Do you have good or bad microbiome? Or do you have the microbiome you deserve?
Gut Microbiome, the new Open Access journal from Cambridge University Press and The Nutrition Society has published its first papers, including the animated abstract above from the paper: Hill, C. (2020) “You have the microbiome you deserve,” Gut Microbiome, Cambridge University Press, 1, p. e3.
Access the paper here: https://bit.ly/3bFOjc7
According to a recent study, obesity increases the risk of dying of Covid-19 by nearly 50%. Governments around the world are now hoping to encourage their citizens to lose weight. But with so much complex and often contradictory diet advice, as well as endless food fads, it can be hard to know what healthy eating actually looks like.
How many pieces of fruit and vegetables should you eat a day? Will cutting out carbs help you lose weight? Is breakfast really the most important meal of the day? Speaking to Tim Spector, professor of genetic epidemiology at King’s College London about his new book Spoon-Fed, Madeleine Finlay asks why we’re still getting food science wrong, and explores the current scientific evidence on snacking, supplements and calorie labels.
Tim Spector is a Professor of Genetic Epidemiology and Director of the TwinsUK Registry at Kings College, London and has recently been elected to the prestigious Fellowship of the Academy of Medical Sciences. He trained originally in rheumatology and epidemiology. In 1992 he moved into genetic epidemiology and founded the UK Twins Registry, of 13,000 twins, which is the richest collection of genotypic and phenotypic information worldwide. He is past President of the International Society of Twin Studies, directs the European Twin Registry Consortium (Discotwin) and collaborates with over 120 centres worldwide. He has demonstrated the genetic basis of a wide range of common complex traits, many previously thought to be mainly due to ageing and environment. Through genetic association studies (GWAS), his group have found over 500 novel gene loci in over 50 disease areas. He has published over 800 research articles and is ranked as being in the top 1% of the world’s most cited scientists by Thomson-Reuters. He held a prestigious European Research Council senior investigator award in epigenetics and is a NIHR Senior Investigator. His current work focuses on omics and the microbiome and directs the crowdfunded British Gut microbiome project. Together with an international team of leading scientists including researchers from King’s College London, Massachusetts General Hospital, Tufts University, Stanford University and nutritional science company ZOE he is conducting the largest scientific nutrition research project, showing that individual responses to the same foods are unique, even between identical twins. You can find more on https://joinzoe.com/ He is a prolific writer with several popular science books and a regular blog, focusing on genetics, epigenetics and most recently microbiome and diet (The Diet Myth). He is in demand as a public speaker and features regularly in the media.
Does reducing salt improve our blood pressure?
There is consistent evidence that moderate reductions (i.e. a decrease of 3 to 5 g or ½ to 1 teaspoon a day) in salt intake can lead to a reduction in blood pressure.5,6 However, these effects may not be the same for everyone and will depend on an individual’s starting blood pressure (greater benefits are seen in those with higher blood pressure), their current level of salt intake, genetics, disease status and medication use.
It is important to note that salt is not the only lifestyle factor that can influence our blood pressure. Other factors such as eating enough potassium, maintaining a healthy body weight, not smoking, and being physically active are also important when it comes to reducing blood pressure. You can find 7 lifestyle tips to help reduce blood pressure here.
High salt foods:
- Processed meats such as bacon, salami, sausages and ham
- Gravy granules, stock cubes, yeast extracts
- Olives, pickles and other pickled foods
- Salted and dry-roasted nuts and crisps
- Salted and smoked meat and fish
- Sauces: soy sauce, ketchup, mayonnaise, BBQ sauce
What is salt?
Salt is the common name for sodium chloride (or NaCl). It consists of 40% sodium and 60% chloride. In other words, 2.5 g of salt contains 1 g of sodium and 1.5 g of chloride.
Why do we need salt?
Both sodium and chloride are essential for many body functions. They help regulate blood pressure, control fluid balance, maintain the right conditions for muscle and nerve function and allow for the absorption and transport of nutrients across cell membranes. Chloride is also used to produce stomach acid (hydrochloric acid, HCl) which helps us digest foods.
How much salt do we need per day?
The exact minimum daily requirement for salt is unknown, but it is thought to be around 1.25 g – 2.5 g (0.5 – 1 g sodium) per day.1 As salt is found in a large variety of foods the risk of deficiency is low.1,2 The European Food Safety Authority (EFSA) has stated that a salt intake of 5 g per day (equivalent to 2 g of sodium) is sufficient to meet both our sodium and chloride requirements as well as reduce our risk of high blood pressure and heart disease.1,2 This is equivalent to around 1 teaspoon of salt per day from all sources.
Both sodium and chloride are released from our body through our urine and when we sweat. This means bouts of heavy sweating such as during exercise can increase our salt requirements slightly. However, as most people consume well above required levels it is usually not necessary to increase salt intake during these conditions.1
Registered Dietitian and Certified Diabetes Educator Sherri Shafer discusses the importance of carbohydrates in the daily diet. Shafer then offers a plan for how much protein, fat and carbohydrate would be healthy in a day.
There is consistent evidence that higher amounts of body fat are associated with increased risks of a number of cancers (6), including:
- Endometrial cancer: Obese and overweight women are two to about four times as likely as normal-weight women to develop endometrial cancer (cancer of the lining of the uterus), and extremely obese women are about seven times as likely to develop the more common of the two main types of this cancer (7). The risk of endometrial cancer increases with increasing weight gain in adulthood, particularly among women who have never used menopausal hormone therapy (8).
