Blog/Latest News

                                    Smoking and obesity found to increase risk of severe COVID-19 by 65% to 81%

Researchers from the School of Public Health, LKS Faculty of Medicine of The University of Hong Kong (HKUMed), in collaboration with The Chinese University of Hong Kong (CUHK)'s Faculty of Medicine (CU Medicine), confirmed smoking, obesity and lower socioeconomic position (SEP) likely increase the risk of contracting mild to severe COVID-19, using data from large scale genome-wide association studies.

one standard deviation (SD) increase of body mass index (BMI) likely:

• increases risk of severe COVID-19 by 81%
• Increases risk of COVID-19 hospitalization by 55%
• increases risk of contracting COVID-19 by 18%
• This study is one of the largest studies to explore the role of various risk factors in different severities of COVID-19 using Mendelian randomization. It reiterates the relevance of obesity and smoking, which are key factors contributing to disease burden, according to the World Health Organization.

Exercise has a number of biological effects on the body, some of which have been proposed to explain associations with specific cancers, including:

• Lowering the levels of hormones, such as insulin and estrogen, and of certain growth factors that have been associated with cancer development and progression
• Helping to prevent obesity and decreasing the harmful effects of obesity, particularly the development of insulin resistance (failure of the body's cells to respond to insulin)
• Reducing inflammation
• Improving immune system function
• Altering the metabolism of bile acids, resulting in decreased exposure of the gastrointestinal tract to these suspected carcinogens 
• Reducing the amount of time it takes for food to travel through the digestive system, which decreases gastrointestinal tract exposure to possible carcinogens [colon]

According to the Australian Institute of Health and Welfare’s ‘Cancer in Australia 2019’ report, 1 in 2 Australian men and women are being diagnosed with cancer by the age of 85. Every day, 396 people are diagnosed with cancer making cancer, in 2019, a leading cause of death in Australia.

Scientific research, around the benefit of exercise for people with pre- during and post-cancer treatment, has established exercise as a particularly potent medicine for the management of cancer.

Exercise is Medicine Australia underlines exercise (both pre- and post-diagnosis) as having a great link with positive cancer outcomes – function, fitness and quality of life. There is also a growing body of evidence that indicates exercise, after diagnosis, may improve long-term survival rates, at least in breast and colorectal cancer.

Exercise guidelines for fitness professionals for people with cancer

The 2019 ESSA ‘Exercise medicine in cancer management’ position statement encourages fitness professionals to guide their cancer patients through an individualised exercise prescription that is specific to them, their cancer and their needs. The exercise prescription that works best is defined by a variety of aspects including patient assessment, identification and consideration of general and cancer-specific health issues, and patient-driven goals.

The ESSA position statement on exercise in cancer care suggests moderate intensity exercise for people with cancer. Most exercise programs can include a mix of aerobic and resistance type exercises and, each session, should be adjusted based on how the person is feeling on certain days. Everyone is different when it comes to exercise prescription and, depending on the type of cancer and the current cancer treatment cycle, exercise should be customized accordingly.

FURTHER BENEFITS OF RESISTANCE EXERCISE

Recent studies from Iowa State University have shown that lifting weights for less than an hour a week may reduce your risk for a heart attack or stroke by 40-70 % .The benefits of strength tarining are independent of running, walking or other aerobic activity. The study analysed data of nearly 13,000 adults .As well as this, the resistance programme showed a 29 % lower risk of developing Metabolic Syndrome which increases the risk of heart disease, stroke and diabetes. The risk of hyercholesterolaemia was 32% lower.

Nutrigenetics and Nutrigenomics - Is this the future? 

The fundamental hypotheses underpinning the science of nutrigenetics and nutrigenomics are the following:

• Nutrition may exert its impact on health outcomes by directly affecting expression of genes in critical metabolic pathways and/or indirectly by affecting the incidence of genetic mutation at the base sequence or chromosomal level which in turn causes alterations in gene dosage and gene expression.

• The health effects of nutrients and nutriomes (nutrient combinations) depend on inherited genetic variants that alter the uptake and metabolism of nutrients and/or the molecular interaction of enzymes with their nutrient cofactor and hence the activity of biochemical reactions.

• Better health outcomes can be achieved if nutritional requirements are customised for each individual taking into consideration both his/her inherited and acquired genetic characteristics depending on life stage, dietary preferences and health status.

Precision nutrition has a promising future in treating the individual according to their phenotype and genetic characteristics, aimed at both the treatment and prevention of disease.

The Role and Impact of Genetics and Epigenetics in relation to Weight Management. .

Obesity results from interactions between environmental and genetic factors.  Despite a relatively high heritability of common non-syndromic obesity (40-70%), the search for genetic variants contributing to susceptibility has been challenging. while large genome-wide association studies (GWAS) have identified a number of genetic loci associated with obesity risk, the ~100 most common genetic variants only account for a few percent of variance in obesity More than 40 genetic variants have been associated with obesity and fat distribution. However, the variants do not fully explain the heritability of obesity and so other variations involving epigenetics must be considered. Emerging evidence connecting epigenetic (heritable changes which affect gene function but do not modify DNA sequence) events with obesity.

While genetic factors undoubtedly play a role in determining individual susceptibility to weight and obesity, the identified genetic variants only explain part of the variation. This has led to growing interest in understanding the potential role of epigenetics as a mediator of gene-environment interactions underlying the development of obesity and its associated comorbidities.

Advances in epigenetic methodologies and the reduced cost of epigenome-wide association studies (EWAS) have led to a rapid expansion of studies in human populations. These studies have also reported epigenetic differences between obese/T2DM adults and healthy controls and epigenetic changes in association with nutritional, weight loss, and exercise interventions. There is also increasing evidence from both human and animal studies that the relationship between perinatal nutritional exposures and later risk of obesity and T2DM may be mediated by epigenetic changes in the offspring.