US - European perspectives on potential impact of promoting cycling

As a response to my summer notes on 'city cycling', I was sent a link by @jenicarhee to a graphic (see below) on potential impact of regional schemes to promote cycling. Projected advantages include for health, environment and financial benefit. This approach lends itself to regular update on actual outcomes and imaginative ways to assess impact. See for yourself via: 'How bikes can save us [infographic]'.

City cycling: beyond the obvious benefits

Cycling sounds an attractive approach to better personal health, reduced carbon footprint and therefore a generally healthier urban environment. Rojas-Rueda and colleagues in a British Medical Journal paper have recently modeled the health risks and benefits of the Barcelona bike sharing scheme (Bicing), based on the over 180,000 Barcelona residents using the Bicing scheme.  They conclude there are greater health benefits than risks in Barcelona, and a large reduction in annual carbon dioxide emissions.
For Barcelona and elsewhere, bike-sharing appears to offer the opportunity to introduce regular cycling as a way for many in the population to return to, or increase exercise, on a sufficient scale for both public health and environmental benefits.
After Milan's earlier efforts to provide affordable and enjoyable city centre cycling - yellow bikes disappearing around Europe to Geneva and beyond - Paris (launched 2007) and London (launched July 2010) are also addressing the challenge of encouraging exercise and reducing car travel on city centre streets - with some extra effects on healthy mind and body. This includes 'water-cooler' bonding as initiates explain how to use the cycle pay columns or how to free a tricky bike. And more than intended exercise in several forms. Cyclists often need to return for a fresh hire after realising too late that their chosen cycle is faulty - punctured, chain off, saddle collapse syndrome, sticky wheels and so on (a Paris code is to reverse the saddle and or collapse the saddle support on a faulty bike); or moving from full cycle rack to next cycle station looking for a post at which to return a cycle at busier city locations. For the less pressed, this is another opportunity to meet fellow cyclists while waiting, and to compare notes on nearby velib station options. A peak time problem at busier sites is of course there being no bike available; more exercise, locating then walking to the next available station. Paris is trying hard - from the velib website at the end of August, 1233 locations were declared - enough hire and return capacity for this to be more than a tourist or freetime gimmick. The Paris website includes a colour-coded webmap: green for stations with available spaces, red for full cycle stations. The Paris Velib system leads the way globally in number of sites and available cycles. Paris also has the advantage of many wide pavements, and, in some areas, proper cycle lanes - although partnering these with buses and taxis is a source of recurrent adrenaline surge.
A reporting option on the booking terminal at cycle stations would be a good addition, so that the next hirer does not have the same problem; also helpful would be a less sticky webmap for locating alternative Velib stations: not a very mobile phone friendly website. And a review in Paris is planned of the economics of the scheme, with 80-90% of cycles reported in need of repair or replacement due to damage or theft; much less respected than the earlier  Lyon scheme (established May 2005, now with around 340 bike stations, and as for Paris, run as a partnership with advertising company JCDecaux).

© DRJ Singer

Provence, the Rhone estuary and the 'French paradox'

The ‘French paradox’, coined in 1992, refers to apparent unexpectedly low cardiovascular disease rates despite reported high exposure to factors predisposing to increased cardiovascular risk such as alcohol, cheeses high in saturated fats, and the stereotypical Gitane cigarette or modern equivalent. Obvious explanations for such a paradox include protective genetic factors, cardioprotective factors in the French lifestyle, and ascertainment bias in recording cardiovascular disease.
What insights are evident to explain the French paradox from visiting the Mediterranean reaches of the Rhone valley? Unlike for some northern European populations, the southern French are not averse to leafy green vegetables (the Provencal variant - ‘mesclun’), tomatoes, or other salad ingredients. And garlic and other alliums are popular in local recipes.
Cheese intake appears relatively low and goat and sheep’s cheese are popular. That raises an obvious question: does the species source of cheese matter for cardiovascular risk? Alcohol intake in public appears modest. That combined with evidence from Roger Corder and others for possible cardiovascular protective effects of certain red wines may contribute to reduced cardiovascular risk.
The typical local build is lean. However increasing numbers of young and older French men and women are developing abdominal obesity.
Smoking outdoors is still very prevalent, particularly among young women and men. There remains scope both for active and passive smoking to be continuing risk factors for increasing risk of cardiovascular disease.
What about access to health prevention and medical treatment? Every variety of doctor is available, with rooms in large and small towns, brass or marble plaques advertising their specialty, diploma – especially when from Paris, or even the gift of ‘expertise’. This health provision is complemented by a large number of pharmacies, and the newer vogue for parapharmacies, providing expertise and/or access to conventional, as well as plant-derived and other complementary remedies.
Do these other ‘remedies’ work? Certainly herbal and other plant extracts can have potent medical effects. For example, St John’s wort can reduce the expected clinical effects of treatment both by reducing absorption of drugs through activation of drug transporters in the gut, and by increase drug breakdown through activation of liver enzymes responsible for drug breakdown.
And grapefruit juice may lead to potentially serious interactions with over 50 prescribed and over-the-counter drugs, through reducing their breakdown, therefore leading to greater than expected effects of these medicines. Pomelos and Seville oranges may have similar actions.
The afternoon promenade is popular and there is ample opportunity for outdoor activity, whether from walking, more relaxed or extreme forms of cycling, riding the ‘wild’ Camargue horses, or active engagement in the local bull-friendly pursuit of trimming the bull’s fringe. This involves rapid evasive action from the charging bull, by leaps over high wooden barriers by the bull-trimmers (razeteurs). There is also ample opportunity to release aggression as a spectator, or as a participant in local bull- or horse-related spectacles.
Taken together, there are obvious dietary and lifestyle opportunities available in Provence to reduce cardiovascular risk. These are potentially offset by smoking, development of abdominal obesity and the degree to which exercise and alcohol feature in an individual’s lifestyle. And, at least for cardiovascular mortality, ascertainment is increasingly difficult, as fewer post-mortems are performed to verify cause of death.
The best strategy for cardiovascular prevention is effective public health advice, combined with effective management of cardiovascular risk factors by lifestyle and drugs, with advisors and members of the public well-motivated to adopt effective evidence-based measures to reduce cardiovascular risk. That of course begs several questions on existence or strength of the evidence base for cardio-protective effects of dietary factors, including different regional wines. These questions are key themes included within a Symposium on cardiovascular effects of ‘healthy foods’ to be held in London on Thursday 8th December 2011, with discussants including Professor Roger Corder (Wm Harvey Institute, London) and Professor KT Khaw (University of Cambridge).
For further details see my recent blog on 'What foods protect cardiovascular health?'