Regular Blood Donation May Influence Cancer Risk

Updated Mar 12, 2025 | 11:00 PM IST

SummaryAs and when people age, their blood and other cells naturally develop mutations and some of them can also increase the risk of cancer. When anyone donates blood, his or her body compensates by producing new blood cells, which can influence the genetic diversity of stem cells in the bone marrow.
Can blood donation reduce cancer risk?

Credits: Canva

A recent study suggests that people who donate blood regularly may have genetic changes in their blood that could in fact reduce the risk of developing cancer. It is conducted by the researchers at the Francis Crick Institute, and the study has now provided new insights into how and why blood cancers develop. The study is published in the journal Blood and was conducted by the scientists from Heidelberg and the German Red Cross blood donation center. There is yet a need for further research to confirm these findings.

What Did The Study Find?

The researchers examined the blood of two groups of healthy male donors in their 60s:

  • One group had donated blood three times a year for 40 years.
  • The other group had donated only about five times in total.

The goal was to analyze genetic mutations in their blood and assess whether frequent donation had any impact on their genetic makeup.

How Can Blood Donation Affect Stem Cells?

As and when people age, their blood and other cells naturally develop mutations and some of them can also increase the risk of cancer. When anyone donates blood, his or her body compensates by producing new blood cells, which can influence the genetic diversity of stem cells in the bone marrow. The study also found that both groups had a similar number of mutations. For instance the frequent donors had 217 mutations, while the irregular donors had 212 mutations.

However, the nature of these mutations differed. In the frequent donors, 50% of the mutations were of a type not associated with a high risk of blood cancers, compared to only 30% in the irregular donors.

Further laboratory analysis showed that these specific mutations behaved differently from those linked to leukemia, a type of blood cancer. When human blood stem cells with these mutations were injected into mice, they were found to be highly effective at producing red blood cells, which is considered a positive outcome.

Dr. Hector Huerga Encabo, one of the study authors, emphasized that these mutations do not indicate an increased risk of leukemia. The findings suggest that regular blood donation may influence how stem cells evolve, but whether this translates into a lower cancer risk remains uncertain.

Read More: Who Can Donate Blood To Whom?

Limitations

One notable disadvantage is the "healthy-donor effect"—because blood donors are often healthier than the general population, their lower cancer risk could be unrelated to blood donation.

Dominique Bonnet, senior researcher and head of a stem-cell laboratory at the Francis Crick Institute, stressed the need for larger studies with female volunteers to confirm the findings.

Despite ongoing research into potential health benefits for donors, the primary goal of blood donation remains saving lives. NHS Blood and Transplant emphasized that while the study is interesting, further research is required to draw firm conclusions. The organization also noted that blood supplies are currently critically low and encouraged eligible individuals to donate.

Also Read: How Long After a Tattoo or Piercing Can I Donate Blood?

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World Zoonoses Day 2026: Monsoon Season And The Rise Of Zoonotic Diseases

Updated Jul 6, 2026 | 07:00 AM IST

SummaryAbout six out of every ten infectious diseases known to affect humans started in animals at some point. COVID reminded the whole world of this. We have been living with zoonotic threats for years, quietly, every rainy season.
World Zoonoses Day 2026: Monsoon Season And The Rise Of Zoonotic Diseases

Credit: iStock

Every year on July 6, we mark World Zoonoses Day. The date marks the day in 1885 when Louis Pasteur gave the first rabies vaccine. It falls right in the middle of our monsoon, which is exactly when zoonotic diseases claim the most lives. So this year, instead of a routine health advisory, let us go through the questions I get asked most often, by patients, by family, and honestly, by fellow doctors too.

Q: What Is A Zoonotic Disease?

A zoonosis is any disease that spreads from animals to humans. The animal could be a rat, a dog, a bat, or even livestock in your backyard. Sometimes the animal itself looks perfectly healthy while carrying the germ that makes us sick. About six out of every ten infectious diseases known to affect humans started in animals at some point. COVID reminded the whole world of this. We have been living with zoonotic threats for years, quietly, every rainy season.

Q: Which Zoonotic Diseases Does India deal with most commonly?

If I had to list the usual suspects, it would be this:

  • Leptospirosis
  • Scrub typhus
  • Nipah virus, linked to fruit bats, with Kerala's Kozhikode and Malappuram having seen outbreaks in past years
  • Rabies from animal bites, mainly dogs and cats, and occasionally other animals
Some of these are with us all year round. Others wait for the rains.

