When was the last time you measured your waistline? If you assume that BMI is the only number to focus on when it comes to your health, think twice. New research has revealed a shocking revelation—your waist circumference might be a far better predictor of men's cancer risk than BMI.

The study finds that for each 4-inch increase in waist size, a man's risk of cancer increases by a staggering 25%. Meanwhile, BMI, commonly regarded as the gold standard for assessing obesity, raises cancer risk by only 19% for the same weight gain. So, if you've been dismissing that pesky belly fat, it's time to take notice.

But why is your waistline so important? The reason is visceral fat—the hidden, deep fat that accumulates around your organs. Unlike other body fat, visceral fat is a stealthy troublemaker, causing inflammation, insulin resistance, and abnormal blood fat levels—all of which combine to create a cancer-perfect storm.

Obesity has been associated with an increased risk of numerous health conditions, including cancer, for decades. The research, though, indicates that a specific measure of the body—waist circumference—may be an even more reliable forecaster of cancer risk in men than the more frequently employed Body Mass Index (BMI). This finding emphasizes the need to pay particular attention to the distribution of fat and not merely to the weight of the body.

BMI has been the go-to measure for years for gauging health risks related to obesity. New research, though, that appears in The Journal of the National Cancer Institute indicates that waist measurement is a better predictor of cancer risk in men. According to the research, four more inches (10 cm) around the waist will add 25% to a man's cancer risk. Conversely, a 3.7 kg/m² rise in BMI (from a BMI of 24 to 27.7) increased cancer risk by only 19%.

Why is waist circumference a better predictor, then? Unlike BMI, which measures weight relative to height, waist circumference actually measures abdominal fat—specifically, visceral fat. This type of fat encircles internal organs and is also linked to higher levels of inflammation, insulin resistance, and abnormal blood lipids, all of which are factors in cancer growth. BMI, however, does not measure fat distribution, so two individuals with the same BMI can have very different levels of health risk depending on where fat is deposited on their bodies.

Why Men Are at Higher Risk?

Interestingly, the research identified a significant difference between men and women when it came to waist circumference and cancer risk. Although waist circumference and BMI were linked with obesity-related cancers in women, the relationship was weaker than for men. An increase of 12 cm (4.7 inches) in waist size or a 4.3 rise in BMI (from 24 to 28.3) raised the cancer risk in women by just 13%—a much lower percentage than for men.

Experts credit this difference to the way that fat is stored in the body. Men are more likely to carry fat around the abdomen, especially as visceral fat, which is more metabolically active and associated with cancer-producing biological alterations. Women, by contrast, store fat in peripheral sites such as the hips and thighs, where it is less likely to drive systemic inflammation and metabolic disturbances.

A possible reason is that men tend to depot fat more in the visceral regions, whereas women tend to carry more subcutaneous and peripheral fat," wrote the researchers. "This may render waist circumference a more robust risk factor for cancer in men and account for why waist circumference provides additional risk information beyond BMI in men but not women."

Cancer Types Most Linked to Abdominal Fat

The research used the International Agency for Research on Cancer (IARC) data to define obesity-related cancers. These cancers are esophageal (adenocarcinoma), gastric (cardia), colorectal, rectal, liver, gallbladder, pancreatic, renal, and thyroid cancers, and multiple myeloma and meningioma. In men, abdominal obesity is especially significant in raising the risk of these cancers through high levels of insulin and markers of inflammation.

For women, the research proposes that both waist circumference and hip circumference may give a more accurate estimate of visceral fat and cancer risk. "Adding hip circumference to risk models could strengthen the link between waist circumference and cancer, especially in women," researchers observed.

What This Means for Men's Health and Cancer Prevention?

With these results, doctors advise men to be more mindful of their waistline than only their BMI. Waist size is an easy method to gauge health risk, and its maintenance through lifestyle changes might be the key to cancer prevention.

How To Reduce Cancer Risk In Men?

Track Your Waist Size: Regularly measure your waist circumference and try to keep it in a healthy range (below 40 inches for men, according to medical advice).

Eat a Balanced Diet: A diet containing high fiber, lean protein, and healthy fats can assist in limiting visceral fat gain.

Exercise Consistently: Regular exercise with a combination of aerobic and strength training will help maintain a healthy waistline.

Control Stress and Sleep: Persistent stress and inadequate sleep tend to cause weight gain, especially in the midsection of the body.

