JAMA  23/30 Nov 2011  Vol 306
2221   “There is a fifth dimension, beyond that which is known to man,” intones Rod Serling in accents strange, “…we call it The Twilight Zone.” Fans of the 1950 series will enjoy this week’s episode, where a bewildered reviewer finds himself in a parallel universe where he is doomed to read the same studies over and over again. Sitting at a bare table, his fingers move listlessly through straggles of unkempt hair as he opens a journal strangely like the JAMA he once knew. His narrowed eyes fall on the first paper. He removes his spectacles, wipes his brow, and peers more closely. The date on the page is November 2011! And yet the paper is still about what clopidogrel dosing does to platelet function tests… there must be some mistake. Surely this is the same paper he read ten years ago, before he … O what is happening? Mary-Lou, are you in the labratory? Where are you, Mary-Lou?
2229   Back among that which is half-known to man, the effect of salt intake on cardiovascular events is amongst the most fiercely debated. Salt restriction lowers elevated blood pressure, say the zealots, so it must reduce cardiovascular harm on a population level. Nonsense, say the sceptics: BP is a surrogate, the effects are small, and compensating mechanisms may well work in other directions. Look at all the studies that show no effect or adverse effects. Pah, say the zealots, look at all the better-conducted positive studies. Could both camps actually be right? The only way would be for the sodium-harm relationship to be U-shaped: and that is just what it proves to be in this analysis of sodium excretion in two large observational studies. The ideal daily intake is between 3 and 6G per day, judging from a single estimate of excretion: but this debate is far from over. We need better prospective studies, with regular measurements of sodium output. So if your bewildered reviewer opens a JAMA in 2021 and finds another study of sodium excretion and cardiovascular events, he won’t need to cry out for Mary-Lou.

NEJM  24 Nov 2011  Vol 365
1959   Two recent papers in the British journals appear to have settled the question of obesity management in primary care decisively in favour of Weight Watchers. But now two papers in the USA’s leading medical journal open up the field once more. What if it could all be done quite effectively over the telephone? That’s the intriguing prospect offered by this study in a real-life American population of significantly obese (mean BMI 36.6) participants, 41% black, mean age 54, and all with at least one cardiovascular risk factor. Over two years, controls randomized to self-management lost 0.8kg; those who received telephone support lost 4.6 kg; and those who received in-person support lost 5.1kg. So telephone advice and encouragement less than once a month seems to be almost as good as individual and group sessions plus remote support on tap, and very much cheaper and more convenient. Watch out, Weight Watchers.

1969   The second trial is less compelling. The study population was roughly the same, but the interventions here were usual care, brief lifestyle counselling, or enhanced counselling with the use of drugs (sibutramine, orlistat) ad libitum. The last group did best with a mean loss of 4.6kg at 2 years. Phone calls, which achieved exactly the same in the first trial, still seem like the best bet to me.

1980   You probably don’t much care, but cardiologists are still doing trials of various blood-thinning agents for use during percutaneous coronary interventions, in this case for non-ST elevation myocardial infarction. One lot received bivalirudin, and they did as well in terms of recurrent infarction or the need for urgent revascularization as the lot who received abciximab and unfractionated heparin, who bled more. So a win for bivalirudin. Strange how these names, which seemed so odd and exotic a few years ago, now seem quite passé.

1990   Now here’s the gem of the week: a meticulously designed and conducted study showing that daily low dose inhaled steroids are no better than high dose inhaled steroids at the first sign of respiratory symptoms in toddlers and pre-school kids who get wheezy when they get upper respiratory infections. The intervention was inhaled budesonide and the outcome measure was number of episodes requiring oral steroids. Reading the first part of the paper, I was again struck by the flimsy nature of the evidence that led “experts” to tell us that we should give pointless and potentially growth-suppressing continuous treatment to such a large swathe of the pre-school population. It is time to stop doing this.

2002   A survey of US hospital emergency room attendances provides a salutary reminder of the drugs which get older people admitted to hospital. All such surveys have the same top four winners: warfarin, insulin, aspirin, and oral hypoglycaemics. Opioids, benzodiazepines and “high risk” medications trail by a long distance. Digoxin gets a significant place in the American league, but I hope not the British, since I can’t think of any good reason to use this drug at all. Half of these patients are over 80. You may have to give warfarin or aspirin to a good many of them for stroke prevention, but do you really need to give many 80-year old diabetic patients sulfonylureas or insulin?

Lancet  26 Nov 2011  Vol 378
1847    Back in The Twilight Zone, our bewildered reviewer searches the laboratory for Mary-Lou, but finds only cobwebs and a coffee mug with dried mould at the bottom. He sits down again at the bare table in the empty room, but the journal that lies there is no longer the NEJM but The Lancet. When he last opened a Lancet ten years earlier he read about encouraging results from Phase One studies of stem cell implantation to regrow damaged myocardium. But this Lancet bears a date of November 2011! What can have happened between? Opening the shiny pages of unfamiliar typeface, he wipes his brow again. A phase one study of stem cells to regrow damaged myocardium…much promise…improved ejection fraction…longer studies needed… A fly lands on the page, and then buzzes away. The parking lot outside is full of dust.

BMJ  26 Nov 2011  Vol 343
Here is the much-publicised systematic review that claims to show that cereal fibre and whole grains protect against bowel cancer, whereas fibre from fruit and vegetables does not. This seems a bit odd to me, but I cannot possibly interrogate the evidence in the way that these authors have. On first principles, I would have thought that eating fruit and vegetables was bound to have some protective effect, since they contain salicylates and we know that salicylates prevent bowel cancer. Eating muesli and grainy bread has never much appealed to me; nor has the whole idea of organizing my diet to prevent some disease or other. One of the authors is a Dutch “professor of diet and cancer”, a most regrettable position. Eat what you enjoy and take your chances, say I: you will never get out of this world alive.