Q: So Which Of These Actually Rise During The Monsoon, And Why?

Leptospirosis is the one that rises sharply and predictably every single monsoon. The bacteria live in the kidneys of rats and other rodents and are released into soil and water through their urine. When the rains come, our fields, drains, and waterlogged roads become the perfect place for the infection to spread. Anyone walking barefoot through flood water, working in paddy fields, or wading through stagnant water near their home is at risk.

Scrub typhus rises a little later, once the rain eases and people go back into overgrown fields and gardens to clear vegetation, exposing themselves to the mite larvae hiding there. Our own data from KIMSHEALTH, based on 241 patients over seven years, shows this pattern clearly. Cases start climbing in September, peak in December, and drop off by January.

This means the disease follows the cool, humid weeks right after the monsoon leaves, not the rainy months themselves. Low temperature and high humidity suit the mites best, which is why the weeks just after the monsoon, not the heavy rain itself, are scrub typhus season. Our data also showed a smaller rise between June and August, so the risk is actually spread across two windows around the monsoon, not just one.

This year, our own health department figures have already shown this pattern. Fever clinics across the state have been seeing well over 10,000 patients a day at the peak, with leptospirosis and Shigella infections climbing sharply. Northern districts of Kerala Kannur, Kozhikode, and Malappuram have reported some of the sharper spikes, and rat fever sadly remains the biggest killer among these in most years.

Q: What about Nipah?

Nipah is not strictly a monsoon disease. It tends to appear when fruit bats are under stress, often during their breeding season or when their natural food is disrupted. Kerala has had confirmed cases in recent years. The good news is that Kerala now has one of the fastest outbreak response systems in the country for Nipah, with quick contact tracing and isolation.

Q: What can we do to protect ourselves?

For leptospirosis:

  • Avoid walking barefoot through flood water or muddy fields, especially if you have any cuts or wounds on your feet
  • Wash your legs and feet well with soap after any contact with flood water or waterlogged areas
  • If you must work in fields or clean drains during the monsoon, wear boots and gloves
  • Doxycycline tablets taken as prevention work well for people at high risk, such as farmers, sanitation workers, and flood relief volunteers. Please take this only on your doctor's advice, at the right dose and timing
  • Keep the rat population around your home and workplace under control. This sounds like a small thing, but it matters more than any tablet

For scrub typhus:

  • Avoid sitting directly on grass or vegetation when you go out for farm work or a walk in overgrown areas
  • Wear long sleeves and full-length trousers when clearing bushes

For rabies:

  • Any animal bite, however small it looks, needs immediate washing of the wound with soap and running water for at least fifteen minutes, followed by a visit to a doctor for vaccination
  • Do not wait to see if the animal "seems fine." Rabies is fatal once symptoms begin, with no exceptions
  • Get your own pets vaccinated regularly. This protects your family as much as your animal

Q: When Should Someone Actually Go See A Doctor?

See a doctor without delay if you have a fever along with any of the following:

  • Fever lasting more than two days, especially if you have had recent contact with flood water, muddy fields, or rodents
  • Severe muscle pain, especially in the calves, along with fever
  • Yellowish color in the eyes or skin
  • Passing less urine than usual
  • Bleeding from gums, nose, or skin rashes with fever
  • Severe body ache
  • Breathlessness or confusion along with fever
  • Any animal bite, no matter how small it seems

Leptospirosis in particular can look just like an ordinary viral fever in its first two or three days, and then get worse quickly, leading to kidney failure or bleeding problems. Starting antibiotics early makes a big difference to the outcome. This is not a disease where it is safe to simply wait and watch.

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Chronic Fatigue: More Than Just Lack of Rest

Updated Jul 4, 2026 | 07:00 PM IST

SummarySometimes a vitamin deficiency is part of the problem of chronic fatigue. Others may include key nutrient deficiencies such as iron, vitamin B12 and folate.
Chronic Fatigue: More Than Just Lack of Rest

Credit: iStock

With less time and more work, chronic fatigue has become a moniker of modern society. However, this not only reduces the quality of life but also constitutes a social issue that affects work efficiency and leads to accidents. On the surface, the cause of fatigue is often attributed to not getting enough rest, but there may be another underlying issue—the lack of proper nutrition.

