Harvard Neuroscientists Explore the Science of Acupuncture

Acupuncture is a traditional Chinese technique that has been used for millennia to treat chronic pain and other health problems associated with inflammation, yet the scientific basis of the technique remains poorly understood.

This article is a repost which originally appeared on SciTechDaily
HARVARD MEDICAL SCHOOL - NOVEMBER 2, 2021
Edited for content and readability - Images sourced from Pexels 
DOI: 10.1038/s41586-021-04001-4

Now, a team of researchers led by neuroscientists at Harvard Medical School has elucidated the underlying neuroanatomy of acupuncture that activates a specific signaling pathway.

In a study conducted in mice and published October 13, 2021, in Nature, the team identified a subset of neurons that must be present for acupuncture to trigger an anti-inflammatory response via this signaling pathway.

The scientists determined that these neurons occur only in a specific area of the hindlimb region—thus explaining why acupuncture in the hindlimb works, while acupuncture in the abdomen does not.

“This study touches on one of the most fundamental questions in the acupuncture field: What is the neuroanatomical basis for body region, or acupoint, selectivity?” said lead investigator Qiufu Ma, HMS professor of neurobiology at Dana-Farber Cancer Institute.

One area of particular interest to the research team is the so-called cytokine storm—the rapid release of large quantities of cytokines that frequently drives severe, systemic inflammation, and can be triggered by many things, including COVID-19, cancer treatment, or sepsis.

“This exuberant immune response is a major medical problem with a very high fatality rate of 15 percent to 30 percent,” Ma said. Even so, drugs to treat cytokine storm are lacking. (https://mojokc.com/)

Adapting an ancient technique to treat aberrant inflammation

In recent decades, acupuncture has been increasingly embraced in Western medicine as a potential treatment for inflammation.

In this technique, acupoints on the body’s surface are mechanically stimulated, triggering nerve signaling that affects the function of other parts of the body, including organs.

In a 2014 study, researchers reported that electroacupuncture, a modern version of traditional acupuncture that uses electrical stimulation, could reduce cytokine storm in mice by activating the vagal-adrenal axis—a pathway wherein the vagus nerve signals the adrenal glands to release dopamine.

In a study published in 2020, Ma and his team discovered that this electroacupuncture effect was region specific: It was effective when given in the hindlimb region, but did not have an effect when administered in the abdominal region. The team hypothesized that there may be sensory neurons unique to the hindlimb region responsible for this difference in response.

In their new study, the researchers conducted a series of experiments in mice to investigate this hypothesis. First, they identified a small subset of sensory neurons marked by expression of the PROKR2Cre receptor. They determined that these neurons were three to four times more numerous in the deep fascia tissue of the hindlimb than in the fascia of the abdomen.

Then the team created mice that were missing these sensory neurons. They found that electroacupuncture in the hindlimb did not activate the vagal-adrenal axis in these mice. In another experiment, the team used light-based stimulation to directly target these sensory neurons in the deep fascia of the hindlimb.

This stimulation activated the vagal-adrenal axis in a manner similar to electroacupuncture. “Basically, the activation of these neurons is both necessary and sufficient to activate this vagal-adrenal axis,” Ma said.

In a final experiment, the scientists explored the distribution of the neurons in the hindlimb. They discovered that there are considerably more neurons in the anterior muscles of the hindlimb than in the posterior muscles, resulting in a stronger response to electroacupuncture in the anterior region.

“Based on this nerve fiber distribution, we can almost precisely predict where electrical stimulation will be effective and where it will not be effective,” Ma explained.

Together, these results provide “the first concrete, neuroanatomic explanation for acupoint selectivity and specificity,” Ma added. “They tell us the acupuncture parameters, so where to go, how deep to go, how strong the intensity should be.”

He noted that while the study was done in mice, the basic organization of neurons is likely evolutionarily conserved across mammals, including humans.

However, an important next step will be clinical testing of electroacupuncture in humans with inflammation caused by real-world infections such as COVID-19. Ma is also interested in exploring other signaling pathways that could be stimulated by acupuncture to treat conditions that cause excessive inflammation.

“We have a lot of tough chronic diseases that still need better treatments,” he said, such as inflammatory bowel syndrome and arthritis. Another area of need, he added, is excessive immune reactions that can be a side effect of cancer immunotherapy.

Ma hopes that his research will ultimately advance scientific understanding of acupuncture and provide practical information that can be used to improve and refine the technique.

Testosterone Levels: Can Specific Foods or Diets Boost Them?

Can Specific Foods or Diets Boost Your Testosterone Levels?

What you eat or drink may affect levels of the male sex hormone, but whether a diet can increase libido or energy depends on many things.

By Randi Hutter Epstein, M.D.

Nov. 2, 2021 Updated 12:15 p.m. ET

This article is a repost which originally appeared on The New York Times

Edited for content.

Can I increase my testosterone levels through the foods I eat? And if so, which foods or diets work best?

Many men, particularly as they age, are concerned about their levels of testosterone, the male sex hormone touted to build muscle, sex drive and vigor. But individual foods are unlikely to have an impact on testosterone levels — though drinking excessive amounts of alcohol might. If you are overweight, altering your diet to lose weight may help, since carrying excess pounds is a common cause of low testosterone. But in terms of specific foods or diets, any uptick you achieve may not have a noticeable impact on libido, energy or muscle mass.

