Dear Doctor: I just read that some parts of the medical community may finally be taking the idea of fecal transplants seriously. What are the latest advances? And what's taking so long?

Dear Reader: We think you may be referring to a study about fecal transplants that made quite a few headlines when the results were published in the New England Journal of Medicine in June. Researchers from Norway assessed the efficacy of various treatments on patients with a dangerous and potentially deadly intestinal infection caused by a type of bacteria called Clostridium difficile, also referred to as C. diff. The bacterium causes symptoms that include frequent diarrhea, high fever, nausea and dehydration that can adversely affect heart rate, blood pressure, kidney function and overall health. In the most severe cases, C. diff causes a type of inflammation of the colon that can lead to death.

In the study, 20 patients with C. diff infections were randomly assigned to either undergo standard treatment with antibiotics or to receive a fecal transplant. For those unfamiliar with the concept, that's the process by which specially prepared stool from a healthy individual is transferred into the colon of the sick person. The idea is that the "good" bacteria from the healthy individual will populate the colon of the patient and vanquish the C. diff bacteria. People who donate stool for a fecal transplant undergo extensive testing be sure no pathogens, such as bacteria, fungi, viruses or parasites, get transferred to the recipient.

Of the nine C. diff. patients in the study who received the fecal transplant, five were cured immediately. Five of the 11 patients who received antibiotics were also cured. In this particular study, fecal transplants were shown to be as effective as antibiotics for the treatment of C. diff. In a time of increasing antibiotic resistance, this is an important development. However, the study, with just 20 patients, is too small to use to draw definitive conclusions. The researchers have announced plans to repeat their work with 200 patients in the near future.

As to why progress in the arena of fecal transplants appears to be slow, we think it's a combination of things. Any new approaches in medicine have to undergo comprehensive testing, studies and clinical trials to be sure that they are safe, and to fine-tune the specifics of treatments, dosage and procedures. Compared to how quickly information gets shared these days, the bench-to-bedside process may appear to move at a glacial pace. It's also true that new ideas can face resistance in the medical community. We're thinking of how, in the early 1980s, the idea that peptic ulcers and gastric cancers were caused by certain bacteria was thought to be ludicrous. Two decades later, though, the Australian doctor who came up with the theory, which was eventually proven to be correct, won the Nobel Prize.

At this time, although fecal transplants are permitted by the FDA, they are to be used only when treatment with antibiotics has failed. This new study, despite its small size, may offer a persuasive argument for more extensive research with an eye toward revisiting treatment priorities.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: I recently saw a TV show in which a physician said sweets cause dementia. Is this true? As a sweet-aholic, I hope not.

Dear Reader: How I used to love sugar as a child. My parents didn't have many sugary foods in the house, so I would gorge on sweets at my friends' houses or when the ice cream man made his rounds. At age 11, however, I began to understand the health consequences of sucrose -- I knew that it increased the risk of diabetes and was directly connected to weight gain. I learned much later about the less tangible dangers -- metabolic changes, heart disease risk and a potential link to cancer.

Many people, however, continue to indulge in sweets well into old age. While some can do so with relative control, others cannot. The problem for everyone is that, as we grow older, our ability to process sugars declines, leading to an increased risk of obesity and diabetes, among other things.

The dementia connection has to do with how our brains receive nutrients and oxygen. While many large blood vessels supply blood flow to the brain, equally important are the small blood vessels that nourish the neurons. Small blood vessels are quite susceptible to injury, especially those caused by high blood pressure and diabetes. That's why people with poorly controlled diabetes are at risk for slow-to-heal ulcerations: The small vessel disease in the lower legs leads to poor blood flow and nerve dysfunction. Similarly, poorly controlled diabetes can also lead to small blood vessel disease in the brain and the death of neurons. Multiple epidemiologic studies have shown a correlation between diabetes and dementia, as have MRI studies in animals.

