early-stage, animal, or laboratory findings that cannot yet be generalised to real-world cancer prevention.
A 2020 review examining the anticancer potential of fermented foods notes that while diet plays an important role in cancer prevention, stating that “30–40% of cancer can be prevented by modifiable risk factors and behavioural changes, including dietary habits”—the evidence specifically linking fermented foods to cancer prevention remains limited. The review highlights that fermented foods contain bioactive compounds and probiotic microorganisms that may have beneficial effects, including immune modulation and reduced oxidative stress. However, it clearly cautions that “the most significant evidence for the anticancer effects of fermented foods is obtained from more animal studies, with evidence from human studies… still limited in numbers,” adding that “there have not been enough human trials to test these products.”
More recent research echoes this uncertainty. A 2023 review exploring fermented foods and cancer outcomes suggests that such foods “may alter gut microbiome composition and, in turn, improve immunity.” It describes fermented foods as a “promising dietary intervention,” particularly in the context of improving responses to cancer treatments.
However, the authors stress that “there is scarce evidence to suggest how gut microbiome compositional changes mediate associations of fermented food consumption and health outcomes,” and underline that “further research among human populations with rigorous study designs addressing limitations described above are critically needed. In addition to the questions above, there are many gaps in knowledge pertaining to the associations of fermented foods with health.”
Similarly, a 2024 review on probiotic foods and cancer highlights potential therapeutic roles but stops short of confirming preventive effects. It notes that probiotics “have been shown to have therapeutic promise in the management of cancer” and may help through mechanisms such as immune system stimulation and production of anti-carcinogenic compounds. Some studies suggest that certain strains can “prevent the growth of cancer cells, trigger apoptosis, and reduce angiogenesis.” However, the review emphasises significant limitations, including variability in strains, dosages, and patient factors, concluding that “more research is necessary to find the long-term safety and efficacy” of such interventions.
#Claim 3: Metabolic walking can significantly reduce cancer risk by starving cancer cells of glucose and improving oxygen supply
Fact: Dr Li suggests that a specific form of walking can directly prevent cancer through metabolic changes in the body.
Research consistently shows that regular physical activity, including walking, is associated with a lower risk of several cancers and improved overall health outcomes. However, these benefits are linked to general factors like metabolism, weight control, and inflammation—not a specific method like “metabolic walking” or the idea of “starving cancer cells.”
A 2018 review on exercise and cancer notes that “physical exercise has been shown to reduce cancer incidence and inhibit tumour growth,” highlighting that exercise may influence cancer through multiple pathways, including immune function and overall physiological changes. However, the study frames exercise as part of a broader system of health benefits rather than a targeted mechanism like “starving cancer cells.”
More robust causal evidence comes from a 2020 Mendelian randomisation study, which found that higher physical activity levels were associated with lower risks of certain cancers. The study reports that “a one standard deviation increment… was associated with lower risks of breast cancer… and colorectal cancer,” suggesting a potential causal link. However, these findings relate to overall activity levels, not a specific type or timing of walking.
Further supporting this, a 2023 review examining molecular mechanisms concludes that exercise “may be a complementary part of the medical treatment of cancer patients,” and may contribute to prevention through improvements in metabolism, weight control, and inflammation. It also notes that “moderate physical activity has inversely been associated with cancer risk,” and that individuals walking more than four hours per week showed “a 54% lower risk of pancreatic cancer.”
More recent data also points to modest but consistent associations. A 2024 study using UK Biobank data found that walking frequency and pace were linked to a reduced risk of lung cancer, with results showing that “number of days/week walked for 10+ minutes was associated with a reduced risk” and usual walking pace also contributing. However, the effect sizes were small, and walking duration alone did not show a significant association.
Similarly, a large prospective study of over 85,000 participants found that higher overall physical activity was associated with a 26% lower cancer risk, with benefits seen across both light and moderate-to-vigorous activity. The study also found that daily step counts were inversely associated with cancer risk, with benefits plateauing at around 9,000 steps per day.
Global health bodies also support these findings. The World Cancer Research Fund states that there is “strong evidence” that moderate-intensity physical activity, including brisk walking, reduces the risk of cancers such as colon and post-menopausal breast cancer, largely by helping maintain a healthy weight and improving metabolic health.
