Melanesians, Non-Western Diet, And Cardiovascular Disease Risk

Why do some non-Western populations have low rates of stroke and heart disease?  Here is a paper looking at one such population.  Abstract (containing one spelling correction):

OBJECTIVES:

To compare cardiovascular risk factor levels between non-westernized Melanesians, apparently free from stroke and ischaemic heart disease, and healthy Swedish populations, and to analyse, among adult Melanesians, relations with age, sex and smoking status.

DESIGN:

Cross-sectional survey.

SUBJECTS:

(i) Traditional horticulturalists in Kitava, Trobriand Islands, Papua New Guinea, uninfluenced by western diet. this study tested 151 males and 69 females aged 14-87 years with 76% and 80% smokers over 20 years. (ii) Healthy Swedish reference populations.

MAIN OUTCOME MEASURES:

Sitting systolic and diastolic blood pressure, weight, height, body mass index, circumferences of waist, pelvis and mid upper arm, triceps skinfold thickness, fasting serum total cholesterol, triglycerides, high-density lipoprotein cholesterol, estimated low-density lipoprotein cholesterol, apolipoprotein B, apolipoprotein A1 and apolipoprotein (a).

RESULTS:

Compared to Sweden, diastolic blood pressure, body mass index and triceps skinfold thickness were substantially lower in Kitava, where all subjects > or = 40 years were below Swedish medians. Among males > or = 20 and females > or = 60 years systolic blood pressure was lower in Kitavans. Fasting serum total cholesterol, low-density lipoprotein cholesterol and apolipoprotein B were 10-30% lower in Kitavan males > or = 40 and females > or = 60 years. Triglycerides were higher in Kitavans aged 20-39. High-density lipoprotein cholesterol did not differ while apolipoprotein A1 was lower in Kitavans. Apolipoprotein (a) tended to be lower in Kitavans, but the differences were small.

CONCLUSIONS:

Of the analysed variables, leanness and low diastolic blood pressure seem to offer the best explanations for the apparent absence of stroke and ischaemic heart disease in Kitava. The lower serum cholesterol may provide some additional benefit. Differences in dietary habits may explain the findings.

So, dietary differences leading to lean body structure, lower blood pressure, and lower cholesterol levels may explain the better stroke/heart disease profile in Melanesians vs. Swedes.  Of course, genetic differences, not mentioned in this abstract, between the two populations may influence this as well.  What I would like to see is a study comparing people within each population, each group having a different diet.  For example, do Melanesians with a Western diet have higher rates to stroke and heart disease?  What about Swedes on a healthier diet?

Immune Memory And Neurological Disease

Innate immune memory in the brain shapes neurological disease hallmarks; abstract:

Innate immune memory is a vital mechanism of myeloid cell plasticity that occurs in response to environmental stimuli and alters subsequent immune responses. Two types of immunological imprinting can be distinguished-training and tolerance. These are epigenetically mediated and enhance or suppress subsequent inflammation, respectively. Whether immune memory occurs in tissue-resident macrophages in vivo and how it may affect pathology remains largely unknown. Here we demonstrate that peripherally applied inflammatory stimuli induce acute immune training and tolerance in the brain and lead to differential epigenetic reprogramming of brain-resident macrophages (microglia) that persists for at least six months. Strikingly, in a mouse model of Alzheimer's pathology, immune training exacerbates cerebral β-amyloidosis and immune tolerance alleviates it; similarly, peripheral immune stimulation modifies pathological features after stroke. Our results identify immune memory in the brain as an important modifier of neuropathology.

Oxygen masks for all, including our doctors

At a recent meeting dedicated to a community health initiative, all attendees were marveling at the slide above, which is from the webinar “CDC's CommunityGuide:Improving the Science of Built Environment and Public Health for Physical Activity”, presented by David Hopkins (Centers for Disease Control and Prevention, 05/06/2015). 

The graph illustrates the dramatic ability of physical activity to decrease all major diseases in the Westernized world. As we were discussing the slide, a physician exclaimed, ”There is not a single medication that can achieve these results”. The inevitable thought was, “If our medications are so ineffective, why are not physicians prescribing physical activity before considering any medication?”
 
There are probably many reasons; however, two may be crucial. The first is that most patients prefer an “easy fix”, something that helps their health without testing their willpower. The second is that most doctors do not practice healthy lifestyle themselves. In fact, physicians frequently function at the brink of physiological and psychological breakdown.
 
Remember the recommendations on the use of oxygen masks on a plane? In case of decompression, oxygen masks are available; however, the rule is that “if you are traveling with a child or someone who requires assistance, secure your mask on first, and then assist the other person”. The same rule of “take care of your own condition first” should apply to our physicians, because if they do not adopt a healthy lifestyle themselves, they are not fit to fulfill their duties of healers. In fact, the same responsibility is relevant to everyone who is in charge of someone. Parents should be an example for their children, teachers should be an example for their students, and bosses should be an example for their employees. 

The American Institute for Cancer Research recommends 30 minutes of physical activity a day for adults. This activity does not have to be strenuous or associated with expenses (e.g., a gym membership), but could be walking, gardening, or cleaning the house. The exercise does not have to be continuous for 30 minutes, one could do “bursts of activities” of five minutes several times a day anywhere, even in front of the TV, in the waiting room, or in the office. In this manner, we can enhance our own health and be role models, representing a healthy lifestyle, to others.


Here is more on taking care of yourself: