New Under the Sun:
Volume 3, Issue 4
that April with his showres soote
Chaucer, The Canterbury Tales
It’s April. Flowers are blooming. Life is bursting forth. This is a good month to “spring clean” outmoded, unhealthy behaviors and organize for a happier, healthier life.
Breast Feeding and SIDS: Sudden Infant Death Syndrome or SIDS is a major fear among parents of young infants living in the US. SIDS is a form of sleep apnea: the infant is difficult to arouse and quits breathing. The incidence of SIDS is highest during the first six months of life, with a peak during the second and third months. SIDS rates have been reduced by eliminating two factors: sleeping on the stomach and parental, particularly maternal, smoking. However, even in the absence of those two factors, SIDS continues to occur in the US at higher rates than in non-western, more traditional cultures. Researchers decided to determine whether there was a difference in arousability between infants who are breastfed versus those who are bottle-fed. For 43 healthy infants aged two to three months, the researchers found no difference in arousability during quiet sleep periods, but did find a difference during active sleep periods. Breastfed infants were significantly more arousable during active sleep than was true of those infants receiving bottle feeding. The conclusion is that breast feeding may be another factor that will help prevent SIDS. Horne RS, Parslow PM, Ferens D, Watts AM, Adamson TM. Comparison of evoked arousability in breast and formula fed infants. Arch Dis Child. 2004; 89(1):22-5.
Comment: Anthropological research has shown that traditional cultures tend to have extremely low rates of SIDS. Breast feeding probably does play a role in this difference. However, another major factor which does not get enough attention is that infants in these cultures are never left alone. Someone is always carrying or playing with them. And the infant sleeps with the mother at night. This not only facilitates breast feeding, but ensures that the infant will be constantly exposed to movements and noises which encourage arousability. An infant in these cultures is never placed in a separate bed in a separate room that is kept unnaturally quiet.
Vitamin A and Hip Fractures: Yes, you can get too much of a good thing. Vitamin A is necessary for good health, but it is one vitamin on which one can easily overdose. Because it is fat soluble, like vitamin D, it can remain in tissues for a long time. Researchers conducted a longitudinal study of women, supplements, and fracture risk. They found that women using supplements with the currently high levels of vitamin A had a higher risk of hip fractures than those who did not use any supplements. They concluded that the amount of vitamin A in supplements needs to be reduced. This is in accord with the USDA which recently lowered the daily recommended intake of vitamin A. The researchers suggested that instead of taking a multi-vitamin supplement, it would be better if older individuals who were worried about hip fractures made sure they ate nutritiously and did weight-bearing exercise (such as walking) each day. Lionel S. Lim, et al. 2004: Poster 4 presented at annual meeting of the American College of Preventive Medicine (ACPM).
Comment: It probably seems somewhat counter-intuitive that taking a multi-vitamin would increase the risk of hip fracture since, as readers of AnthroHealth know, supplements are one way to obtain vitamin D, which helps prevent bone fractures. The answer is that other research has shown that the ratio of vitamin A to vitamin D is quite important. Too much vitamin A inhibits the effectiveness of vitamin D. The current ratio of A to D in multi-vitamins is very unbalanced: A is far too high and D far too low. This is why AnthroHealth continually recommends a supplement of cholecalciferol (vitamin D3) of at least 1000 IU/day unbound to anything else, particularly vitamin A, but also calcium. And we agree with Lim et al. that a healthy diet and daily walk are also necessary to maintaining good bone health.
Music, Exercise, and Cognitive Ability: Despite conflicting evidence, large numbers of parents swear by the Mozart Effect: that playing classical music to their infants will improve the infant’s IQ. The research described in this section was a pilot study to test whether classical music and exercise would improve the cognitive abilities of those infants’ grandparents. Cardiovascular disease is a risk factor in vascular dementia. Other research has shown that exercise can improve cognitive functioning. The researchers in this study wanted to test whether listening to classical music (in this case Vivaldi’s Four Seasons) while exercising resulted in even more improvements. To test this hypothesis they enrolled in their study 33 men and women between the ages of 51 and 73 who had recently had heart bypass surgery. Each individual completed two exercise sessions, one without music and one with music. The order of the sessions was randomly assigned. Prior to and upon completion of each exercise session, the participants filled out a questionnaire that assessed their degree of anxiety or depression. They also completed a test of verbal fluency that involved generating lists of words on various topics. The researchers found that exercise alone improved mood; the music did not add to or detract from that. However, those who listened to music while exercising did show significant improvements in cognitive functioning following that exercise session whereas exercise without music showed no cognitive change. Emery, the primary author of this study, concluded that, “The combination of music and exercise may stimulate and increase cognitive arousal while helping to organize cognitive output." This was a small study, so further research is required to confirm their results. But certainly it can’t hurt and may help to listen to some “great” music while you get your body moving. Emery CF, Hsiao ET, Hill SM, Frid DJ. Short-term effects of exercise and music on cognitive performance among participants in a cardiac rehabilitation program. Heart Lung. 2003; 32(6):368-73.
Cold Temperatures and Heart Disease: Researchers in Britain analyzed the temperature data for the birth dates of 4,286 women from 23 British towns who were born between 1919 and 1940 to determine whether being exposed to cold temperatures at the time of birth was a factor in developing heart disease later in life. Analysis of results did show a significant relationship between cold temperatures at birth, generally occurring between December and March, the winter months, and later onset of heart disease. However, this relationship only held for those women whose fathers were either unemployed or employed as manual laborers at the time of the woman’s birth. The researchers concluded that exposure to cold at time of birth and to the colder living conditions associated with poverty were important risk factors for heart disease. They supported this conclusion by noting that countries such as Gambia, in west equatorial Africa, have no seasonality of temperature, but do have extreme seasonality of food availability. However, in these countries there seems to be no relationship between food shortages during gestation and infancy and later heart disease. Lawlor DA, Davey Smith G, Mitchell R, Ebrahim S. Temperature at birth, coronary heart disease, and insulin resistance: cross sectional analyses of the British women's heart and health study. Heart. 2004; 90(4):381-8.
Comment: Regular readers of AnthroHealth have probably already said to themselves, “But what about latitude, UVB radiation, and vitamin D?” The authors of the cold temperature study do mention latitude, but only to say that it overlaps almost entirely with temperature. No mention is made of vitamin D deprivation, which is associated with hypertension. This omission would be rather curious except that to include it would serve to undermine their entire hypothesis that it is cold temperature that is the primary factor. As the authors mention, they could find no seasonal pattern of heart disease in Gambia. However, they do not mention that heart disease is significantly less common in Gambia than in Britain. What is one of the major differences between the poor of Gambia and the poor of Britain? The poor of Gambia receive abundant UVB radiation and so, unless they spend their entire day inside, should have optimal vitamin D levels. The poor of Britain are hard-pressed to obtain optimal vitamin D levels even during the summer months. Therefore, it should not be surprising that a relationship exists between cold temperature/winter month of birth and heart disease in Britain when these are also associated with the peak period of vitamin D deprivation and optimal vitamin D levels are important for heart health.
AnthroHealth Tip of the Month: If you’ve let your exercise schedule slide during the winter months, April is a great month to get outside and start walking again. Although listening to music while you walk may be cognitively helpful per the research reported above, it can also distract you from enjoying the beauty around you. So save the headset for those times when there is little to see. Get great shoes, wear a wide brim hat if it’s sunny, and enjoy the burgeoning life for your 2 – 3 mile walk.
© 2001-2009 Kathleen E. Fuller, PhD. All rights reserved.