#Claim 4: Sulforaphane prevents cancer
Fact: Lab and early research show sulforaphane can affect cancer cells and activate protective pathways, suggesting potential anti-cancer benefits. However, most evidence comes from cell and preclinical studies, with limited human trials. It is considered promising, but not proven to prevent cancer on its own.
A 2014 laboratory study demonstrated that sulforaphane can act against cancer cells under controlled conditions. It found that the compound “inhibited cell viability and induced apoptosis in T24 [bladder cancer] cells in a concentration-dependent manner,” with effects linked to oxidative stress and mitochondrial pathways. The study further noted that sulforaphane “triggered reactive oxygen species (ROS) generation” and activated the Nrf2 signalling pathway, suggesting potential anti-tumour mechanisms. However, these findings are based on cell-line experiments, not real-world human outcomes.
Building on this, another study highlights that sulforaphane is still “a promising agent under preclinical evaluation,” meaning it is being tested primarily in experimental models. It explains that sulforaphane interacts with cellular pathways like Keap1-Nrf2, enabling “activation of its transcriptional program” and enhancing the body’s defence against carcinogens. While small clinical trials using broccoli sprout preparations showed improved detoxification of harmful substances, the research suggests this may “attenuate… health risks, including cancer,” rather than directly prevent cancer itself.
More recent reviews continue to support its biological potential but emphasise existing gaps. A 2023 review notes that sulforaphane “provides cancer protection through the alteration of various epigenetic and non-epigenetic pathways” and is considered a “potent anticancer phytochemical.” At the same time, it clearly states that “there is still a need for further research… and the development of a standard dose.”
Similarly, a 2024 review reports that sulforaphane has shown “significant preventive and therapeutic cancer effects” across different cancer types in research settings. It outlines multiple mechanisms, including “induction of apoptotic pathway in tumour cells, inhibition of cell cycle progression, and suppression of tumor stem cells.” However, these conclusions are drawn from mechanistic and experimental studies, not large-scale human trials.
The latest 2025 review further expands on these mechanisms, noting that sulforaphane can influence processes like apoptosis, autophagy, and metastasis, and may even enhance the effectiveness of chemotherapy. It highlights that the compound “shows significant promise in cancer therapy,” particularly when combined with existing treatments. Yet, this again positions sulforaphane as a supportive or emerging therapeutic candidate, not a proven standalone preventive measure.
#Claim 5: Sleep prevents cancer
Fact: Scientific evidence suggests that sleep plays an important role in overall health, but its direct link to cancer prevention remains inconclusive and complex.
Early clinical evidence on melatonin (a hormone linked to sleep) comes from a small 2001 study on 20 metastatic cancer patients. The study found that while overall tumour progression was not significantly reversed, “non-progressing patients (MR + SD) showed a significant decline in VEGF mean concentrations,” suggesting that melatonin “may control tumour growth at least in part by acting as a natural anti-angiogenic molecule.” However, this was a small, treatment-focused study, not evidence of prevention in healthy individuals.
Building on broader population-level research, a 2015 study examining sleep and cancer risk noted that scientific findings are mixed and inconsistent. As it states, “the limited number of published studies on sleep duration and cancer risk have yielded provocative, yet highly inconsistent results,” with some studies linking both short and long sleep to higher cancer risk, while others found no association at all.
A larger 2018 meta-analysis, covering over 1.5 million participants, further reinforces this uncertainty. It found that “neither short nor long sleep duration was associated with increased cancer risk” overall. While some subgroup patterns emerged, such as increased risk among Asian populations or colorectal cancer with long sleep, these findings were not consistent across analyses, and the study concluded that more robust research is needed to establish causality.
More recent evidence from a 2024 cohort study suggests a possible association, rather than a definitive link. It reported that sleeping less than 6 hours was associated with a modest increase in cancer risk, particularly for digestive and respiratory cancers. However, longer sleep durations also showed potential risk increases, though inconsistently. The authors emphasised that these findings require further validation.
Reflecting the broader scientific consensus, the American Cancer Society states that, “it’s unclear. Researchers continue to study how sleep might affect cancer risk.” While chronic disruption of sleep cycles may increase risk, this does not establish sleep as a guaranteed preventive measure.
This story is done in collaboration with First Check, which is the health journalism vertical of DataLEADS