New research suggests that walking about five miles a week may help slow the progression of cognitive illness among seniors already suffering from mild forms of cognitive impairment or Alzheimer's disease.
In fact, even healthy people who do not as yet show any signs of cognitive decline may help stave off brain illness by engaging in a similar level of physical activity, the study team noted.
An estimated 2.4 million to 5.4 million people in the United States are believed to have Alzheimer's disease, which causes a devastating, irreversible decline in memory and reasoning, according to the National Institute on Aging.
The researchers presented the findings at a meeting of the Radiological Society of North America (RSNA).
"Because a cure for Alzheimer's is not yet a reality, we hope to find ways of alleviating disease progression or symptoms in people who are already cognitively impaired," lead author Cyrus Raji, MD, PhD, of the department of radiology at the University of Pittsburgh, said in a RSNA news release.
Details of the Study
"We found that walking five miles per week protects the brain structure over 10 years in people with Alzheimer's and MCI, especially in areas of the brain's key memory and learning centers," Dr. Raji said. "We also found that these people had a slower decline in memory loss over five years."
To assess the impact that physical exercise might have on Alzheimer's progression (as well as that of less severe brain illnesses), the researchers analyzed data from an ongoing 20year study that gauged weekly walking patterns among 426 adults.
Among the participants, 127 were diagnosed as cognitively impaired-83 with mild cognitive impairment (MCT), and 44 with Alzheimer's. About half of all cases of MCI eventually progress to Alzheimer's. The rest were deemed cognitively healthy, with an overall average age of between 78 and 81.
A decade into the study, all the patients had 3-D MRI scans to assess brain volume. In addition, the team administered a test called the mini-mental state exam (MMSE) to pinpoint cognitive decline over a five-year period.
After accounting for age, gender, body-fat composition, head size and education, Dr. Raji and his colleagues determined that the more an individual engaged in physical activity, the larger his or her brain volume. Greater brain volume, they noted, is a sign of a lower degree of brain cell death as well as general brain health.
In addition, walking about five miles a week appeared to protect against further cognitive decline (while maintaining brain volume) among those participants already suffering from some form of cognitive impairment.
This indication was bolstered by the mini-mental state exam results, which revealed that cognitively impaired patients who met the walking threshold experienced only a one-point drop in cognition scores over a five-year period. By contrast, those who didn't walk experienced an average decline of five points.
Physical activity had a similar impact on the protection of cognitive abilities in healthy adults, although their exercise threshold was deemed to be about six miles per week of walking.
"Alzheimer's is a devastating illness and, unfortunately, walking is not a cure," Dr. Raji said. "But walking can improve your brain's resistance to the disease and reduce memory loss over time."
Robert Friedland, MD, chairman of the neurology department at the University of Louisville's School of Medicine in Kentucky, expressed little surprise at the findings, but cautioned against inferring a direct cause-and-effect link between walking and protection against cognitive decline.
"In an observational study like this, undoubtedly people who are developing cognitive disease or are likely to be in the early stages are also likely to become less active," he noted. "So, it's not possible to be sure that they're observing a direct effect of walking on the disease, because diminished walking in the group that is progressing more rapidly could have been a direct result of the disease itself.
"But that's not to say that I don't think walking is a good idea," Dr. Friedland added. "Many people, including my group, have shown that physical as well as mental activity may be protective against developing disease during midlife-that is, between [ages] 20 and 60. And I'm sure that this is also true in later life.
"And there are many reasons why. Physical activity improves blood flow to the brain, and it changes neurotransmitters and improves cardiac function," he said. "It lessens the risk of obesity, improves insulin resistance and lowers the risk of diabetes, and lowers your blood pressure. And all of these things are risk factors for Alzheimer's disease.
"So, I would say that everyone at all ages should be encouraged to get as much physical exercise as they can tolerate," Dr. Friedland concluded. "Of course, we don't want people to exercise excessively if they have heart disease, for example. But with a physician's advice and supervision, walking is an excellent form of activity."
Since the research was presented at a medical meeting, the data and conclusions should be seen as preliminary until published in a peer-reviewed journal.