The world moves at a hectic pace these days. If you feel like you're constantly running on empty, you're not alone. Many people say that they just don't have the energy they need to accomplish all they need to. Sometimes the cause of fatigue is obvious — for example, getting over the flu or falling short on sleep. Sometimes a vitamin deficiency is part of the problem. It might be worth asking your doctor to check a few vitamin levels, such as the three we've listed below.

Key Nutrient Deficiencies That Can Cause Fatigue

- Iron

Anemia occurs when there aren't enough red blood cells to meet the body's need for oxygen, or when these cells don't carry enough of an important protein called hemoglobin. Fatigue is usually the first sign of anemia. A blood test to measure the number of red blood cells and the amount of hemoglobin can tell if you have anemia. The first step in shoring up your body's iron supply is with iron-rich foods (such as red meat, eggs, rice, and beans) or, with your doctor's okay, over-the-counter supplements.

- Vitamin B12

Your body needs sufficient vitamin B12 in order to produce healthy red blood cells. So a deficiency in this vitamin can also cause anemia. The main sources of B12 are meat and dairy products, so many people get enough through diet alone. However, it becomes harder for the body to absorb B12 as you get older, and some illnesses (for example, inflammatory bowel disease) can also impair absorption. Many vegetarians and vegans become deficient in B12 because they don't eat meat or dairy. When B12 deficiency is diet-related, oral supplements and dietary changes to increase B12 intake usually do the trick. Other causes of B12 deficiency are usually treated with regular injections of vitamin B12.

- Vitamin D

A deficit of this vitamin can sap bone and muscle strength. This vitamin is unique in that your body can produce it when your skin is exposed to sunlight, but there also aren't many natural food sources of it. You can find it in some types of fish (such as tuna and salmon) and in fortified products such as milk, orange juice, and breakfast cereals. Supplements are another way to ensure you're getting enough vitamin D (note that the D3 form is easier to absorb than other forms of vitamin D).

What Does Research Say?

Taking this into account, a research group led by Professor Hiroaki Kanouchi at Osaka Metropolitan University's Graduate School of Human Life and Ecology focused on nutritional status and water-soluble vitamin deficiencies found in unbalanced diets. The team hypothesized that a lack of folate (B9) and vitamin B12 may be related to fatigue, and centered their research around homocysteine (Hcy), a biomarker known to increase when these deficiencies are present.

Blood concentrations of Hcy, folate, and vitamin B12 in approximately 600 healthy Japanese participants were measured. Participants' fatigue and motivation were assessed using the Chalder Fatigue Scale questionnaire and the Visual Analog Scale. The initial results showed that individuals with higher blood Hcy levels had lower levels of vitamin B12 and folate, regardless of sex.

The Link Between Homocysteine and Fatigue

The researchers then examined the relationship between homocysteine levels and fatigue separately for men and women. In their analysis, factors that may influence fatigue, such as age, sleep duration, workload, and dietary habits, were simultaneously accounted for.

The results revealed that higher Hcy levels were associated with greater physical fatigue in men, while higher levels were associated with decreased motivation in women.

(Dr Alex Mathew, Senior Consultant – Internal Medicine, Max Super Speciality Hospital, Patparganj)

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The 'Weekend Warrior' Trap: Why A Sunday Soccer Match May Be Starving The Heart Of Oxygen

Updated Jul 5, 2026 | 07:00 AM IST

SummaryRoughly one in five sudden cardiac deaths overall occur during or immediately after physical exertion, underscoring exercise's specific role as a trigger rather than simply a background risk.
The "Weekend Warrior" Trap: Why A Sunday Soccer Match May Be Starving The Heart Of Oxygen

Credit: iStock

A casual match still feels like exercise. For a heart that has not been conditioned to meet sudden, competitive demand, it can briefly become something closer to a stress test it never agreed to take. The risk lies less in the sport itself than in how unprepared the body is for it.

Ninety Minutes the Heart Never Trained

For Sunday mornings across recreational pitches host a familiar ritual: amateur footballers, most with desk jobs and six quiet days since their last real exertion, sprinting straight into competitive play. From the sideline, the scene reads as a picture of health, a weekly act of discipline squeezed into a busy schedule. Beneath that surface, the cardiovascular system experiences something closer to an ambush than a workout.

This is the territory of the so-called weekend warrior, an individual whose physical activity arrives in concentrated, high-intensity bursts rather than a steady weekly rhythm, with a heart and coronary arteries rarely tested anywhere near as hard as they are about to be for the next ninety minutes.

