Dear Doctors: I stopped eating sugar while I was losing weight last spring and summer. When holiday sweets started showing up at the office and at parties, I really indulged. I noticed that hip pain from rheumatoid arthritis, which stopped while I was dieting, came back again. Did the sugar do this?

Dear Reader: For a few decades now, studies have identified added sugars in the diet as a contributing factor to a range of adverse health conditions. These include Type 2 diabetes, increased body fat percentage, obesity, cardiovascular disease and metabolic syndrome.

More recently, as researchers have widened their focus, a number of studies have drawn a connection between added sugar in the diet and an increased risk of developing chronic low-grade inflammation. Although inflammation is often understood to be a bad thing, the key word in that previous sentence is “chronic.”

Low-grade inflammation is actually an important tool the immune system uses to fend off potential threats. When things are working properly, immune cells known as inflammatory macrophages get alerted to a problem. They arrive at the site, perform needed maintenance and, when their work is done, recede. The departure of the macrophages ends that particular episode of inflammation. But sometimes the immune system malfunctions. The macrophages don’t retreat, which means that the low-grade inflammation persists. This leads to gradual and ongoing damage to the body’s own tissues.

Chronic low-grade inflammation is known to play a role in a wide range of autoimmune diseases. This includes rheumatoid arthritis, or RA, the condition your mention in your letter. RA is a chronic inflammatory disorder that can affect not only the joints in the body, but also the internal organs. Unlike osteoarthritis, in which physical wear and tear gradually erodes the tissues of the joints, the damage in RA occurs due to chronic low-grade inflammation. It’s a mistaken response by the immune system, which has gone off-message and begun to attack the body’s own tissues.

The link between excessive sugar intake and inflammation is pretty straightforward. It involves cytokines, which are proteins that modulate inflammation. There are pro-inflammatory cytokines, which trigger an immune response, and anti-inflammatory cytokines, which ease the attack. Research shows that when the diet gets loaded up with added sugars, pro-inflammatory cytokines are released. They act as messengers, summoning and urging on the immune cells needed to deflect an invader. The result is inflammation and its accompanying physical symptoms. That includes the pain, swelling, stiffness and sensation of heat that are part of RA.

Based on the sequence of events you described, it’s possible the sudden and significant increase in sugar may have played a role in the RA flare. When you have RA, your levels of pro-inflammatory cytokines are already high. You went from removing a potential source of inflammation during the months you cut sugar from your diet to suddenly adding it in high amounts.

With the holidays are over, it would be wise to return to an anti-inflammatory diet. You don’t have to cut out sugar completely, but do prioritize your intake, and choose wisely.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10960 Wilshire Blvd., Suite 1955, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctors: I faceplanted while ice skating and got a big bruise on my chest. The skin on that part of my breast got puckered up, and my mom kind of freaked. She says it can be a symptom of breast cancer. Is that true? Should I be worried? The bruise and the puckering are both gone now.

Dear Reader: When someone develops breast cancer, it means that some of the cells within the breast have become abnormal and are growing out of control. This often causes changes in the breast that can be felt or seen. The most common, which many women are familiar with, is a lump or a thickening. It may occur within the breast tissue or in the area of the armpit. Additional symptoms of breast cancer include changes to the appearance of the nipples, discharge from a nipple, an increase in the size of a breast, a sensation of heat within the breast and unexplained pain. And, yes, your mother is correct that certain changes to the surface of the breast can also be an indicator of cancer. This includes skin that becomes dimpled, rippled or puckered.

These changes to the appearance of the breast occur because as the cancer cells multiply, they distort the natural architecture of the breast tissue. The growth of a tumor within the breast may pull at the tissue above it, which can cause the skin to dimple. A tumor growing close to the surface of the breast may cause the skin above it to ripple. A rare form of breast cancer, which occurs in the cells of the milk ducts, can also cause dimpled skin. All of this makes it important for women who do a regular breast self-exam to include a visual assessment of any physical changes.

Another possible cause of puckered or dimpled skin on the breast is something known as a breast hematoma. The word “hematoma” refers to an area where blood has pooled and then clotted. It’s typically due to the presence of broken or damaged blood vessels. This can occur as a result of physical injury, and it can also be a side effect of surgery.

A breast hematoma can form a lump that is palpable below the skin. It can also exert the same type of tugging pressure as a tumor, and thus cause the skin above it to pucker, ripple or become dimpled. However, the lumps formed by breast hematomas are not cancerous.

In most cases, the body’s natural processes will heal the damaged walls of the blood vessels and prevent additional blood from pooling. Meanwhile, certain cells in the immune system will break down and carry away the dead blood cells and other debris.

Just as it takes time for a bruise to vanish, a breast hematoma will often gradually resolve. Because the dimpling on your breast appeared in the area of your injury and disappeared as the bruised area healed, it has the hallmarks of a breast hematoma. But if the dimpling persists, or you are concerned, seek guidance from your health care provider.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10960 Wilshire Blvd., Suite 1955, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctors: I live in Boston, and the news here seems to be fixated on a brand-new COVID-19 variant. Omicron was all everyone talked about for a long time. Does this mean the new variant we are hearing about is worse? What are we supposed to do to protect ourselves?

Dear Reader: You’re referring to XBB.1.5, an offshoot of the omicron variant. Omicron is itself one of the numerous descendants of SARS-CoV-2, the novel coronavirus that launched the COVID-19 pandemic three years ago. The reason you’re hearing so much about this new variant, which is being referred to simply as XBB, is that it has become the dominant strain of the novel coronavirus in your area.

According to the Centers for Disease Control and Prevention, genetic testing suggests that the majority of new cases of COVID-19 in the northeastern U.S. are now caused by XBB. Nationally, XBB has gone from causing fewer than 2% of COVID-19 cases at the end of 2022 to more than one-fourth of all cases at the start of 2023.

As with all viral variants that begin to circulate in great numbers, the success of XBB is due to the presence of certain mutations. In coronavirus variants, mutations include changes to the spike proteins on the outer shell. These structural changes make the variants more successful at slipping past the body’s existing defenses. This includes evading both naturally acquired immunity and immunity conferred by vaccines and boosters.

While XBB has proven to be more contagious than its predecessors, it does not appear to be more dangerous. At this time, there has not been a spike in either hospitalizations or deaths due to XBB infections. However, this will likely change as the variant continues its geographic spread.

What’s particularly worrisome is that XBB has arrived at a time when vaccination rates against COVID-19 have dropped precipitously. Only 15% of those who are eligible have received the newer bivalent vaccine, which was developed with the variants in mind. On top of that, the majority of people in the U.S. have largely stopped taking protective measures, including the use of masks. That, along with indoor living that is necessitated by the cold winter weather, has increased the risk of infection.

And that brings us to your final question, which is how to guard against infection with XBB. The answer is to get back to the basics. It’s crucial to stay up to date with coronavirus vaccines and boosters, which have proven to be effective in protecting against severe illness. We urge anyone who hasn’t yet received the bivalent booster to do so. When spending time in public places, wear a good-quality and well-fitted mask. If you do become sick with COVID-19, see your doctor. Antiviral medications can ease symptoms and shorten the duration of illness. The coronavirus and its variants are with us for the foreseeable future. It’s up to us to remain vigilant and protect ourselves and those around us.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10960 Wilshire Blvd., Suite 1955, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)