Which brings us neatly to the subject of successful ageing. To me, successful ageing would mean doing as much as possible that is both fun and useful in the time left, followed by dropping dead at an appropriate moment. It strikes me that one of the biggest factors that prevents successful ageing in the USA is health anxiety and the potential cost of illness, despite Medicare coverage. This American trial tried an intervention called “integrated care” which bears a striking resemblance to a more sophisticated intervention known to the British as general practice. The main difference was freer use of a depression questionnaire. People in the intervention group got more drugs for depression, cardiovascular risk factors and diabetes. What happened to them after that is anyone’s guess. At the start of the study their mean age was 57. At the end of the study it was 58.

Plant of the Week; Spinach

Once again, I am relying on the good offices of Eric Larson, the ebullient and sagacious keeper of the Yale Botanical Garden, for this week’s botanical instruction:

This week’s plant is also growing in the Marsh Gardens greenhouse, but not in our diversity collection. We have a large number of spinach plants that one or more classes use in discussing plant evolution. Spinach is one of the minority of species in the plant kingdom that are dioecious. This term that, according to my spell-checker is not in the dictionary is from the Greek. Roughly translated, it means “two houses,” which means that sexual propagation requires two separate plants, one being male and the other being female.

Most plants, as in last week’s chocolate tree, bear flowers that have male pollen-bearing structures and female seed producing capabilities. This arrangement is referred to as monoecious. Dioecious plants, although in a minority, are not rare. Other plants with this arrangement include Hollies and marijuana. There are some instances where a plant will have a little of both. These are referred to as polygamodioecious. When under certain environmental stresses, a plant that is normally dioecious will revert to monoecious to ensure that it propagates itself. Marijuana is a good example, partially because it is an annual plant, which means it germinates from seed, matures, flowers, and sets seed within a calendar year. Plants that rely on seeds alone to propagate (as opposed to forming stolons, bulbs, or other vegetative reproduction) will revert to a hermaphroditic form to make sure that they do so. Of course, extensive research has rewarded the author in his pursuit of these anomalies.

(RL’s note: I believe that the author must be referring to his liking for spinach, though one is puzzled by his frequent references to marijuana.)

Spinach is such an ancient plant in terms of its relationship with man that we don’t have a clear idea what part of the world it is native to, although one reference mentions Iran. The Latin binomial for spinach is spinacia oleracea. The genus name derives from the Latin spina, probably referring to the spiny seeds of all of the members of the genus, and especially spinach itself. The specific name also derives from Latin, meaning “vegetable, of kitchen gardens.” The family is chenopodaceae, or the goosefoot family. Other members of this rather small group (250 species)
include orach, lamb’s quarters, goosefoot, pigweed and beets.

Spinach is an annual plant, prefers cooler weather, although hybridization has resulted in some varieties that tolerate heat, and even long day length. Most Spinach varieties bolt, or send up flower scapes, as the days lengthen in June, or when the weather is hot. This is in keeping with the assumption that, when under stress, plants try to propagate themselves.

Spinach really prefers a neutral or even slightly alkaline soil, which requires some care here in the East: relaxation of the clean air act means that more acid rain is headed our way from Midwestern coal-fired electric generating plants. Soil tests, free from the Connecticut Agricultural Station right here in New Haven, should be done on your garden soil every year. Most garden vegetables prefer a soil that is within a few points of neutral (7 on the scale from one to fourteen, one being about like hydrochloric acid and fourteen being like fresh lye soap).

Spinach is a heavy eater, meaning the overall availability of nutrients in your soil should be high, with Nitrogen, Phosphorus, and Potassium being the macro-nutrients, and a long list of micro-nutrients behind. I prefer using organic means of fertilising, when necessary, which means using manure or other compost for most of the Nitrogen plants need, along with bone meal, wood ashes, green sand (a marine deposit) and other like materials to feed the soil. This is important, folks. Feed the soil, not the plants. The relationship between the soil biota and plants is complicated and complex, with no sure answers at hand. But one thing is for sure that if we approach the nutrition of plants like many people approach nutrition of people (that is, just look at the chemical composition, the place on the food pyramid and no more) then we are overlooking a major part of the chain of biotic interplay, or what makes gardening sustainable. For more on this, I invite you to get in touch with Josh Viertel and Melina Shannon-DiPietro, who manage the Yale Sustainable Food Project.

Spinach should be started by seed in the ground as early in the spring as the soil can be worked. Raised beds are ideal for spinach cultivation for this reason, because they dry out and warm up quickly in the spring, making them easier to work and not damage the structure of the soil. Try several varieties of spinach to find one that works for you. As I mentioned earlier, there are varieties that will survive summer weather much better than others, and there are some with more wrinkled leaves, some with less wrinkles, some with a different flavor.

Start harvest as soon as the plants have three sets of true leaves, and even before if you have planted them thickly. Young tender spinach is one of God’s gifts to rabbits, groundhogs and humans. Succession planting, or planting every ten days, will help to prolong the harvest. By late May or early June it is almost not worth the effort, as they bolt to seed right away, becoming bitter in the process. So, after the Ides of July, start planting again, right up until mid-September, or later if you have row-covers or a cold frame to grow them in.

Plant of the Week is a publication of the Marsh Botanical Gardens. Opinions expressed herein do not reflect on the official policies of Yale University. Contact: Eric Larson (eric.larson@yale.edu)