Utafiti mpya unaonyesha kwamba kutembea umbali wa maili tano kwa wiki kunaweza kusaidia kupunguza maendeleo ya ugonjwa wa utambuzi miongoni mwa wazee ambao tayari wanateseka kutokana na aina ndogo za ulemavu wa utambuzi au ugonjwa wa Alzheimer. Hata watu wenye afya ambao hawaonyeshi dalili za kupungua kwa uwezo wa kutambua mambo wanaweza kuzuia magonjwa ya ubongo kwa kufanya mazoezi ya mwili. Takriban watu milioni 2.4 hadi 5.4 nchini Marekani wana ugonjwa wa Alzheimer, ambao husababisha kupungua kwa kumbukumbu na kufikiri, kulingana na Taasisi ya Kitaifa ya Kuzeeka. Watafiti hao walitoa matokeo hayo kwenye mkutano wa Shirika la Radiolojia la Amerika Kaskazini (RSNA). "Kwa sababu tiba ya ugonjwa wa Alzheimer bado haijaonekana, tunatumaini kupata njia za kupunguza maendeleo ya ugonjwa au dalili katika watu ambao tayari wana matatizo ya utambuzi, ""mwandishi mkuu Cyrus Rajie, MD, PhD, wa idara ya radiolojia katika Chuo Kikuu cha Pittsburgh, alisema katika taarifa ya RSNA." "Tunaona kwamba kutembea maili tano kwa wiki hulinda muundo wa ubongo kwa zaidi ya miaka 10 kwa watu wenye ugonjwa wa Alzheimer na MCI, hasa katika maeneo ya kumbukumbu muhimu ya ubongo na vituo vya kujifunza, ""alisema Dk Raji." "Tulikuta pia kwamba watu hao walikuwa na kupungua kwa polepole kwa kupoteza kumbukumbu kwa muda wa miaka mitano". Ili kuchunguza athari za mazoezi ya mwili kwenye maendeleo ya ugonjwa wa Alzheimer, watafiti walichanganua data kutoka kwa utafiti wa miaka 20 unaoendelea ambao ulipima mifumo ya kutembea ya kila wiki kati ya watu wazima 426. Kati ya washiriki, 127 walipatikana na matatizo ya utambuzi, 83 walikuwa na matatizo ya utambuzi ya kiasi kidogo (MCD), na 44 walikuwa na ugonjwa wa Alzheimer. Karibu nusu ya visa vyote vya MCI hatimaye huendelea kuwa ugonjwa wa Alzheimer. Wengine waliathiriwa kuwa na afya nzuri ya akili na umri wa wastani wa miaka 78-81. Baada ya miaka kumi ya utafiti huo, wagonjwa wote walifanyiwa uchunguzi wa MRI ya 3D ili kutathmini kiasi cha ubongo. Kwa kuongezea, timu hiyo ilifanya mtihani unaoitwa Mini-Mental State Exam (MMSE) ili kugundua kupungua kwa utambuzi kwa kipindi cha miaka mitano. Baada ya kuzingatia umri, jinsia, uzito wa mwili, ukubwa wa kichwa na elimu, Dk Raji na wenzake waliamua kwamba mtu anapofanya mazoezi zaidi, kiasi cha ubongo wake kinakuwa kikubwa zaidi. Uwezo mkubwa wa ubongo ni ishara ya kiwango cha chini cha kifo cha seli za ubongo na afya ya jumla ya ubongo. Kwa kuongezea, kutembea maili tano kwa wiki ilionekana kulinda dhidi ya kupungua kwa utambuzi (wakati wa kudumisha kiasi cha ubongo) kati ya washiriki ambao tayari wanateseka kutokana na aina fulani ya kasoro ya utambuzi. Matokeo ya uchunguzi wa hali ya akili ya mini yalionyesha kuwa wagonjwa wenye ulemavu wa utambuzi ambao walifikia kizingiti cha kutembea walipata kupungua kwa pointi moja tu katika alama za utambuzi kwa kipindi cha miaka mitano. Kwa kulinganisha, wale ambao hawakufanya mazoezi ya kutembea walipata kupungua kwa wastani wa alama tano. Utendaji wa kimwili ulikuwa na athari sawa kwa ulinzi wa uwezo wa utambuzi katika watu wazima wenye afya, ingawa kizingiti cha mazoezi yao kilionwa kuwa karibu maili sita kwa wiki ya kutembea. "Ugonjwa wa Alzheimer ni ugonjwa wenye kuangamiza na, kwa kusikitisha, kutembea si tiba", Dakt. Raji akasema. "Lakini kutembea kunaweza kuboresha uwezo wa ubongo wako wa kukabiliana na ugonjwa huo na kupunguza upungufu wa kumbukumbu baada ya muda". Robert Friedland, MD, mwenyekiti wa idara ya neva katika Chuo Kikuu cha Louisville, Kentucky, alisema kuwa haishangazi sana matokeo hayo, lakini alionya dhidi ya kugundua uhusiano wa moja kwa moja kati ya kutembea na ulinzi dhidi ya kupungua kwa utambuzi. "Katika utafiti wa uchunguzi kama huu, bila shaka watu ambao wana ugonjwa wa utambuzi au wana uwezekano wa kuwa katika hatua za mapema pia wana uwezekano wa kuwa na shughuli kidogo, ""alibainisha." "Kwa hiyo, haiwezekani kuwa na uhakika kwamba wanaona athari ya moja kwa moja ya kutembea juu ya ugonjwa, kwa sababu kupungua kwa kutembea katika kundi ambalo linaendelea kwa kasi zaidi inaweza kuwa matokeo ya moja kwa moja ya ugonjwa wenyewe. """ "Lakini hilo halimaanishi kwamba sidhani kwamba kutembea ni wazo zuri", akaongeza Dakt. Friedland. "Watu wengi, kutia ndani kikundi changu, wameonyesha kwamba utendaji wa kimwili na pia wa kiakili waweza kulinda dhidi ya kupatwa na ugonjwa wakati wa umri wa kati - yaani, kati ya [miaka] 20 na 60.""" Na nina hakika kwamba hilo ni kweli pia katika maisha ya baadaye. "Na kuna sababu nyingi za kufanya hivyo. "Kazi ya mwili hupunguza mtiririko wa damu kwenye ubongo, na inabadilisha neurotransmitters na kuboresha utendaji wa moyo,"" alisema." "Huondoa hatari ya kuwa mnene kupita kiasi, hupunguza upinzani wa insulini, hupunguza hatari ya kupatwa na ugonjwa wa kisukari, na hupunguza shinikizo la damu. Vitu hivi vyote ni sababu za hatari ya ugonjwa wa Alzheimer. "Kwa hiyo, ningesema kwamba kila mtu wa umri wowote anapaswa kutiwa moyo afanye mazoezi mengi ya kimwili kadiri awezavyo kuvumilia", Dakt. Friedland akafikia mkataa. "Bila shaka, hatutaki watu wafanye mazoezi kupita kiasi ikiwa wana ugonjwa wa moyo, kwa mfano. Lakini kwa ushauri na uangalizi wa daktari, kutembea ni aina bora ya utendaji." Kwa kuwa utafiti huo ulionyeshwa kwenye mkutano wa kitiba, data na hitimisho zinapaswa kuonekana kama za awali hadi kuchapishwa katika jarida la ukaguzi wa wenzao.