A simple prescription for healing chronic disease

I have spent the last 16 years working as a doctor in the field of haematology, a medical speciality that is leading the technological and genomics revolution. The first chromosomal abnormality in cancer was discovered in chronic myeloid leukaemia (CML), a seminal finding that led 30 years later to the development of the first cancer drug to target a specific genetic abnormality. This has resulted in a normal life expectancy for people living with CML, a remarkable achievement. The first antibody therapy for cancer was introduced for the treatment of lymphoma more than 100 years after Paul Ehrlich suggested that antibodies might be a ‘magic bullet’ for the treatment of medical diseases.

In more recent times, haematological research has paved the way for the introduction of CART-cell therapy, which harnesses the power of the patients own immune system to recognise and kill cancer cells. Haematology will be the first cancer speciality in England to roll out whole genome sequencing for all patients with acute leukaemia. When it comes to the precision or personalised medicine revolution, the premise is that a better understanding of an individual’s DNA can better prevent and treat their illness thus improving health and survival.

A simpler prescription for health & well-being

So why is it that despite these successes in my field of work, I find myself more passionate about a simpler prescription for health and well-being? It took 13 years working as an NHS doctor for me to truly understand the impact of socioeconomic and lifestyle factors on health outcomes and the greater impact we could have on population health by addressing inequalities in access to healthy diet and lifestyle habits. The pandemic has only further highlighted these systemic, societal issues. Although COVID-19 is an infectious disease, we know that those at risk of the worst outcomes have underlying health conditions. A recent study from the U.S. examining more than 900,000 hospitalisations for COVID-19 found that over 60% of hospital admissions were attributable to four cardiometabolic conditions: hypertension, type 2 diabetes, heart failure and obesity. These risks were higher in people of Black and South Asian origin. The data from the UK is not dissimilar, with the highest risk of death from COVID-19 in those with underlying health conditions, socioeconomic deprivation and of Black and South Asian origin.

Chronic disease

Beyond the pandemic, a recent study from the Global Burden of Disease highlighted that despite progress in improving life-expectancy, we are spending on average 12 years in ill health, and there is at least a 10-year difference in life expectancy between the richest and poorest areas in the UK. This ill-health is caused by non-communicable diseases such as cardiovascular diseases, type 2 diabetes, dementia, cancer, respiratory diseases and include illnesses related to alcohol, tobacco and drug use.

We know from decades of research that at least 80% of chronic disease could be eliminated by addresses health behaviours and the socio-economic conditions that influence them. This includes a plant-predominant diet, regular physical activity, maintaining a healthy weight and avoiding tobacco and alcohol consumption. Focussing on diet, research shows that 1 in 5 deaths are caused by unhealthy diets, characterised by the overconsumption of processed and animal-derived foods and underconsumption of fruits, vegetables, whole grains, beans, nuts and seeds. In fact, whole plant foods are the only foods associated with better health outcomes.

The Eat-Lancet Commission estimated that 11 million deaths could be prevented globally if we all adopted a predominantly plant-based diet with the co-benefits of keeping the food system within crucial planetary boundaries. When considering cancer, 40% of cases could be prevented by addressing lifestyle habits whereas less than 10% are due to inherited genes. A real-life example of the power of diet and lifestyle intervention can be found in the North Karelia Project, from Finland. This was a population-level diet and lifestyle intervention started in the 1970s that led to a greater than 80% reduction in mortality from coronary heart disease. The study concludes ‘Population-based prevention through changes in lifestyle and environment is the most cost-effective and sustainable way of controlling cardiovascular and other major non-communicable diseases’.

Precision & genomic medicine

In contrast, we do not have the same level of evidence to support the vast amount of resource currently being ploughed into precision and genomic medicine. I quote from a paper from 2019; ‘nearly two decades after the first predictions of dramatic success, we find no impact of the human genome project on the population’s life expectancy or any other public health measure, notwithstanding the vast resources that have been directed at genomics’. We have gone down a metaphorical ‘rabbit hole’ of molecular biology for decades and at present, it seems the benefits are most apparent for the industries that are heavily invested in the relevant technologies.

It is private industry and not the NHS that will perform whole genome sequencing for patients in England. CART-cell therapy is being manufactured by pharmaceutical companies despite academic institutions in the UK being capable. Sadly, nutrition research seems to have fallen down the same ‘hole’ and turned to ‘precision nutrition’, despite studies showing plant-predominant diets predict better health regardless of genetic variation. Diet and lifestyle habits can change the expression of genes for better or for worse, an impact much greater than the genetic variation in individual DNA sequences.

Healthy plant-based diets

This is why I believe in education and advocacy on healthy plant-based diets. More and more doctors and healthcare professionals are finding their way back to more simple and actionable solutions. Diet and lifestyle approaches can have a profound impact on personal, population and planetary health.