But it is hard to perform what scientists call "controlled experiments" in human beings. In a controlled experiment, the scientist can change one and only one factor, such as the amount of a particular chemical, and then measure the effect of that change on some other measurable phenomenon, such as the amount of antibodies produced by a particular type of immune system cell when it is exposed to the chemical. In a living animal, and especially in a human being, that kind of control is just not possible, since there are so many other things happening to the animal or person at the time that measurements are being taken.
Despite these inevitable difficulties in measuring the relationship of stress to immunity, scientists are making progress. Almost every mother has said it: "Wear a jacket or you'll catch a cold! Probably not, exposure to moderate cold temperatures doesn't increase your susceptibility to infection.
There are two reasons why winter is "cold and flu season. Also the influenza virus stays airborne longer when air is cold and less humid. But researchers remain interested in this question in different populations.
Some experiments with mice suggest that cold exposure might reduce the ability to cope with infection. But what about humans? Scientists have performed experiments in which volunteers were briefly dunked in cold water or spent short periods of time naked in subfreezing temperatures.
They've studied people who lived in Antarctica and those on expeditions in the Canadian Rockies. The results have been mixed. For example, researchers documented an increase in upper respiratory infections in competitive cross-country skiers who exercise vigorously in the cold, but whether these infections are due to the cold or other factors — such as the intense exercise or the dryness of the air — is not known.
A group of Canadian researchers that has reviewed hundreds of medical studies on the subject and conducted some of its own research concludes that there's no need to worry about moderate cold exposure — it has no detrimental effect on the human immune system.
Should you bundle up when it's cold outside? The answer is "yes" if you're uncomfortable, or if you're going to be outdoors for an extended period where such problems as frostbite and hypothermia are a risk. But don't worry about immunity. Regular exercise is one of the pillars of healthy living. It improves cardiovascular health, lowers blood pressure, helps control body weight, and protects against a variety of diseases.
But does it help to boost your immune system naturally and keep it healthy? Just like a healthy diet, exercise can contribute to general good health and therefore to a healthy immune system.
As a service to our readers, Harvard Health Publishing provides access to our library of archived content. Please note the date of last review or update on all articles.
No content on this site, regardless of date, should ever be used as a substitute for direct medical advice from your doctor or other qualified clinician. With this Special Health Report, Living Better, Living Longer , you will learn the protective steps doctors recommend for keeping your mind and body fit for an active and rewarding life. Thanks for visiting. Don't miss your FREE gift. Sign up to get tips for living a healthy lifestyle, with ways to fight inflammation and improve cognitive health , plus the latest advances in preventative medicine, diet and exercise , pain relief, blood pressure and cholesterol management, and more.
Get helpful tips and guidance for everything from fighting inflammation to finding the best diets for weight loss Stay on top of latest health news from Harvard Medical School. Recent Blog Articles. Why is topical vitamin C important for skin health? Preventing preeclampsia may be as simple as taking an aspirin.
Caring for an aging parent? Tips for enjoying holiday meals. A conversation about reducing the harms of social media. Menopause and memory: Know the facts. How to get your child to put away toys.
Is a common pain reliever safe during pregnancy? Can vaping help you quit smoking? How to boost your immune system February 15, During sleep, your immune system releases cytokines molecules that recruit other immune cells to the site of an infection and regulate their behavior in order to help combat an infection or inflammation.
Conversely, sleep deprivation can decrease the production of cytokines, as well as T cells and infection-fighting antibodies. What is melatonin? Understanding sleep: An in-depth review. Although not commonly touted for its immune-boosting properties, a growing number of studies find that curcumin can modulate the growth and cellular response of various types of immune cells. For example, studies show that supplementation with curcumin can:. For this reason, looking for an optimized curcumin supplement that circumvents low bioavailability issues is highly recommended.