I'm sorry to add that, even if you're a sweet-aholic who doesn't have diabetes, you may be at risk too. A review of eight studies in Japan assessed the levels of hemoglobin A1c, a marker for diabetes, and the rate of dementia within the general Japanese population. The authors found a concordance between an increased rate of elevated hemoglobin A1c and increased rates of dementia.

Increased memory impairments were even correlated with hemoglobin A1c levels greater than 6, which does not meet the threshold for diabetes. This may be related to increased production of insulin in people with higher intakes of sugar and carbohydrates, which subsequently leads to insulin resistance. Insulin resistance, in turn, may lead to a difficulty in the ability of neurons to transmit information to one another.

Of course, eating sweets also increases the likelihood of obesity, and midlife obesity itself has been correlated with dementia. There are many theories as to why this is the case, including that fat cells secrete brain-damaging inflammatory compounds or that fat cells store dangerous pesticides from the environment. What appears more likely is that obesity increases the risk of hypertension and sleep apnea, both of which increase the risk of dementia.

I understand that sweets bring pleasure and that telling people they shouldn't eat them seems cruel, but when you look at how much damage sweets create in both the body and mind, as a doctor, I find it difficult to condone their consumption. Consider that Native American populations have been ravaged by diabetes and poor health related to sweets, which were never traditionally part of their diet -- and this is a lesson all of us ignore at our peril.

Kicking this addiction will lead to improved physical and mental health and lower your risk for dementia. I know you can do it.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)

Hello again, dear readers, and welcome to late summer! Please indulge us as we remind you (yes, again) to wear sunscreen, use bug sprays, watch for ticks and stay hydrated. We hope the recent columns about the dangers of excessive heat and the warning signs and physical effects of dehydration were of use to you.

-- Speaking of summer, here's an interesting tip from a reader about keeping kids safe in the water. "When swimming and diving, children should be reminded that they have grown taller and weigh more than they did a year ago," she wrote. These physical changes can mean that the spot where they safely dove or jumped into a pool or pond last summer may no longer be deep enough for them this year, she said.

-- Regarding the idea that some senior citizens feel safer taking their daily walks in an enclosed shopping mall, a reader had a different view. "People are more likely to maintain an exercise program if they do their walking in neighborhoods and parks, where the environment is pleasant, and the scenery is nice," he wrote. "A shopping mall is anything but pleasant and nice. By walking in neighborhoods and parks (progressive cities even provide special walking trails), people can exercise their bodies and their aesthetic sense at the same time."

-- After reading the column about sushi lovers who wound up with intestinal tapeworms after eating raw salmon, a reader in Gastonia, North Carolina, wondered about the safety of the canned salmon that's a regular lunch staple. The good news is that canned salmon is fully cooked and thus is not a risk for tapeworm.

-- A reader from Fresno, California, who suffers from fibromyalgia wrote to ask whether we know of any clinical trials that she could take part in. The best resource for identifying a clinical trial, which is a rigorously controlled study to evaluate a new medical, surgical or behavioral intervention, is the website clinicaltrials.gov. It's a database that contains both privately and publicly funded clinical studies that are being conducted throughout the world. Fill in the simple form on the home page, press enter, and you'll get a list of relevant research.

-- We recently cited a study that evaluated changes to muscle mass in obese adults in their 60s who were dieting to lose weight. It's an important topic because maintaining lean muscle mass is tied to healthy aging. The results of the study were surprising and, it seems, counterintuitive, and we got quite a few letters. We're happy to repeat (and confirm) the results.

In this study, participants who dieted and did aerobic walking lost more muscle mass than did those who dieted and did no exercise. The group that dieted and lifted weights lost the least muscle mass. Specifically, muscle mass accounted for 20 percent of weight lost in the walking group, 16 percent in the dieting alone group, and 10 percent of weight lost by the weight lifters. Total fat loss was significantly greater among those who combined exercise with diet than in those who only dieted. Dieters who are concerned about maintaining muscle mass may consider adding resistance training to their exercise routine.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)