Regular Health Screenings: Early identification of cancer risk factors through regular screening can greatly enhance long-term health status.

As pollution season creeps back in Delhi, N95 masks outdoors and air purifiers are once again most likely to become the primary go-to protective measures for the public.

Both are known to lower exposure to harmful particles significantly, but neither can completely nullify the health risks of polluted air. So before you invest in an air purifier or buy a dozen N95 masks, understand how much you will be protected as you step out during smog everyday.

How Much Protection Does An N95 Mask Offer?

Also read: Delhi Pollution: What Are The Different Types Of Anti-Pollution Masks?

A properly fitted N95 respirator can filter at least 95% of airborne particles under standard environment. That makes it substantially more protective against fine particulate matter like PM2.5 than regular surgical or cloth masks.

But just wearing an N95 does not mean you are breathing toxins-free air. Its effectiveness depends heavily on fit. Gaps around the nose, cheeks or chin can let polluted air to bypass the filter.

An N95 also does not protect equally against every pollutant. It is designed primarily to filter particles, not gases like nitrogen dioxide or ozone. So if you spend most of your time outdoors during severe pollution, wear a well-fitted, certified respirator to reduce exposure.

Protection from PM2.5 is key as these particles are small enough to seep deep into your lungs and, in some circumstances, even cross over to enter the bloodstream. Long-term exposure to PM2.5 has been associated with cardiovascular disease, respiratory disease and other serious health problems.

Is An Indoor Air Purifier Enough To Tackle Outdoor Pollution?

The effectiveness of an air purifier depends significantly on the purifier, the size of the room and how it is used. A purifier equipped with a HEPA filter can remove fine particles from indoor air. When outdoor PM2.5 levels are high and polluted air enters homes through windows, doors and ventilation systems, this could be one of the best ways to protect yourself.

However, simply switching on a purifier in a large room does not guarantee clean air. The purifier needs to have sufficient clean air delivery rate (CADR) for the size of the room.

Keeping doors and windows closed during periods of extreme outdoor pollution can also help reduce the amount of polluted air entering. Filters need to be replaced according to the manufacturer's recommendations because a heavily loaded filter can reduce performance.

Also read: Delhi Air Pollution Is Back: What Days Of Poor AQI Can Do to Your Lungs

One of the limitations is that HEPA filtration primarily addresses particles. A purifier needs additional technologies, like an activated-carbon filter, to reduce some gaseous pollutants, and even then it cannot remove every pollutant completely.

For Delhi's pollution season, these two measures address different exposure issues. N95 masks help reduce inhalation of polluted particles while outdoors. Air purifiers help lower indoor concentrations of particulate matter. Using both can therefore provide greater protection than relying on either measure alone.

People with asthma, COPD, heart disease or other respiratory and cardiovascular conditions, as well as children and older adults, can be more vulnerable to the effects of air pollution.

Even healthy people can experience symptoms like coughing, throat irritation, wheezing, eye irritation and breathing discomfort when pollution levels rise.

Dry eyes are common among people who spend long hours on screens, and lubricating eye drops are often used for relief. But using the wrong drops, keeping an opened bottle for too long or even sharing eye drops can create problems.

Estimates suggest that up to 50% of adults experience dry-eye symptoms, making artificial tears a common part of self-care. But persistent symptoms should not simply be treated indefinitely without identifying the underlying cause.

So, how often can you use eye drops, and what should you keep in mind?

We spoke to Dr. Ritika Sachdev, Director at Centre for Sight, New Delhi, to understand the common mistakes people make while using eye drops.

Eye Drops For Dry Eyes: When Should You See A Doctor?

Dr. Ritika said persistent or bothersome dry eye symptoms should be assessed by a doctor because dryness can have several causes.

These may include:

• Eyelid inflammation
• Allergies
• Contact lens use
• Makeup
• Incorrect spectacle power causing eye strain

“Sometimes even not wearing your right spectacle power contributes to eye strain which can be misread as dry eye,” she said.

Lubricating drops can help support dry eyes, but prolonged use should be discussed with an eye specialist.

Using Eye Drops For Long? Check For Preservatives

Also read: Eye Drop Recall: Nearly 750,000 Products Pulled Over Sterility Concerns in US

Several eye-drop products have been recalled in the US in recent years over contamination and other safety concerns. This makes proper storage, handling and hygiene particularly important when using eye drops.

Dr. Ritika cautioned that some eye drops contain preservatives that may worsen dryness when used for a long time.