- Esophageal adenocarcinoma: People who are overweight or obese are about twice as likely as normal-weight people to develop a type of esophageal cancer called esophageal adenocarcinoma, and people who are extremely obese are more than four times as likely (9).
- Gastric cardia cancer: People who are obese are nearly twice as likely as normal-weight people to develop cancer in the upper part of the stomach, that is, the part that is closest to the esophagus (10).
- Liver cancer: People who are overweight or obese are up to twice as likely as normal-weight people to develop liver cancer. The association between overweight/obesity and liver cancer is stronger in men than women (11, 12).
- Kidney cancer: People who are overweight or obese are nearly twice as likely as normal-weight people to develop renal cell cancer, the most common form of kidney cancer (13). The association of renal cell cancer with obesity is independent of its association with high blood pressure, a known risk factor for kidney cancer (14).
- Multiple myeloma: Compared with normal-weight individuals, overweight and obese individuals have a slight (10% to 20%) increase in the risk of developing multiple myeloma (15).
- Meningioma: The risk of this slow-growing brain tumor that arises in the membranes surrounding the brain and the spinal cord is increased by about 50% in people who are obese and about 20% in people who are overweight (16).
- Pancreatic cancer: People who are overweight or obese are about 1.5 times as likely to develop pancreatic cancer as normal-weight people (17).
- Colorectal cancer: People who are obese are slightly (about 30%) more likely to develop colorectal cancer than normal-weight people (18).A higher BMI is associated with increased risks of colon and rectal cancers in both men and in women, but the increases are higher in men than in women (18).
- Gallbladder cancer: Compared with normal-weight people, people who are overweight have a slight (about 20%) increase in risk of gallbladder cancer, and people who are obese have a 60% increase in risk of gallbladder cancer (19, 20). The risk increase is greater in women than men.
- Breast cancer: Many studies have shown that, in postmenopausal women, a higher BMI is associated with a modest increase in risk of breast cancer. For example, a 5-unit increase in BMI is associated with a 12% increase in risk (21). Among postmenopausal women, those who are obese have a 20% to 40% increase in risk of developing breast cancer compared with normal-weight women (22). The higher risks are seen mainly in women who have never used menopausal hormone therapy and for tumors that express hormone receptors. Obesity is also a risk factor for breast cancer in men (23).In premenopausal women, by contrast, overweight and obesity have been found to be associated with a 20% decreased risk of breast tumors that express hormone receptors (22).
- Ovarian cancer: Higher BMI is associated with a slight increase in the risk of ovarian cancer, particularly in women who have never used menopausal hormone therapy (24). For example, a 5-unit increase in BMI is associated with a 10% increase in risk among women who have never used menopausal hormone therapy (24).
- Thyroid cancer: Higher BMI (specifically, a 5-unit increase in BMI) is associated with a slight (10%) increase in the risk of thyroid cancer (25).
From The Lancet Diabetes & Endocrinology (June 2020):
Our findings show that the intensive lifestyle intervention led to significant weight loss at 12 months, and was associated with diabetes remission in over 60% of participants and normoglycaemia in over 30% of participants. The provision of this lifestyle intervention could allow a large proportion of young individuals with early diabetes to achieve improvements in key cardiometabolic outcomes, with potential long-term benefits for health and wellbeing.
Obesity is at the root of silent epidemics such as type 2 diabetes and nonalcoholic fatty liver disease.
Laura Schmidt explores the causes and solutions, taking lessons from tobacco: reducing the availability of harmful substances reduces consumption, thereby reducing harms to health. She talks about the UCSF Healthy Beverage Initiative and the effects it has had on employee health.
Recorded on 02/13/2020. [5/2020] [Show ID: 35586]
From a BMJ Study article (April, 2020):
Compared with usual diet, moderate certainty evidence supports modest weight loss and substantial reductions in systolic and diastolic blood pressure for low carbohydrate (eg, Atkins, Zone), low fat (eg, Ornish), and moderate macronutrient (eg, DASH, Mediterranean) diets at six but not 12 months. Differences between diets are, however, generally trivial to small, implying that people can choose the diet they prefer from among many of the available diets (fig 6) without concern about the magnitude of benefits.
The worldwide prevalence of obesity nearly tripled between 1975 and 2018.1 In response, authorities have made dietary recommendations for weight management and cardiovascular risk reduction.23 Diet programmes—some focusing on carbohydrate reduction and others on fat reduction—have been promoted widely by the media and have generated intense debates about their relative merit. Millions of people are trying to lose weight by changing their diet. Thus establishing the effect of dietary macronutrient patterns (carbohydrate reduction v fat reduction v moderate macronutrients) and popular named dietary programmes is important.
Biological and physiological mechanisms have been proposed to explain why some dietary macronutrient patterns and popular dietary programmes should be better than others. A previous network meta-analysis, however, suggested that differences in weight loss between dietary patterns and individual popular named dietary programmes are small and unlikely to be important.4 No systematic review and network meta-analysis has examined the comparative effectiveness of popular dietary programmes for reducing risk factors for cardiovascular disease, an area of continuing controversy.