On criticism in bio-medical research--a tribute to Uffe Ravnskov.

The great importance of criticism in science--and its ups-and-downs due to human prejudices and emotions--is discussed in a historical perspective. Towards such a background, attempts are made to evaluate present controversies concerning the widely assumed cause-effect relations between diet-adipositas per se and disorders, like diabetes 2 and atherosclerosis. Seen from a physiological angle, it appears that the real culprits are to a great extent of a different nature, though easily overlooked in e.g. mass screenings. Thus, the human brain reacts to the many mental challenges of modern hectic-competitive life with the same protective response patterns as seen in all mammals, i.e. with defeat- and/or defence-reactions. Here the hypothalamic-hypophyseal-glucocorticoid axis, respectively the hypothalamic-sympatho-adrenomedullary one, serves to support the associated behavioural expressions. Experiments in group-living mammals show how mentally induced prolonged engagements of these neuro-endocrine links end up in serious metabolic and organ-system disturbances, also if factors like diet are kept unchanged. To this comes that in 'civilized' man the respective behavioural expressions are commonly suppressed, whereby most 'inside' neuro-hormonally induced changes occur in vain. An aggravating component is inherent in generally dwindling physical activity, implying that the many bodily and mental advantages of regular exercise are much reduced. Towards such a background, it appears strange that 'The metabolic syndrome' and its sequalae are not even more common today.