“Many of the eye drops have preservatives which if used over a long period of time actually cause more dry eye,” she said.

According to her, preservative-free drops or those with very mild preservatives may be preferable for people who need regular use.

Don't Keep An Open Eye Drop Bottle Forever

"Once opened, an eye drop bottle can become contaminated if it is not handled or stored properly," Dr. Ritika said.

The expert advised:

• Note the date when you open the bottle.
• Follow the product's storage instructions.
• Do not let the bottle tip touch your eye.
• Discard the bottle according to the manufacturer's instructions.
• Do not continue using an opened bottle indefinitely.

“Once the bottle is open, it often may get contaminated,” she said. “If it gets contaminated, it is a source of infection.”

Read More: Andrew Huberman’s Sleep Trick: Can Eye Movements Help You Fall Back Asleep?

How Many Eye Drops Should You Use?

More drops do not mean more relief.

“The capacity of the eye is only one drop,” Dr. Ritika said.

Putting two or three drops at once can cause the excess to spill onto the surrounding skin and simply waste the product. One properly administered drop is generally enough at a time, she said.

Avoid Squeezing Your Eyes After Using Drops

Dr. Ritika said people often squeeze their eyes tightly after putting in drops because they think this will keep the medicine inside. But squeezing can push the drop back out.

Instead:

• Gently pull down the lower eyelid.
• Place the drop into the eye.
• Avoid touching the bottle tip to the eye.
• Do not squeeze the eyes tightly immediately afterward.

Why Do Eye Drops Sometimes Reach The Throat?

Some people experience an unpleasant sensation in the throat after using medicated eye drops.

Dr. Ritika explained that tears can travel from the eye through the tear duct to the nose and then the throat.

She suggested gently pressing near the inner corner of the eye for a while after applying the drop to reduce this drainage.

Never Share Your Eye Drops

Sharing eye drops may seem harmless, particularly within families, but Dr. Ritika advised against it.

If the bottle tip accidentally touches an infected eye, the bottle can become contaminated and potentially transmit infection when used by someone else.

“Eye drop is something that is for your personal hygiene and it should therefore be kept by you and used by you,” she said.

Clear vision does not always mean that the eyes are healthy. Diabetes can damage the retina the sensitive layer at the back of the eye long before a person notices any change in eyesight.

This happens because high blood sugar can weaken the blood vessels that supply the retina causing them to leak fluid or blood.

What happens as retinopathy progresses?

Diabetic retinopathy is a complication in which high blood sugar damages the blood vessels. In the stages these vessels may swell or develop small areas of bleeding without affecting vision.

As the condition advances, reduced blood supply can cause abnormal new blood vessels to grow. These vessels are fragile. May bleed into the vitreous the clear gel inside the eye. In some cases, scar tissue can pull the retina away from its normal position leading to retinal detachment and potentially permanent vision loss.

Also read: Eye Drop Recall: Nearly 750,000 Products Pulled Over Sterility Concerns in US

How diabetes affects central vision

Diabetes can also affect the macula, the part of the retina responsible for sharp detailed vision. When fluid builds up in this area it can cause macular oedema and gradually affect the quality of vision.

It may lead to:

• Distorted central vision
• Difficulty reading or recognising faces
• Problems with activities that require clear detailed vision, such as driving

Diabetic macular oedema can occur at different stages of diabetic retinopathy and does not always cause symptoms in the early stages.

Also read: Eye Twitching: Is It Just Stress Or Something Serious?

Who is at risk?

The likelihood of eye damage increases with the duration of diabetes and poor blood sugar control. High blood pressure, abnormal cholesterol levels and kidney disease can further increase the risk.

Women with diabetes may also need monitoring during pregnancy as hormonal and blood sugar changes can worsen existing retinal disease.

Why regular eye examinations matter

On World Sight Day, doctors recommend that a routine eyesight test may not detect damage to the retina. People with diabetes should therefore undergo an eye examination, including a dilated retinal examination at intervals recommended by their ophthalmologist.

Keeping blood sugar, blood pressure and cholesterol, under control can help reduce the risk of complications. If damage is detected treatment may include eye injections, laser therapy or surgery depending on its severity.

Diabetic eye disease can often be managed effectively when identified early. Regular retinal examinations remain important when a person can see clearly as changes may develop before symptoms appear.

By Dr Ashu Agarwal, Senior Consultant, Opthalmology, Indraprastha Apollo Hospital, Delhi