While nutritional strategies for enhancing immune health are certainly not infallible, the research reviewed here suggests that increasing your intake of immunity-enhancing dietary factors represents a prudent strategy for optimizing immune functioning and overall health. Adaptive immune cells: Highly specialized lymphocytes B cells and T cells that eliminate pathogens or prevent their growth by neutralizing the virus or killing the virus-infected cell.
Antibodies: Specialized proteins produced and secreted by B cells that bind onto antigens in order to protect the body from foreign invaders. B cells: A type of white blood cell that develops in the bone marrow and destroys pathogens by producing and secreting antibodies to specific pathogens. Bioavailability: The proportion of a substance that enters the circulation when introduced into the body and is able to have an active effect.
Cytokine: Proteins and peptides that are secreted by cells and have a specific effect on the interactions and communications between cells. Gene expression: The conversion of genetic information into molecules that carry out the genetic instructions. Innate immune cells: White blood cells designed to prevent infection and eliminate invader pathogens through a number of non-specific mechanisms; includes macrophages, neutrophils, dendritic cells, NK cells, basophils, eosinophils, Langerhans cells, mast cells, and monocytes.
Intestinal epithelium: A dynamic cellular layer that serves as a barrier between the contents of the intestines and the underlying immune system. Macrophage: A type of white blood cell responsible for the detection and destruction of bacteria and other harmful organisms.
Neutrophil: A type of white blood cell that helps heal damaged tissues and resolve infections. NK cells: A type of white blood cell that plays a major role in the host-rejection of virally infected cells.
Pathogenic: Capable of causing disease; usually refers to a virus, bacteria, or other type of germ. Phagocytic: A process wherein a cell typically a macrophage or neutrophil destroys a virus or infected cell by engulfing it and initiating adaptative immune responses. Looking for ways to stay well, while staying at home? Everyone knows about vitamin C, but few understand the important role vitamin D plays in immune system regulation. The immune system encompasses a diverse group of cells that perform important immunity enhancing functions throughout the body Research suggests that omega-3 fatty acids EPA and DHA, vitamin D, probiotics, melatonin, and curcumin can help regulate immune functioning and enhance overall health Increasing your intake of immune-boosting nutrients and dietary factors is a prudent strategy for optimizing your immune health.
She holds a doctorate in Human Development, and has published several research articles on children's cognitive development. Gina enjoys studying and educating others on strategies for optimizing health and wellness throughout the lifespan. Glossary Reference. A yogurt or kefir drink per day might help keep infections at bay. That's because these foods contain probiotics, bacteria that stimulate immunity cells in the gastrointestinal tract. In addition to their protective effect in the GI tract, probiotics also may help stimulate immune-cell production system-wide.
In a recent study of 33 women from the University of Vienna, Austria, those who ate ordinary yogurt daily for two weeks raised their T-lymphocyte cell count by nearly 30 percent.
What to do: Look for yogurt or kefir that contains "live active cultures," indicating helpful bacteria. Along with diet, exercise is key to shedding extra pounds. What to do: "Increase your physical activity from 30 minutes a day to 60 to burn more calories," Fernandes says. In a yearlong study of men and women, researchers from the University of South Carolina found those who exercised moderately were 25 percent less likely to develop a cold compared with those who rarely exercised.
The subjects simply walked at a brisk pace. As with diet, moderation is critical; too much exercise or exercising to the point of exhaustion can boost the body's production of adrenaline and cortisol, two hormones that temporarily suppress immune function. E-mail to a friend. Copyright Cooking Light magazine.
All rights reserved. Stacey Colino is a writer in Chevy Chase, Maryland. Her work has appeared in dozens of national magazines. Story Highlights A balanced diet can help maintain a healthy immune system in flu season If you don't eat enough protein, you'll produce fewer protective white blood cells High-fat diets appear to decrease immune system function Next Article in Health ».
By Stacey Colino. From the Blogs: Controversy, commentary, and debate. Sit tight, we're getting to the good stuff.
0コメント