The Other Muscle That Needs Oxygen

Working skeletal muscle during competitive football consumes oxygen at a rate many times its resting baseline, since contraction and sustained movement depend on aerobic metabolism and a steady oxygen supply.

To meet that demand, the heart itself must work harder: heart rate and contractile force both rise, meaning the heart muscle, the myocardium, needs more oxygen simply to keep pumping blood to the rest of the body.

Under normal circumstances, the coronary arteries that feed the heart respond by dilating, widening to allow greater blood flow exactly when it is needed most. That system performs well when demand rises gradually. Sudden maximal exertion, the kind that defines an unplanned sprint for a loose ball, can push myocardial oxygen demand upward by as much as fivefold almost instantly, leaving far less margin for the coronary circulation to compensate, particularly if the vessels are not entirely healthy to begin with.

The Tipping Point Between Workout and Warning Sign

Roughly one in five sudden cardiac deaths overall occur during or immediately after physical exertion, underscoring exercise's specific role as a trigger rather than simply a background risk. That role intensifies when vigorous activity follows a long stretch of inactivity, which describes the typical week of a recreational footballer far more than a trained athlete's training calendar.

The sequence generally begins with sympathetic nervous system activation: a surge of stress hormones, principally adrenaline, released the moment competitive exertion begins. This catecholamine surge raises heart rate and blood pressure almost immediately, driving myocardial oxygen demand upward at the moment the heart is least prepared for it.

The same surge can act on the coronary arteries directly, provoking constriction or spasm rather than the dilation exercise normally calls for, a paradox that includes rare stress-related conditions such as Takotsubo syndrome. For someone carrying an often undiagnosed plaque burden, a narrowing in the range of 25 to 50 percent of the vessel, this combination can convert a previously silent lesion into one that becomes hemodynamically significant under load. What follows is demand ischemia: a mismatch between the oxygen the heart needs and what the coronary circulation can deliver, arising not because a vessel has abruptly blocked but because demand has outrun supply.

In some cases, this transient oxygen deprivation is severe enough to qualify as a Type 2 myocardial infarction, distinct from the more familiar plaque-rupture heart attack but no less serious.

Not Every Player on the Pitch Carries the Same Risk

Risk concentrates most heavily among adults who are otherwise sedentary, since their cardiovascular systems have had no recent opportunity to adapt to exertion, and among those carrying undiagnosed coronary artery disease that produces no symptoms until it is tested by genuine physical stress. Diabetes, hypertension, a history of smoking, obesity, and elevated cholesterol all raise the likelihood that some degree of coronary plaque exists before a single whistle blows. This is a meaningfully different population from trained athletes.

Notably, even habitually active masters-level endurance athletes can show a higher prevalence of coronary atherosclerosis than sedentary peers with similar risk profiles, though their plaques tend to be more stable, which may blunt rupture risk. The weekend warrior, by contrast, often brings unmanaged risk factors and an unconditioned cardiovascular system to the same ninety minutes.

Conditioning the Heart Before the Whistle Blows

Clinical guidance translates into a handful of concrete principles. Progressive conditioning, building tolerance gradually rather than asking an unconditioned heart to meet maximal demand in a single afternoon, is foundational, alongside regular weekly activity rather than sporadic, all-or-nothing bursts. Easing into intensity rather than launching directly into competitive sprinting gives the cardiovascular system time to adjust.

For adults with elevated risk, particularly relevant family history, multiple risk factors, or symptoms during past exertion, screening, a physical examination, a resting ECG, and, in some cases, formal exercise testing, can surface disease before it is exposed on the pitch. Equally important is recognizing warning signs that should end a match rather than be played through: chest discomfort, disproportionate breathlessness, an unexplained drop in pace, palpitations, or impaired consciousness.

With those precautions, a safe return to recreational sport remains achievable for most adults, including many with treated cardiovascular risk.

Steady Beats Sudden

None of this indicates football, or recreational sport more broadly. The danger lies not in the game itself but in asking an unconditioned cardiovascular system to absorb sudden, maximal physiological stress without preparation. The heart adapts well to demands placed on it steadily and repeatedly. It adapts far less gracefully to demands sprung on it once a week, after six days of stillness. Consistency, not occasional intensity, is what ultimately protects it.

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