“If someone was not overweight, I wouldn’t put them on a specific diet to raise testosterone based on the data we have now,” said Alexander Pastuszak, an assistant professor of urology and surgery at the University of Utah in Salt Lake City, who co-authored a review on alternatives to testosterone therapy.

In men, normal testosterone levels range from 300 to 1,000 nanograms per deciliter of blood. Ups and downs within that normal range are unlikely to have any impact on sex drive or vitality. Only when levels consistently drop below 300 points — as confirmed in two blood tests by an accredited laboratory — are symptoms like low libido, erectile dysfunction, fatigue, low mood or loss of muscle mass likely to appear, a medical condition known as hypogonadism.

Starting at around age 40, men’s testosterone levels start to decline by about 1 percent per year. But the drop can vary tremendously, with some older men maintaining levels similar to healthy young men. The trajectory of falling testosterone is steeper among men who gain a lot of weight, said Dr. Shalender Bhasin, professor of medicine at Harvard and the director of the Research Program in Men’s Health: Aging and Metabolism at Brigham and Women’s Hospital.

Studies on foods or diets and testosterone levels have generally been small and the findings far from conclusive. A recent British review that pooled data from 206 volunteers, for example, found that men on low-fat diets had testosterone levels that were about 60 points higher, on average, than men on high-fat diets. Men who followed a vegetarian diet tended to have the lowest levels of testosterone, about 150 points lower, on average, than those following a high-fat, meat-based diet. Still, Joseph Whittaker, the lead investigator and a nutritionist at the University of Worcester in Britain, said he would not recommend a man increase the fats in his diet unless he had low testosterone levels and symptoms of low T and was already restricting fats.

Another study in the Journal of Strength and Conditioning Research tested two styles of diets in 25 fit men between the ages of 18 and 30. Calories consumed were the same, but one group ate a high-fat, very-low-carb, ketogenic-style diet, consisting of 75 percent of calories from fats, 5 percent from carbohydrates and 20 percent from protein. Men in the other group ate a more traditional Western style, low-fat diet, containing 25 percent of calories from fats, 55 percent from carbohydrates and 20 percent from protein. After 10 weeks of eating the high-fat diet, testosterone increased by 118 points, on average, while after the low-fat diet, levels declined by about 36 points

Similarly, a study of 3,000 men found that those who reported eating a low-fat diet had slightly lower testosterone levels — about 30 points lower — than men who ate higher-fat diets. But none of the men had low testosterone.

“The moral is that healthy men who are of normal weight with no significant comorbidities are unlikely to benefit from restrictive diets,” said Dr. Richard J. Fantus, one of the study’s authors and a urologist at NorthShore University HealthSystem in Evanston, Ill.

Diet studies are complicated, because changing one component of the diet, such as fat intake, alters so many other things, such as the amount of carbohydrates, protein and micronutrients consumed. It’s unclear which component of the diet may have prompted the hormonal changes, Dr. Bhasin said. Furthermore, testosterone levels may also be shaped by how much a person sleeps, or whether they are jet-lagged, or if they are eating most of their calories at night or in small meals throughout the day.

Dr. Faysal Yafi, chief of the division of Men’s Health and Reconstructive Urology at the University of California, Irvine, says his patients who opt to follow specific diets tend to start exercising more and drinking less alcohol, all of which can raise testosterone levels. He suspects any links between diet and testosterone may be the result of an overall healthier lifestyle.

Some men worry that eating lots of soy foods may cause their testosterone levels to fall, because soy is rich in isoflavones, which mimic the structure of estrogen. But the evidence doesn’t support their concerns, even if men eat foods like miso, tofu or soy milk at every meal. (Doctors did report one anecdotal case in which a 19-year-old man with Type 1 diabetes who followed a vegan diet containing 360 milligrams of soy daily — nine times higher than a typical Japanese diet, and 100 times higher than the typical American diet — developed low testosterone levels along with low libido and fatigue. His symptoms improved when he stopped eating the soy-heavy, vegan diet.)

Long-term alcohol abuse lowers testosterone by damaging cells in both the testes, which make testosterone, and the liver, which alters testosterone metabolism. But binge drinking every now and then does not appear to have much of an impact — it lowers testosterone for only about 30 minutes, according to one study, after which levels bounce back to baseline.

Obese men who have low levels of testosterone can increase levels by cutting calories and losing weight — the type of diet does not matter, studies suggest. On the opposite extreme, Dr. Bhasin said he is seeing an increasing number of men at his clinic who have body dysmorphic issues and are suffering from low libido and fatigue. Strict calorie restriction, exercising intensely and being chronically stressed can all cause testosterone levels to plummet and are likely to blame, he said.

The bottom line is that for otherwise healthy men who are following a reasonably healthy lifestyle, fiddling with specific foods or the composition of the diet is not likely to make much of a difference on the testosterone score card. As Dr. Fantus of NorthShore University put it: “I don’t think there is a way to game the system to get really large increases by changing the diet.”