Health
Obesity has overtaken smoking as the leading preventable cause of cancer in the United States and is responsible for 600,000 cancer deaths each year. Cancer is caused by genetic errors in protein synthesis, resulting in abnormal cell growth that often spreads to other parts of the body. Normal cells can correct sequencing errors in the DNA. Cancer develops when these safety mechanisms do not function properly.
Obesity impairs intercellular signaling, resulting in genetic errors in protein synthesis and abnormal cell development.
Anabolic hormones such as insulin and IGF-1, whose levels increase with obesity, promote progression to early stages of cancer development. Esophageal cancer, liver cancer, kidney cancer, breast cancer, gallbladder cancer, pancreatic cancer, prostate cancer, ovarian cancer and uterine cancer are particularly sensitive to metabolic changes caused by obesity.
Fortunately, even modest weight loss can cause metabolic changes that reduce the risk of these cancers.
(The Scientist, November 2015)
Prostate cancer is the most common form of cancer in men and the second most common cause of cancer-related deaths (lung cancer is the leading cause). Cancer is caused by defects in DNA metabolism that cause abnormal cell growth. Normally, genes can repair defects in cell growth. Gene mutations caused by environmental stress factors or inherited defects can undermine cell control mechanisms, which can trigger uncontrolled cancer growth. Radioactive radiation and carcinogenic chemicals can also cause DNA mutations. Foods such as green, leafy vegetables, which reduce cellular inflammation, may reduce the incidence of these mutations, while fried or burnt foods may increase the incidence. Prostate cancer rates vary widely in different countries around the world, ranging from 111.6 per 100,000 people in the South Pacific, to 4.5 million in South Central Asia. Chicken consumption could increase the risk of this disease.
A study led by Qian He of Tongji Medical College in China found no link between poultry consumption and prostate cancer. The scientists combined the results of 25 studies involving a total of 500,000 people living in Western countries, Asia and South America.
Many athletes specifically include poultry in their diet. This is because poultry contains the least fat of all types of meat and is an excellent source of protein.
The consumption of poultry does not increase the risk of prostate cancer.
(PeerJ 4: e1646 https://doi.org/10.7717peerJ.1646, 2016)
Different cultures have different dietary patterns. For example, almost 70 percent of Italians eat their main meal at lunchtime, while people living in England eat their main meal in the evening. This could explain, at least in part, why the obesity rate in Italy is 7.6 percent and in England 20.1 percent. Studies carried out on humans and animals show that time-restricted eating, where most of the calories consumed each day are eaten by lunchtime, reduces the risk of obesity.
British scientists surveyed 460 people about their eating habits. People who ate the least amount of calories at lunchtime had the highest body mass index (ratio of weight to height). Factors that prevented lunchtime eating included working hours, the cost of food available at lunchtime, lack of motivation, family dietary patterns and difficulties in changing habits.
Cultural factors may play a role in the cause of obesity.
(Proceedings of the Nutrition Society, 75: E12, 2016)
The United States spends 8,731 dollars per person per year on healthcare costs, which is twice as much as other countries in the world. Despite this, Americans only rank 34th in life expectancy behind countries such as Lebanon, Korea, Canada, Japan, the United Kingdom and Chile. Of the countries in the top 10, seven are Mediterranean countries (Spain, Andorra, Italy, San Marino, France, Monaco and Cyprus). Many experts believe that the Mediterranean diet, which is rich in olive oil, lean meat, fruit and vegetables, whole grains and red wine, could help people in these countries to live longer.
Olive oil contains an average of 73g of unsaturated fatty acids per 100g, which have a positive effect on the cardiovascular system. Unsaturated fatty acids can also help burn fat - but should not be consumed in excess.
A literature review led by Lucia Fernandez del Rio from the University of Cordoba in Spain concluded that the consumption of olive oil could be the key to longer life for these people. Olive oil works by stabilizing genes, protecting cell telomeres (preventing DNA degradation), maintaining metabolic control and protecting stem cells.
(Molecules, 21: 163, 2016)
68 percent of Americans are overweight or obese. Obesity refers to an over-fat condition that is accompanied by a group of health problems that scientists call obesity syndrome. These problems include poor blood sugar regulation, abnormal blood lipid levels, type 2 diabetes, high blood pressure and increased fat storage in the abdominal area. Scientists do not yet fully understand how people become obese, but they are making progress.
A groundbreaking study led by Guenther Boden of Temple University found that excessive calorie intake (6,000 kcal per day) for one week caused metabolic stress in men, which triggered insulin resistance. Free radicals generated by the excessive food intake caused the degradation of many proteins including GLUT4 - an important glucose transporter that is crucial for blood sugar regulation.
Increased oxidative stress due to excessive calorie intake could be an important trigger for the "obesity syndrome".
(Science Translational Medicine, 7(340): 304re7, 2015)
